(GE) AK Breakers

2018-02-16

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AIR CIRCUIT BREAKERS

Type AK-1-50
Electrically

VOLTAGE SWITCHGEAR OEPARTHEHT

GENERAL^ ELECTRIC
PHILADELPHIA.

RECEIVING, HANDLING, AND STORAGE

INSTALLATION
LOCATION
MOUNTING

I I!*.!*.*.*.*. II 16

INSPECTION
REPAIR AND REPLACEMENT
TROUBLE SHOOTINO

BASIC BREAKER COMPONENTS
POLE UNIT ASSEMBLY
AUXILIARY SWITCH

OPERATING MECHANBM

INSTANTANEOUS UNDERVOLTAGE TOIP^G DEVICE

SERIES OVERCURRENT TRIPPING DEVICE

REVERSE CURRENT TRIPPING DEVICE

MISCELLANEOUS
SHUNT TRIPPING DEV^ • . • • ;
BELL ALARM AND LOCKOUT DEVICE

ELECTRICAL CLOSING DEVICES AMD CONTROIB

''*^*TuSe DELAY^UNTORvbLTAGEVRIPPDW

*
RENEWAL PARTS

AIR CIRCUIT BREAKERS

TYPE AK-l-SO-1, AND AK-1-50-2
ELECTRICALLY OPERATED
INTRODUCTION
Before unpacklBg. Installing, or attemiAlne to

These clrcutt breakers are gener^yused

operate tjie Type ^-1-50 Air Circuit Brewer

for protection and control of f^r smd toanA

thoroughly and carefully read.

dustries, power Nations and for marine apiuicar

describedhereby these Instritctlons should be

tlons within the ratings desIgnited.

The ratings for the AK'l-SO is as follows:
Continuous
Current
Ratine
IMS Amoeres

lnterriq>tlng
Rating

circuits, Including equipment In buildings, in

F CONTACTS
t whenreo.

CONNECTION DIAGRAM

i icHo^ ;«*« I

alternate wiring used withfollowing

customer wiring •

POWER VOLTAGE RATING'
380/230 V. AC 50 "P

FACTORY WIRING-

460/230 V AC 25 "P

46(V230 U AC 50 «/<
460/230 V. AC 60 «/•

for ENCUOSEO brxhs
CUSTOMER WIRING FOR
STATIONARY BRRRS.

5T5/230 U AC 25
575/230 V AC 50 •/•
575/230 V. AC G0«/*
•C+)X

t ICT IV ABaBFVIATIOHS

A-TERMWAL 80AR0 lOCATED LEFT SIDE

8-TERMINAL 80AR0 LOCATED LEFT SOE
FRONT VIEW

^JcUT OFF tWITCHES
K-CLOSINO RELA/ TYPE HGA-tX)
1^AUXILIARY SW.V8*b* CONTACTS
» TYPE S8.-I2 LAOX.SWi
M-8HUNT TRB» CXO

EL£MENTARY DIAGRAM
.'wa£

P« PUSH 80TT0N CLOSING SW ON BRXR.|FBi
R-CIOStNO SPRING CHARGING MOTOR tM)

T-AUXILIARY POWER TRANSFORMER tTRANS)
OBRMctlee Dlasr*

Air Wrcutt Breaker TjpeAK-1-50
exceeding the specUted temperature rise. Con
necting cables or bus bars should be supported so
that the breaker stute will not be subjected to un

which In turn opens contads ? <8-4) and K(3-7)

and closes contacts K (8-2)
th«.
cultthru contacts K(8-2) and F (4-3) seals Mthe

necessary strains.

Fig. 1 shows the typicalelementary and cc.' Vjt
1-

WITH
ACLEAN CLOTH IN ORDE^R TO AVOIDANT
ACCUMULATION OF DIRT OR DUST.
The use of cotton waste to

7.Shaft For M«)ual
Haintenance OosinB ll«»dle

l.AuBiliafT Snit^
3.0m>ei 9>ipe4l

B.Sprint Charied-DIacharced

B.Uoter Oit-Off

5.UmJal Trip Botten

In order to repair or replace

sting mechanism or the overcurrenl device, the

10. Arc Qjendjar

e.Cleiint Button

might
migni become
Dei:oui«cui»".6»-entaneled under the
V- bearing
- surface

3. Side Barrier

7. &«vet«>d Sivport

«. Steel Beck Plata

Of «re Oeeeeber. T. to.." 1-". SU^ *.d r.d>.t O.rrl.r.
ASSEMBLY

Each pole unit assembly consists of a «t of

arcing contacts, a set of
S« FU 5
atlng linkage and the mounting base. See kig. o.

The stationary arcing ""'^ct consists of a «t
of parallel
V2T'w^^ chp??vtde'conlln..nu3

fSVfUll tra'vel of the conta s.

Flulble braid leads shunt the pivot pin to prevent
pSli
pUtlng at the pivot polntwhen Interrupting
nigh currents.

The movable arcing contact assembly consists

of parallel contact
mechanism.

Air Clreutt Bredier Tjp«AK-l-BO

Stfl. Arcing Gsntnct

Pin (Stn. Arcltif Ctont.)
HoraUc Arcing Cbotnet
Brnid
Morabic Bain Obnt.
7. Shouidercd Pin

Pin (Arcing Obnt. UiA)
lawlating Link

10. Pin (Intuinting LiiA)
11. Pin (Sid* Liidt) .
12.
13.
14.
15.
IC.

Unk
a«ri*
Qeri* Pin
Lnver Stud
PbI* Qkit Base

17. ^rittg (Bain Ifevrftie Obnt.)
18. Pin (Barrfila Bain Obnt.)
Fig. 8

Pol* Bnlt AatMbly

19. Pin (Borafala Arcing Cbot.)
20. Side Link

21. soring (Sta. Bain Obnt:)

22. soring (Sta. Arcing Ooot.)
23. Oppar Stud

24. Pin (Sta. Bain Obnt.)
25. Statlcoarg Bain Omtaet
26. Sere*
27. Scrac

Air Circtdt Breaker Type AK-1-50

The stationary malncwitact assembly Indira
main contacts and intermedlde contacts. The
Intermediate contact surface extends beyOTd the
main contacts and will, therefore, make before Uie
The number ofcontacts for eachrating is given to

Sain contacts and briak
Table 1.

The movable maincontacts plvctarowd a sta

tionary pin (18), which hol^ them to
lowe*blociC motion Is obtained 'rom a second pin P),
connected by an insulated link (12) tothebreaker

mechanism. Steel sprtap (17) force

against the pin to prevent pitting d the pivot poW.
The movable main contacl assembly alsocontatos
main and Intermediate contacts.

In wilerlo funcUon propCTly, a finite ynomit

of contact pressure and mtad wipe mud ««
between we movable and stationary cent acts.

Table I gives thefigures for cmtact wipe rad «ir
tact pressure. Both wipe rad pmsure
cb^ed daring the regiw InspecUon period.

ftttermedlate Contacts

AK-1-50-1
For A.C.

55-65 1/18-3/32

55-65 1/19-3/92

Arcing Contacts

5/16-7/16
5/16-7/16

to contact wipe.

REPLACEldENTS, FIG. S

MEASimmG CONTACT PRESSURE, FIG. 5
1 Remove arc quenchers, (see replacements

* under "Arc Quencher").

2. With the breaker open, measure the
dimension of the statlraiary arcing contoct
withthe spring (22) full compressed.
3, Place a push-type scale against the datlonary arcing contact and push the ccmtacl

Stationary Arcing Contacts (2)
1. Remove the iqiper plate by removing two
screws (1).

2. Remove screw from braid (5J.

3. Remove pin (3) allowing the stationary eentacts andsprings (22) to fall free.

4. Iietall new springs and stationary arcmg

backward until the "B" dimension Is I flV
more than the measurement taken to item
2. The scale should then be read.

contacts to reverse order.

5. Adjust contact wipeand pressure (see A«

judlng Contact Wipe and Pressure*?.

MEASURING CONTACT WIPE, FIG. 5

Movable Arcing Contacts (4)

1. Remove the arc quencher.

The movable arcing contacts should be re

2. With the breaker open, measure the horl

placed when thestationary arcing contacts are re

zontal distance from the ecfceof the|^t^
to the surface behind It.

1. Separate the front frame from the polealt
frame (see 'Repair and Replacenwnt y.
2. Remove pins (ft) and (19) and withdraw Ihe

3. Close the breaker and repeat Item 2. The
difference between the readings In Item
"2 and 9' determines the wipe of the con
tacts. For safety reasons be extremely
careful not to trip the breaker.

8, Reassemble parts In the reverse order.

ADJUSTING CONTACT WIPE AND PRESSURE,

Stationary Intermediate Contacts (9), Fig. • ^

1. With thebreaker cq»en, measure dimension
1. Remove screws tt7) and remove braAet
which holds pin (24) to place. See Fig. 5.
2. Remove clamp which holds lower part of

2. l^move the clevis pin (14) and tacre^e

dimenslon"A" to Increase the wipe,and de
crease dimension "A" to decrease the wipe
by turning the clevis (13).

stationary contact.

3. Remove pin (24) and screws
4. Lift out the Intermediate contara.

NOTE: If the proper contact P^assure dj^not
limits, the stationary contacl springs

5. Replace the contacts remembering to nulch

exist when the contacl wipe Is within Its

the Intermediate contacts on each pole.
6. Re-assemble to the reverse order.

shoula be replaced.

Air Circuit Breaker Type AK-t-W

Movable Intermediate Cmtacts (8), Fig. 8
1. Remove the movable arcing cootacts as
described above.

2. Loosen spring (17). See Fig. 6.

3 Slide link (12) to the side and off of pin (7).
4. Slldepins(18) and (7)far enough to the side

to allow the movable intermediate contact
to be replaced.

6. Re'assemble parts In reverse order.
Always check the contact wipe and pressure
following contact replacement.

The electrically operated mechanism includes
a motor and a gear reduction tmlt, which charges
the closing springs (16) Fig. 7, through a crank
shaft (14) Fig. 7. The crank shaft has an arm with
a roller (12) Fig. 7, which rides on the closing
cam (2) Fig. 8. The position of this closing cam
roller Is shown In Figs. 8A, 8B, and ec. The clos
ing cam is connected to the center pole unll thru a
clevis, and through a cross bar controls the open
ing and closing m the contacts on all pole units.

1. stationary Arcing S. Movable Main Contact
6. Creaa Bar

2. Hov^la Ardng

With the breaker open and the closing springs
discharged, thesequence of operatloo Is as follows:

3. Stationary Main

7. Seriea Orercurroit BbHc*
B. Movriile Inteiwedlata
Cbntaet

9. Stationary IntaraadiaCa

CHARGING THE CLOSING SPRINGS, FIG. 7

1. The mechanism In position shown in Fig.

Front Viev Of Back frwie AaMbly

2. The motor turns the crank (10) Fig. 7,
which is mounted on the output shaft of the

8. The prop (16) engages the closing can Q),
locking It m this position until the broker

gear reduction unit. The charging roller,

which is on the face of the crank, has paddle
arm (U) bearing on it.
3. As the crank turns, the roller pushes the

7. The motor will continue to operate mill H

has recharged the closing springs (16)
Fig. 7, In preparation for the next opting

paddle arm upward, thereby charging the
closing springs through the spring charging
arm (15) of the crank shaft.

4. As the charging roller approaches dead

and closing c^eratlon.

OPENING THE BREAKER, FIG. 8

centera cut-offswHchopens, de-energlzlng

1. The rotation of the trip shaft (11) by »v of

the motor circuit.

the trip devices allows trip latch (W) to
release the prop (5) and the forces fawn

5. The breaker is now ready to close.

the contact and opening springs reposMoo
the linkage of the operating mechanism Mo
position shown in Fig. 8A.
2. The operating cycle can now be repeated.

CLOSmC THE BREAKER

1. Mechanism tn reset positicm, closing
springs charged.

2. When the closing circuit Is energized, the
motor rotates causing crank (10) and roller
(7) to move past dead center.
3. The crank 0®) Is ^ree to rotate counter

clockwise. This permits release of the
charging springs, rrtaling the crank shaft
(14).

All adjustments should be made with the oper

ating mechanism in the reset position ^ shon tn
Fig. 8B.

(The mechanism stkould be reset by

manual operation).

4. Referring to Fig. 8B and Fig. BC, rotation

' 1. The gap between the trip latch (10) andtbe

of the crank shaft causes the closing

tweenl/84 to 1/32 Inches. ThisadJustaMit

roller (15) to push the closing cam (2) Into

the position shown In Fig. 6C.
5. With the closing cam in this position, the
breaker contacts are closed through a
clevis and linkage.

roller of the reset latch (fl) should be he-

can be obtained by turnlne screw (6).

2. Thecenler line of the trip latch (10) ah^d

pass through the center of the roller P),
rorm the stop (14) to m;-''e this adJustmcM.

Air Circuit Breaker Type AK-1-80

3. The stance between the roller on link P)

and prop (S) should be 1/84 to 1/32 of an

inch. To obtain this gap advance or retard
the nuts on the bottom ring
10. Becker Ann
11. Pin
13. Can

13. 'b' OBntseta

14. *0* Teminala
15.'
Tcfminala
16. Barriar

Itotary toiltlary Switch
<

Air Circntt Breaker TypeAK-MO

or closed position it operates a trian^ar link (6)

through an operating rod (5). The triangular link

rotates the operating shaft (8) of the auxiliary

switch, which, through cams located on this shut
opens and closes the auxiliary switch contacts.
The top termhuds of the switch are 'V contacts
(open when the breaker is open) and the Ixittom

terminals are 'V*contacts (closed when the breaker
is open).
BEPLACEMEKT, FIG. 10
Disconnect all leads to auxiliary switch.
Remove two mounting bolts.

l^engage' auxiliary switch shaft (B) from
the trmngular link (6).
Set arrow on new auxiliary switch shaft as

I^h auxiliary switch shaft (8) into square
hole in link breaker t»en).
Replace mounting hardware and wiring.

shown in Fig. 10.

ELECTRICAL CLOSING
DEVICES AND CONTROLS

A closing switch and motor mechanism are

providedfor closingthe breaker electrically.
CLOSING SWITCH

The closing button is mounted on the right side
of the front escutcheon. When the closing button

is pressed inward it engages a rod which in turn
operates a switch, which is mounted on the front
frame to the right of the operating mechanism.

To replace the closing switch, disconnect the
wiring and remove the nuts which bold the switch
to its mounting bracket.
CUT-OFF SWrrCHES

2. Innlation
3. - r Switch

$. Retaining Ring
6. Lever Bracket
7. Ntg. Bracket

The motor cut-off switches are mounted on the
side of the front frame as shown in Fig. 12. At the

end of the charging stroke, the cut-off switch (1)
onens de-enereizing the motor circuit. The cut-

Motor Cat-Off Switdi

^Tswitch (3) closes, When the closing control
circuit is energlz^ the motor operates to to-

charge the closing springs and close the brcMer.

should be replaced by disconnecting the wiring!
removing them from their mounting bracket.

SS^itch (1) closes, and the above cycle can be

fUter this is completed, the cut-off switch (3)
opens, de-energizing the motor circuit. The cidrepeated.

The control relay Is mounted m the left!
of the front frame. It is used to open and close Oe
motor circuit. To replace remove wiring and

if the switches do not function properly, they

holding screws.,

PROTECTIVE' DEVICES
TIME DELAY ONDERVOLTAGE
TRIPPING

This device Is mounted to a bracket «»the

left side of the operating mechanism (looking from
the front). The purpose of this device te to trip
the breaker for undervolt-ge. For rated voltage.

the armature (3) is attracted by the magnrt (1^

If the voltage falls tielow the predetermined vot
the magnet (14) releases the armature (3). Spitng
(4)then pi^ armature (3) upward against Ue re
straining force of the oil in cylinder (10); tib
action caused a time delay. When the spring
comes the restraining force of the oil, the

Air Circuit Breaker Type AK-l-S®

ffi
t'h'.'bSSlS!'
refer to Fig. t3)«

4. iSSltS,"*.!..

adjustments, fig. 13

nsed to allow from 1/33 to i/*w

1 Disconnect leads tocoU.

after tripping the breaker.

Adjusting sCTe*^^^ 80% SnOTmSJouie

'RWe-ehafetegl,"-

v'."LVA«?P-"«''S«icE

time delay setting.
From 1/4 10

the oil, the cfiinder may

Ihl «P O™ .Tllc.n.-f

SisSISv ei .lSB=!?«"4e ri««14 be »ed I.
the cylinder.

Time Delay Undervottage Dealce, Fig. 13

S SdlSoltage tripping derlce.

1. Disconnect coil leads.

o2'>
o3"
o4o
olo

(52U.V)
8. MiuatlntNua

3. Miostlnt Sew
fc Nut

5. SiadlRt kin*
6. Pin

11. Csmeetlan Bad
13. Plunte*
13. a«o

• 14. Nafnet
15. Call

16. SercM
17. Pin

IS.
19.
30.
31,
22.

Adjuatinf Screw
lodkiof «re

Adlusting Serewa
Itountins Screaa Trip Paddla
BOW

belay imdervollago Tripping Dewlca

Air Clroiii Breaker TjpeAK-l-BO

E
9
T
bratlonsprlng(U). Alter the magnetic force,
produced by an overcurrent condition, overcomes
this reslrabilng force, the "mature movement to
further retarded by the How of slliconc oW ^ *
dashpot, which produces an ^n'®"®
characteristic. The mechanism to shown on Fig.

To sdjust for approximately 1/W overtravei
i. Check trip latch engagemert. See rAdJoMments - Operating MechMtom .
1. Loosen the locknut and

screw (19) on the trip arm W""S
should not touch the trip paddle
"f
breaker is 'H^pcrf'and the latch to rw^

but should have a clearance n
U1
tn

m nOTotrr-30,19.0(1
9 SECOND

SPeOTWELV IAT600X Of
UW« TUC OO.W RCIHIP

Imort-twc deiat

.WJUBTABiE nnn iiem
n o BREAKER mnn

MSTkNTANEOVS rtCR-UV

SET •«»CT0(W-*1- 4.,

4TOI9TWC9 . I.-:

BUMHtf* BREAKER
RATM-TIME

TME ADJUSTABLE Bl

ncTCRT- osnojBBi

OR 0.199 9EC0R0S _ --

OR EC RESREOTIVBUfl «
t9oa or WORT t
ocunr ncN-OP

CURRENT IN TIMES BREAKER RATI4G
FIf. 16

CURRENT M TIMES BREAKER RAIMG

Tialcal TiB»>CBrreRt ChoracterlBtlc
w

Air Circuit Breaker Tjpe AK-l-SO

8. SIprinf
7. Ftotcntlsl OpH
8. Cslibrstlon Nut

1. Trip Pwldle
3. Scries Oiil

3. Trip a»4
4. Trip Crsi*
5. SctUnc Seailfig Sere*

9. Pole Pieces
10. Arueture

11. Qiunter 9eiilit
13. Step Sets*

13. HMmting
Sere*
14. Sere*

teserse OBrrsnt Tripping Pevlcn

Air Circuit Breaker •TType AX-1-3
calibration spring (6). When the current reversal
exceeds the calibration setting^ the armature re*
Tolves clockwise causing the trip rod (3) to move

adjusting nut on the trip rod untU you can Justtrl

upward engaging the trip paddle (t), thereby trip*
pug the breaker.

additional 1*1/2 turns, thereby assuring poslllv
tripping. Lock adjusting aid.

ADJUSTMENTS, FIG. 17

Be extremely cautious not to have hands aea
moving parts of the breaker wbm making this ad

No adjustments should be made In the Held
with the exception ot checking for overtravel of the

the breaker by lifting the trip rod (3) as far as -

will go. Then advance this same adjusting nut a

trip rod. Prmer overtravel of the trip rod Is pro*
vlaed. If the trip rod advances the trip paddle be

coll the reverse current device can be remove

tween 1/3F' to ^4" beyond the point where the
adjust for this amount of over-

travel, lift the trip rod as high as possible after
backing off the adjusting nut on the trip rod (3) so
that It will not touch the trip paddle (1). Advance

After removing tlie wiring for the potealb
and replaced t>y following the procedure ontllae
for replacing the series .ovcrcarrent device. Fc
wiring, see Fig. 17.

MISCELLANEOUS
.ADJUSTMENTS

SHUNT TRIPPING DEVICE

The shunt tripping device (refer to Fig. 18)
Is mounted on a bracket attached to the left side of

the operating mechanism (lookingfrom the front).

A remote switch or relay contacts are used to
close the circuit of the device causing the arma

ture (9) to otgage the trip paddle (li), thereby
tripping the breaker. The spring (2) Is used to

From i/32" to l/18"overtravelof thearmaftur

Is required when the breaker Is tripped. If an
adjustment Is necessary to provide tills amomdc
overtravel, the trip lever Is bent in or oid ac
oordlngly.

REPLACEMENT * COIL 0)* FIG. 18
1. Disconnect leads to coU.

return the armature to the neutral {Kisttlon after

2. Remove magnet (6) and coll from framep
3. Bend lower ad of clamp (8) straight an

the breaker trips.

To prevent overheating, the coll (7) Is cut off

4. Remove coll and Install new coll In re

by contacts of the auxiliary switch which are open
when the breaker Is open.

11. Trip Paddle

10. Ameture Aiw

4. Pin
5. Screw

Shmt Tripping Device

Air Circuit Breaker TjpeAK-l-60

ETuSSfLtoSSKm'SS'

BELL ALARW AND
LO CKOUT OEVICE

*n vi* » Wbea tte Vreaket Is trlw***

I. with the brieaker

rc»s£>rbr.5K^

ShX(9)
dears
the werload
the trip shaft
by l^r
toS^*. paddles «•

the irontlramesssenibledtotoeb^
••a With
f.S.iM_rfg^5gjs5^dUl?
s;^.i jR« «sss'Tt^r'^
Snra^ Dnle^- HeplaCB»«U."
deviceoperates cm*
WHEN BHEAKEBIS

tripped oh ovehcurremt.

MANUAL RESEI W S*lJ^
CONTACTS

1. ReMt Button
a. Soi«ai
3. Pn»

p. AusllietT Oialt

dars Ini Udioet Oevlce

13. AdluaUhf
Setco

Air Circuit Breaker Type AK-l-SO

The disconnects are attached to the circuit
breaker studs at the rear of the breaker.

Each disconnect consists

fingers (5), four retainers fl)>

two screws (1), one retaining ring (6), four
washers (2) and four springs (3|. The parts are

assembled as shown in Fig. 20.

ADJUSTtlENTS, FIG. 20

• Tighten the nuts on screw (1) compressing
springs (3) so that the spring length from retainer
to washer does not exceed 1-1/32 Inches.
I.Sere*
Lfcaher

Grease contact fingers (5}wlth General Electric
Company grease specification D50H28.

AGbrlnc
4.GbK«r

6.letainif>s Ung
T. Betainer

Seceadary glscennect

RENEWAL PARTS
When ordering renewal part^ address the
nearest Sales Olllce of the General Electric Com

pany, specifying the quantity required. The parts
should be described and the complete nameplate

Renewal parts, which are furnished, may net
be identical with the original parts since Im

provements are made from time to time. Parts

which are furnished will be Interchangeable.

data of the breaker should be given.

7
G£. - VOLUME 1 - TYPE "A K" L.V. BREAKERS

CATALOG SECTION 1

AK Breakers with Stored Energy

Msiritenance/iristruciionsManual

AK-2/3/2A/3A-25

AKU-2/3/2A/3A-25

Instructions Manual

Renewal Parts Data

Instructions / Installation / Operation Manual

AK-2/3/2A/3A-16

AK-2/3/2A/3A-25

AKU-2/3/2A/3A-25

AK-2/3/2A/3A-25

AK-2/3/4/5/2A/3A/4A/5A-50/50S
AK-2/3/2A/3A-75/75S
AK-2/3/2A/3A-100/100S
AKT-2/3/50/50S
AKU-2/3/2A/3A-25

AKU-2/3/'V5/2A/3A/4Ay5A-50/50S
AKF-2/2A-25

Injtpjctiofis IInstallation / Operation Manual

AK-1-15/25/50/75/100

AK-2-15/25/50/76/100

AK-2A-15/25/50/75/tOO
AK-2-6OS/75S/1G0S
AK-2A-50S/75S/100S
AKF-1A-25

AKF-1B/1C/2C/1D/2D

AKU-2-25/5C/60S
AKl>2A-25/S0

ir^structions I Maintenance Manual

ins^dions / Maintenance Manual

AK-1-1S and AK-1-25

Stored energy provides p ositive, nign-speed closing
of General Electric Type AK low voltage Ijreakers
All frame sires uf General Electric low voltage power circuit

breakers employ spring-operated, stored-energy mechanisms
for manual or electrical operation.The stored-cnergy principle

Type AK-:JA and AK-3A breakers ace rugged nwitchiog
and overload and ahort-circui prol irtivedevice ior main, tie
or feeder circuits. Theypsovic.e a r.n. ar.s for switchiogcifcuits

provides aquick-make, quick-break operating mechanism that

and equipment, disconnecting circu.ts for maintenance and

the operating force. Positive, controlled closing prevents uniiBCfisary arcing between movable and .stationary contacts.

starting and automatic throw-over.

assures positive high-speed closing ofbreaker, independent of

construction and provide short-circuit protection. They also

perform a wide variety of control functions such as motor

This results in longer contact and breaker life.

Typ» AK.3A-50«l»ctritollyopsKi'*«l p«w>r drcvit brMker.

VELECTRIGAILY OPEWED^T, j;

STORED. ENERGirt
TDttfy
ElectficaK stored-en

iSto-ed-energy ipn'ttB end

id. In
n the srii

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carbide lipi fer

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INSTRUCTIONS
GEK-7302B

Supersedes GER-2021D

POWER CIRCUIT BREAKERS

Installation and Operation
Types
AK-2/3/2A/3A-15

AK-2/3/2A/3A-25

AKU-2/3/2A/3A-25

AK-2/3/4/5/2A/3A/4A/5A-50/50S
AK-2/3/2A/3A-75/75S
AK-2/3/2A/3A-100/100S

AKU-2/3/4/5/2A/3A/4A/5A-50/50S
AKF-2/2A-25
AKF-2C/2D/2E

SWiTCHGEAR PRODUCTS DEPARTMENT

GENERALS ELECTRIC
PHILADELPHIA. PA.
TAf? J3

AUXILIARY DEVICES SPECIFICATIONS

TYPE LOAD
OR P. F.

75 - 85%
Lagging

30 - 35%
Lagging

Bell Alarm
Switch

EC-1
Switchette

INTERRUPTING RATING (AMPS)
Switch

Continuous Rating (Amps)

Closing Rating (Amps)30-35% PF^

Limited to 5.0 A continuous rating of #16GA. wire on Drawout Breakers.
**

Adequate for use with AK Breaker Shunt Trip Coils of the voltage ratings
listed in above table. (Maximum current of 12.3A for the 120V. AC coil)

OF TYPE AK POWER CIRCUIT BREAKER
RECEIVING, HANDLING AND STORAGE
Before Installing, or operating these
circuit breakers, make a careful reading
of the sections of these instructions which
are pertinent to the anticipated work.

portation company and notify the nearest
General Electric Sales Office.

Unpack the circuit breaker as soon as

possible after It has been received. Exer

If the circuit breaker is not to be placed

in service at once, store It in a clean, dry
location In an upright position. Support it

to prevent bending of the studs or damage
to any of the breaker parts. Do not cover

the breaker with any packing or other
material which absorbs moisture, that may
parts are missing or left In the packaging cause corrosion of breaker parts. A
cise care in the unpacking to avoid damage

Upon receipt of a circuit breaker, im

mediately make an examination for any

damage or loss sustained in shipment. If
injury, loss or rough handling is evident,
file a damage claim at once with the trans

to the breaker parts. Be sure that no loose
material. Blow out any dirt or loose parti

cles of packaging material remainingon/or

covering of kraft or other non-absorbent

paper will prevent dust from settling on the

in the breaker.

INSTALLATION
Typical Outline

In choosing a location for the installa
tion of an AK Circuit Breaker, there are

two factors to be considered.

of these Is the effect of the location on
the breaker Itself.
Much better per

formance and longer life may be e;q>ected
if the area is clean, dry, dust-free, and
well ventilated, than if the opposites to
these conditions exist. The second con
sideration is convenience for operation
and maintenance. The breaker should be

easily accessible to the operator, and
there should be sufficient space allowed
for maintenance work to be done if tliis
becomes necessary.
MOUNTING

AK-2-1S and 25
AK-3-15 and 25

AK-2-50 Man. Oper.

AK-2-50 Eloc. C^er.
AK-3-50 Man. Oper.
AK-3-50 Elec. Oper.
AKT-2-50 Man. Oper.
AKT-2-50 Elec. Oper.

AKT-3-50 Man. Oper.
AKT-3-50 Elec. Oper.
AK-2-75 Man. Oper.
AK-2-75 Elec. Oper
AK-3-75 Man. Oper

AK-3-75 Elec. C^er.
AK-2-100 Man. Oper.

AK-2-100 Elec. Oper.
AK-3-100 Man. Oper.
AK-3-100 Elec. Oper.
AK-4-50 Man. Oper.

Drawing No.
695C116
121C7570
845C281
238C123
121C7553
121C7555

102C3650
102C3651

121C7589
121C7590
U45C284
269C225
121C7583
121C7557
845C290
269C227
121C7585
121C7559

134C2600
134C2601
134C2610
134C2611

AK Circuit Breakers are designed to
be mounted in any one of three ways.
These are dead front mounting. Individual

AK-4-50 Elec. Oper.

and drawout mounting In which the breaker

The surface on which the breaker is
mounted must be flat throughout in order

or control board.

the breaker unit. The supporting structure
must be rigid enough to avoid any pos

mountingv:iththe enclosure beingprovided,
is designed for insertion Into a cubicle
in drawout equipment such as a substation
DEAD FRONT BREAKERS

These breakers are designed for mount

ing In a switchboard or enclosing case of
the customer's design and construction.

Mounting in this instance consists ofbolting

AK-5-50 Man. Oper.

AK-5-50 Elec. C^er.

not to Impose any internal distortion on

conduits or cables. Steps in the procedure

for installing enclosed breakers follow:

1. If the breaker is an AK-15, AK-25

or an AK-50, remove it from the enclosure.
With AK-50 breakers, a handle and cam

arrangement is used for that part of toe

breaker movement that involves toe dis
engagement or engagement of the primary
discotmect. AK-75 and AK-100 breakers
are bolted solidly to the enclosure frame
and need not be removed from the en
closure.

2. Remove cover plates of enclosure

and prepare them to accommodatewhatever
power entrance means is used.
3. Mount enclosing case to supporting
structure.

4. Replace cover plate and make
power connections to stationary terminals
enclosure.

5. If the breaker is a type AK-15,
AK-25 or AK-50 and has been removed
from the enclosure, it may now be re

Control power connections to the

terminal board should be made as required.
(See CONNECTIONS).

6. Before energizing the power cir

cuit, operate toe breaker several times to

sibility of the breaker studs supportingthe

be sure that it is functioning properly.

dimensions, as given by the appropriate
outline drawing, must be maintained to
provide adequate electrical clearance.

AK-4/5-50 breakers which are individ
ually enclosed will have enclosures of the
AKD5 drawout type. These breakers will
be straight drawout breakers, types AK-4A-

weight of the breaker. Minimum cutout

INDIVIDUALLY ENCLOSED BREAKERS
Individually enclosed breakers are

(See OPERATION).

necting the power buses or.-cables, and

supplied with several types of enclosures,

50 and AK-5A-50. (See instructions in this
book under the heading, "Drawout Breakers
AKDS Equipment")

most common is the general purpose type or

The front cover of the breaker enclosure

the weather resistant type. The former is
used for favorable indoor locations and
the latter for outdoor locations or indoor

DRAWOUT BREAKERSAKD EQUIPMENT

locations that may be subject to unfavorable

simply placing the breaker in the proper

the breaker frame to a supporting structure
within the switchboard or enclosure, con

making any necessary control cdnnections.
may be a hinged door or a plate bolted to
the panel. In either case, It should have

a section cut out, through which the front
escutcheon of the breaker may protrude.
Outline drawing numbers giving the dimen
sions needed for preparing a suitable

All of the enclosures are pro- •

Mounting drawout breakers consists of

position with respect to its enclosure,

enclosure or cubicle for the various types

wails or supporting framework. Removable
cover plates are supplied with the en

sliding or rolling it to a stop position, ai^
by means of a racking handle and mech
anism, racking it through the lastpartof its

of AK breakers are given below. These
are for standard 2 or 3 pole breakers.

to accommodate the entrance of bus ducts.

movable halves of the disconnects engage.

vided with suitable means for mounting on

closures which may be drilled or machined

movement during which the stationary and

These intlrvefions do not purport to cover all details or Yoriations in equtpment nor '<>
for weir
conlingener to be me/ in conneetion with installation, operation or maintenance. Should further mformofion be dewrt

or toooW particular problems arise which ore not covered tufficiently for /he purchaser s purposes, the matter shoud
be referred to the General fleetric Company.

GEK-7302 Installation and Oneration ot Type AK Power Circuit Breakers
Large drawout breakers are fastened to a
telescoping tray which extends out from the

the breaker carriage. This is the safety

cause the breaker to be trip free. Tighten

breakers have guides on their side plates

secondary contacts are disengaged. Again
lift the position stop handle. Slide the

front holes of the drawout tray during step

Both large and small breakers have a test

enclosure to receive the breaker.

which slide In channels In the enclosures.

position in which the secondary disconnects
are engaged, but the primary disconnects

are not. In this position, the breaker may
be operated electrically without energizing
the load cable or bus.

Use O50H47 lubricant on the disconnect

terminals to reduce the force required to
insert the breaker.

Inserting Breaker AK-15 and 25

1. Trip the breaker.

2. Raise the breaker until the guides

on the sides of the breaker are level with

their mating supporting channels in the

enclosure, and slide the breaker part way
into its enclosure.

out the racking pin.

1. Trip the breaker open. If the
breaker is not open, the interlock lever of
the drawout mechanism will not permit

to prevent further travel. (Note - Refer to
section describing "Test Position" in these
instructions.)

notch on the cam, push the handle down
again to its normal position. This causes

Withdrawing Breaker AK-15 and 25

5. Depress the test position stop han
dle and pull the breaker out of its com

partment as far as the drawout tray will

Repeat this operation five times to rack the

breaker into its final operating position,
bterlocks hold the breaker trip free until

it is racked into the fully contact^ position.
The fifth stroke of the handle is only a

partial stroke and does not result in any

9. Push the tray all the way back

The "Test Position", as referred to In
the previous instructions, is that breaker
position where the primary power discon
nect contacts are safely disengaged but the
secondary control disconnects are engaged.
In this position, the breaker may be tested
or operated, manually or electrically with
out energizing the primary power circuit,
provided the racking handle has been moved
to the completely down position, thus re
leasing the trip Interlock.

further movement of the breaker. It does
serve three useful purposes: itpositions the

For a more complete description of

cam so that it cannot rotate and allow the

breaker to lack out under short circuit

drawout mechanisms and enclosures see
AKD DRAWOUT EQUIPMENT INSTRUC

position stSOURCE FOR

Rreafcer tnaertion AK-2A/3A - With thein-

ner housing in the connected position pro

ceed as follows:

Insert handle on Jackscrew shaft located
on left band side of compartment right

TO (a) CONTACT OF
AUXILIARY SWITCH

ai^e indicator.
Rotate handle counter clockwise until

jackscrew is stopped. (Indicator should
read DISC).

Remove handle and open compartment
door.

Rotate the two track lock links and

er until the breakers mounting pins

When moving a breaker from

one position to another, l)e sure breaker

(Indicator should

Rotate the two track lock links

to lock the breaker in place.
the compartment door.

Using a lifting device, raise the break

are approximately one inch above the

longer be rotated,

Push the breaker in against the track

pull the right track to the limit of ^

is tripped open.

Breaker Insertion AK-4A/SA - With the
inner housing in the connected position,
proceed as follows:

1. Open door and remove wooden wedge
in the lower guide slot of the inner

Pull the remaining track out to the

limit of its travel and lower breaker
so the breaker mounting pins drop into
the slots in the track. Remove the
lifting device.

Insert handle on Jackscrew shaft and
rotate clockwise to move breaker into
the compartment. Breaker is in con
nected position when Jackscrew can no

Pull inner housing forward as far as
possible.

NOTC-WHEN SEPARATE
STA.SEC.
DISCONNECTS

PWR. SOURCE FOP

CLOSING IS ^
USED. OMIT L.

JUMPERS
AI-A3 &

yo 1(yj-chh
xyn

NECT PWR.o-is2o
TOAI&AZ
4

STA. SEC DISCONNECTS
LOCATED AT TOP OF COMR

o-ls-b
FURNISHED

®-^ONLY WHEN
REOUIRED

FURNISHED ONLY
WHEN REOUIRED

Front Vlou AK-IS and 25 Brealicr Cor:partn(>nt

3rroli-r Conpartnent

GEK-7302 Installation and Operation of Type AKPower Circuit Breakers
Rotate the two track lock links, and
ptiUthe right track all the wayforward
4.

Move the breaker and Inner housing to

the fully withdrawn position.

Breaker Insertion, Steps 1, 2 and 3).

Using a luting device and the spreader

grovlded for these breakers, raise the
reaker and position It so ^at the

mounting pins on the side of the breaker
line up with the slots In the track and
are about 2 Inches above the track.

clear the compartment.

engage the slots in the tracks.
6.

escutcheon, sliding the cover below It

to the right, and inserting the handle
on the jacksbaft.
Turn the handle counterclockwise as

far as It will go, (U It will move, in
that direction) and remove the hanAe.
8.

Move the inner housing to the connected
position by pushing the tracks back
against the track stops and then follow
Steps 7 and 8 under Breaker Insertion.
The inner housing is now in the con
nected position and the breaker is free
from Its compartment.

Engage the racking handle. This Is done
t>y pushing the trip button In the breaker

Push the breaker in against the track

Engage the handle and rotate It counter
clockwise. If the breaker closing spring
is fully charged, it will be discharged

customers external connections

DRAWOUT BREAKERS

The customers external control con
nections to these breakers are made to

the quick-closing mechanism is Sesame as
the other breakers described in this book.

quick-close breakers will be equipped with

the stationary secondary disconnected lo
cated In the breaker compartment as shown
;ln Figs. 2 and 3, AKD Equipment and Figs. 4

'and 5 AKDS Equipment.

breaker is used In a General Electric Com

pany, Drawout Swltchgear Equipment, all

an interlock that prevents the manual dis

external connections must be made to
terminal blocks located In the rear vertical

charging of the closing springs while the

wiring trough of the equipment.)

TRIP a05&^
SOURCE SOURCE

TRIP CLOSE
SOURCE SOURCE
REMOTE

(x) (y)(x) (yj puses

(X)(Y)00(Y) ^ CLOSE

STA. SEC. DISCONNECTS
LOCATED AT TOP OF COMR

and pull the breaker all the way forward.
The breaker may now be lifted from

The only difference occurs with drawout
breakers. The compartments that house the

INDIVIDUALLY ENCLOSED AND
STATIONARY BREAKERS

Open the door, unlock the track locks,

100S/AKF2C/2D and breakers e4>

FRONT VIEW AK - |A-|5,25 & AK-2A-I5, 25

FRONT VIEW AK-2A-50/5,100

breaker compartment

BREAKFR COMPARTMENT

TYPICAL WXaiNG DIAGRAMS

Installation and Operation of Type AK Power Circuit Breakers

AK-15/25 manually operated breakers
are closed by turning the handle 90 degrees
counterclockwise

and then clockwise 90

degrees back to the original position. The
initial counterclockwise movement resets

the closing mechanism.

movement closes the breaker.

The closing mechanism of the AK-2/3
50/75/100 manual breakers is a spring
charged mechanism similar to the one

used on AK-2/3-50/75/100 electrically op
erated breakers. AK-2/3-50/75/100 manual
breakers are closed by rotating the closing
handle counterclockwise through approxi
mately 120 degrees, and then clockwise

back through 120 degrees to the normal

handle position. Four such complete move
ments of the handle are required to close
the breaker. During the four counterclock
wise movements and the first three clock

wise movements of the handle, the springs
are charged. After approximately 70 de
grees travel of the fourth clockwise handle
movement, the spring charged mechanism
is

complete handle movements that have been
performed.

AK-4/5-50 manual breakers are also
closed by means of energy released through
the discharge of a closing spring. The
charging of the spring is done lay a single
stroke of the breaker handle. This involves

raising the handle counterclockwise from
the vertical position until a stop is en
countered after about 140 degrees of rota

The spring is then emended to its

fully charged position as the handle is re
turned to its normal vertical position.
Release of the spring, and resultant closing

of the breaker, occurs when the "close'"
button in the escutcheon is pushed.

breaker will close only ifthe racking mech
anism is in the "CONN" or "TEST" position.)
ELECTRICAL CLOSING

(Figures 6 and 7)
STANDARD BREAKERS

AK-15 and AK-2S electrically operated

breakers are closed by a solenoid coil. I'he
armature of the solenoid is linked to the

breaker mechanism and its movement,
operating through the mechanism, closes
the breaker. The closing solenoid circuit
may be operated by a push button closing
switch on the breaker or by a remote
switch or relay, depending on the individual
arrangements desired.
When a closing
signal is given, the X relay coil is ener

gized and it in turn closes its contacts. One
of these seals in the X coil circuit; the

other three, which are arranged in series,
energize the solenoid closing coil. As the
breaker closes, a mechanically operated
switch opens one pair of iis contacts (bb)
and. closes another (aa).
The contacts
which open cut out the X relay coll. The
contacts which close energize the Y relay
coil, whose contacts now seal in the Y coil
and hold open the X relay coil circuit. This
prevents another closing operaiion if one
of the protective devices operates to trip
ihe breaker before contaci ai the closing

LEGEND
CC-CUDSINO aCtAY COIL

D - Ct.OSJNG relay CO^ACTS,.

C - ANTI-PUWP R£LAY contacts
r ag^mecham:
ICALLY OPERATtO SwiTChCS
L

pfSWlTCH
-AUXmAQY

® - CLOSING MOTOR

W - ANTI-PUMP relay COIL
-CONTBCl celay contacts
-CONTTOL relay CC»L
- normally open switch CONTACTS
- normally closed SWITCH CONTACTS

switch is released.

over-center and the breaker

closes. A charge-indicator, numbered 1 to
4, viewed through the breaker front es
cutcheon, moves with each complete handle
movement

Large AK breakers (AK-50/75/100)

are closed by the discharge of a closing
spring. This rotates a crankshaft which,
by means of an attached roller, operates
a closing cam, forcing the movable breaker
contacts against the stationary contacts.
The closing spring is charged through the
operation of a motor and gear reduction
unit.

The electrical control system is com
prised of an X relay, two double contact

mechanically operated switches (F and G),
a push button closing switch and any means
for remote closing which the user may
Incorporate into the system. When voltage
is first applied to the breaker, (before any
closing signal is given) the motor is ener
gized through two of the X relay contacts
and the two G switch contacts.

then compresses the closing springs to the
"pre-charged" position ai which point the
mechanically operated F and G switches
are operated. This opens the G contacts,
stopping the motor, and closes the P con
tacts, which readies the system (or ihe
actual closing of the breaker. When the
push button or remote switch signals for
a closing operation, the X relay coil is

energized, (derating the X contacts. This
seals In the X relay and energizes the
motor once again and the closing operation
takes place.

QUICK CLOSE BREAKERS
(Figure 8)
Functionally, the quick close mech
anism differs from the standard electrical

mechanism in that the pre-charge operation

is extended to completely charge the closing
springs. At the end of the charging opera-

Mon, which takes approximately 5 seconds,

(2 seconds for AK-4/5-50 breakers) a latch
olate engages the prop roller to prevent the
closing springs from discharging.
With the closing springs fully charged
the breaker Is ready for a closing operation
upon release of the prop roller. This may
'}e accomplished either manually, by de
pressing the closing lever on the breaker,
or electrically by closing the remote closing
switch.
Upon the release of the prop
roller the closing springs discharge and
close the breaker in the same manner as

on the standard electrical breaker. AK-4/550 breakers are closed through a remote
switch or the close button in the escutch

eon, (if the breaker is equipped with a push

button closing switch).

• CLOSING MOTOR
X RELAY COL
V • X RELXT CONTACT

y • Y RELAY CONTACT
• MECHANICALLY OPERATED SWITCHES

'f • NORMALLY OPEN SWITCH CONTACTS

^ • NORMALLY CLOSED SWITCH CONTACTS

• RELAY CONTACT

pse • MECHANICALLY OPERATED SWITCHES

4 • HORMALLT OPEN SWITCH CONTACTS
if • NORMALLY CLOSED SWITCH CONTACIS
L • AUXILIAav SWITCH CONTACT

With control voltage applied, ihe motor
is energized through the G switch contacts,
and charges the closing springs. When the
springs reach the fully charged position,
the mechanically operated switches operate,
reversing their contacts. Upon operation
of these switches the motor is stopped by

the opening of the G switch. The closing
of the F switch prepares the breaker for
a closing operation.

Rutntam performance of your, eouipment For full information aoout thete

Allentown 16109 . . . . . . 588 C. Highland St.
(Delaware ValleyiCherry HtU. N.J.. 08094

Johnatown 15602

1790 E. Marlton Pike
641 Oak 81.

• Philadelphia 19124 . . . 1040 Eaet Erie Ave.
• • (Pitteburgh) WtetMimtnl5122
•

4930 Buttermilk Hollow Rd.
54 N. Harriton fit

(Charleeton) No. Chirleatoa 29401

e * Kaneaa City 64120.

9959 Larimer St

• * (Southlagton) PlantevUle 06479

970 Atwater St.
FLORIDA
e " Jackeonvllle 92209 . . .

2020 w. Beaver St.
. 1062 Eaet 28th St.

e « Tampa 99601 . . . 1 . ..

. 19th li Grant Ste.

(AtUnta) Chamblee 20941
5095 Peachmtelnduetrial^Blvd.
Atlanta
2379 John Glenn Dr.

4« Chicago 50698 .. . /6049 S.NottlT«ham Ave.
INDIANA

a Evmnavtlle 47711 ... 40lN.Congreea Av*.
• Ft. Wayne 46809
1791 Sdeall Av*.
•

1198 154th Place

e • MtanapclU 45222 . .. 1740 W.Vermont St.,

St. Louie 69110

NEW JERSEY
• Sew Bruniviek 00602

Albuquerque 67109 .

(Davenport) Sencndorl 52722 . 1025 Stau St.

KENTUCKY
e LoutevUle 40209.

. 3900 Crfttenden Drive

Knoxvllle 97914:

2621 Governor JohnSevler Hwy.

. 4420 McLeed Rd.KE

• .Meatphte 28107

1097 Ceniral Ave.

\ . 6001 Tonnelle Ave.

• (New York City) Clifton. N.J. 07012
9 Brighton Rtf.
1 Rtver Rd. >
* £. Scheneetady 12905
e Syraeuae 19206. . . . 1015 E. Hiawatha Blvd.
NORTH CAROLINA

Charlotte 28208 .

2926 Thrift Rd.

Houaton 77036 .
Midland 79701 .

. 6916 Harwia Dr.
704 8. Jehniton fit.

salt Lake City 64110 .

9018. Tih Weet fit.

Richmond 29324 . .

.. 1409 tngram Avt.

Roanoka 24019 . . .

1004 River Ave.iSE

* Spokane 99211
e

9422 Flret Avt..Smith

E. 4922 Mteelen fit.

Akron (Canton) 44720

Cincinnati 45202
Cleveland 44125

444 Weet 9rd St.
4477 Eaet 49th St.

6860 Huntley Rd.

» * Toledo 43605 . . . . . . . 405 Dearborn Av*.
e Youngetown 44507. . 772 E. Inditnola Ave.

Charltiion 25226

.306 btoeCorUe Ave. .fit

e (Appleton) Menaeht 54910 . . 1725 Racln* St.
e

Milwaukee 59207 . . . 225 W.Oklahoma Ave.

r*"Electrteal/Mechantcal Service Shop *InetfureeBtatton 8hop .1 Special Manufacturing Shop |

1490 W. Cardinal Dr.

Corpue Chrtid 78401 . . . . . . 115 Waco St
Dallaa 75295
9202 Mamr Way
Houetofl 77026 ... <5594 Harvey Wileen Or.

• * (Buffalo) Toaawanda 14150 .. 175 Mllena Rd.

(Long Uland) Old Bethpage 11604
189 Bethpage*Sweet Hollow Rd.
(New York City) North fiergtn. N. J 07012

708 North btaln St

. . . . . 7900Whlppl* Avt.N.W.
IOWA

. 2490 Debonair St.
TENNESSEE

•
9 Lawrence St.

(Miami) Hlaleah 99010.

. 9525 Gardner Ave.

GENERAL ELECTRIC COMPANT, PHILADELPHIA, PA.

POWER CIRCUIT BREAKERS
INSTALLATION AND OPSMTION
Types

AK-2/3/2A/3A-15
AK-2/3/2A/3A-25
AK-2/3/2A/3A-50/50S
AK-2/3/2A/3A-75/75S

AK-2/3/2A/3A-lOO/lOOS
AKT-2/3/50/50S
AKU-2/3/2A/3A-25
AKO-2/3/2A/3A-50/50S
AKF-2/2A-25
AKF-2C/2D/2E

SWITCH6EAR DEPARTMENT

GIMIHAL® ItiWie
PHIlABEtRHIft. PA-

POWEP ClilCUiT BSIEA&CER

RECEIVING, HANDLING AND STORAGE
Before installing, or operating these
circuit breakers, make a careful reading

portation company and notify the nearest
General Electric Sales Office.

of the sections of these instructions which

•re pertinent to the anticipated work.
Upon receipt of a circuit breaker, im
mediately make an examination for any

damage or loss sustained in shipment, u
Injury, loss or rough handling is evident,
file a damage claim at once with the trans

Unpack the circuit breaker as soon as
possibie after it has been received. Exer
cise care in the unpacking to avoid damage
to the breaker parts. Be sure that no loose
parts arc missing or left in the packaging

material. Blow out any dirt or loose parti

If the circuit breaker is not to be placed
in service at once, store it in a clean, dry
location in an upright position. Support U
to prevent bending of the studs or damage
to any of the breaker parts. Do not cover
the

breaker with any packing or other

material which absorbs moisture, that may

corrosion of breaker parts. A

covering of kraft or other non-absorbent

cles of packaging material rematningon/or

paper will prevent dust from settling on the

In the breaker.

INSTALLATION
T^lcal Outline

LOCATION
Breaker

In choosing a location for the Installa

tion of an AK Circuit Breaker, there are
two factors to be considered. Hie first
of these Is the effect of the location on

the breaker Itself.
Much better per
formance and longer life may be expected

If the area is clean, dry, dust-free, and
well ventilated, than if the oppositcs to
these conditions exist.

sideration la convenience for operation
*

and maintenance.

The breaker should be

easily accessible to the operator, and
there should t>e sufficient space allowed
. _

for maintenance work to be done if this

-^'"^^becomea necessary.

AK Circuit Breakers are designed to
be mounted in any one of three ways.
These are dead front mounting, individual
mounting with the enclosurebeingprovided,
and drawout mounting in which the breaker
Is designed for Insertion into a cubicle
In drawout equipment such as a substation
or control board.

AK-2-S0 Man. Oper.'
AK-2-50 Elcc. Oper.
AK-3-S0 Man. Oper.
AK-3-50 Eiec. Cper.
AKT-2-S0 Man. Oper.

AKT-2-50 Elec. C^er.
AKT-3-S0 Man. Oper.
AKT-3-S0 Elec. Oper.
AK-2-75 Man. Oper.
AK-2-75 Elec. Oper
AK-3-75 Man. Oper
AK-3-7S Elcc. Cper.

AK-2-100 Man.(^er.

AK-2-100 Elec. Oper.
AK-3-100 Man. Oper.
AK-3.100 Elec. Oper.

695C116
121C7570
84SC281
238C123
121C7553
121C7555
102C3650
102C3651
121C7589
I21C7S90
8450284
2690225
121C7583
121C7557
84SC290
2690227

12107585
12107559

The surface on which the breaker is

mounted must be flat throughout in order
not to impose any internal distortion on

the breaker unit. The supporting structure

must be rigid enough to avoid any pos

sibility of the breaker studs supporting tlie
weight of the breaker.

dimensions, as given by the appropriate

With AK-50 breakers, a handle and cam
arrangement is used for that part of the
breaker movement that involves the dis

engagement or ei^agement of the primary
disconnect.

AK-75 and AK-100 breakers

are bolted solidly to the enclosure frame
and need not be removed from the en
closure.

2. Remove cover plates of enclosure
and prepare them to accommodate whatever
power entrance means Is used.
3. Mount enclosing case to supporting
structure.

Sower connections to stationary terminals
1 enclosure.

5. If the breaker is a type AK-15,
AK-25 or AK-50 and has been removed

from the enclosure, it may now be re
placed. Control power connections to the
terminal board should be made as required.
(See CONNECTIONS).
6. Before energizing the power cir
cuit, operate the breaker several times to
be sure that it is functioning properly.

(See OPERATION).

outline drawing, must be maintained to

provide adequate electrical clearance.

DRAWOUT BREAKERS AKD EQUIPMENT

DEAD FRONT BREAKERS

These breakers are designed for mount

ing In a switchtxard or enclosing case of
the customer's design and construction.

Mounting in this instance consists of bolting
the breaker frame to a supporting structure

individually ENOLOSED BREAKERS

supplied with several types of enclosures,
most common is the general purpose type or
the weather resistant type. The former is

within the switchtxard or enclosure, con-

used for favorable indoor locations and

f" making any necessary control connections.

locations that may be subject to unfavorable

necting the power buses or 'cables, and

The front cover of the breaker enclosure

may be a hinged door or a plate bolted to
. the panel. In either case, it should have
a section cut out, through which the front
escutcheon of the breaker may protrude.

Outline drawing numtiers giving the dimen
sions needed for preparing a suitable
enclosure or cubicle for the various types
of AK breakers are given below. Hiese
•re for standard 2 or 3 pole breakers.

the latter for outdoor locations or indoor

conditions. All of the enclosures are pro
vided with suitable means for mounting on
walls or supporting framework. Removable
cover plates arc supplied with the en
closures which may be drilled or machined

to accommodate the entrance of bus ducts,

conduits or cables. Steps in the procedure

for installing enclosed breakers follow:

1. If the breaker la an AK-15, AK-25

or an AK-50, remove it from the enclosure.

Mounting drawout breakers consists of

simply placing the breaker in the proper
position with respect to its enclosure,
sliding or rolling it to a stop position, and,
by means of a racking handle and mech
anism, racking it through the last part of its
movement during which the stationary and

movable halves of the disconnects engage.
Large drawout breakers are fastened to a

telescoping tray which extends out from the
enclosure to receive the breaker.

which slide in channels in the enclosures.
Both large and small breakers have a test

position in which the secondary disconnects
are engaged, but the primary disconnects

In this position, the breaker may

be operated electrically without energizing
the load cable or bus.

There Initniethiu do not purport to cover off dtlaili or vonafioni hi eqwpmeni nor to prorido for every portibfe
coAffflptncy to he not in conneefion with imtottation, oporalien or mehrfenonce. Should further information bo dodrod

orAould partieulor problatttt arito which ore rat eovo^ affidonii/ for fhe purthatar'o purpotoo, the moHor AouU
he referred to fhe Generof llodtk Company.

breakers have guides on their side plates

GEK-7302 Installation and Operation of Type AK Power Circuit Breakers

Use DS0H47 lubricant on the disconnect

terminals to reduce the force required to
insert the breaker.

secondary contacts are disengaged. Again
lift the position stop handle.
Slide the
breaker slightly forward to remove it from
the enclosure.

The procedure for Inserting and with
drawing a drawout breaker from its en
closure Is as follows:

1. Trip the breaker.
2. Raise the breaker until the guides
on the sides of the breaker are ievel with

their mating supporting channels in the
enclosure, and slide the breaker part way
into Its enclosure.

(Note - The breaker

will t>e obstructed by a position stop at the
bottom of the enclosure after the breaker

has traveled only a short distance into the
'cubicle.
Lift the position stop handle,
located at the bottom right of the enclosure,
vhich will release the position stop and
.tUow the breaker to travel further into the

proximately six inches above the height of
the compartment tray.

1. Trip the breaker to release the
positive racking interlock.

2. Pull the drawout tray out under the
breaker as far as the tray will travel.
NOTE - When installing an individual
skeleton housing for a drawout AK-SOor 75,

2. Lift the racking handle as far as it
will go.

locate a bolt head over the two front trattom

limit stop (or the drawout tray.

the remainder of the racking operation.
Note that here the cam is rotated by lifting

3. Lower the breaker about 1/2" above
the dowel pins on the tray and push the

of pushing the handle down.

mounting holes of the housing to provide a

breaker back into Its compartment so that
the rear bottom angle of the breaker is

against the guides on the tray directly back

of the dowel pins.

4. Slowly lower the breaker onto the

tray and at the same time guide it so that
the holes in the rear angle of the breaker
fit over the two dowel pins on the tray. If
the breaker is correctly positioned on the

dowels, its rear and side Imttom frame

and up as far as its travel will permit and
push the breaker into the enclosure until
the rackout pins on the handle assembly
tear against the housing rackout cams on
the side of the enclosing case.

angles will aU sit firmly on the tray.

, die forcing the pins on the handle up into

5. Insert two 3/8 inch hex. head screws

through the holes in the front of the side
angles on the breaker and thread them part
way tnto the tapped holes in the tray. Do not
tighten screws firmlv. This provides
better alignment of the primary stationary

the slot in the stationary cam plate. This
action forces the breaker through a final

studs and the primary disconnects for the

short portion of its movement into the en-Clt
losure and allows the operator to provide
force necessary to make the primary
•connects enrage ihe stationary studs in
.•e enclosure, inperformtng this operation,

6. Push the breaker into the compart
ment until the "test" position stop enrages

make sure that the handle is rotated down

subsequent racking operation.

to prevent further travel. (Note - Refer to
section describing "Test Position" in these
instructions.)

This operation will re-engage the trip
interlock to hold the breaker trip-free for

the handle, whereas In racking the breaker
tn, the operation is performer as a resul*^
3. Reset the

handle to its lowered

position and lift it arain. This operation
must be performed 5 times to completely
disengage the cams from their racking

Alter the fifth lifting stroke let the

handle drop to its normal position.
4. Pull the breaker out of its com

partment tmtil the test position stop engages

to hold the breaker in the "test" position.
5. Depress the test position stop han
dle and pull the breaker out of its com
partment as far as the drawout tray will
travel.

6. Remove the two 3/8 hex. head
screws which hold the breaker on the tray.

7. Attach a lifting device to the
frame of the breaker.

8. Lift the breaker approximately 1/.
Inch off the dowel pins on the tray and

and then pull the racking handle down to
be sure the trip interlock is released.
(Note - When the racking handle is in any
Msltion other than completely down, the
breaker cannot be operated and is held
trip-free by the trip interlock. This ap

7. Release the test position stop by
depressing its lever and push the breaker

then pull the breaker forward until its
primary contacts clear the compartment.

back into the compartment until the racking
pins on the housing butt against the outer
surface of the racking cam. In this posi
tion, the racking pin has lifted the locking

9. Push the tray all the way t>ack
into its compartment. The breaker is now

handle to be lifted enough to allow the pawl
to engage the first notch on the cam.

Withdrawing Breaker AK-15 and 25

8. When the pawl engages the first
notch on the cam, push the handle down
again to its normal position. This causes

the previous instructions. Is that breaker
position where the primary power discon

wards as far as Us free travel wiU permit

plies to the "fully In" and "test" positions.)

1. Trip the breaker open.

breaker is not open, the interlock lever of
the drawout mechanism will not permit

operatton of the rackout handle.

arm on the cam which allows the racking

the cam to rotate about the racking pin.

Repeat this operation five times to rack the
breaker into its final operating position.

Interlocks hold the breaker trip free until
it is racked into the fully contacted position.

2. Pull the racking handle up and for
ward as far as it wUl travel, disengaging

the primary disconnects.

Withdrawing Breaker AK-SO. 75 and ICQ

3. Raise the rackout handle forward

4. Push downward on the rackout han-

5 of this operation. The breaker Is no-

the operating position.

Inserting Breaker AK-SO, 75 and 100

1. Lift the breaker to a position ap

inserting Breaker AK-15 and 25

cause the breaker to be trip free. Tighten
the 3/8 inch hex head screws inserted in the
front holes of the drawout tray during s'

The fifth stroke of the handle is only a

partial stroke and does not result in any
further movement of the breaker. It does

free from its compartment.

The "Test Position", as referred to in

nect contacts are safely disengaged but the
secondary control disconnects are engaged.

In this position, the breaker may be tested
or operated, manually or electrically with
out energizing the primary power circuit,
provided the racking handle has teen movcd^^
to the completely down position. Urns re-'
leasing the trip interlock.

serve three useful purposes: it positions the
3. Slide

position stop engages in the front slot in
the bottom of the breaker carriage. The
breaker

is now in the "test" position,

where its primary disconnects are safely
disconnected from the line and load ter

minals of the enclosure. (Note - Refer to
section describing "Test Position" in these

instructions.)
4. To remove the breaker from Us

enclosure, lift the position stop handle and

slide the breaker forward until the position

cam so that it cannot rotate and allow the
breaker to back out under short circuit

stresses; the partial stroke signals that the
racking operation is complete, and it re
leases the trip interlock which was engaged

by the racking pin during the previous four
pumps of the racking arm. NOTE: Once a
racking operation has been started, it must
be completed, as the breaker cannot be
reversed until the racking operation is
completed.

9. After completing the fifth racking

engages the rear slot tn the bottom of

stroke, lift the handle as high as it will go

jitton stop where both the primary and

NOTE: Any strokes teyond this point will

^ breaker carriage. This is the safety

and allow it to drop to its normal position.

For a more complete description of
drawout mechanisms and enclosures see

AKD DRAWOUT EQUIPMENT INSTRUC

TIONS, CEH-lB30andAKDSDrawoutEqulpment Instructions GEI-908B0.

DRAWOUT BREAKERS AKD5 EQUIPMENT
NOTE: AKDS breakers are identified by

letter "A" appeartngafter breaker number example, "AK-2A-15".
Drawout Mechanism Operation - There

lour positions oi the drawout mechanic

Installation and Operation of Type AK Power Circuit Breakers OBK-7302
The Connected Position • the breaker In

the operating position, both primary and

secondary contacts made and the door

The Test Position - the primary (power)
contacts not made tnit the secondary

NOTE- TERMINAL BOARO LOCATED

ON RiONT SIDE OF BREAKER FOR

breaker test not involving power maybe
made in this position. The door may be
closed in this position.

~^CLOSE SW.
CLOSING

AKHS/eS with external CONN' 0 4 0

ECTiONS MADE TO RIGHT SIDE

3. Disconnect Position - neither the pri

mary nor the secondary contacts made.
The door may be closed.

FOR AK-50/75/100

BOARD LOCATED ON

LEFT SIDE WITH EXTERNAL

CONNECTIONS MADE TO LEFT

4. Fully Withdrawn Position - the breaker

completely out of its compartment ready

(or removal from the inner housing. The
door must be open in this position.

"K UNDERVOLTAGE
TRIPPWG

NOTE: The mechanism is designed to

reverse automatically in the connect
and fully disconnected position. Once
an operation is started It must be com
pleted. Completion of an operation is
indicated by the red knob retracting to
its original position.

TO (a) CONTACT OF

iAUXJUARY SWITCH

Brci^er insertion AK-2A/3A - With thein-

ner housing in the connected position pro

Using a lifting device, raise the break
er until the breakers mounting pins
are approximately one inch above the

ceed as follows:
1.

Insert handle on Jackscrew shaft located

on left hand side of compartment right

above indicator.

Rotate handle counter clockwise until

Pull the remaining track out to the

Jackscrew Is stopped. (Indicator should

BO the breaker mounting pins drop into

Remove handle and open compartment

Is tripped open.

Insert handle on Jackscrew shaft and

Push the breaker in against the track
stops. Rotate the two track lock links

toe compartment. Breaker is in con
nected position when Jackscrew can no
longer be rotated. (Indicator should
read CONN).

lifting device.

Rotate the two track lock links and

pull the right track to the limit of
its travel.

rotate clockwise to move breaker into

NOTEt-WHEN SEPARATE
PWR. SOURCE FOR

CLOSING IS o
USEOiOMiT C

NOTE: When moving a breaker from
!
board on the breaker or to the statlonar

100S/AKF2C/2D and breakers equipped
1*

Trip the breaker.

same as the other breakers described in

this tiook. The only difference occurs with
drawout breakers. The compartments that
house the quick-close breakers will be

Move the breaker and inner housing to
the fully withdrawn position. (See
Breaker Insertion, Steps 1, 2 and 3).
3.

equipped with an interlock that prevents the
manual discharging of the closing springs
while the breaker Is in the racked in (con
nected position).
This interlock will be

Rotate the two track lock links and

provided with both AKO and AKCS equip
ment that require quick-close breakers.

pull the breaker out to the limit of
the track travel. Attach lifting device
and lift breaker up and away from
compartment until primai'y disconnects
clear the compartment.

Depending on the breaker type, those con
parts of the secondary disconnects.
INDIVIDUALLY ENCLOSED AND
STATIONARY BREAKERS
The

customers external connectlone

for operation of breaker control components
and accessories are shown In Fig. 1.
DRAWOUT BREAKERS

All electrical connections should be

Move the inner housing to the connected
position by pushing the tracks back
against the track stops and then follow
Steps 7 and 6 under Breaker Insertion.
The inner housing is now in the con>
oected position and the breaker is free
from its compartment.

made to assure good conductivity. Mating
surfaces should be parallel and firmly
bolted or clamped together. Contact sur

faces should be clean and have a smooth

finish. The bus or cable connecting to the
breaker should have adequate currentcarrying capacity to prevent excessive
heating. Control circuit connections should

be made according to the wiring diagram

The customers external control con
nections to these breakers are made to

(he stationary secondary disconnected lo
cated in the breaker compartment as shown
In Figs. 2 and 3, AKD Equipment and Figs. 4

and 5 AKD5 Equipment.

breaker Is used In a General Electric Com

pany, Drawout Switchgear Equipment, all
external connections must be made to
terminal blocks located in the rear vertical

wiring trough of the equipment)

OPEeSATION
counterclockwise and then clockwise 00

degrees back to the original position. The

AK-15/25 manually operated breakers

Initial counterclockwise movement resets

are closed by turning the handle 90 degrees

the closing mechanism.

TRIP CLOSE
SOURCE SOURCE

(X) wSlfiT
REMOTE
TRIP

SOURCE SQUIRE
REMOTE
CLOSE

movement closes the breaker.

The closing mechanism of the AK50/75/100 manual breakers Is a spring

TTI/^. "^'^CO^NECTS

STA. SEC. DISCONNECTS
LOCATED AT TOP OF

A A A A A A A__A A A A A A A

HkXXkirXkkXJikX
E

\
FURMShEI)
ONLY WHEN
REQUIRED

FURNISHED ONLY
when REQUIRED

FRONT VIEW AK-IA-I5,25 i AK-2A-I5, 29

FRONT VIEW AK-2A-50,75,IOO

BREAKER COMPARTMENT

BREAKER COMPARTMENT

Installation and Operation of Tjrps AK Power Circuit Breakers GEK-7303
charged mechanism similar to the one used

on AK-50/7S/100

electrically operated

f ' breakers.
AK>SO/75/l(H>
manual
( ^^Kiweakers are closed by rotating theclosing
Nndle counterclockwise through approxl-

iitely 120 degrees, and then clockwise
oack through 120 degrees to the normal
handle poslllon. Four such complete move
ments of the handle are required to close
the breaker. During the four counterclock

wise movements and the first three clock
t0

are charged. After approximately 70 de
grees travel of the fourth clockwise handle
movement, the spring charged mechanism
Is

wise movements of the handle, the springs
hi

closes. A charge-Indicator, numbered 1 to
4, viewed through the breaker front
escutcheon, moves with each complete

(S) • CLOSWa HOTOR

# • X KxM CMTxer

handle movement and indtcates the number

rac • HeCHAmCALLT OfCRATeO SWITCHES

y • Tiis.«r eoNTwT

of complete handle movements that have
been performed.

4 • NaraMLCT orcN switch cwtacts
§ • MORHALLV CLOSeO SWITCH COKTACTS

M-t» • HeclUKtCU.LV OXERATCD SWITCHn

^ • MOAtULLY OPCH SttlTCM OmTXSTt

I • AUXIUARY SWITCH CONTACT

4 •NORMUU OnSEO SWITCH CONTACTS
ELECTRICAL CLOSING

(Figures 6 and 7)
STANDARD BREAKERS

AK-IS and AK-25 electrically operated
breakers are closed by a solenoid coll. The

Sliapliriod Eleccntary Diagraa
Intomal Wlrlnc AX-15 and 85

Slstplifled Elenentary Siagraia

Internal Hiring tX-50, 75 and 100

armature of the solenoid is linked to the

breaker mechanism and its movement,
operating through the mechanism, closes
the breaker. The closing solenoid circuit
may be operated by a push button closing
switch on the breaker or by a remote

switch or relay, depending on the Individual

^arrangements desired. When a closing
signal Is given, the X relay coil is ener
gized and It in turn closes its contacts. One

of these seals in the X coil circuit; the

..vUch opens one pair of Its contacts (bb)
and closes another (aa).
The contacts

switch Is released.

Large AK breakers (AK-50/75/100)

are closed by the discharge of a closing
qirlng. This rotates a crankshaft which,
by means of an attached roller, operates
a closing cam, forcing the movable breaker
contacts against the stationary contacts.

The closing spring is charged through the

operation of a motor and gear reduction
unit.

prised of an X relay, two double contact

mechanically operated switches (F and G),
a push tmtton closing switch and any means
for remote closing which the user may
Incorporate into the system. When voltage
Is first applied to the breaker, (before any
closing signal is given) the motor ts encr-

The electrical control system Is com

gtzed through two of the X relay contacts

and the two G switch contacts. 'The motor

then compresses the closing springs to the

"pre-charged" position at which point the
mechanically operated F and G switches
are operated.

This opens the G contacts,

stopping the motor, and closes the F con-

f >!*cta, which readies the system for the
f

Functionally, the quick close mecha
nism differs from the standard electrical

mechanism In that the pre-charge operation

of the protective devices operates to trip
the breaker before contact at the closing

ts extended to completely charge the closing
springs. At the end of the charging opera
tion, which takes approximately 5 seconds,
a latch plate engages the prop roller to
prevent the closing springs from dis

which open cut cut the X relay coil. The
contacts which close energize the Y relay
coil, whose contacts now seal in the Y coll
and hold open the X relay coil circuit. This
prevents another closing operation if one

QUICK CLOSE BREAKERS

tther three, which are arranged in series,

firpze the solenoid closing coll. As the
^er closes, a mechanically operated

energized, operating the X contacts. This
seals bt the X relay and energizes the
motor once again and the closing operation
takes place.

closing of the breaker.

•h Initton or remote switch signals for
« closing operation, the X relay coll Is

and de-energize the control relay. The
auxiliary switch contact opens preventing
the control relay from being energizeduntll
the breaker Is tripped open. With the 6
switches closed, the motor charges the
closing springs ready for the next closing
operation.
MANUAL OR MAINTENANCE CLOSING
OF ELECTRICAL BREAKERS

All electrical breakers may be closed
manually by means of the maintenance
handle furnished with the breaker or switchgear.

With the closing springs fully charged
the breaker is ready for a closing operation
upon release of the prop roller. This may

be accomplished either manually, by de

pressing the closing lever on the breaker,
or electrically by closing the remote clos

ing switch. Upon the release of the prop
roller the closing springs discharge and

close the breaker in the same manner as
on the standard electrical breaker.

With control voltage applied, the motor

of the F switch prepares (he breaker for
a closing operatton.

and complete the circuit through the closing
relay coll. With the closing relay coll
energized the breaker closes as described

above. At the same time the closing relay
contact closes to energize the antt-pump

SMSftJJSUtACTS
*NTt-PUMV
CONTACTS

liTtCHANlCAVtY OPCRATM SWllDCS

AUXIltMT SWITCH CONWT&
CLOScNC MOIOA
ANTl^PuUC AUAr CCtL

kOAIAAUy OPtN SWITCH CONTACTS
NCAMAUT aosco SWITCH contacts

SlMPiirtCV CltVCNTARY ClAOftAM

Itwai WhthOQU>b( CLOk ahCARCR

relay causing Its contacts to reverse pro

viding the anti-pump feature.

When the breaker closes, the mechani
cal operated G switches close to energtze
the motor again and the F switches open

is energized through the G switch contacts,
and charges the closing springs. When the
springs reach (he fully charged position,
the mechanically operated switches operate,
reversing their contacts. Upon operatton
of these switches the motor is stopped by
the opening of the G switch. The closing

A closing signal now given energizes
the control relay X whose contacts close

GEK-7302 Installation and Operation of Type AK Power Circuit Breakers
To close AK-15/25 breakers:
I.

Place the two small hooks of the handle
Into the two slots located in the lower

portion of the front escutcheon.

Botation of the long end of the handle
downwards forces the shorter end of

the handle upwards against the bottom
of the solenoid armature, and closes

the breaker's contacts.

springs which closes the breaker's con

To close AK-S0/7S/100 breakers:
Place the ratchet type maintenance
handle on the shaft that protrudes from
the gear reduction unit.

Operate handle until the spring charge

Indicator reads charged.
Continue to operate handle tmtil the
closing springs discharge and close the
contacts.

To close AK-50S/75S/100S, AKF2C,

20 breakers and breakers equipped with
the quick closing mechanism:

NOTE: All AKD, or AKD-S drawout type
breakers equipped with the quick closing
mechanism cannot normally be closed man
ually when in the racked in (connected
position), due to mechanical designed inter
ference between the

With the ratchet type maintenance hand
le applied to the gear box shaft, operate
the handle until the springs are fully
charged. The fully charged position is
indicated by the spring charge indicator
and by solid resistance to any further
handle operation.
Push down on the push to close lever to
release the energy stored in the closing

enclosure and the

spring discharge lever on the breaker. If
manual closing is desired with the breaker
racked In, the interference feature must be
removed, otherwise the breaker can be

manually closed in the test position or fully

packed cut position only.

tacts.
TRIPPING

The breaker is tripped open by the
displacement of a mechanism latch, which
allows a toggle linkage supporting the
movable contacts in the closed position to
collapse.
This trip latch is fastened

rigidly to a trip shaft which runs hori

zontally from left to right through the
breaker. All of the means provided for
tripping the breaker operate through striker
arms which displace the mechanism trip
latch by moving against trip paddies fastened
on the trip shaft. Looking at the breaker
from the right, counterclockwise rotation

of the trip shaft causes the breaker to trip;

clockwise movement resets the mechanism

latch. The manual trip button, overload
devices, shunt trip, undervoitage tripping
device, and reverse current trip all operate
in this fashion to trip the breaker. The
movement of the striker arms of all of

these, when activated, should move from

ated devices (one per breaker pole) each
wired in parallel to corresponding breaker

These devices are mounted on the

left hand side of the breaker (looking from

moving the channel shaped retaining bar.
BEFORE INSPECTION OR ANY MAIN

4. Inspect arc quenchers and contacts

THE BREAKER IS IN THE OPEN POSI

for breakage or excessive burning.

TION. ALL ELECTRICAL POWER, BOTH

Should arc quencher barriers or contacts
be eroded to half their original thickness
they should be replaced.

breaker Is recommended at least once a

year. More frequent inspections are recom

moisture, or other unfavorable conditions
exist.

Always inspect the breaker after a
abort circuit current has been interrupted.
At the time of inspection, the following
checks should be made after the breaker

has been de-energized.
. 1. Manually operate the breaker
several times, checking for obstructions
or excessive friction.

2. Electrically operate the breaker

several times (if breaker has electrical

fiBBjtrol) to ascertain whether the electrical

A^ments are functioning properly.

of their trip devices. Any attempt to carry
higher currents for a prolonged period will
cause overheating and possible damage.
All AK-3 type air circuit breakers will
be equipped with Power Sensor* overcurrent
trip devices. The time current band as well

as the pickup settings of this device are

adjustable. A single captive thumb screw

adjusts all three phases for any particular
characteristic or setting. Should a thumb
screw be inadvertently left loose the Power
Sensor*

revert to the "minimum"

pickup settings or "maximum" time delay
bands accordingly. If after installation,
nuisance tripping occurs, check the Power
Sensor* for proper settings as required for

the specific application and tighten all the
thumb screws on the Power Sensor*.
For a more detailed discussion of the

construction, operation, and application of
overcurrent trip devices refer to the follow
ing publications:

1. Maintenance manual for specific

breaker Involved (see "Maintenance").
2. "Selection and Application of Power

the closed air gap positlo

allowing the reset button to extend forwar
indicating which fuse has blown, and simul
taneously holding the breaker in the tripfree position until the latch closed armature
Is released by the operating of the manual
reset tnitton.

general nature concerning the installation
and operation of Type AK power circuit
breakers.

If more complete and specific

information Is required, such as might be

needed for overhauling the breaker, trouble
shorting, or replacing parts of the breaker,
refer to the complete instruction for the
particular breaker type involved. These
are:

mended, if severe load conditions, dust,

eous alone. Breakers are designed to carry

up to 100% of the continuous current rating

3. Remove the arc quenchers t>y re

PRIMARY AND
CONTROL SOURCES
SHOULD ALSO BE DISCONNECTED.

either of the dual magnetic type (instantan

eous and time delay tripping) or instantan

FUSE-BREAKER COIV3BINAT&ON5

front). The purpose of this device is to
trip the breaker upon the blowing of anyone
of the breaker fuses. This energizes the
coil of the device causing the armature to
engage the trip paddle, thereby tripping the
breaker. Once operated, the armature is

TENANCE WORK IS DONE, BE SURE THAT

Most AK-2 air circuit breakers are t ^

quipped with series overcurrent trip devices

BEFORE MAKING ANY ADJUST- ' Circuit Breakers" GET-1113.

TYPE AKU AND BREAKERS W8TH
This device may be furnished with any
die above type breakers. The open fuse
lockout device consists of 3 separately oper

POSITION AND CONTROL POWER RE- i-v
MOVED.
•A

1/32 to 1/16 inch beyond the point at which

tripping occurs. This is what is meant by
the expression, "positive tripping".
NOTE:

!n Fuse Lockout Device

MENTS TO TRIP DEVICE SETTINGS, THE *
BREAKER SHOULD BE IN THE OPEN

general, tiie circuit breaker re

quires moderate lumbricatlon.
Bearing
points and sliding surfaces should be lub
ricated at the regular inspection periods
with a thin film of CE Lubricant DS0H15.

Maintenance
Manual

AK-2/2A/3/3A-15125, AK

GEI-g3863
GEK-7303

AK-2/2A/3/3A-50/75/100,
AKU-2/2A/3/3A-50
AK-2/2A/3/3A-50S/75S/

Before lubricating remove any hardened
grease and dirt from latch and bearing
surfaces with kerosene.
ALL EXCESS
LUBRICANT WHOULD BE REMOVED WITH
A CLEAN CLOTH TO AVOID ANY AC

IOCS, AKF-2C/2D/2E

Power Sensor Solid State
Test Instructions

CUMULATION OF DORT OR DUST.

On drawout breakers, the contact sur
face

disconnect studs should be

cleaned andgreased withGEGreaseSpecifi
cation D50H47.

These instructions have as their pur
pose the imparting of information of a

Renewal parts txilletins for the various types
of breakers are:
BuUeUn
GEF-4140
GEF-41S0
GEF-4151

*Trade-M^rk of General Electric Company

AK-2-15/25
AK-2-50

Gi^EHALS ELiOTRIS

lO^M'OlTAGE AIR CIRCUIT BREAKERS

Aps^BSccifaoBi Isnforme^ion

frlZOV POWER
MOTOR
-

?fl ,T
Co-ordinated system provides best possible
combination of continuous power,
continuous protection
The highest degree of service reliability can be secured by the
careful selection of main and feeder circuit breaker time-current

characteristics with proper relation to one another. This is what
b meant by circuit breaker co-ordination.

Electrical distribution systems—no matter how carefully
constructed and thoroughly insulated—can have faults. With

proper co-ordination, it is possible to protect the system from
unnecessary downtime caused by faults. This is achieved by

matching the characteristics of protective devices from tiie
power source to utilization in order to achieve the highest de
gree of service reliability. This co-ordination is provided in
addition to proper mechanical design of the equipment, insu
lation levels, thermal capacity and short-circuit bracing. Co
ordinated, the system provides the most desirable combination
of continuous power and continuous protection.

TABLE OF CONTENTS

Applicotion Factors
Interrupting Ratings
Short-time Ratings

Distribution Systems

Application Tobies

D-c Power Systems....:

Breoker Operating Mechanisms
Overcurrent Tripping Mechanisms
Trip Characteristic Curves

Accessories and Enclosures.

10W-V0LTA6E AIR CIRCUIT 8RSAKERS

AppHccstioin Bnforimci?i®n

FOREWORD
The selection of power circuit breakers
for the protection of low^voltage circuits
is similar to the problem of selecting other
types of electrical equipment. To be
properly applied, a circuit breaker should
be suited to the power system on which
tC: is to be used; it should be able to withataai^ the service conditions to be en

countered, and should provide the neces
sary overcurrent protection either by
itself or in co-ordination with other pro

value of the maximum available shortcircuit current which the breakers must

interrupt. Thb must be determined either
by calculation or with assistance from the
local power company. The characteristics
of the load to be supplied and the co

ordination required with other breakers
in the system, dictate the type of overcurrent trip devices which should be
selected for a particular breaker.
The material in this section is intended

tective devices.

to assist in the selection of general-

Most of the factors pertaining to the
characteristics of the power system and

purpose low-voltage power circuit break
ers and their trip devices as recommended
by the NEMA Standards. A summary of
breaker types and ratings is given in

the service conditions under which the

breakers will operate will be obvious by
inspection. One exception to this b the

i
(flieia 8017150)

TABLE I—^Summary of Breaker Types, Ratings
OvnrcurrnnI Trip Onrle* Rallrta

httmiptlae Raliag
Voll-

SMS Syramntrlcol

MIn.
wilh
Initonfontoul
CharaeInrittie

Oiarnc- Chsroe.
Iniitlk
loritlic

Short CheuS
Umll for

Roline
co8o OperaSymfflolrieal lion Amperoi
Amportt
RMS
SyRimoIrlesI

(Thtta 8017150)

Fig. 4.
•IS
25
...SO
AX.75

AX-lOO
M-15
AX-2S
AX.50

AX-IS
AK-25
AK-50
AK75
AX-IOO

14,000
22.000
42A)00
85,000
85,000

V.OCO
22,000
42,000
85,000
85,000

22,000
30,000
50,000
85,000
85,000

9,000
22,000
50,000
85,000
85,000

9fi00
22,000
50,000
85,000
85/100

100
175
350
2000
2000

125
200
400
3000
2000

150
350
500
2000
2000

225
800
1800
3000
4000

9,000
32,000
43,000
85,000
85,000

20
100
400.
2000
2000

too
175
350
2000
2000

225
800
1800
3000
4000

ISO
250
500
2000
2000

125
200
400
3000
2000

250
500
2000
3000

100
175
350
2000
2000

9,000
22,000
85,000
85,000
9/100
23/>00

50,000
85/)00
85,000

85,000
42,000
80,000
85,000
85.000
85,000

50,000
85,000
100,009
130.000
130,000

IFhelo 8017150)

APPLICATION FACTORS
In selecting power circuit breakers, the
following factors relating to the charac
teristics of the power system to which the
breakers are to be applied and the con
ditions under which they will operate
should be considered.

1. Circuit voltage.
3. Circuit-load current.
3. Available short-circuit current.

4. System frequency.
5. The ambient temperature.

6. Frequency of operation.
7. Altitude.
irhela 8024IOS)

IRiala 8024132)

8. Local electrical codes.
9. Unusual service conditions.

10. Special duty cycles.

iOW-VOLTAGE AIR CIRCUIT BREAKERS
Poge

These factors should be given the con>
sideration indicated in the following para*
graphs. Note, when reference to the

Company is indicated, inquiry should be
made to the nearest Apparatus Sales
Office for referral to the Low Voltage
Svntchgear Marketing Section, Phila

delphia.
1. Circuit Voltage

The voltage rating of the circuit breaker
diould equal or exceed the nominal volt
age of the circuit to which it is to be
applied.

quencies of 60-25 cycles or d-c. Special
recommendations should be requested

from the Company for applications of
circuit breakers to circuits of higher fre
quencies or circuits on which higher order
harmonics are present, such as capacitors,
rectifiers, or induction furnaces.

be referred to the Company.
9. Unusual Service Conditions

It is recommended that, wherever pos
sible, steps should be taken at the site of
installation to control unusual service

5. Ambient Temperature
General Electric power circuit breakers
arc designed in accordance with NEMA
Standards to carry rated current without
exceeding allowable temperature rises
when operated in an ambient temperature
of 40 C. When the circuit breakers are

2. Circuit-load Current

characteristics in order to meet certain

city, state, or other electrical codes should

conditions so that standard equipment
can be installed. When such steps are not
practical or standard equipments such as
dust-tight, watertight, dripproof, or
explosion-proof enclosures adaptable to
the unusual condition are not listed,
recommendations for special features
necessary to adapt the equipment to the

iced by the circuit. In this connection
attention is directed to the following quo
tation which is a paragraph under Section

mounted in enclosures the average am
bient temperature inside the enclosure
may be not more than 15 degrees higher
than the standard ambient temperature
of 40 C outside the enclosure. Applica
tions requiring operation in ambient tem
peratures in excess of 40 C should be
referred to the Company with complete
information relative to temperature and

SG3-3.03 of NEMA Low-voltage Power
Circuit Breaker Standards, Pub. No.

ventilation conditions at the proposed

2. Exposure to steam.
3. Exposure to salt air.
4. Exposure to oil vapors.

site of installation.

The continuous current rating of a cir
cuit breaker should equal or exceed the
maximum-load current which the circuit

will carry as established by the overload
or thermal ratings of the apparatus serv

"NOTE: Circuit breakers are rated upon a
maximum basis. They are circuit inter

rupters and protective devices and, as such,

may1^ catled uponat any timesuccessfully
to remove from service other equipment or
circuits. Furthermore, after such a circuit

interruption, their current-carrying ability
may be materially reduced. Because of these
conditions which differ from those for gen
erators, motors, transformers, and similar

apparatus, it is not practical to establish
standard overload or thermal ratings."

3. Available Short-circuit Current
The available short-circuit current at a

given point in a power system is the
maximum current which the power sys

tem, when operating with maximum gen
erating capacity and connected motor
load can deliver to zero impedance short
circuits simultaneously applied from all
phases or polarities to ground. For a-c

systems the calculated value of the shortdrcuit current available must be less

Power circuit breakers may be applied
to ..most of the more commonly en
countered power circuits such as gen
erator, transformer, and feeder circuits
without normally questioning the fre

quency of operation. Where repetitive
operationsare involvedsuch as on circuits
feeding industrial process motors, fur
naces, etc., the application should be con
sidered in light of the published informa
tion on page 23, Table XII.

1. Exposure to damaging fumes or
vapor.

6. Exposure to dust, abrasive dus*
magnetic dust, or metallic dust.
7. Exposure to dripping water c.
falling dirt.

8. Exposure to explosive mixtures of
dust or gases.

9. Exposure to abnormal vibration,
shock, or tilting.
10. Seasonal or infrequent use.
11. Unusual insulation requirements.
12. Exposure to extreme temperatures

or sudden changes in temperature.
13. Unusual space limitations affecting

In the rarefied air above 3300-ft alti

tude, both insulation and current-carry
ing capacity are affected, and for such

applications the published ratings of
power circuit breakers are modified by
multiplying the ratings by the following
factors established in ASA, AIEE, and
NEMA stan(jards:

use or installation.

14. Unusual configuration of enclosing
rooms causing hot air pockets,
rooms not having normal ventila
tion, or rooms containing large
amounts of magnetic material.
15. Unusual operating duty, frequency
of operation, or difficulty of
maintenance.

CMfttllaa raclen
Altlturf*
la fatt

16. Unusual or special operating re
quirements.

For a discussion of the interrupting

0.994
0.99
0.94

4. System Frequency

the order. Among such unusual conditions
are the following:

6. Frequency of Operation

than the interrupting rating of the circuit
breaker. For d-c systems the maximum
steady-state current should be less than
the interrupting rating of the circuit
ratings of G-E breakers, refer to pages 3

unusual conditions should be obtained

from the Company in advance of placing

8. Local Eloclrical Codes

10. Special Duly Cyclos
Breakers are used occasionally on spe
cial duty cycles, including currents above
the normal rating for short periods, fol
lowed by rest periods, etc. Under these
conditions it may be necessary to inte

grate the combined effect of the various. _

The frequency rating of the circuit

All G-E standard power circuit break

breaker should agree with the nominal

ers are built to conform to applicable pro

frequency of the power system. Standard

visions of the ASA and NEMA standards.

cycle as far as heating effect is concerne*. J

Requirements for breakers having special

It is seldom necessary to use a breaker of

G-E circuit breakers are rated for fre

load currents atdifferentparts ofthe du*

lOW-YOLTAGE AIR CIRCUIT BREAKERS

Application informcstion

_ Page 6
rating cormponding to the highest current of the duty ^le. Recommendations
for such applications should be requested
from the Company.

ciVcuif with an X/R ratio of not less than
6.6.

* Copies are available from the American
Standards Association, Inc., 70 East 45th
Street, New York 17, N. Y.

INTERRUPTING RATINGS
Modern design circuit interrupters such
as are used on General Electric low-

voltage power circuit breakers have inter
rupting capabilities which are a function
of voltage. This is reflected in the differ
ences in interrupting ratings assigned to
drcuit breakers with instantaneous trip
devices at the three voltage levels of 600,

The circuit breaker shall be able to

inferrupf the rms symmetrical current
rating as well as every degree of asym
metry up to an X/R ratio of not less than
6.6. Verification of breaker interruption
rating shall be made by:
1. A single-phase test with line-to-line
voltage across the circuif-breaAer

pole with the alternating-current
component of current equal to or
greater than 86.7 percent of the
symmetrical rating, and
2. A single-phase test with maximum
degree of asymmetry associated
with par. I and with line-to-line
voltage across the breaker pole, and
3. A fAree-^Aase (esf at rated voltage
with the 3-phase average asym

480, and 240 volts. Table I indicates these

ratings, as well as the interrupting ratings
without instantaneous trips, which are
not a function of voltage. The latter rat
ings are to be used when breakers are

applied without instantaneous trips, as
they would be when equipped with selec
tive trips or when direct-acting overcurrent trips are omitted—for example,
when separate overcurrent relays are

metrical current not less than 1.17

jitage not less than the rated voltage.
Interrupting ratings ofGeneral Electric
power circuit breakers are based on the
test procedure, applicable operating duty

times the symmetrical rating.
The transient characteristics of the
testing circuit shall be such that the 3phase average alternating-current com
ponent of current at the end of 30 cycles
(based on a 60-cycle frequency) shall be
not less than 85 ^ercenf of the average
alternating-current component of current
at the end of the first half-cycle.

(du^ cycle), performance and conditions

The rated interrupting current is the
maximum current at the rated voltage
which a circuit breaker is required to

! yflajnterrupt under the operating duty speci-

dand with a normal frequency recovery

given in paragraphs SG3-3.08 and SG3-

3.19 of ^e NEMA Standard for lowvoltage power circuit breakers. The latter
paragraph reads as follows.
DETERMINATION OF INTERRUPTING
RATING

Operating Duly-for Determining the
Interrupting Rating (Duty Cycle)

The operating duty for determining the
interrupting rating of circuit breakers
with instantaneous oi/erctirrenf trip de
vicesfor fault currents shall consist of an

opening operation, followed after a 15-

second interval by a close-open operation.
The test proeedme and eharaeteristics
The operating duty for determining the
of the test circuit to be used Jot verifying interrupting rating of circuit breakers
Oie cbdity of the circuit breaker to inter'
with delayed overcurrent trip devices for
rupt the total rms amperes given by the
fault currents shall consist of an opening
interrupting rating for the applicable
operation, followed after a 15-second
operating duly shaB be as follows:

interval by a cfose-o^en operation, the

tripping being delayed by the associated
tripping devices.

RMS ToIgI Amparos

The rnu total amperes shall be deter
mined by measuring the current flow as
follows:
The circuit breaker shall be short
circuited or omitted.

The symmetrical current shall be
measured at an instant one-half cycle
after the short circuit occurs and shall be
ealeutated in accordance with the Ameri-

Standard Methods for Determining

RMS Value ofa Sinusoidal Current

jve and a Normal-Frequency Recovery
Voltage*, C37.5-m3. The degree of
asymmetry for the asymmetrical tests
shall be determined on the basis of a test

At the end of any performance at or
within its interrupting rating, the circuit
breaker shall be in the following con

current at rated voltage for a limited
time but not necessariiy ivitAout ex
ceeding the rated temperature rise.
After a performance at or near its
interrupting rating, it is not to be inferred
that the circuit breaker can again meet its
interrupting rating ivitAout being in
spected and, if necessary, repaired.
D.

The conditions which are assumed in

assigning an interrupting rating to a cir
cuit breaker include the stored electro

static and magnetic energy of the system,
the re-establishment of an arc under
transient voltage conditions, the decre

ment of the system and other variable
conditions. These conditions are con

sidered as not differing widely in average
systems and are to be taken into account

in the factor of safety employed in the
rating of the circint breaker.
SHORT-TIME RATINGS
The short-time rating of a circuit
breaker must be taken into account when

the breaker is applied without directacting overcurrent trips.
The rated short-time current is the
maximum current which a circuit breaker

will carry without injury for specified
short-time intervals. The rating recog
nizes the limitations imposed by both
thermal and electromagnetic effects.
Short-time ratings of General Electric
air circuit breakers are based on the test

procedure, operating duty (duty cyde),
performance, and conditions given in
paragraphs SG3-3.10 and SG3-3.16 of
the NEMA Standard for low-voltage

power circuit breakers. This paragraph
reads as follows:
DETERMINATION OF SHORT-TIME
RATING

The test procedure for determining the
short-time current rating shall be as
follows:

RMS Total Ampere*

Determined same as for interrupting
rating.

8. Operating Duly (Standard Duty Cycle)
The short-time duty cycle shall consist
of maintaining rated short-time current
for two periods of one-half second each,
with a IS-second interval of zero current

between the one-half second periods.

1. Mechanical—The circuit breaker

shall be in substantially the same

At the end of any performance at or
within its short-time rating, the circuit
breaker shall be capable of carrying rated
continuous current without exceeding the

shall be capable of loitAstondiny
rated voltage in the open position
and of carrying rated continuous

rated temperature rise of its various parts
and shall be capable of meeting its inter
rupting rating.

mechanical condition

beginning.
2. Electrical—The

•lOW-VOtTAGE AIR CIRCUIT BREAKERS

Application Information

A-C POWER SYSTEM APPLICATION

NUMBER OF POLES AND TRIPS REQUIRED

The following data gives the correct power circuit breaker for protection of the more commonly used circuits.

A. Stngtcpheta,

wlrt, ungrounded

S. Slngle-phoie,
wire, grounded

One 2*pole breaker with
two overcurrent trips

i One l-po1e breaker with
overcurrent trip

One 2-poIe breaker with
two overcurrent trips

One 2-pole breaker with
two overcurrent trips

Slnglo.phais, two*

wIro, ungrounded

One 2-pole breaker with
two overcurrent trips

Pig. 14.' 1Iirea.phote,
tliree.wlro, grounded

One 3-poIe breaker

Pig. II. Slngle.ptiote, llireawire, ungroonded

One 3-poIe breaker with

three overcurrent trips

Pig. IS. Three.phait,
Itiree-wlre, grounded

One 2-poIe breaker

Fig. 12. Slngle.phoie, Ihreo.
wire, grounded

T One 2-pole breaker with
two overcurrent trips (one
m each conductor, except
neutral)

Pig. 16. Three-phote,
four-wlro, grounded

T One 3-po!e breaker

with three overcur

with two overcurrent

with three overcur

trips (one in each un
grounded conductor)

^ On incoming service lines, where the
Underwriters' rules apply, provide some
means of disconnecting the grounded neutral in accordance with the following re
quirements; 230-70 (i) of the Notional Elec
trical Code: "If the switch or circuit breaker

docs not interrupt the grounded conductor,
other means shall be pro-/ided in the service
cabinet or on the switchboard for discon
necting the grounded conductor from the
interior wiring."

{ Provides overcurrent and short-circuit

Hiree-wiro, ungrounded

One 3>pole breaker
with three overcur-

ThratvphaiOg
p«R«ralcr

One 3-pole breaker
with three overcur

rent trips, t See note
below.

protection only. Switchgear relays can be
furnished to give reverse power, undervolt-

age, phase sequence, ground-current pro

tection, etc. Such application should be
referred to the Company.

lOW-VOLTAGE AIR QRCUIT BREAKERS

Page 8
A-C POWER SYSTEM APPLICATION

cost. Power is supplied to the load center unit substations at the
primary voltage level, stepped down to utilization voltage, and

Four basic circuits for power distribution have evolved from
the many possible types and variations of substations and
circuit arrangements.

distributed to utilization devices on relatively short, low-volt

age feeders. Selective co-ordination of protective devices is
recommended where processes require continuous power. G-E
load centers can be provided for any of these arrangements.
Combinations of the various systems may be utilized.

The load center philosophy of power distribution that is,
the use of substations located in or near the load area- -is basic

to all of these arrangements providing good design at minimum

SECONDARY-SELECTIVE SYSTEM

ify for moil power tervice requlremenfs. There
b only one prtinory feeder and one trentformer

Secondory selective tystem it -in effect two
rodiol tystemt with o tecondory tie between
Ihem. Eilher source of power moy be energised
and power con be mode ovoileble on both tec»,

teuree power mecnt lost of the entire tubtlotion

moln breoVer end ctosing the lie breoker. This

Simple radiol (yilem It moil economical leodctnftr distribulioft syilem, hot tuflicieni reUobit*

through whi^ o tecondory but it terved. loit of

onKI Iho trouble hot been cleofed.

ondory buses by opening the proper substotion
tyttem costs from 25 to 50 percent more thon
the rodiol tystem.

SPOT-NETWORK SYSTEM

Spot network (yilem porolleli the fransfarmer
tecendoriet to provide centinuevt tervice for
on outage ef one primory circuit, failure ol
trentformer or primary feeder reiuitt In outoeielic removal of the faulty equipment.. Thit

tyttem coitt from 20 to SO percent more than
Ifce radial tyttem.

PRIMARY-SELECTIVE

Primary teleciive tyttem provide, on olternole
tupply to the primary of each trantformer. If a
primory fault occur., the otiaciated primary
breoker openi and Interrvpti tervice to half of
the lead area. The de-energized trantformer.
. . . out of tervice .. . ore manuolly twitched to
the other feeder, Coit It IS to 40 percent mere
then radial tyttemt.

lOW-VOlTAGE AIR CIRCUIT BREAKERS

Applkca^ion Snformcition

A-C POWER SYSTEM APPLICATION
TRANSFORMER SECONDARY
BREAKER

A transrormer secondary breaker is
recommended for one or more of the

following purposes:
1. To provide a fast method of remov
ing all load from the transformer. Article
/30-70 (g) of the NEC speciiles that the
disconnecting means for service con
ductors may consist of not more than six

including a breaker which supplies more

motor controller. Because of the high

than one motor branch circuit. Circuit
breakers may also be used for motor-

inrush current associated with motor

ments of a motor branch circuit are

breaker is providing either branch circuit

or motor-running overcurrent protection

the breaker and its trip devices must
have the following characteristics:
1. Continuous current-carrying capa
city at least 115 per cent of motor fullload current. (Enclosed motors may have

MOTOR enwcH
ORCurr ovER-

circuit breakers;

CVRRENTprotection

2. To provide required transformer
secondary overcurrent protection in ac

cordance with NEC Article 450-3;
3. To provide protection for faults on

starting, only breakers with either an
electrically or manually operated storedenergy mechanism should be used.
In single-motor circuits where the

running overcurrent protection and as the
motor controller for starting. The ele

dsecKNccTnoiaMS

other service factors.) See table below for

MOTOR GRANCH
CROUIT CONOUCTORS'

the selection of the continuous current

rating.
2. Interrupting capacity sufficient for

MOTOR RUWIMO OVERCURRENT OEVieS

4. To provide a disconnect for mainte
nance purposes;

available short-circuit current.

3. To provide for throwover, automatic
or manual, to an alternate source in the

3. Sufficient time delay in the overload
trip to ride over the starting current of

D I MOTOR CONniai.LCR

case of failure of a primary feeder or
transformer (Secondary selective circuit
arrangement);
6. To back-up lower rated cascaded

The breaker ratings indicated in the
table below, when equipped with a lB-3
trip characteristic, are satisfactory for

feeder breakers;

7. To simplify key interlocking schemes

starting normal motors and their loads

Eltmcnlt oT o moler-branch circuit

with locked rotor currents up to 6 times

when the number of feeder breakers

exceeds the practical limit.
Selection of the rating of the transform
er secondary breaker should be based
on the fact that forced cooling may be
applied at some future time to increase
the transformer rating as much as 33

motor full-load current.

4. Instantaneous tripping for protec

A circuit breaker with its accessories

will provide some or all of the elements of
a motor circuit shown in NEC 430-1,

tion of the motor and its circuit, set low

enough to protect, and not so low that
tripping occurs on transient inrush. A

either in itself or in combination with a

GENERAL PURPOSE FEEDERS

For a-c circuits, there should be one

breaker pole with overcurrent trip in
each ungrounded conductor. For poly

TABLE II—Application of Power Circuit Breakers to Full-voltoge Starting
and Running Duty of 3-phase, 60-cycle, 40 C Rise Induction Motors
Kofitpowtr Rating of 3-phoio
AlltrnotlfiO'CttrrGnt Molort

phase circuits, it is essential that all

phases be disconnected simultaneously:
therefore multipole breakers are used.

The dual-magnetic trip (Long timeinstantaneous) with a IB long time-delay
characteristic is commonly used for
general purpose a-c feeders. Instan
taneous trip settings should be deter
mined on the basis of the type of load and
the type of protection desired. For

instance, where arcing fault protection is
a consideration, as low a setting as is
consistent with the inrush characteristic
of the load should be used.

hdvcllon Moteri
220 V«»i

A motor branch circuit is a circuit

including a single motor and a single
breaker. A motor feeder circuit is a circuit

nomically and from good system design
viewpoint for motors rated above 100 hp.

A-C MOTOR STARTING AND

They are particularly suited both eco

Low-voltage power circuit breakers
may be applied in motor branch circuits.

Qrcuil
Btoolior

FEEDER BREAKERS

Metoc Tiill-loed

Trip CoO
RflHno of

125
ISO
200
250

40 Cyclei
Ainparai*

120
140
240
320

1000
1200
1400
1400

109
131
152
174

225
250
300
350

144
140
192
224

194
21S
241
304

1800
2000
2400
2800

400
500
400
SOO

348
435
522
494

8000
9400
i2aoo

Mas.
r«mlii%la

Locked-rotor currents ore bosed upon motors having NEC code letters "a" through "j"
inclusive. If the locked-rotor current exceeds this value, select the circuit breaker having
the next higher continuous current rating, provided there is a calibration point on the
breaker which is less than 140 percent of the motor full-load current.

lOW-YOlTAGE AIR CIRCUIT BREAKiRS

AppliccsHon IniForn?cation

A-C POWER SYSTEM APPLICATION
Mttingof 2 times the lockedrotor current
te considered adequate for most condl>

using Type AK Power Circuit Break

mining the interrupting rating required.

ers as motor controllers, the control will

This current may be 7 to 15 times the

continuous current rating of the generator.

NUMBER OF OPERATIONS

be arranged so that the Thermo-tector
trips the circuit breaker by opening the
undervoltage device or by dropping out

In applications where the AK lowvoltage power circuit b performing the

an auxiliary relay to trip the breaker by
means of the shunt trip device.

function of motor controller as well as

The branch circuit breaker for motors

motor branch circuit protection, the
number of operations which the breaker

with inherent thermal protection should
be provided with the usual instantaneous
overcurrent trips set at twice locked rotor

can perform without maintenance should
be considered. Based on closing currents

current and with long-time overcurrent

up to 600% of the frame size rating and

trips for cable and for back-up protection

opening currents equal to the frame size
rating, AK breakers can be expected to
perform at least the number of operations
without inspection and servicing, indi

and with sufficient delay to allow motor
to start. Since the breaker long-time trip
element is not being depended upon for
motor running overcurrent, or stalled

cated in Table III.

rotor protection, the long-time trips can
be' set somewhat higher than usual for
motor circuits, usually 150-200 percent of
motor rating depending on the cable size.

Frequently, a particular frame size of
f breaker will be used to control a motor

considerably smaller in size than those
shown under the column headed "Maxi
mum HP at 440 Volts." In these cases

The short-circuit current from a gen

erator is the large value determined by
the sub-transient reactance. This current

decays with time until it reaches a lower
sustained value that is dependent on

machine synchronous reactance and exci
tation system characteristics. The actual
sustained value may be any value be
tween substantially zero and about three

times generatorcontinuouscurrent rating.
The plotted values of generator output
current and time under short-circuit con
ditions is called the decrement curve. It
determines the settings and time-current
characteristics required on the generator
and feeder breakers in a selective system.

The decrement curve of a particular gen

erator may not be available, but the two

most important points, the initial value
and the sustained value of short-circuit

GENERATOR CIRCUITS

current, can be obtained from the manu
facturer.

tween inspection and possible servicing
will increase appreciably.

The power circuit breaker for a genera
tor should be fast closing for synchroniz
ing and should have a continuous current

SRENT MOTOR PROTECTION—

mum current rating of the generator.

the number of operations which the
breaker can successfully perform be

rating of about 125 percent of the maxi
Each pole of the breaker should be pro

THERMO-TECTOR®

vided with overcurrent trip devices hav

Additional protection for the motor

ing the following characteristics:

may be obtained through the use of
separate thermal relays or Thermo-tectors

1. Long time, set for about 125 per
cent of the generator continuous current
rating and for maximum time, for con
tinued moderate overcurrent protection

built into G-E motors. Either of these

protective devices can be used to trip the
breaker in response to abnormal con

of the generator.

2. Short time, set at about 2.5 times
generator continuous current rating, or
as required for selectivity with feeder
breakers, for protection against bus faults.

A Thermo-tector device is a specially

designed heat-sensing switch embedded in
the stator windings of some G-E motors.

It is responsive to rate-of-rise of tempera
ture as well as actual temperature. It will

3. Instantaneous, set at 10 to 12 times

protect for locked rotor, overload, high-

generator continuous current rating, for
generator circuit protection on internal

ambient, loss of ventilation, and single

phase operating conditions; in fact, any ° faults fed from other sources in system.
short- or long-time abnormal condition
The generator breaker must have an
that can raise the temperature of a

interrupting rating equal to or greater

winding to a dangerous degree.
Each Thermo-tector (there are at least
three) has a single normally closed con
tact (circuit opening on rising tempera
ture) that must be connected in the coil

than the available short-circuit current

circuit of the motor controller. When

at the breaker location from all power
sources on the system, .including motors.

Self-excited generators (generator field
or exciter field energized from generator

voltage) require special consideration be
cause of the rapid decrement of shortcircuit current to zero. Proper tripping

of the generator breaker, and sdectivity
between the generator and feeder break
ers, can be obtained with such generators

only if provision is made in the excitatiori
system for forcing the generator to sus
tain short-circuit current of sufficient

magnitude and duration to operate the
overcurrent trip devices.

For better protection of the generator,
induction type overcurrent relays with
voltage restraint, type IJCV, may be
used to provide tripping through a shunt
trip device on the breaker. D-c tripping
power, or capacitor trip, is required for
reliable trip untfer short-circuit condi
tions. Suitable current and fwtential
transformers and a lockout relay are

required in addition to the IJCV relays.
When generators are operated in paral
lel with other sources, a reverse power

calculated from the generator sub-tran

relay should be included for anti-motor
ingprotection.A shunt trip device, which
may be a-c operated, is required on the

sient reactance should be used in deter

The initial value of short-circuit current

TABLE III—AK Breakers for Molor-slorling Applltollons
Endurance

Induction
Max. Motor

Hortopowar Raiings

At Max. Rated Horsepower
(No. of Operations on Motor

Starting Dulyt)

of inf^rrvpting vnil parti. Jhata numb#'* opptf ontf to fvlty

phtaS itorti, end not to intorrvptod tiarti tvth et iegging, TAcnin0«
ovfofnofre lequtnelng Of prototityo rotof optreliOAS. Stt ASA-C-37.IX

mornrvnon<« o«

Y Numbir of op9roftont h^for* fpair whith moY

rating do not •Wmlflcrf* fb* nood for penod^t
in

epplUehlo imtnttHon boeic for tho

f MoTor ratittpi oro limifod by fli« mo*fmw*n rotingi of futoi whIth con
b«

OA AXV brcoAcrc.

lOW-VOlTAGE AIR CIRCUIT BREAKERS
n

A-C POWER SYSTEM APPLICATION

RESISTANCE WELDING
MACHINE CIRCUITS

Certain forms of low voltage power
circuit breakers are particularly adapta
ble to and recommended for the pro
tection of circuits which feed welding ma
chines for spot, seam, projection, and
flash welding.

Welding-type breakers are equipped
with instantaneous trips and will
promptly and safely interrupt overcurrents or short circuits and permit
immediate restoration of service.

Breakers with time delay overcurrent
trip devices are not recommended for use

Referring to Chart II (kva at 440volts)
on page 10, the point of 600 during-weld
kva and 0.15 duty cycle is below the
maximum loading curve of the AK2SY1 (or AK.S0Y3). This breaker is
suitable for the conditions given.

(b) During-weld current <> 1360amp
••0.15

Referring to Chart IV on page 10, we
find that the point of 1360 amperes
during-weld current and 0.15 duty cycle

is below the maximum loading curve of
tte AK-25Y1 (or AK-50Y3), which

in circuits feeding welding machines
because the relatively high intermittent

is the breaker to select.

welding currents sometimes cause undue
weat in trip devices, resulting in calibra

tion changes and nuisance tripping.
Where overload protection is required,
thermal overload relays and current
transformers give better results.

during-weld ampere and kva values, at

The breaker which should be selected

The following tables list the maximum
various duty cycles,

AK-15Y1andAK.25Y2 breakers (Cont.)

WHEN OURINC-WEID CURRENT IS KNOWN

breakers can be used. The values are
obtained from the curves in the charts

4S4
419
375
342

215
164
165
150

266
231
306
166

AK-25Y1 and AK-S0Y3 Breakers
OAS

261
244
216
199

563
467
436
396

is one whosemaximum load curve is just
above the greatest load (during-weld
current or kva) at a duty-cycle value for
the welding application. After this has
been selected, the maximum available

RMS Symmetrical short current must be
determined to complete the breaker
application.

Exomplet for Selecting a Breaker
WHEN DURING-V/nO KVA IS KNOWN

(a) During-weld kva a 600
Duty cycle
-O.IS
Voltage
••440

AK-50Y2 Breaker
Durtns-w*M Kto
DvifngDuly
Cytia

AK-15Y1 and AK-25Y2 Breakers
OAS
A4

10660
9260
6260

3380
2925
2620
2390

744
644
576
526

TABLE V—Available Resistance Welding Breakers
Inlarrupllng Roflng
RMS

Ransa at
htlsntaneaut Tilp

SyiRmafrlcol Amperat
60 Cyclei A.C

Type ef Sraaker

600 ta 1500, cr

1400 la 4000, ar
2000 ta 5000

1000 te 2500. ar

2000 ta 5000, or
4000 ta 10000

* Where the interrupting capacity required
for a particular installation is in excess of
that of the rating of the breaker identified

in the charts on page 10 as suitable for an
application, then a breaker of the required

interrupting rating should be selected in
each case.

LOW-VOITAGE AIR CIRCUIT BREAKERS

, »age 12
A-C POWER SYSTEM APPIICATION
MAXIMUM LOADING CURVES FOR WELDING-TYPE BREAKERS
Chert il-For 440 Veils

Chert I—For 220 Veils
2000

31000
X 900
800
700
• 600

006 QOeOJO
020
Duty cyelt

a03 0.04 0.060.080.10

Duly cycle
Fig. 30

Chart Ili-For 550 Volts

toooo
3000
8000
7000
6000

2000
i 1000
• 900

Duty cyels
Fig. ai

006 008 010
O20
Duty cycle
Fig. 32

The dut/^ cycle is (he fraction of time that current flows in any one minute.

lOW-VOlTAGE AIR CIRCUIT BREAKERS
Page 13

A-C POWER SYSTEM APPLICATION
GENERAL PURPOSE FEEDERS
For a-c circuits, there should be one

breaker pole with overcurrent trip in
each ungrounded conductor. For polyphase circuits, it is essential that all

phases be disconnected simultaneously;
therefore multipole breakers are used.

The dual-magnetic trip (Long time-

ii»tantaneous) with a IB long time-delay
characteristic is commonly used for
general purpose a-c feeders. Instan
taneous trip settings should be deter
mined on the basis of the type of load and
the type of protection desired. For
instance, where arcing fault protection is
a consideration, as low a setting as is
consistent with the inrush characteristic
of the load should be used.

SYCTEM APPLICATION OF BREAKER

System Application of Breakers—A com
plete application study considers the

breaker in relation to the equipment
which it protects, as well as in its re
lation to other breakers in the system.

Load Center Unit Substations are per
haps the principal method of using
breakers in which the functioning of
one breaker with respect to another

than the available short circuit current.

These breakers are equipped with gen
eral-purpose trip devices combining
long time delay and instantaneous trip
characteristics. No intentional time de

lay is introduced in the tripping char
to achieve selective tripping between

In considering a load center unit

substation and the low voltage distri
bution circuits which are fed from it,
two circuit areas become apparent:

protective devices.
The current level of a fault on a

feeder circuit depends on the location
of the fault along the feeder conductors
and may be as high as that available
at the load terminals at the feeder
breaker.

Due to the difference in current rat

time delay for a given level of fault
current, some selectivity might exist

depending on the magnitude of the

fault current and the settings of the
instantaneous trips.

In order for selectivity to exist for
all possible levels of fault current on a

SELECTIVE SYSTEM-The selective sys
tem is a term used to identify a series of
protective devices, i.e. relays, breakers,
and fuses, the time current character

istics of which have been selectively
coordinated, so that under fault condi

ance with NEMA Standards they
must be backed-up with a fully rated

ers. Such a substation is sometimes
referred to as a "selective substation."

breaker—also must be electrically
operated from a remote position.

This type of selective coordination is

rOliy RATED SYSTEM—The fully rated

not to be confused with the "primary
selective" or "secondary selective" load

system uses main and feeder breakers

center distribution systems.

interrupting ratings equal to or greater

feeder breaker will be for all prac
tical purposes the same magnitude
as faults at the load terminals of the

b instantaneous for short circuits. tions power is removed only, from that
b. with selective trips—tripping is portion of the system on which the
intentionally delayed up to. inter ' fault exists. The first place on a lowvoltage distribution system that such
rupting rating of breaker.
coordination is usually established is
2. Cascade breakers are applied above within a unit substation between the
their interrupting rating. In accord
main secondary and the feeder break

which are fully rated, that is, they have

protective devices is so small, tW
faults at the load terminals of the

main breaker. For selectivity to

carefully considered.

1. Fully rated breakers are applied with
in their interrupting ratings:
a. with instantaneous trips—tripping

breaker and any one feeder breaker.
The impedance between these two

ings between the main and feeder

able short-circuit current roust also be

Basically there are two types of sys
tems of breaker application:

1. The area that takes in the main

breakers and therefore the amount of

stantaneous trips.

must be taken into account — the rela

paneiboards, and the like.

the main and feeder breakers and/or
the feeder breaker and branch circuit

tionship of interrupting ratings to avail,

More than just trip characteristics

system is extended beyond the load
center to include motor control centers,

acteristics at short circuit current levels

feeder circuit, it is necessary that the
main breaker be equipped with selec
tive trips, that is, combinations of long
time and short time delay wilhout in

must be taken into consideration.

tinuity of service increases it is usually
found that the "selective coordination"
of protection devices or the selective

As manufacturing processes become
more critical and the need for con

exist between these two breakers,
at all levels of short circuit current

up to the maximum available, the

main breaker must be equipped
with long-time and short-time delay
trips.

2. The area which encompasses tb
feeder breaker, the feeder cable
and the next protective device which

is frequently a molded case breaker,
part of a combination starter in a

grouped motor control equipment.

In this area which overlaps the first
area to the extent of the feeder

breaker, appreciable impedance may
exist between the feeder breaker
and the fault at the load terminals

of the combination starter.

means that fault current at the load

terminals of the starter may be ap
preciably less than fault current
which would exist for a fault at the
load terminals of the feeder breaker.

Even for short cable runs (50 feet)
this can be true depending on the
size of the cable.

The second area permits the use of the
feeder breaker equipped with long- and
short-time delay trips having an addi
tional instantaneous element with its

setting equal to or greater than the
available short circuit current at the
motor control center bus.

lOW-VOlTAGE AIR CIRCUIT BREAKERS
Page 14
A-C POWER SYSTEM APPLICATION

protective device and instantaneous trip

ping for faults between devices (cable

100 pfUMittv SMeor CM^cmr ovi

4ito/4Mvoi.r
.iooorv*

circuits) gives rise to the term "zone
selective system."
The requirements for applying power
circuit breakers to obtain selective trip

ping are given in the following para
graphs. The discussion centers around
Fig. 23, but the principles are basic to any
application.
1. All circuit breakers, both main and

feeder, must have interrupting ratings

at least equal to the maximum avail

able short-circuit current. The inter
wo AMP

rupting rating is a function of the

voltage and the presence or absence
of an instantaneous trip device. A
suitable selection can be made from
Tables I or VI.

2. Breaker A is a typical main breaker,
unthout an instantaneous trip, and

must be applied on the basis of ratings
listed for breakers without instantane
3.

ous trips.
Feeder breaker C, which is selective
with breakers D in the motor control

center, should be selected on the same
basis as A.

Feeder breaker B is equipped with
instantaneous trips as well as with

long time and short time delay trips,
following the concept of a zoneselective system. This method of ap

plication may permit the use of a
t s

smaller frame size circuit breaker, as
in the example.
Feeder breaker E, which is not re

cumttNT IN t»rei too

STANDARD SEIECTIVE SYSTEM

ZONE SilECTIVE SYSTEM

short-circuit protection for the feeder

the feeder breaker to trip on short-time
delay. The AK breaker will therefore be

cable and, where needed, backup for the

selective with molded case breakers.

The instantaneous element provides

molded case breakers in the starters.

Tests indicate that, for the limit of
application of 100 ampere frame molded
case breakers in starters of General

Electric motor control centers, selectivity
is obtained with an instantaneous trip
setting of 12,000 amperes on the AK
feeder breaker. For faults beyond the
starters, the short-circuit current will be
below the instantaneous trip setting and
in the region of current that would cause

quired to be selective with a down
stream protective device, is equipped
with an instantaneous trip and ap
plied on that basis.
The overcurrent tripping devices of
the main breaker A must be so co

ordinated with the feeder breakers,
that all feeder faults are cleared by
the feeder breaker involved. The main

The. requirements for zone selective

breaker will trip only in the case of

feeders established in this manner differ

bus faults or the failure of the feeder

from the requirements for the selective
main breaker, AK breakers using a com
bination of long time delay short time
delay, and instantaneous trip character
istics can be applied up to the interrupt
ing rating with instantaneous trips.

breaker to trip. A feeder fault is,
therefore, always cleared without
interruption of service on other

The practice of providing selective
tripping for faults beyond the second

Proper coordinating steps should be
taken in fuse and relay application
on the high-voltage side of the trans
former when coordination

rest of the system is desired.

10V/-V01TAGE AIR CIRCUIT BREAKERS

ApplSccafion Enform^fion

A-C POWER SYSTEM APPLICATION

When short circuits occur, motors (both
synchronous and induction) in operation
from the same source become generators

for the time being and add their contri
butions to the short-circuit current.
Where accurate data are not available it

b customary to assume, for 240-, 480-,
and 600-volt systems, that the motor load

b equal to the kva rating of the source,
and that the characteristics of the motors
are sudi that the motor short-circuit con
tribution will be four times the normal

current. In 208 or lower voltage systems,
lighting, heating, welding, and other
classes of nonregenerative load are likely
to be present and hence, for such systems.
It b customary to assume the motor load

to be 50 percent of the total available
power and the motor short-circuit contri
bution will be two times the normal
current.

Short-circuit contributions from induc

tion motors are very short-lived and by
the time the breakers have opened they

will have decreased to very low values.

Synchronous motors, however, maintain
their voltage for longer times and conse
quently they impose a heavier opening
duty on the breakers. This may affect the
satisfactory operation of the "C" breakers
in the cascade (Fig. 24). Accordingly it

ance with NEMA Standards, so that
it will trip when the fault current
through the feeder breaker reaches
80% of the feeder breaker interrupting
rating. The dirfcrcnce in fault currents

sources of power which feed current
through breaker F must be considered.
Source

between bre.nkcrs "M" and "C" due
to motor contributions must be taken

into account in calculating the maxi
mum allowable instantaneous trip
setting on breaker "M."
Under the cascade system of applica
tion, a short circuit on a feeder breaker
will be very likely to trip the main breaker
and thus remove power from all feeder
breakers. Herein lies the advantages of
the fully rated system with selective
trips on the main breaker. Since the
feeder breakers of a fully rated system
are able to open on a short circuit without
assistance from the main breaker, selec

tive trips delay tripping of the main
brewer and permit it to ride over a fault
on a feeder. In case of a bus fault between
the main and feeder breakers or some

unusual condition which prevents the
feeder from clearing, the main breaker
will open and remove the short circuit.
NEMA Standards state the operation
/~N C

This means, for Fig. 25, for example,
that the current through F, to a fault in
the left-hand feeder, is supplied not only
from the two sources through breakers M
but also from the motors operating in the
two feeder circuits at the right of the
feeder under consideration. The settings
of the breakers M must take the motor

contributions into account and be of pro

portional value. This can best be illus
trated by an example, as follows:
EXAMPLE; Assume that each source

in Fig. 25 is a 1000-kva, 480-volt trans
former capable of supplying an rms sym
metrical short-circuit current of 20,500

amperes, and that the motor load on each
feeder will contribute an rms symmetrical
short-circuit current of4800 amperes. The

has been made a condition of cascading
that if more than 25 percent of the motor

load is synchronous the problem should

of breakers in excess of their interrupting

2 X20,500 •f2 X4800 = 50,600 amp

be referred to the Company for recom

Each of the breakers M

mendations. The ratings in Tables VII,

capacity (as in cascade) is limited to one
operation, after which inspection, main

VIII, IX, and X are based on these

tenance, and repair may 1^ required.

ing, this inherently provides breakers of
42,000-ampere interrupting rating, which

CASCADE SYSTEMS

EFFECT OF TWO SOURCES

is more than ample for the 20,500-

Low-voltage power circuit breakers
may be applied on circuits where the

involved, as in Fig. 25, the total short-

total short-circuit current in the left-hand

considerations.

Where two or more power sources arc

available fault current exceeds the inter-

circuit current to be considered in the

nipting rating of the breaker but these

determination of the interrupting rating

conditions must be fulfilled:

of breakers F can be taken as the sum of

1. Provided there is a fully rated breaker

the currents (torn all sources that are

backing up the breaker so applied.'

added together as if coming from one

This is illustrated in Fig. 24 where
b the fully rated main breaker

and "C" is the cascaded feeder breaker

applied above its interrupting rating.
2. The feeder breaker "C" must have

instantaneous trips. NEMA Stand
ards recommend that these breakers

be electrically operated.

3. The back-up breaker "M" must have
its instantaneous trip set in accord

The continuous current requirements
for each breaker M usually result in these

breakers having adequate interrupting
ratings for any faults. The M breakers
must be adjusted so that all trip instan
taneously before the fault current through
the F breakers, from all sources, exceeds

80 percent of the interrupting rating of F.
In order to conform to this rule, all

feeder through breaker F then will be:
must be

of 1600-ampere continuous current rat

ampere requirement. At F with a total
short-circuit current of 50,600 amperes

available, it is necessary to choose a
breaker which has a minimum idterrupt-

ing rating of halfof this amount, or 25,300
amperes, which meansan AK-1-25breaker.
Of the 50,600-ampere toul available
short-circuit current for a feeder fault,

20,500 amperes is contributed by each
transformer. Since the breakers M should

trip when the current passing through
breaker F is 80 percent of its interrupting
rating at 480 volts, or
30,000X80% = 24,000 amp

the trip setting of breakers M will be
20,500 X

lOW-YOlTAGE AIR CIRCUIT BREAKERS

Page 16
A-C POWER SYSTEM APPLICATION
The application tables on the following

TABLE VI—Application Range—AK Circuit Breakers

pages list the proper low voltage power
circuit breakers for load center applica
tions. The power circuit breakers have
been co-ordinated with transformer and

system capacities—electrically, thermal
ly, and mechanically.
BASIS FOR APPLICATION TABLES

Application tables are based on the
following:

1. A three-phase bolted fault at the
low voltage terminals of the substation;

fnlutrupllng RoflnO
In Ampirti,
O-E
BrMtur

VollaBU
Rallng
60

AK-IS
AK-25
AK-50
AK-75
AK-tOO

2. Transformer impedances listed in

4. Total connected motor kva does not

> exceed SO percent of transformer rating
' on 208Y/l20-volt and 100 percent of
transformer rating on 240-, 480-, and 600volt systems:
5. The motor contribution is taken as
2t0 times the normal current of the trans
former at 208Y/t20 volts and 4.0 times

AK-IS
AK-2S
AK-50
AK-75
AK-lOO

Wlllioiil
Inil.

14.000
22,000
42.000
65,000

7,000
22,000
42,000
65,000
85,000

175
350
2000
2000

100
175
350
2000
2000

7,000
22,000
50,000

20
100
400
2000
2000

7,000
22,000
50.000
65,000
85,000

30
150
600
2000
2000

25,000
42,000
240

Short Clrcutl
MIn.
with
Inlton-

22,000
30,000
450

OvpKurrnnI Trip Ouvlcn Rollng^Amptrai

3. Only source of power to the second
ary is the substation transformer;

SMS Symmttttkst

:r applied at its maximum inter
im,...ng rating at the specified circuit
voltage. Smaller coils may be used if

2-«lpp Copnodp Oporatlon Amporpp

150
250
500
2000
2000

225
600
1600
3000
4000

7,000
22.000
42,000
65,000
85,000

25,000
42,000
85,000
85,000
85,000

125
200
400
2000
2000

150
250
500
2000
2000

225
600
1600
3000
4000

7,000
22,000
50,000
65,000
85,000

42,000
60,000
85,000
85,000
85.000

125
200
400
2000
2000

225
600
1600
3000
4000

7,000
22,000
50,000
65,000
85,000

50,000
85,000
100,000
130,000
130,000

Omro<- Chorottprllllc
Mrlillc

STANDARD CONTINUOUS CURRENT RATINGS
O-E BfCoEtr

ConMfiuoui Currvnl Rotlnsi

(Obwrv* minimum limllt tut by appUcatlDn loblat nbavn and an
pag«« tS-li)

normal at 240, 480, and 600 volts;

^/^*^yCoil sizes are listed foe a circuit

AK.I5
AK-I5
AK-SO
AK.7S
AK-lOO

15, 20, 30, 40, 50, 70. 00, 100,125,150,175, 200, 225
40, 50,70, 70,100, 125,150,175, 200, 225, 250, 300,350, 400, 500, 600
200, 225, 250, 275, 300, 350, 40O, 500.003, SOO, 1000,120O. 1000
2000, 2500, 3000
2000, 2500, 3000, 4000

available short-circuit current is less;
7. Tabulated values of short circuit

current are in terms of RMS symmetrical

amperes per NEMA Standard SG-3.
SUBSTATION ELECTRICAL
ARRANGEMENT
Substations are available in a selective,

fully rated, or cascaded arrangement.
Care should be taken to specify the
arrangement that provides the balance of

selectivity and protection required by the
power system.
SELECTIVELY CO-ORDINATED
SUBSTATIONS

A selectively coordinated substation uses
fully rated breakers with long-time and
short-time trip characteristics (LS) to
delay the opening of the main circuit
breaker until the faulted feeder has had

an opportunity to clear. This provides
service continuity for all but the faulted

desirable when the load-center feeder
serves a motor control center.

FULLY RATED SUBSTATIONS

Fully rated arrangements use fully rated
breakers with long-time and instantane

ous trip characteristics (LI) on both main
and feeder circuit breakers. The main

circuit breaker may, or may not, trip for a
feeder fault—depending on fault mag
nitude.

CASCADED SUBSTATIONS
Cascaded arrangements allow feeder
breakers to be applied on circuits that are
subject to fault currents in excess of the
normal published interrupting rating of
the breakers.'

Under the cascade system a short cir

Selectivity may be carried a step fur
ther in

instantaneous trips. This is called the
Zone-Selective arrangement and is often

the substation by specifying

selective feeder circuit breakers that in

cuit on the feeder circuit may trip the
main breaker. NEMA standards state

that the operation of breakers in excess of

corporate long-time and short-time char-

their interrupting rating (as in cascade) is

/'^S^stics (LS) to allow downstream de-

limited to one operation after which in
spection, maintenance or complete re
placement may be required. It is further
recommended that all feeders applied in
cascade be power operated from a re

' o clear faults within their area.

. cfinemcnt of the selective feeder in

corporates the long-time, short-time with
high-set instantaneous characteristics

(1^1) to provide selectivity without
sacrificing instantaneous fault protection.
Further, this combination of trip char
acteristics permits application of the
breaker up to Its interruptina rntina with

proper G-E breakers for use with each
system. For instance, using a fully rated
system, a lOOO-kva, 480-volt load-center
unit substation with a primary source

having a ISO mva maximum available
short-circuit capacity, requires an AK-SO
main breaker with AK-2S feeder breakers.
Should either the main circuit breaker,

or feeder circuit breakers be equipped
with selective trips, the appropriate
breakers may be found under the columns
headed Main-Selective, and Feeder-Selec
tive or Zone-Selective. The main circuit

breaker is the same size whether fully
rated (LI) or selective (LS). However,
the frame sizes of feeder breakers will de

pend upon whether they are applied as
fully rated (LI), selective (LS) or zone
selective (LSI).
Further, the tables indicate the main

(LI) and cascaded feeder breakers (LI)
for cascaded systems with a wide range of
primary available short-circuit capacities
and transformer sizes.

CONTINUOUS CURRENT

The breaker types listed under the system
headings satisfy the requirements for
interrupting capacity. They may not be
large enough to satisfy the requirements
for continuous current rating, in which

The tables make it easy to select the

cosci the next larger type should be used.

lOW-VOlTAGE AiR CIRCUIT BREAKERS

Appliccation Informcation

A-C POWER SYSTEM APPLICATION

TABLE Vil—Low^vollago Power Circuit Breakers—

208 Volts, Three-phase

Seadar Circvit Sraelara

AffrongttiiBAit

Ming
S-plMI*
K>a aad
hiptdsM*
rwttiit

Short*
CifCUil
Amilablo
ftom

SO
100
ISO
3S0
SOO
rso
UoRxitod

rso
SOO
rso
Uolioiitod

teee*N*>e
Skerhlime

38000
3960O
31300
33300
33000
33200
33600

28700
37000
33300
34400
33300
3S60O
36300

38600
39400
39800
40400

43100
46600
47300
48200

100
ISO
rso
soo
rso
Uttlimilad

3S300
rrsoo
rsroo
39SOO
30300
30400
30800

irsoo
17700
ISOOO
18300
18400

18000
19000
19400
19700
30000
30000
30300

leng-Mme
(nttonlenaoul

MMaaoie |,aehar end Coil Site Ratemmanded

long-time
lailaMenaowi

Shert-tima
Initantaaeeat

Meter Ceelrel
CeAter

SO
ISO
2S0
SOO
rso
IMIiaUod

RMS SyiemeMeei Amp
Nenrol*
lead
CeetliHieui
Cvrtenl

OitfribwtieA er

Avflileblo
froM

Nermot*
toed
Coftllmiout
Coffont

50
100
150
350
500
750
Unfimitad

14300
15000
15400
15600
I5B00
15900
16000

100
150
350
500
750
Uollmittd

34000
3490O
35600
36100
36300
36700

50
100
ISO
350
500
750
UnlimiUd

Motor Control
Center

Shorl*1Imo
iMloatonteift

MEnSmoa^ Ireober and Cert Ske Reccmaiended
tfooker

17100
17900
18300
18500
I87C0
18800
18900

33100
35000
36100
37000
37800
38000
38600

'45300
47100
48700

50100
50600
51500

67900
71300
74100
75000
77300

• If Urser trip coils are required, see Table VI—page 16.
L -Long-time delay trip (overload tripping).
S —Short-time delay trip (selective fault tripping).
I —Instantaneous trip (high fault fast tripping).

•-Minimum impedance.

34900
37600
36900
39600
30600
30600
3U00

60600
llAi:fii4t«d

toft9-tiioo
lAftOlltOfltOtfS

350
500
750
Unliffliltd

tono»timo
bifteotonootfi

Sliort-lSmo
Trontformer
AIoao

Oiflribvtion or

Lenp-llmo
Slioft-droilt Corf onf
RMS Symtwoffkot Amp

IHoAlmvm
Sherl*

lOW-VOlTAGE AIR CIRCUIT BREAKERS

Page 19
A-C POWER SYSTEM APPLICATION

TABLE IX—low-vollago Power Circuit Dreakeri-

Taadar Clrcvll Iraabtri

460 Volli, Threo>r

OhfribyflQA er
Me'er Cenirel
CeMqr

Dittitbvlien er
Metor Centrel
CtAter

SlSe«1-liHflie
tAslenleneeut

laap'Knia
Shert'Ctrcvtf Curranr

Inptdoi^M
#«4C*nl

NofmalImO
Coflliweut
CwnMl

long-llma
Sharl-llma
Trant*
l«im«r
Alena

IMS Symmattlcol Amp

MMmam* Iraabar and CoR Six* taeamraandad
Sraakar

tM
2S0
JOO
750
Uiil!nll«d

9100
9300
9300
9300
9400

10900
I2000
12400
12800
13100
13200
13400

14400
14800
15300
15500
15600
1580O

M
100
150
250
500
750
UnlUnlud
50
100
150
250
500
750
VnKialtait

100
150
250
500
750
Ihrwiltad

16100
17500
18000
18500

15500
17800
18800
I960O
20200
20500
20900

33600
23600
34400
35000
35300
2)700

34900
36700
38400
29800
30300

33100
33900
35600

50
too
150
250
500
750
IhGaiUd

43600
46300
48700
49600

150
250
500
750
UnlifiiitaS

40500
44500
46100
49500
53300

53500
56SOO
60100
61500
6430O

5I90O
56800
58700
63700

250
500
750
UnliaijftJ

31100
36700
39100
40000
41900

500
750
Ualbailad

12500
13900
t4400
14900
15300

lang-Kma
lAiIantanaaui

loAg-Hflie
tnitenlonqeui

66300
71300
73100
77100

• If laitier trip eoils are requtred. see Table VI—page 16.
L atLong-tiinr delay trip (overload tripping).
S mShorl-tinir drlay trip (selective fault tripplna
•
.
••

L0W-V01TA6E AIR CIRCUIT BREAKERS

App9i€Ci?io9i Information

A-C POWER SYSTEM APPUCATION
\

•fLE X—low'voltage Power Circuit Breokers600 Volts, Three-phose

P«Ad«p Cirevit lr*ok«ri

^tlv RoUtf
o# Cotcorft

Siltcthttly
Coer^tnoUd

Oiltrtbvtton Of
AAoter Control
CoAfor

DiitrtbvtioA or
Motor Control
Conlor

Sbort'timo
(AilOAtOAOOOt

loAO'limo
Traniformop

Rot{ii9
)-pKoio
Kvo ood

Slierf'ClrCvIt CvrroAl

Moitmuffi
Sliort*
23

lolly ratod
AK40

20000
20200
20600

22300
23700
380O

27200
28300
29600
30000

27400
32300
34900
37100
38900
39700
41200
32000
38800
42000

33700
38300
39600
41900

41600
43300
47000
30200

14800
13100
13200

300
730
Unlifldtnd

100
130
230
300
730
Unlimltnd

19700
24800
27200
29400
31200
32000
33300

8700
9600
10000
10200
10300

10600
11300
11900
12100
12400
12400
12600

l9AQ«flmO
tailofttoAOoiif

loAQ^timo
lAllontOAOOttt

* If larger trip coils are required, see Table VI—^page 16.
L "Long'time delay trip (overload tripping).

f^Short-time delay trip (selective fault tripping).
oiMatatitaHMiii trio (hlBii talilt fdsl (rlbblnaV

43300
48100
49300

488CO
33100
37000
38300
61700

lOW-VOLTAGE AIR CIRCUIT BREAKERS

Page 21
D-C POWER SYSTEM APPLICATION

D-C MACHINE CIRCUITS

D-c rotating machines are subject to

burning of the commutator and brushes
and to possible flashover on currents
above the commutating limit, which is
usually about 200 percent of the con
tinuous rating. For this reason, it is
necessary to disconnect such machines

quickly from the circuit. Hence, power
circuit breakers with instantaneous over-

current trip devices, adjustable from 80

to 250 percent of the breaker rating, are

generally recommended for d-c machines
and feeders. For marine service, and such

other applications where some sacrifice
in machine protection is justified to en
sure maximum continuity of service,

the dual-magnetic trip, with inverse
time tripping from 80 to 160 percent
of the breaker rating, and instantaneous
tripping at 8 to 12 times rating, can
be used for d-c machines rated 250 volts
and below.

For d-e generators and synchronous
converters for general two-wire service,
the recommended arrangements are shown

in Fig. 26 and Fig. 29, with explanatory
notes. Circuits to d-c motors should

high-current breakers which ordinarily
would be required. For these machines,
instantaneous overcurrent relays in the

armature circuit (which function to re
duce the generator field current) gener
ally afford sufhcient protection.
For exdiort, it is not customary to fur
nish overcurrent protection. Sometimes,
however, several exciters may be oper
ated in parallel. In such cases, current-

For d-c, 3-wire machines, overcurrent

protecrion is required in both sides of
the armature, as shown in Fig. 28.

Time overcurrent protection is recom
mended for the neutral circuit, generally

as part of an additional pole on the ma
chine breaker. Usually the continuous

rating of the machine neutral is approxi
mately 25 percent of the full-load line
current of the machine. This requires

that the center pole on the 3-pole breaker
shown in Fig. 28 be of lower capacity than
the other poles, with calibration adjust
able from 80 to 250 percent of the pole

REVERSE-CURRENT PROTECTION

For d-c generators and synchronous
converters operating in parallel, or in

directional protection is recommended

paralld with another source, particularly

for each exciter. This should be of such a

in machines above 300 kw, it is desirable

characteristic that it will trip its circuit
breaker only on values of reverse current

current devices on the drcuit breakers

above those which may be caused by

to prevent abnormal interchange of cur

inductive action between the a-c machine
armature and its field circuit, when a

system disturbance occurs. Because the
required settings of the current-direc
tional device may be above the continu
ous-current rating of the breaker, it is
generally necessary to provide separate

to provide current-directional or reverserent between the machines; also, to

give more sensitive end faster internalfault protection than is afforded by the
overcurrent tripping devices. These re-

verse-current tripping devices (or sep

reverse-current relays rather than direct-

arate reverse-current rdays), used to trip
the circuit breakers, are particularly
recommended for d-c generators and

acting, reverse-current devices on the
breakers. A two-pole nonautomatic

synchronousconverters whidi have timeovercurrent trip on the generator drcuit

breaker with a shunt-trip device, or a

breakers. The setting of these reverse-

contactor, is required for each exciter for
this application.

current devices should be as low as oper

ating conditions will permit, but it mu'
be high enough to prevent unnecessat.

have the same arrangements as the d-c
feeders.

It is recommended that the rating of the
equalizer drcuit and the devices be
approximately one-third to one-half of
the maximum or overload rating of the

EQUALIZER CIRCUITS

Although knife switches can be used
in the equalizer circuits of compound-

tripping on normal values of regenerated
load, or on slight interchange of current
between the machines at light load. The
setting of standard G-E reverse-current

wound machines, the use of power circuit

devices is 10 percent of the breaker

breakers (as indicated in Fig. 27 to 29)

usually offers advantages in switchgear,
station layout, and operation. Because
the equalizer circuit can in most applica
tions be closed and opened simultane

chine drcuit breaker requires the same
number of reverse-current tripping ele

ously with the armature circuit, it is
advantageous to use multipole breakers

To give the best protection, each ma

ments (whether devices on the breaker,
or separate relays) in the armature drcuits as there arc overcurrent trips. In
d-c, 3-wire machines, however, reverse-

for combining both functions. The equal
izer breaker poles need not be provided
with overcurrent tripping, as the over-

current protection is frequently provided

rating.
When two 2-wire generators are con
nected in series to supply power to a

current protection to a machine must be

machine protection.

3-wire system which gives a full-capacity
neutral, a 3-pole breaker which has one
pole in the positive lead, one in the nega

the series fields of both generators are
connected in the neutral side of each

tive, and the third in the common neu
tral circuit of the two generators is

recommended. Eadi pole is provided
with overcurrent protection, as shown
in Fig. 29.

For very low-voltage d-c generators

provided in the armature circuit.
In two two-wire generators in series,

in one side only, at some sacrifice in

In some applications, protection from
loss of driving power is necessary. In
these cases, and in unattended (auto
matic) stations, current-directional relays

armature. A separate, two-pole equalizer

rather than the reverse-current devices

breaker should be furnished for parallel

on the breakers themselves must be used

operation, as illustrated in Fig. 29. This
breaker (or double-pole switdi, if switch
is used) must be closed before the line
breaker is dosed, and opened after the

to obtain the required degree of sensitiv

line breaker trips.

(of about 25 volts or less), such as are
used for electrolytic service, it is usually

Normally, the amount of current in an
equalizer circuit a small, but this drcuit

not considered necessary to employ the

must have a low resistance to be effective.

ity. Such sensitive protection is liable
to trip the machine under conditions of
regenerated load, or of momentary inter
changes of current among several ma
chines that operate in parallel, and,
accordingly, these applications require
spedal consideration.

LOV/-VOLTAGE AIH CIRCUIT BREAKERS

AppSiccafion Information

D-C POWER SYSTEM APPLICATION

Direct'curran} Machine Circuits

(b) Grounded negative
One 1-poIe breaker with
one overcurrent trip
two overcurrent trips
fig. 36. D>«> 3-wirs, shunt*wound gsnsroter or tynchreneus con
varlar, or cempaund-wound mathlna, far Italalsd optrallan

(a) Ungrounded negative
One 3-poIe breaker with

(a) Ungrounded negative
One 3-po1e breaker with

(b) Grounded negative

One 3>po1ebreaker with
one overcurrent trip
D*<, 3«wlra, campavnd-wauad ganaraloi
canvsr1tr< far parallat aparallan

two overcurrent trips

' Nala A—^Por 3-wire, d-c machines, Pig.
38, a circuit-breaker pole with trip is shown
in the neutral circuit. Por 6-phase, 3-wire,
d-c synchronous converters, some means

must be provided additionally for diseonneeting and segregating the transformer
neutrals during the starting period (when
the starting is done by means of taps in the
low-voltage transformer windings).

Fig. 2S. D<«, 3>wlra, thvnf>
wavnd gansralar or tyn<
chranaiit canvartar, er cain>

Fig. 3f9. 0-«. 3-wlrs ganaratars

gaund>weand machlna, far

In tarlai far a>wlra tarvlca, far

lseteladop«rellan,graundsd

parotlal apsratlen with athar

•r oagraandid naulrol

similar moehlnn, graundad ar
ongroandad nsutral

One 3-po1ebreaker with

* The overcurrent device on the breaker

pole in the neutral circuit is usually of
reduced capacity (25%), and should be
calibrated for setting from 100 to 300 per
cent of the neutral pole rating.

One 3-pole main and neu

joree* overcurrent trips

tral breaker with three over-

current trips and one 3-pole

equs^er breaker with no
overcurrent trips

D-C FEEDER CIRCUITS
Figs. 30 to 34, inclusive, show the reqtured arrangements of breaker poles and
overcurrent trip devices for the protection

of feeder circuits on the various types of

machine circuits should be followed in

d-c systems. Since a mcgority of the

selecting the overcurrent trip devices.

feeder loads will be motors the recom

mendations for the protection of d-c

fT
Fig. 30. Twe-wirs, ongroondsd

ft
Fig. 32. Two-wlrs, cen-

Fig. 31. Two-wlrs,
groondsd

ntelsd lo ouhlds wirtt

of Ihrse-wirs grounded

t One 3-pole breaker

^ One 1-pole breaker

with two overcurrent

with one overcurrent

nsulrol eireull

One 2-pote breaker

III
Fig. 33. Thrse-wira,
ongroundsd

One 3-pole breaker

? One 3-pole breaker

with three overcurrent

with two overcurrent

trips (one in eadi con
ductor, except neutral)

with two overcurrent

t Exception may be made for certain types

feeders using single-pole circuit

incoming service lines, where the

National Electrical Code applies, reference
should be made to paragraph 33Sla. If the
switch or circuit breaker does not interrupt

the grounded conductor, other means shall

be provided in the service cabinet or on the
switchboard for disconnecting the grounded
conductor from the interior winding.

lOW-VOlTAGE AIR CIRCUIT BREAKERS

AppHcafion Information
D-C APPLICATIONS (Cont'd)

OPERATING MECHANISMS

UNDERVOLTAGE DEVICES

Power-circuit breaker operating mecha
nisms perform the function of closing and

opening the breaker contacts in response
For d-c generators or synchronous con
verters which operate in parallel with
another source, it is desirable to insure
the disconnection of the machine from

either to a manual effort or an electrical

signal. Basically, operating mechanisms
fall into two categories.
a. OiracI ocllng in which the closing

the system, both on normal and emer
gency shutdowns, in order that the
machine cannot subsequently be • sub
jected to voltage from the system source.
For manually operated breakers this

solenoid or motor (electrical).
b. Stored energy (both manual and
electrical) in which an energy storing

requires a direct-acting undervoltage

source and the breaker contacts.

device with its coil connected across the

machine armature circuit. For syn
chronous converters or for motor-driven

generators, the coil of the undervoltage
device should be placed in series with
the normally open awciliary switch on
the running breaker or held contactor,
whichever closes last in the starting

sequence. Also, for d-c machines equipped
srith ovetspeed or other protective de
vices, or a control switch for remote
tripping, and without a reliable source

of tripping power in the station (such as
an operating or tripping storage battery).

force is furnished by an operator (manual)

means is interposed between the control

In recent years, there has been a strong
trend towards stored energy operating
mechanisms because of the important
advantages they offer. These include:
increased safety of operation, prolonged
contact and breaker life, wider breaker

application, particularly selective tripping
and motor starting, reduced maintenance

and a reduction in control power require
ments for electrical breakers.

General Electric Type AK circuit
breakers utilize stored energy closing
-mechanisms. Models are available for

either manual or electrical operation.
STORED ENERGY CLOSING

FIELD DISCHARGE BREAKERS

These breakers are equipped with a
field discharge clip using silver-alloy con
tacts. Thu clip is cormected to the maincontact operating shaft and; therefore,
iqrerates independently of the breaker
mechanism. The field-discharge clip closes
BEFORE the main circuit is broken, thus

assuring positive protection for field coils

against high induced voltages when the
breaker is opened either normally or by a

protective device or relay. With the AKF
breakers the field-discharge clips overlap
the main contacts both opening and
closing.

Double-pole field breakers are available
as follows:

A spring-operated "stored energy"
closing mechanism provides fast, con
stant-speed closing for either electrical or
manual AK-2-1S and AK-2-2S power
circuit breakers. This mechanism, an

Axr-is
Axr-zc
MMO

Votlap*
•ollias

Vetlop* totlAp—

350/375/500
350/375/500

Electrically operated models use an
a-c or d-c solenoid to charge the closing
spring and provide total closing time of
less than 5 cycles from the instant the
close button is energized. The solenoid is
small, compact, has a low total-energy re

quirement, and affords greater accessi
bility for adjustment of overload trip
devices. Electrically operated breakers
are normally furnished without manual
handles, but with a maintenance closing
device.

The electrical stored energy closing
mechanism .utilizes energy stored in
powerful closing springs to close the
breaker

motor, which can be operated from ac
or dc, drives a gear reducer unit. The
output of this unit charges the closing
springs through a charging crank and
cam.

In the charged position, the springs are
positively blocked by the "advance of
center" location of the charging crank
with respect to the charging cam. When
the closing switch is operated the motor
quickly drives the crank over center,
releasing the springs and closing the con
tacts. Once the springs are released, the
contacts will close regardless of continuity
of control power. This is important when
breakers are accidentally closed in on a
short circuit and the control power source
is the main bus.

Recharging is done immediately after
a closing operation at a low rate of energy
input. This means low closing current- only 4 amp at IIS volts ac. The springs,
therefore, are always charged and ready

extension of the principle long used in
large-sized AK breakers, provides a clos
ing speed completely independent of the
operator (manual) or the voltage level of
the control power source (electrical).
A manually operated breaker uses an
insulated plastic handle. To close the

Contacts require considerably more
energy for closing under short circuit or

breaker, the handle is first rotated counter

overload conditions than under normal

clockwise through approximately 100 de
grees. This resets the mechanism and par
tially stores energy in the closing spring.
The handle is .then rotated clockwise,
completing the charging of the springs.
As it approaches the normal rest position,
the mechanism goes "over center," re

load. Each time the springs are charged,
there is enough energy stored to close the

leasing energy to close the contacts. Upon
Typ*

to close the breaker.

contacts under full short-circuit condi

tions. Energy in excess of that required
to close the breaker under a particular
load is absorbed by the flywheel effect of
the gear box, and u returned to the
closing springs.
A second set of springs is used to open

receiving a tripping impulse, the breaker
contacts are driven open at high speed by
the same springs that are used for closing.
A unique "rebound latch" which operates
only during opening, prevents the con
tacts from rebounding in the closing

A detachable ratchet handle, which
can be slipped over the extension shaft of
the gear Imx, is provided for maintenance

the contacts when the breaker receives a

lOW-VOLTAGE AIR CIRCUIT BREAKERS

AppBieafi'son Informcafion

OPERATING MECHANISMS

id
(rhoto BOIiSISI

CUTAWAY VIEW or manual tlor^i
antrgy mtchanlim

^'*"V«cls (arrow) art In epsn posllton.

Fig. 36. AS HANDLE IS ROTATED ceunlsr.
cleckwlio, peworfvl cladng spring (arrow) It

ANDLE IS
IS RETURNED
RETUa
Fig. 37. AS HANDLE
to original
dlschorgsl and cenlacli
i
petllten. spring dltchorgat
(arrow)

art cloisd qotddy and llrmly

CLOSING
• SPRING
CHARGING CAM

FLOATING
RING GEAR

CLOSING CAM
CHARGING CRANK
ORMNO RING GEAR

melo eouwc]
Fig. 33

Fig. 39
Elsslrlcal tlorod snsrgy closing mseliantimt

LOW-VOLTAGE AIR CIRCUIT BREAKERS

C0NTR01.P0WER REQUIREMENTS

Note: The following control-power transformers are recom

Successful operation of electrical breakers is dependent on a
reliable control-power source. The operating currents of the
closing mechanisms and shunt trip coils together with control-

mended where only one breaker at a time is being closed.
AK.2-15, -25
3 KVA (All control volt

circuit fuse ratings and operating voltage ranges are listed in
Table XI.

ages)
AK-2-S0. AK-2-75,
AK-2-100

H KVA (All control voltages)

TABLE XI—Operating Currenlsi^
Slivnt Tilp

doting Mochonlttn
IU.'olt, 40.crc>*
(OporoVing Rongo
9S-I2S V)

Amperei ol
RotedVoItt

AK.2.IS
AK-3-7S

230-veII, 40-crclt
(Operating Rongo
190-230 V|

Ampero
Rating
af
Roto

Operating Current In'Amp

l23.voit, D'C
(Operating Roitga
90-130 VI
Operating
Current
to

Anperet at
Rated Vciti

Ampere
Rating
af
Futo

MIn Recommended fine Rating for

All Trip CIrtulli

Amperet el
Rated Volti

vfliuva iiaLca ivr

230-eelt, D-c
(Operating Range
180-340 V)

should be used for estimating purposes only,

d Inrush/sustained.

REPETITIVE DUTY

Circuit breakers are designed primarily

tions under full-load operation and inrush

to perform the function of circuit tnterfuption under short-circuit conditions.

conditions such as encountered in motor

starting applications. Industry standards

Nevertheless modern circuit-breaker

have been established for the minimum

mechamsms are capable of many opera

performance which is indicated in Table

XII. With adequate maintenance G-E
breakers can be expected to exceed the
standards. Refer to Switchgear Market
ing when questions arise with respect to
specific applications.

TABLE Xli—Repetitive Duty and Normal Maintenance
Number ol Opetalieai
OrcuM Rreoter

Tgpa ttf
treater

Detlgnallen
InletrvpHng
Rating. Amperot

Nenfoull,
For. C
t.F,0,
H,and J

Fault,
For. C, E,
F,O.K,
LondK

Nonfault,
Far, D,

Far. 8,
E.F,G,
H,andl

Fault,
For. 0. E,
F, C, N,
LondK

3000
3300
loco
300
300

4000
2800
800
400
400

Number of
Operallant
Rermeen

of the continuous current rating of the circuit breaker at voltages up to the maximum
design voltage.
OPERATINO CONDITIONS

E. With rated control voltage applied.
F. Frequency of operation not to exceed
20 in 10 minutes or 30 in one hour. Rectifiers

AX.t5
AX-23
AX.30
AX73
AX.IOO

15,000
23,000
50.000
73,000
100,000

or other auxiliary devices may further limit
the frequency of operations.

G. Servicing at no greater intervals than
shown in Column 2 of the table.
CONDITION OF THE CIRCUIT BREAKER AFTER
THE OPERATIONS SHOWN IN THE TABLE

NOTES FpR TABLE Xli
Power-operated circuit breakers, when

operating under usual service conditions,
shall be capable of operating the number

A. Servicing shall consist of adjusting,
cleaning, lubricating, tightening, etc. as
recommended by the manufacturers. The

of times spedlied in the above table. The

operations listed are on the basis of servic
ing at intervals of six months or less.

effect of such operations upon the breaker
are given in the following lettered para

anCUIT CONDITIONS

Operating conditiotu and the permissible

B. When closing and opening no load.
C.
When closing and opening currents up
listed in the column heading must be given
to the continuous ctirrent rating of the
eonsideratioiu
This standard applies to all parta of a ' circuit breaker at voltages up to the maxi
mum design voltage and at 80 percent
eircuit breaker that function during normal
operation. It does not apply to other parts, power factor or higher.
D. When dosing currents up to 600 per
such OS overcurrent tripping devices, that
function only during infrequent abnormal cent and opening currents up to 100 per

graphs. For each column, oil paragraphs

eircuit conditions.

cent (80 percent power factor or higher)

H. No parts shall have been replaced
except as qualified by par. K.
I. Circuit breaker shall be in a condition

to meet all of its current, voltage and inter
rupting ratings.
J. The circuit breaker shall be in a con
dition to meet all its current and voltage
ratings but not necessarily its interrupting
rating.
OPERATION UNDER FAULT CONDITIONS

K. If a fault operation occurs before the
completion of the permissible operations, it
if not to be inferred that the breaker can

meet its interrupting rating or complete its
number of operations without servicing and
making replacements if necessary.

lOW-VOlTAGE AIR CIRCUIT BREAKERS
Page 26

ApplieciHon InformcaHon

>
. .cRCURRENT TRIPPING
DEVICES
General Electric low-voltage power
circuit breakers are equipped with trip
ping devices used for two distinct func

Inilanloneewt
piclvp

a. As a means of opening the breakei

during the process of normal switch
ing operations initiated by an opera
tor or an automatic switching equip

Calib ration
indieelor

b. As a means of automatically open

ing the breaker under abnormal
power-system conditions for circuit- protective purposes.

Normal switching tripping is efiected.

by one of the following devices:
>

1. Manual trip button—supplied on
an breakers both manually and
dectricany operated.

delay
pickup
adjustment

displacement
oil

Pig. 41. Type EC-3A magnetic overcurrent tripping devtee.Serle*
trip for 335, MO, and 1600 amp Irome lize breaker*

2. Shunt-trip device—supplied on all
dectrica! breakers and optionaUy
A

available on manual breakers. Shunt

trips are normally energized from a
reliable constant potential source
such as a storage battery or control

power transformer.

/^^rtomatic protective tripping is
:ed by one of the following devices,
Ovpending on the type of breaker and
the means employed for initiating the
tripping:
1. Direct-acting series overcurrent

tripping device Type EC-1 and

Adjustment
for long
time delay
pickup

displacement
^eil piston
(shown
cutaway)

lime delay
pickup
Calibration
tndicolor

EC-IB embodying instantaneous,
short time-delay and long timedelay dements or specified com

Mechanical escapement
(hidden by cover)

binations thereof. This trip is used

Fig. 43. Type EC-1 magnetic avereorront tripping dewlce.Series trip

primarily for selective tripping of

for 335, 600, and 1600 amp frame site breakers

breakers. Table XIII and Fig. 45

and 46 show the calibrations and
time-current characteristics of these
dements available for various rat

ings of breakers.
Vibration

2. Direct-acting series overcurrent
tripping device Type EC-2A em
bodies instantaneous and long time-

delay elements with adjustable
instantaneous pickup and long timedelay elements. This trip is used on
breakers in fully-rated and cascaded
systems. Table XIII and Fig. 44

%
Adjustment
for

inslontoneous^'**->»adj. 15 to 38 ite*

80ot60% colibroted ot
80a 100, 120, UO OAd
and 160% offcoitroling

{ |I6| fntornicdlote-edi. 7^ to 18toe» V
\ jlC) MinlmviW'Odi. 3J to 8.3 IOC. f

6-12X co!l ffoKttg

f Soltct ont rengo^6 to 12X fumlshod

circuit The undervoltage device

1 18—18 toe.
(

may have either instantaneous or
time-delay action depending on the
application requirements.
The timing device is static, con
sisting of a capacitor-resistor com

t Not available with long time delay.

bination. Time delay is readily

TRIPS FOR 225-, 600-, AND 1600-AMP FRAME SIZE BREAKERS

adjustable over a range of I to 5
seconds. The device is adaptable
for use with Thermo-tectois and

for remote tripping.
$

factory
Setting*

toogt of ficliwp
Adttiitniant*

4^X coil rating
O-ISX coll rating

1 1unlott ethorwiio iptcifitd
f

80*-2M% coll ratingt |

EC-1 Selective Trips combine long time and short time elements for intentional delay
up to the interrupting rating of the breaker. (See Table I, Col. 4.) For spedal ap
plications,instantaneous may be added.

4. Reverse-current trip device—op
tionally available for mounting on

pole units of d-c breakers for the
detection ofchange in current direc*

iongt of fickttp

AvallebtB
ChoFGCttfUriCt

80-160% _
(factory tot of 100%}

tion in d-c circuits. They are poten

tial polarized by coils rated 125 or

2-5 Bcoil rofing

250 volts and are set to trip on
Rverse current equal to 10 percent

of the breaker continuous current

Type EC overcurrent trip devices are
magnetically operated, using a series coil
or single conductor and an associated
magnetic structure to provide tripping
force. Three basic characteristics—long

time delay, short time delay, and instan
taneous—can be used singly or in com
bination for a wide variety of applica
tions.

Long time delay is accomplished with a
positive-displacement oil piston. Sealing
of the assembly eliminates variations
caused by dust and dirt. Accurate madiining of the piston and cylinder, a cali
brated orifice, and silicone oil keep varia
tions in time delay due to changes in
ambient temperature to a minimum.
Short time delay is accomplished with
a rugged mechanical escapement.
Instantaneous tripping is obtained with
a tension spring in series with the long
time-delay piston.

3-7 s coil roting

4-10 K c^l rating

factory
Setting

30 toe. at 6 X pldvp

5 tec. ot 6 Xpickop

15 tec. ot6 x plchvp

| f i2A) Max. 24 eyelet ot 216 x pickup
1

16 eyelet ot 3!6 t ptdup

8 cydet ot 2!6 x pickup
AAvtt be tpedfiei

>lofi«erfio»toblo

• Pickup tolerances are =tlO% for EC-2A and EC-1 trip devices.

TRIPS FOR 3000- AND 4000-AMP FRAME SIZE BREAKERS

EC-IB Fuliy Adjustable Trip and Selective Trips for all applications where combina
tions of long time delay, and instantaneous, or instantaneous alone is required—short
time delay also available.
Rongt of fichwp

Av^k»bl«
Oioroct«rUlI(3

80-160% cotlbrotod at
80, 100, 120, 140 ond
160% of ceil roting

TKroo fongoi ovoneblo—
tolect ono

/ 1(88) Mas.
\ (1CC) MIn.

4J tec. 06X pickup
2 tec. <^6X pickup

34 cydet ^2!6X pickup

( (288) Inter.
1(3CC) Min.

4,7. 10X )
*tflifflnteAoeoB

16 cydct W2V^ Xpickup
8 cydet <^216X pickup

Throo rongoB ovoHoblo—
•olict OA*

6-T2X ceil roting

4-9X collrating
0-15X coU rofing

( Select one rengo—

\ ( 6 to 12X furnithed
J I unlett otherwiseipedfled

' Pickup tolerances are a:is% for EC-IB

tOW-VOlTAGE AIR CIRCUIT BREAKERS

?E EC-2A TRIPPING DEVICE CHARACTERISTICS
100 140

umc TIME OELOir PICK UP SETTING ADJUSTABLE

WITH CALIBRATED MARKS AT 80-100-120-140-160
PER CENT OF COIL RATING. SET AT |00 %
WHEN FURNISHED

m
LONG TIME ADJUSTMENT

IA-15 TO 38 SEC
|B-7.5toI8 SEC.
IC.a3T0 8.2sEC
(TIME VALUES ARE
reset table DELAY TIME

AT6 times coil rating)
SEENOTEI

30 40 SO60 80 lOO
USE FOR lA

I9X instantaneous

I. INSTANTANEOUS PICK-UP SETTINGS ADJUSTABLE 4 T09,6TOI2 OR 9 TO IS TIMES- WITH
ONLY ONE RANGE AVAILABLE PER DEVICE. RANGE OF 6 TO 12 TIMES IS FURNISHED UNLESS
otherwise SPECIFIEOstandard instantaneous settings unless otherwise SPECIFIED

ARE9 TIMES FOR 4 T09 RANGE, 12 TIMES FOR 6 TO12 RANGE,19 TIMES FOR 9 TOIS RANGE.
2- TOTAL CLEARING TIME (UPPER LIMIT OP BANO>-IS DURATION OF FAULT CURRENT
INCLUDING ARCING TIME.

3- RESETTABLE delay Time (LOWER LIVITOF 8AN0)-IS DURATION OFJAULT CURRENT WHICH

ILLUST RATED
TOTAL
clearing
TIME

MAY PERSIST AT A GIVEN VALUE AND THEN DROP TO 80% OF THE LONG TIME DELAY PICK UP
SETTING without THE BREAKER TRIPPING.

4- PICK UP tolerance are PLUS OR MINUS 10% FOR LONG TIME AND INSTANTANEOUS- FOR

MORE detail IMFORMATION ORDER DRAWING 0B89B04B6-A,B,C AND 0SB9B0485 FROM

LOCAL APPARATUS OFFICE.

9- LOW VOLTAGE POWER CIRCUIT BREAKERS EQUIPPED WITH ADJUSTABLE TRIP DEVICES ARE
RATED AT lOOY. OF THE CONTINUOUS RATING OF THE TRIP COIL. TRIP DEVICE PiCK-UP
MAY BE SET ABOVE THE 100% POINT FOR COORDINATION PURPOSES BUT SUCH SETTING
DOES NOT INCREASE THE CONTINUOUS CURRENT RATING-

I I 11 III I nil

I • I • tit

I I I nil 11111

CURVES ARE PLOTTED AT 29* C AMBIENT.

4t It tt itttttg

CURRENT IN TIMES PICk'uP

M I III 11 III
I

IDrowing 086980484)

Tlma>curt«nl eharacltrlilitt of Ih* Type EC>3 and EC-2A Itip dtvic* for AK-3-IS, >39 and -SO cirevll braoksr

tOW-VOlTAGE AIR CIRCUIT BREAKERS
Page 29
««*v

MULTIPUS OF CUIlRmr RATTNC
»

l»nBtftloir Unlli
ReiaDflbl*
Dilov Time
Moiimwm Telei

SSMrt'Kmt'detay
Pukup Renffii
4-JOX-i-

Special
IneroA'Dneoat
Unit

Cleoriftg TiAie
AK-15

Applkeriofl
S'la»*

diferminei
tndaf cvrre

Shert-ilA^e-difoy Un**»

MULTIPLES OF CURRENT RATING

SENEHAli^ELECTItC

TYPE AX iOW-VOlTAGT POWESI CIRCUIT BREAKER

EC-1 SERIES TRIP DEVICE

(erfcal litlAft
AKM »y 20. JO. «0. )0. 70. »0. >00. US
ISO. *7S. 2M. 7ii
AC Ji 40. SO. 70. 90. (OO. »7S. >S0. I7J
200. 22S

230. JCO. 930. 400. 300
6C0 100 1000. UOO. 1600

long-lvme-cfefay. Shorr-trmt-deloy
ond InifonTonecui
nmO'CvrrPRT Curvoi

I9;> 4« «*l
f

7 •• St. »

) I* ra. ^ 4 •• 101 •( -V'^r
1l*ii

{Currei oppiy ot 60 tydei loe otnbieni lempefoKm of 23 C1

lOW-VOLTAGE AIR CIRCUIT BREAKERS

MULTIPLES OF CURRENT RATING
m

Delay Time
Moatmum Tolel
IttH

»{>ec{ol
Instentoncovs

rm
20-TSX
IBB-lnl.

Cleortng Time
AK.75DAK.100
2CC-Min.

Appltco|ien
Dilipminci

Shorl»(«me>dtloy Unit

MULTIPLES OF CURRENT RATING

6ENERA10 ELECTRIC

TYPE AK lOW-VOlTAGE POWER CIRCUIT BREAKER
GES-600S

EC-IB SERIES TRIP DEVICE

CfTfintlitliiBt (Aaiperiil
AK-75
AK-lOO

2000. TSOO. 9000

2000. 29C0. 9000. IQOO

Lens'llme-delay, Shorl-lime-delay
and Inilonlaneaut
Time-current Curve.

••MM.ealwf {}<»•• exSw* lo****'

M evirAf
l*Ahaa«ir* «wrr*««

U*>l e..L.o f«•-*•• .aH-as*
3 I* PC. •* 4 •• tec «i
|»S«*cel*WWM UM

(Cweves opply at 00 cyclesfor ombient temperature cl 25 Cl
SWITCHCCAR DCPARTMtNT. PKIIADEIPKIA. PA.

CM* tO •• iM^a

«*•» tee*. 4* •**

GEH-2021D
SUPERCEDES

POWER CIRCUIT BREAKERS
INSTALLATION AND OPERATION
Types
AK-1-15
AK-1-25
AK-1-50
AK-1-75
AK-1 -100
AK- 2-15
AK-2-25
AK-2-50
AK-2-75
AK-2-100
AK-lA-25

AK-2A-15
AK-2A-25
AK-2A-50
AK-2A-75
AK-2A-100
AK-2-50S

AK-2-75S
AK-2-100S
AK-2A-50S
AK-2A-75S
AK-2A-100S

AKF-lA-25
AKF-1B
AKF-IC
AKF-2C
AKF- ID
AKF-2D

AKU-2-25
AKU-2-50
AKU.2-50S
AKU-2A-25
AKU-2A-50

GENERALS ELECTRIC
PHILADELPHIA, PA.

POWER CIRCUIT BREAKER

RECEIVING, HANDLING AND STORAGE
Before installing, or operating these
circuit breakers, make a careful reading

portation company and notify the nearest

If the circuit breaker is not to be placed

Unpack the circuit breaker as soon as

in service at once, store it in a clean, dry
location in an upright position. Support it
to prevent bending of the studs or damage

possible after it has been received. Exer
cise care in the unpacking to avoid damage

to any of the breaker parts. Do not cover
the breaker with any packing or other

Upon receipt of a circuit breaker, im
mediately make an examination for any
damage or loss sustained in shipment. If
injury, loss or rough handling is evident,

to the breaker pskrts. Be sure that no loose
parts are missing or left in the packaging
material. Blow out any dirt or loose parti

material which absorbs moisture, that may
cause corrosion of breaker parts. A
covering of kraft or other non-absorbent

file a damage claim at once with the trans

in the breaker.

General Electric Sales Office.

of the sections of these instructions which

are pertinent to the anticipated work.

cles of packaging material remaining on/or paper will prevent dust from settling on the

noN
Typical Outline

In choosing a location for the installa

tion of an AK Circuit Breaker, there are
two factors to be considered. The first
of these is the effect of the location on

the breaker itself.
Much better per
formance and longer life may be mqtected

If the area is clean, dry, dust-free, and
well ventilated, than if the opposites to
these conditions exist.

sideration is convenience for operation
and maintenance.

"Hie breaker should be

easily accessible to the operator, and
there should be sufficient space allowed
for maintenance work to be done if this

becomes necessary.
/

AK Circuit Breakers are designed to
be mounted in any one of three ways.
These are dead front mounting, individual
mounting with the enclosure beingprovided,
and drawottt mountii^ in which the breaker
is designed for insertion into a cubicle

in drawout equipment such as a substation

AK-1-15
AK-1-25

256C7S3
256C754
6950116
248C703
238C123
845C281

AK-l-SO Man, Oper.

AK-l-SO Elec. C^er.
AK-2-S0 S. E. Man. Oper.
AK-1-75
AK-1-100

AK-2-75 Elec. OP^r.

The front cover of the breaker enclosure

may l>e a hinged door or a plate bolted to

the pwel. In either case, it should have

a section cut out, throuf^ which the front

3. Mount enclosing case to supporting
structure.

4. Replace cover plates and make

power connections to stationary terminals

The surface on which the breaker is

mounted must be flat throu^out in order
not to impose any internal distortion on

5. E the breaker is a type AK-15,

the breaker imlt. The supporting structure

AK-25 or AK-50 and Jias been removed

wei^t of the breaker.

from the enclosure, it may now be re
placed. Control power connections to the
terminal board should be made as required.

must be rigid enough m avoid any pos
sibility of the breaker studs supporting the

dimensions, ais given by ihe appropriate
ouUine drawing, must be maintained to

provide adequate electrical clearance.
INDIVIDUAIjLY enolosed breakers

enclosed breakers are

the weather resistant type. The former is

^making any necessary control connections.

power entrance means is used.

DEAD FRONT BREAKERS

knecting the power buses or •cables, and

2. Remove cover plates of enclosure
and prepare them to accommodate whatever

AK-2-100 Elec. Oper.
AK-2-100 S. E. Man. Oper.

supplied with several typae cd enclosures,
most common is the generalpuipose^eor

the customer's design and construction.
Mounting in this instance consists of bolting
the breaker frame to a siq>portingstructure
within the switchboard or enclosure, con-

and need not be removed from the en
closure.

AK-2-7$ 8. E. M^ Oper.

or cohtrol board.

These breakers are designed for mount
ing in a switchboard or enclosing case of

are bolted solidly to the enclosure frame

used for favorable indoor locations and
the latter for outdoor locatkns or indoor

locations that may be subjecttounfavorable

conditions. All iA the enclosures are pro

vided with suitable means for mounting on
walls or supporting framework. Removable

cover plates are siqgplled with the en
closures which may be mrllled or machined
to accommodate the entrance of bus ducts,
conduits or cables. Steps in the procedure
for installing enclosed breakers follow:

(See CONNECTIONS).
6. Before energizing the power cir
cuit, operate the breaker several times to
be sure that it is functioning prqperly.

(See OPERATION).
DRAWOUT BREAKERS AKD EQUIPMENT

Mounting drawout breakers consists of
simply placing the breaker in the proper
position with respect to its enclosure,
sliding or rolling it to a stop position, and,
by means SOURCE. FOR

NOTE: The mechanism is designed to

a—^(+)|^ CURRENT
"Eyffsf DEVICE

reverse autoniAtlcally in the connect

and fully disconnects position. Once

an operation is started it must be com
pleted. Completion of an operation is
indiratcd by the rS knob retracting to

its original position.
Fig. 1

•Rygaicar tnaartlon AK-2A - With the inner

housing in the connected position proceS

3. Open the housing door and rotate the
two track lock links, releasing the
tracks.

Pull the red knob. Pull the mechanism

Pull the tracks out to the limit

of their travel.
drawn posttion.

operating handle fully out and allow ittb
return to its original position. Repeat
this three more times. The inner house
is now in the test position.

This is the fully with

With a lifting device, raise the breaker
so the mounting pins are about one inch

Pull the red knob again. Pull the mecha

Push the breaker in against the track
stops.

Rotate the two lock links to

lock the breaker in place.

NOTE: When moving a breaker from
one position to another be sure breaker
is tripped open.

above the tracks. Lower breaker so the

nism operating handle two complete
strokes drawing the inner housing to the

breaker mounting pins drop into the
slots in the tracks. Remove the lifting

operating, handle two times until the test

disconnect position.

position is reached.

Pull the red knob. Pull the mechanism

NOTErWHEN SEPARATE

PWJR. SOURCE FOR

a REMOTE TRIP 6

Q:Oc J(X)-*DH l-o<<-o

STA. SEC. DISCONNECTS
LOCATED AT TOP OF COMR

o-4$-o
FURNISHED
ONLY WHEN
REQUIRED

FURNISHED ONLY
WHEN REQUIRED

Front View AK-15 and 25 Breaker Conpartment

Front View AK-SO, 75, 100 Breaker Compartment

Installation and Operation of Type AK Power Circuit Breakers

7. Pull the red knob again and pull the
mechanism operating handle four times.
The breaker will now be completely

A inserted, in its connected position.

NOTE: The installation of AK50S/75S/
100S/AKF2C/2D and breakers equipped
with the quick-closing mechanism is the
same as the other breakers described in

this book. The only difference occurs with
drawout breakers. The compartments that
house the quick-close breakers will be

Breaker Hemoval AK-2A

equipped with an interlock that prevents the
1. Trip the breaker.

manual discharging of the closing springs
while the breaker is in the racked in (con

2. Move the breaker and inner housing to

nected position).

fully withdrawn position,

Breaker Insertion, Steps 1, 2 and 3).

This interlock will be

provided with both AKD and AKDS equip
ment that require quick-close breakersi

which applies to each breaker specifically.
Depending on the breaker type, those con
nections are made either to a

board on the breaker or to the stationary
parts of the secondary dtsconnects.
INDIVIDUALLY ENCLOSED AND
STATIONARY BREAKERS
The

customers external connections

for operation (^breaker controlcomponents
and accessories are shown in Fig. 1.
DRAWOUT BREAKERS

3. Attach lifting device and lift breaker up
and away from compartment unttl pri
mary disconnects clear the compart
ment.

4. Move the inner housing to the connected

All electrical connections should be

The customers external control con
nections to these breakers are made to

made to assure good conductivity. Mating
surfaces should be parallel and firmly
bolted or clamped together. Contact sur

the stationary secondary disconnected lo
cated in the breaker compartment as shown

in Figs. 2 and 3, AKD Equipment and Figs. 4

position by pushing the tracks back
against the track stops and then follow
Steps 6 and 7 under Breaker Insertion.

faces should be clean and have a smooth

and 5 AKDS Equipment.

finish. The bus or cable connecting to the
breaker should have adequate current-

breaker is used in a General Electric Com

pany, Drawout Switcbgear Equipment, all

The inner housing is now in the con

nected position and the breaker is free

carrying c:q>^city to prevent excessive
heating. Control circuit connections should

external connections must be made to
terminal blocks located in the rear vertical

from its compartment.

be made according to the wiring diagram

wiring trou^ of the equipment.)

OPERATION
AK-2-15/25 and AK-i-SO manually

In closing an AK-1-15/25/S0 manual

operated breakers are closed by turning
the handle 90 degrees counterclockwise
and then clockwise 90 degrees back to the
original position. The initial counterclock

breaker on a load, make the handle move
ment with a fast, snapping action in order
to prevent unnecessary heating of the

AK-1-15 and AK-1-25 breakers are

closed by rotating the breaker handle in
a clockwise direction approximately 90
degrees. After tripping, the closing mecha
nism resets automatically by means of
springs.

nism. The clockwise movement closes the
breaker.

TRIP CLOSE
SOURCE SOURCE

breaker contacts.

wise movement resets the closing mecha

SOURCE SOU
REMOTE
CLOSE

The closing mechanism of the AK-2-

50/75/100 manual breakers is a spring

REMOTE
DISCONNECTS

STA. SEC. DISCONNECTS
LOCATED AT TOP OF COMR

FURNISHED
ONLY WHEN
REQUIRED

FRONT VIEW AK-IA-|5,25 & AK-2A-I5, 25

FRONT VIEW AK-2A-50^ 75,100

BREAKER COMPARTMENT

BREAKER COMPARTMENT

Installation and Operation of Type AK Power Circuit Breakers GEH-2021
charged mechanism similar to the one used

AK-50/75/100 electrically operated

breakers.
AK-2-S0/75/1O0
manual
breakers are closed by rotating the closing
handle counterclockwise through approxi
mately 120 degrees, and then clockwise
back through 120 degrees to the normal
handle position. Four such complete move
ments of the handle are required to close
the breaker. During the four counterclock
wise movements and the first three clock
to

wise movements of the handle, the springs
are charged. After approximately 70 de
grees travel (d the fourth clockwise handle
movement, the spring charged mechanism
is

e CLOSING MOTOR

JC,*X RELAY COL

^ - X RELAY CONTACT

with each complete

• RELAY CONTACT

handle movement and indicates the number

of complete handle movements that have
been performed.

closes. A charge-indicator, numbered 1 to
4,
viewed through the breaker front
escutcheon,

FOG « MECHANICALLY OPERATEO SWITCHES

y •Y RELAY CONTACT

• NORMALLY OPEN SWITCH CONTACTS

44-t^ • MECHANtCALLV OPERATED SWITCHES

- NORMALLY CLOSED SWITCH CONTACTS

^ • NCRIIALLV OPEN SWITCH OOHTACTS

L • AUXILIARY SWITCH CONTACT

# • NORMALLY CLOSED SWITCH COMTAOTS

ELECTRICAL CLOSING

(Figures 6 and 7)
STANDABD BREAKERS

AK-IS and AK-25 electrically operated

Fig, 6
simplified Elementary Diagram
Internal Wiring AK-I? and 2^

Fig. 7
simplified Elementary Dlagre-m
Internal Wiring AK-50, 75 and 100

breakers are closed by a solenoid coll. The
armature of the solenoid is linked to the

breaker mechanism and its movement,
operating through the mechanism, closes
the breaker. The closing solenoid circuit
may be operated by a push button closing
switch on the breaker or by a remote
switch or relay, depending on the individual
arrangements desired. When a closing
signal is given, the X relay coil is ener
gized and It in turn closes its contacts. One
of these seals In the X coll circuit; the
other three, which are arranged in series,
energize the solenoid closing coll. As the
breaker closes, a mechanically operated
switch opens one pair of its contacts (bb)
and closes another (an).
The contacts

which open cut out the X relay coil. The

contacts which close energize the Y relay
coll, whose contacts now seal in the Y coil
and hold <^en the X relay coil circuit. This
prevents another closing operation if one
of the protective devices operates to trip
the breaker before contact at the closing

energized, operating the X contacts. This

and de-energize the control relay.

seals in the X relay and energizes the
motor once again and the closing operation

auxiliary switch contact opens prevrating

the breaker is tripped open. With the G
switches closed, the motor charges the

QUICK CLOSE BREAKERS

(Figure 8)
Functionally, the quick close mecha
nism differs from the standard electrical

mechanism in that the pre-charge operation
is extended to completely charge the closing
springs. At the end of the charging opera
tion, which takes approximately 5 seconds,
a latch plate engages the prqp roller to
prevent the closing springs from dis
charging.

are closed by the discharge of a closing

With the closing springs fully charged
the breaker is ready for a closing operation
upon release of the prop roller. This may
be accomplished either manually, by de
pressing file closing lever on the breaker,
or electrically by closing the remote clos
ing switch. Upon the release of the prop
roller the closing springs discharge and

spring. This rotates a crankshaft which,
by means of an attached roller, operates

close the breaker in the same manner as
on the standard electrical breaker.

switch is released.

Large AK breakers (AK-50/75/100)

the control relay from being ener^ed until

closing springs ready for the next closing
operation.
MANUAL OR MAINTENANCE CLOSING
OF ELECTRICAL BREAKERS

All electrical breakers may be closed
manually by means of the maintenance
handle furnished with the breaker or switchgear.

To close AK-1-15/25 breakers:
1. Make sure handle is In proper position.
Handle is stamped this side up.

2. Place the handles fork like fingers above
the armatures stop nut that extends

magnet behind the front

escutcheon and lift up. This forces the

armature down closing the breaker's
contacts.

a closing cam, forcing the movable breaker

contacts against the siationgry contacts.
The closing spring is charged throu^ the

operation d a motor and gear reduction
unit.

The electrical control system is com
prised of an X relay, two double contact
mechanically operated switches (F and G),

a push button closing switch and any means

for remote closing which the user may

incorporate into the system. When voltage

is first applied to the breaker, (before any
closing signal is given) the motor is ener
gized through two of the X relay contacts
and the two G switch contacts. The motor

then compresses the closing springs to the
"pre-charged" position at which point the
mechanically operated F and G switches
are operated. This opens the G contacts,
stopping the motor, and closes the F con

tacts, which readies the system for the

actual closing of the breaker. When the

push button or remote switch slgimls for
a closing cperation, the X relay coU is

With control voltage applied, the motor
is energized through the G switch contacts,
and charges the closing springs. When the
springs reach the fully charged position,
the mechanically operated switches operate,
reversing their contacts. Upon operation
of these switches the motor is stopped tiy
the opening of the G switch. The closing
of the F switch prepares the breaker for
a closing operation.

A closing signal now given energizes
the control relay X whose contacts close
and complete the circuit throu^ the closing
relay cotL With the closing relay coll
energized the breaker closes as described

above. At the same time the closing relay
contact closes to energize the anti-pump
relay causing its contacts to reverse pro
viding the anti-pump feature.

When the breaker closes, the mechani
cal (q)erated G switches close to energize
the motor again and the F switches open

C^SsilfG rIlAV SSnSaCTS

- ANTI-PUMP RELAY CONTACTS

r AG- MECHANICALLY OPERATED SWITCHES
L - AUXILIARY SWITCH CONTACTS

CLOSING MOTOR
ANTI-PUMP RELAY COH

NORMALLY OPEN SWITCH CONTACTS
NORMAUY CLOSED SWITCH CONTACTS

SIMPLIFIED aEMENTAMjDt^AM.^

INTERNAL WIRING CHRCK ClCU, GREAKER

Installation and Operation of Type AK Power Circuit Breakers

To close AK-2-1S/2S breakers:

Place the two small hooka of the handle
into the two slots located in the lower

spring discharge lever on the breaker. If
manual closing is desired with the breaker

of the trip sn^t causes the breaker to trip;

portion of the front escutcheon.

racked in, the interference feature must be
removed, otherwise the breaker can be

Rotation of the long end of the handle

manually closed in the test position or fully
racked out position only.

devices, shunt trip, undervoltage tripping

1. With the ratchet type maintenance handle

movement of the striker arms of ail ot

downwards forces the shorter end of

the handle upwards against the bottom
of the solenoid armature, and closes
To close AK-S0/7S/IO0 breakers:

indicated by the spring cl^ge indicator

Place the ratchet type maintenance
handle on the shaft that protrudes from
the gear reduction unit
2. Operate handle until the spring charge
indicator reads charged.

and by solid resistance to any further

springs which closes the breaker's con
tacts.

displacement of a mechanism latch, which
allows a toggle linkage supporting the
movable contacts in the closed position to
collapse.

manually when in the racked in (connected
position), due to mechanicaldesignedinter

This trip latch is fastened

rigidly to a trip shaft which runs hori

zontally from left to right through the
breaker. All of the means provided for
tripping the breaker operate through striker
arms which displace the mechanism trip
latch bymovingagainsttrippaddlesfastened

TYPE AKU AND BREAKERS WITH
This device may be furnished with any
of the above type breakers. The open fuse
lockout device consists of 3 separately oper
ated devices (one per breaker pole) each

wired in parallel to corresponding brewer

^ai^uses. These devices are mounted on the

The purpose of this device is to

trip the breaker upon the blowing ofanyone

of the breaker fuses.

BEFORE INSPECTION OR ANY MAIN

TENANCE WORK IS DONE, BE SURE THAT

TION. ALL ELECTRICAL POWER, BOTH

Periodic inspection of the circuit
breaker is recommended at least once a

year. Morefrequent inspections are recom
mended, if severe load conditions, dust,

moisture, or other unfavorable conations

Always inspect the breaker after a

short circuit current has been interrupted.

At the time of inspection, the following
checks should be made after the breaker

has been de-energized.

1/32 to 1A6 inch beyond the point at which

with series overcurrent trip devices either

of the dual magnetic type (instantaneous

and time delay tripping) or instantaneous

Breakers are designed to carry up

to 100% of the continuous current rating of

cause overheating and possible
For a more detailed discussion of the

construction, (deration, and a{qilicatlon of
overcurrent trip devices refer to the follow
ing publications;

1. Maintenance manual for specific
breaker involved (see "Maintenance'^.
2. "Selection and Application of Power
Circuit Breakers" GET-U13.

allowing the reset button to'extend forward

indicating which fuse has blown, and simul
taneously holding the breater in the trip-

free position untU the latch closed armature

is released by the operating of the manual

In general, the circuit breaker re
quires
moderate lubrication. Bearing
points and sliding surfaces should be lub
ricated at the regular inspection periods

Maintenance
Manual

AK-l-lS, AK-1/1A-2S Man.
Operated.

AK-l-lS, AK-1/1A-2S Elec.
Operated.

AKF-lB/lA-25 Man. Oper.

Before lubricating remove any hardened
grease and dirt from latch and bearing

AKF-lB/lA-25 Elec. Oper.

surfaces with kerosene.
ALL EXCESS
LUBRICANT SHOULD BE REMOVED WITH

All AK-2/2A-15/2S, AKU-

with a thin film

GE Lubric^ D50H1S.

CLEAN CLOTH TO AVOH) ANY AC

CUMULATION OF DIRT OR DUST.

On drawout breakers, the contact sur
face

disconnect studs should be

All AK-1/2/2A-S0/75/100,
AKU-2/2A-S0, AK-2/2A60S/75S/100S, AKF-IC/

cleaned and greased with GE Grease &ecificaUon D50H47.

operate the breaker

several times, checking for obstructions
or excessive friction.

2. Electrically operate the breaker

several times (if br^er has electrical
control) to ascertain whether the electrical

attachments are functioning properly.
3. Remove the arc quenchers by re
moving the channel shaped retaining bar.
4. Inspect arc quenchers and contacts
r breakage or excessive burning.

these, when activated, should move from

tripping occurs. This is what is meant by
the expression, "positive tripping".

Should arc quencher barriers or contacts
be eroded to half their original thickness
they should be replaced.

THE BREAKER IS IN THE OPEN POSI

PRIMARY AND CONTROL SOURCES
SHOULD ALSO BE DISCONNECTED.

This energizes the

coil of the device causing the armature to
engage the trip paddle, thereby tripping the
breaker. Once operated, the armature is
latched in the closed air gap position

FUSE-BREAKER COMBINATIONS

left hand side of the breaker (looking from

Open Fuse Lockout Device

device, and reverse current trip all operate

their trip devices. Any attempt to carry
higher currents for a prolonged period wiU

The breaker is tripped open by the

NOTE: All AKO, or AKD-S drawout type
breakers equipped with the quick closing
mechanism cannot normally be closed

The manual trip button, overload

Most air circuit breakers are equipped

2. Push down on the push to close lever to
release the energy stored in the closing

the quick closing mechanism:

handle operation.

3. Continue to operate handle until the
closing springs discharge and close the

To close AK-50S/75S/100S, AKF 2C,
2D breakers and breikers equipped with

clockwise movement resets the mechanism

in this fashion to trip the breaker.
applied to the gear box shaft, operate
the handle until the springs are fully
charged. The fully charged position is

the breaker's contacts.

on the trip shaft. Looking at the breaker
from the ri0it, counterclockwise rotation

These instructions have as their pur
pose the imparting of information of a
general nature concerning the installation
and operation of Type AK power circuit
breakers. If more complete and specific
information is required, such as might be
needed for overhauling the breaker, trouble
shorting, or replacing parts of the breaker,

AK-1-15/25 and AKF-IB

AK-l-SO up to and including

refer to the complete instruction for the
particular breaker type involved. These

AK-1-50-10-11 and AK-2-S0

Renewal parts bulletins for the various
^es of.breakers are:

GENERAL ELEaRIC COMPANY, PHILADELPHIA, PA.

AK LOW VOLTAGE
POWER CIRCUIT BREAKERS
INSTALLATION AND OPERATION
Types
AK-1-15
AK-1-25
AK-1-50
AK-1-75
AK-I-100
AK-2-15
AK- 2-25

AK-2-75
AK-2-100
AK-IA-25
AK-2A-15
AK-2A-25
AK-2A-50

AK-2A-75
AK-2A-100
AK-2-50S
AK-2-75S
AK-2-100S
AK-2A-50S
AK-2A-75S

AK-2A-100S
AKE-1A-25
AKF-1B
AKF-IC
AKF-2C
AKF- ID
AKF-2D

GENERALB ELECTRIC
PHILADELPHIA,

CIRCUIT BREAKER

RECEIVING, HANDLING AND STORAGE
Before insUUlng, or operating these

circuit breakers, mSie a careful reading

portation company and notify the nearest
General Electric Sales Office.

of the sections of these instructions which

are pertinent to the anticipated work.

Upon receipt of a circuit breaker, Im
mediately

make an examination for any

damage or loss sustained in shipment. U
injury, loss or rough handling Is evident,
file a damage claim at once with the trans

Unpack the circuit breaker as soon as
possible after it has been received. Exer
cise care In the unpacking to avoid damage
to the breaker parts. Be sure that no loose

in the breaker.

these conditions exist.

and maintenance.

The breaker should be

easily accessible to the operator, and
there should be sufficient space allowed
for

maintenance work to be done if this

becomes necessary.
MOUNTING

AK Circuit Breakers are designed to

mounted in any one of three ways,

liiese are dead front mounting, individual
mounting with the enclosurebeingprovided,
and drawout mounting in which the breaker

is designed for insertion into a cubicle
in drawout equipment such as a substation
or control board.
DEAD FRONT BREAKERS

are bolted soltdly to the enclosure frame
and need not be removed from the en

256C753
256C754
6950116
248C703
238C123
845C281
238C192
238C193
269C22S

AK-1-15
AK-1-25

AK-1-50 Man. Oper.

AK-1-50 Elec. (^er.
AK-2-50 S.E. Man. Oper.
AK-1-75
AK-l-IOO

AK-2-75 Elec. Oper.

AK-2-75 S.E. Man. (^er.
AK-2-100 Elec. Oper.
AK-2-100 S. E. Man. Oper.

2690227
845C290

2. Remove cover plates of enclosure

and prepare them to accommodate whatever
power entrance means is used.
3. Mount enclosing case to supporting
structure.

cover plates and

power connections to stationary terminals
in enclosure.

surface on which the breaker is

mounted must be flat throughout in order

not to impose any internal distortion on

5. If the breaker is a type AK-15,

the breaker unit. The supporting structure
must be rigid enough to avoid any pos
sibility of the breaker studs supporting the

AK-25 or AK-50 and .has been removed
from the enclosure, it may now be re

weight of the breaker.

terminal board should be made as required.

dimensions, as given by the appropriate
outline drawing, must be maintained to
provide adequate electrical clearance.
INDIVIDUALLY ENCLOSED BREAKERS

Individually enclosed breakers are
supplied with several types of enclosures,
most common Is the generalpurposetypeor
the weather resistant type. The former is
used for favorable indoor locations and
the latter for outdoor locations or indoor

vided with suitable means for mounting on

locailons thai may be subject to unfavorable
All of the enclosures are pro

necting the power buses or -cables, and

walls or supporting framework. Removable
cover plates are supplied with the en
closures which may be drilled or machined

making any necessary control connections.

to accommodate the entrance of bus ducts,

The front cover of the breaker enclosure

conduits or cables. Steps in the procedure

may be a hinged door or a plate bolted to
the panel. In either case, it should have
a section cut out, through which the front
escutcheon of the breaker may protrude.

sions needed for preparing a suitable
enclosure or cubicle for the various types
of AK breakers are given below, 'nieee
are for standard 2 or 3 pole breakers.

Mounting in this instance consistsofbolting

Outline drawing numbers giving the dimen

within the switchboard or enclosure, con

Typical Outline

These breakersare designed for mount
ing in a switchboard or enclosing case of
the customer's design and construction.
the breaker frame to a supporting structure

the breaker itself.
Much better per
formance and longer life may be expected
if the area is clean, dry, dust-free, and
well ventilated, than if the opposites to

covering of kraft or other non-absorbent

cles of packaging material remalningon/or paper will prevent dust from settltng on the

two factors to be considered.
The first
of these is the effect of the location on

to any of the breaker parts. Do not cover
the breaker with any packing or other
material which absorbs moisture, that may

parts are missing or left in the packaging
material. Blow out any dirt or loose parti

In choosing a location for the installa
tion of an AE Circuit Breaker, there are

If the circuit breaker isnottobeplaced

in service at once, store it in a clean, dry
location in an upright position. Support it
to prevent bending of the studs or damage

installing enclosed breakers follow:

Control power connections to the

(See CONNECTIONS).
6. Before energizing the power cir
cuit, operate the breaker several times to
be sure that It is functioning properly.
(See OPERATION).
DRAWOUT BREAKERS AKD EQUIPMENT

Mounting drawout breakers consists of
stmply placing the breaker In the proper

position with respect to its enclosure,
sliding or rolling it to a stop position, and,
by means of a racking handle and mech
anism, racking it through the lastpartof its
movement during which the stationary and
movable halves of the disconnects engage.

Large drawout breakers are fastened to a
telescoping tray which extends out from the
enclosure to receive the breaker.

breakers have guides on their side plates
1. If the breaker is an AK-15, AK-25
or an AK-SO, remove It from the enclosure.
With AK-SO breakers, a handle and cam
arrangement is used for that part of the

which slide in channels in the enclosures.

Both large and small breakers have a test

position in which the secondary disconnects
are engaged, but the primary disconnects

engagement or engagement of the primary

are not. In this position, the breaker may
be operated electrically without energizing

the load cable or bus.

breaker movement that involves the dis
AK-75 and AK-100 breakers

ThsM jfufrvcNont do not putpori to coverall delaili or variatiofu in oquipment nor lo provido for every posvbfe

ceniingency (o be mot in connection with installation, operotion or mointenonee. Should further intbrniotren be desired
or theufd partiailarproblems aritt which ore not covered sufficientfy for the purchaser's purposes, the mottor shovid
be referred to-the Generof Etectn'e Company.

GEH-2021 Installation and Operation of Type AK Power Circuit Breakers

Use DS0H47 lubricant onthedlsconnect

terminals to reduce the force required to
insert the breaker.

secondary contacts are disengaged. Again
lift the position stop handle.
Slide the
breaker slightly forward to remove it from
Uie enclosure.

The procedure for inserting and with
drawing a

Withdrawing Breaker AK-50, 75 and 100
1.

Lift the breaker to a position ap

proximately six inches above the hei^t of
the compartment tray.
Inserting Breaker AK-15 and 25

2. Pull the drawout tray out under the
breaker as far as the tray will travel.
NOTE - When
installing
an individual

1. Trip the breaker.
2. Raise the breaker until the guides
on the sides of the breaker are level with

their mating supporting channels in the
enclosure, and slide the breaker part way
into its enclosure.

(Note - The breaker

will be obstructed by a position stop at the
bottom of the enclosure after the breaker

has traveled only a short distance into the
cubicle.

Lilt the position stop handle,

located at the bottom right of the enclosure,
which will release the position stop and
allow the breaker to travel further into the

and up as far as its travel will permit and
push the breaker into the enclosure until

the rackout pins on the handle assembly
bear against the housing rackout cams on
the side of the enclosing case.
4. Push downward on the rackout han

dle forcing the pins on the handle up into
the slot in the stationary cam plate. This
action forces the breaker through a final
short portion of its movement into the en

closure and allows the c^erator to provide
the force necessary to make the primary

disconnects engage the stationary studs in
the enclosure, inperformingthisoperation,
make sure that the handle Is rotated down

wards as far as its free travel will permit
and then pull the racking handle down to
be sure the trip interlock is released.

(Note - When the racking handle is in any
position other than completely down, the
breaker cannot be operated and is held

trip-free by the trip Interlock. This ap
plies to the "fully in" and "test" positions.)

1. Trip the breaker open. If the
breaker is not open, the interlock lever of
the drawout mechanism will not permit
(deration of the rackout handle.

2. Pull the racking handle up and for
ward as far as It will travel, disengaging
the primary disconnects.
3. Slide

position stop engages in the front slot in

the bottom of the breaker carriage.

breaker is now in the "test" position,

where its primary disconnects are s^ely
disconnected from the line and load ter

minals of the enclosure.

(Note - Refer to

section describing "Test Position" in these
Instructions.)
To

locate a bolt head over the two front bottom

mounting holes of the housing to provide a
limit stop for the drawout tray.

3. Lower the breaker about 1/2" above
the dowel pins on the tray and push the
breaker back into its compartment so that

the rear bottom angle of the breaker is
arainst the guides on the tray directly back
of the dowel pins.

4. Slowly lower the breaker onto the
tray and at the same time guide it so that
the holes in the rear angle of the breaker

the breaker is correctly positioned on the
dowels, its rear and side bottom frame
angles will all sit firmly on the tray.

5. Insert two 3/81nchhex.headscrews
through the holes in the front of the side
angles on the breaker and thread them part
way into the tapped holes in the tray. Do not

screws firmly^ This provides

better alignment of the primary stationary
studs and the primary disconnects for the
subsequent racking operation.
6. Push the breaker Into the compart
ment until the "lest" position stop engages

to prevent further travel. (Note - Refer to
sectton describing "Test Position" in these
instructions.)

7. Release the test position stop by
depressing its lever and push the breaker
back into the compartment until the racking
pins on the housing butt against the outer
surface of the racking cam. In this posi
tion, the racking pin us lifted the locking
arm on the cam which allows the racking
handle to be lifted enough to allow the pawl
to engage the first notch on the cam.

8. When the pawl engages the first

Withdrawing Breaker AK-15 and 25

skeleton housing for a drawout AK-50 or 75,

fit over the two dowel pins on the tray. If

3. Raise the rackout handle forward

enclosure, lift the position stop handle and
slide the breaker forward until the position

the 3/8 inch hex head screws inserted in the
front holes of the drawout tray during step
5 of this operation. The breaker is now in
the operating position.

Inserting Breaker AK-50. 75 and 100

drawout breaker from its en

closure is as follows;

cause the breaker to be trip free. Tighten

1. Trip the breaker to release the
positive racking interlock.
2. Lift the racking handle as far as It
will go.
This operation will re-engage the trip

Interlock to hold the breaker trip-free for
the remainder of the racking operation.

Note that here the cam ts rotated by lifting
the handle, whereas in racking the breaker
In, the operation is performer as a result

of pushing the handle down.
3.

position and lift it again.

must be performed 5 times to completely
disengage the cams from their racking
pins.

After the fifth lifting stroke let the

handle drop to Its normal position.
4. Pull the breaker out of its com

partment until the testposltlon stop engages
to hold the breaker In the "test" position.
5. Depress the test position stop han
dle and pull the breaker out of its com

partment as far as the drawout tray will
travel,

6. Remove the two 3/6 hex. head
screws which hold the breaker on the tray.
7. Attach a lifting device to the top
frame of the breaker.

8. Lift the breaker approximately 1/2
Inch off the dowel pins on the tray and
then pull the breaker forward until its

primary contacts clear the compartment.
9. Push the tray all the way back
into its compartment. The breaker Is now
free from its compartment.
TEST POSITION

Repeat this operation five times to rack the
breaker Into Its final Operating position.

The "Test Position", as referred to In
the previous instructions, is that breaker
position where the primary power discon
nect contacts are safely disengaged but the
secondary control disconnects are engaged.
In this position, the breaker may be tested

Interlocks hold the breaker trip free until

or operated, manually or electrically with

notch on the cam, push
handle down
again to its normal position. This causes

the cam to rotate about the racking pin.

It is racked Into the fully contacted position.

out energizing the primary power circuit,

The fifth stroke of the handle Is only a
partial stroke and does not result in any

provided the racking handle has been moved

further movement of the breaker. It does

leasing the trip interlock.

to the completely down position, thus re

serve three useful purposes; It positions the
cam so that it cannot rotate and allow the

breaker to back out under short circuit

stresses; the partial stroke signals that the
racking operation is complete, and it re
leases the trip Interlock which was engaged
by the racking pin during the previous four
pumps of the racking arm. NOTE; Once a
racking operation has been started, it must
be completed, as the breaker cannot be
reversed until the racking operation is
completed.

more complete description of

AKD DRAWOUT EQUIPMENT INSTRUC

TIONS, GEH-1830andAKD5DrawoulEqulpment Instructions GEH-83902.

DRAWOUT BREAKERS AKD5 EQUIPMENT

NOTE; AKD5 breakers are identified by
letter "A" appearing after breaker numberexample, "AK-2A-15".

stop engages the rear slot in the bottom of

9. After completing the fifth racking
stroke, lift the handle as high as it will go

the breaker carriage.

This is the safety

and allow It to drop to its normal position.

Drawout Mechanism Operation - There are

position stop where toth the primary and

NOTE: Any strokes beyond this point will

four positions of the drawout mechanism;

Installatton and Operation «1 Type AK Power Circuit Breakers

1. The Connected Position - the breaker in

the operating position, both primary and

secondary contacts made and the door
may be closed.

2. The Test Position - the primary (power)
contacts not made but the secondary

breaker test not involving power maybe
made in this position. The door may be
closed in this position.

: note:- TERMINAL BOARD LOCATED

ON RIGHT SIDE OF BREAKER FOR

AK-IS/ZS WITH EXTERNAL CONN 0 4 0

ECTIONS MADE TO RIGHT SIDE

3. Disconnect Position - neither the pri
mary nor the secondary contacts made.
The door may be closed.

FOR AK-90/7S/I00
BOARD LOCATED ON

LEFT SIDE WITH EXTERNAL

4. Fully Withdrawn Position - the breaker
completely out. of its compartment ready

CONNECTIONS MADE TO LEFT

for remold from the inner housing. The
door

must be open in this position.

TRIPPING
VOLTAGE
SOURCE

SOURCE FOR
UNDERVOLTAGE
TRIPPING
POTENTIAL

NOTE: The mechanism is designed to
reverse automatically in the connect
and fully disconnected position. Once

-CZ])—^(+)
TO la) CONTACT

an operation is started it must be com
pleted. Completion of an operation is
indicated by the red knob retracting to
its original position.

REVERSE
CURRENT DEVICE

Breaker Insertion AK-2A - With the inner
to
•H

housing in the connected position proceed

Open the housing door and roiate the
two track lock links, releasing the

Pull the red knob.

Pull the mechanism

operating handle fully out and allow ittb
return to its original position. Repeat
this three more times.

NOTE: When moving a breaker from
With a lifting device, raise the breaker
so the mounting pins are about one inch

2. Pull the red knob again. Pull the mecha
nism operating handle two complete
strokes drawing the inner housing to the
disconnect position.

one position to another be sure breaker
is tripped open.

above the tracks. Lower breaker so the

breaker mounting pins drop into the
slots in the tracks. Remove the lifting

6. Pull the red knob. Pull the mechanism

operating handle two times until ihe test
position is reached.

note:-WHEN SEPARATE
PWR. SOURCE FOR
CLOSING IS -

This is the fully with

The inner house

is now in the test position.

STA.SEC.
DfSCONNECTS

Pull the tracks out to the limit

of their travel.
drawn position.

5. Push the breaker in against the track
stops. Rotate the two lock links to
lock the breaker in place. Close the

NECT PWR,o-55.2o
10AI&A2
a.

a REMOTE TRIP a
^ct KXIHCHH

STA. SEC. DISCONNECTS
LOCATED AT TOP OF COMR
FURNISHED
ONLY WHEN
REQUIRED

sntils tsHsis
FURNISHED ONLY

Front Viev AK-15 and 25 Breaker CoBpartment

Front View AK-50, 75, 100 Breaker Compartment

Installation and Operation of Type AK Power Circuit Breakers

Pull the red knob a^ln and pull the
mechanism operating tiandle four times.

NOTE: The Installation of

100S/AKF2C/2D and breakers equipped

which applies to each breaker specifically.
Depending on the breaker type, those con

The breaker will now be completely

with the quick-closing mechanism is the

nections are made either to a

Inserted, in Its connected position.

same as the other breakers described In

board on the breaker or to the stationary
parts of the secondary disconnects.

this book. The only difference occurs with

drawout breakers. The compartments that

Breaker Removal AK-2A

house the quick-close breakers will be
equipped with an Interlock that prevents the
manual discharging of the closing springs
while the breaker is In the racked In (con

INDIVIDUALLY ENCLOSED AND
STATIONARY BREAKERS

Move the breaker and inner housing to

nected position).

for operation of breaker control components

Breaker Insertion, Steps 1, 2 and 3).

provided with t»th AKD and AKD5 equip
ment that require quick-close breakers.

1. Trip the breaker.
2.

fully withdrawn position,

This interlock will be

customers external connections

and accessories are

shown In Fig, 1.

DRAWOUT BREAKERS
3.

Attach lifting device and lift breaker up
and away from compartment until pri
mary disconnects clear the compart-

The customers external control con
nections to these breakers are made to

All electrical connections should be

made to assure good conductivity. Mating

the stationary secondary disconnected lo
cated in the breaker compartment as shown
in Figs. 2 and 3,AKDEquipmentandFlg8i 4

surfaces should be parallel and firmly
4.

tmlted or clamped together.

Move the Inner housing to the connected
position by pushing the tracks back

against the track stops and then follow

Steps 6 and 7 under Breaker Insertion.
The Inner housing Is now In the con

should be clean and have a

and S AKDS Equipment.

The bus or cable connecting to the
should

have adequate current-

pany, Drawout Switchgear Equipment, all

carrying capacity to prevent excessive
heating. Control circuit connections should
be made according to the wiring diagram

nected position and the breaker Is free

from its compartment.

breaker is used in a General Electric Com
external

terminal blocks located In the rear vertical

wiring trough of the equipment.)

OPERATION
AK-2-15/25 and AK-1-50 manually

In closing an AK-1-15/25/50 manual

operated breakers are closed by turning
the handle 90 degrees countercloclmlse

breaker on a load, make the handle move
ment with a fast, snapping action in order
to prevent unnecessary heating of the

AK-1-15 and AK-1-2S breakers are

closed by rotating the breaker handle in
a clockwise direction approximately 90
degrees. After tripping, the closing mecha

and then clockwise 90 degrees back to the

nism resets automatically by means of
springs.

nism. The clockwise movement closes the
breaker.

original position. The Initial counterclock
wise movement resets the closing mecha

SOURCE SOURCE
REMOTE
CLOSE

breaker contacts.

The closing mechanism of the AK-2-

50/76/100 manual breakers Is a spring

STA. SEC.
DISCONNECTS

STA. SEC. DISCONNECTS
LOCATED AT TOP OF COMR
A A A A A

FURNISHED
ONLY WHEN
REQUIRED

FURNISHED ONLY
WHEN REQUIRED

FR(3NT VIEW AK-IA-15,25 & AK-2A-I5^25
BREAKER

FRONT VIEW AK-2A-50,75,100
BREAKER

Installatioa and Operation of Type AK Power Circuit Breakers GEH-2021
charged mechanism similar to the oneused

on AK-50/75/100 electrically operate

breakers.
AK-2-50/7S/100
itianimi
breakers are closed by rotating the closing
handle cotmterclockwlse through approxi
mately 120 degrees, and then clockwise
back throng 120 degrees to the normal
handle position. Four such complete move
ments of the handle are required to close
.the breaker. During the four counterclock
wise movements and the first three clo^wise movements of the handle, the rorings
are charged. After approximately 70 de
grees travel of the fourth clockwise handle

REMOTv3Zr^«2
CLOSE r^,-

XctOStKO I
TSWITCM I

movement, the spring charged mechanism
is driven over-center and the breaker

closes. A charge-indicator, numbered 1 to
4, viewed through the breaker front

(5) • CLOaiNO MOTOR

JS,. X RELAY COL

with each complete

• X REL/nf CONTACT

handle movement and indicates the number
of complete handle movements that have
been performed.

• RELAY CONTACT

TOO • MECHANICALLY CRERATEO SWITCHES

y • YRELAY CONTACT

4 • NORMALLY OPEN SWITOR CONTACTS

ijl • NORMALLY CLOSEO SWITCH CONTACTS

«4-W • HECMANICALLY OPERATEO SWTTCHES

•i' • NORMALLY OPEN SWITCH OCNTAOIS

L - AUXIUARY SWITCH CONTAa

# • NORMALLY ObOSEO SWITCH CONTACTS

ELECTRICAL CLOSING

(Figures 6 and 7)
STANDARD BREAKERS

AK-15 and AK-2S electrically operated
breakers are closed by a solenoid coil. The

Simplified Elementary Diagram

Internal Wiring M-15 and S5

Fig. 7
Simplified Elementary Diagram
Internal Wiring AK-50, 75 and 100

armature of the solenoid is linked to the

breaker mechanism and its movement,
operating through the mechanism, closes

the breaiker. ITie closing solenoid circuit

may be operated by a push button closing
switch on the breaker or by a remote
switch or relay, depending on the individual
arrangements desired. When a closing
signal is given, the X relay coil is ener
gized and it in turn closes its contacts. One

the control relay from beingenergized until

the breaker is tripped open. With the G
switches closed, the motor charges the

QUICK CLOSE BREAKERS

closing springs ready for the next closing
operation.

Functionally, the quick close mecha
nism differs from ihe standard electrical

MANUAL OR MAINTENANCE CLOSING
OF ELECTRICAL BREAKERS

energize the solenoid closing coU. As the
breaker closes, a mechanically operated

mechanism in that the pre-charge operation
is extended to completely charge the closing
springs. At the end of the charging opera

All electrical breakers may be closed
manually by means of the maintenance

switch opens one pair of its contacts (bb)

and closes another (an). The contacts
which open cut out the X relay coU. The

contacts which close energize the Y relay
coil, whose contacts now seal in the Y coil
and hold open the X relay coil circuit. This
prevents another closing operation U one

of the protective devices operates to trip
the breaker before contact at the closing
switch is released.

Large AK breakers (AK-SO/75/100)
are closed by the discharge of a closing
spring. This rotates a crankshaft which,
by means of an attached roller, operates

a closing cam, forcing the movablebrewer

contacts against the stationary contacts.

The closing spring is charged throiigh the

Iteration of a motor and gear reduction
unit.

The electrical control system is com

tion, which takes approximately 5 seconds,
a latch plate engages the prop roller to
charging.

To close AK-l-lS/25 breakers:

With the closing springs fully charged

the breaker is ready for a closing operation
upon release of the prop roller. This may
be accomplished either manually, by de

pressing the closing lever on the breaker,
or electrically by closing the remote clos

ing switch. Upon the release of the prop
roller the closing springs discharge and
close the breaker in the same manner as
on the standard electrical breaker.

With control voltage applied, the motor
is energized through the G switch contacts,
and charges the closing springs. When the
springs reach the fully charged position,
the mechanically (derated switches operate,
reversing their contacts.

a push button closing switch and any means

of the F switch prepares the broker for
a closing operation.

closing signal is given) the motor is ener
gized through two of the X relay contacts
and the two G switch contacts. The motor

then compresses the closing springs to the

"pre-charged" position at which point the
mechanically operated F and G switches

the opening of the G switch.

2. Place the handles fork like fingers above
the armatures stop nut that extends
below the magnet behind the front
escutcheon and lift up. This forces the
armature down closing the breaker's
contacts.

The closing
e supporting structure
should be rigid enough to avoid any possi

board should be made if and as required.
(See CONNECTIONS).

breaker itself.

than if the opposites to these conditions
exist.

The second consideration is con

7. Before energizing the power circuit,
operate the breaker several times to be

venience for operation and maintenance.
The breaker should be easily accessible to

bility of the breaker studs supporting the
weight of the breaker. Minimum cutout

the operator, and there should be sufficient
space allowed for maintenance work to be
done if this becomes necessary.

dimensions, as given by the appropriate
outline drawing, must be maintained to
provide adequate electrical clearance.

Individually Enclosed Breakers

Mounting drawout breakers consists of
simply placing the breaker in the proper
position with respect to its enclosure, slid
ing or rolling it to a stop position, and, by
means of a racking handie and mechanism,

AK Air Circuit Breakers are design

ed to be mounted in any one of three
ways.
These are dead front mounting,
individual mounting with the enclosure being
provided, and drawout mounting in which the
breaker is designed for insertion into a
cubicle in drawout equipment such as a
substation or control bmrd.

supplied with several types of enclosures,

most commonly with the general purpose
type or the weather resistant type. The
former is used for favorable indoor loca
tions and the latter for outdoor locations

or indoor locations that may be subject to
unfavorable

closures are provided with suitabie means
for mounting on floors, wails or supporting
framework. Removabie cover piates are
supplied with the enclosures which may be

Dead Front Breakers

These breakers are designed for
mounting in a switchboard or enclosingcase
of the customer's design and construction.
Mounting in this instance consists of bolting

drilled or machined to accommodate the

entrance of bus ducts, conduits or cables.
Steps in the procedure for installing en
closed breakers follow:

the breaker frame to a supporting structure
within the switchboard or enclosure, con
necting the power buses or cables, and

1. If the breaker is an AK-IS, AK-25
or an AK-SO, remove it from the enclosure.

making whatever control connections are
necessary. The front cover of the breaker

With AK-50 breakers, a handle and cam
arrangement is used for that part of the

enclosure may be a hinged door or a plate
bolted to the panel. In either case, it should
have a section cut out, through which the

front escutcheon of the breaker may pro
trude. Outline drawings giving the dimen
sions

breaker movement that involves the dis

Outline Drawing No.

AK-l-IS
AK-1-2S

AK-1-50 man. oper.
AK-1-50 elec. oper.
AK-1-75
AK-1-100

2S6C7S3
2S6C7S4
248C703
238C123
238C192
238C193

racking it through the last part of its move

ment during which the stationary and
movable halves of the disconnects engage.
Large drawout breakers are fastened to a
telescoping tray which extends out from the
enclosure to receive the breaker.

which slide in channels in the enciosures.

Both large and small breakers have a test

position in which the secondary disconnects
are engaged, but the primary disconnects
are not. In this position, the breaker may
be operated electrically without energizing
the load chble or bus.

For a more complete description of
drawout mechanisms and enclosures see

DRAWOUT EQUIPMENT INSTRUCTIONS,
GEH-I830.

AK-75 and AK-100 breakers

and need not be removed from the enclosure.

CONNECTIONS: Figure 1

2. Remove cover plates of enclosure
and prepare them to accommodate what
ever power entrance means is used.

4. Replace cover plates and make
power connections to stationary terminals
in. enclosure.

5. If enclosure is of a type that makes
use of secondary disconnects, make control

All electrical connections should be

made with a view toward good conductivity.
Mating surfaces should be parallel and

firmly bolted or clamped together.

necting to the breaker should have adequate
current-carrying capacity to prevent ex

cessive heating. Control circuit connections
should be made according to the wiring

diagram which applies to each breaker
specifically.
Depending on the breaker
type, these connections are made either to
a terminal board on the breaker or to the

stationary parts of secondary disconnects.

be melm connection with inttaUafion, operotion or moinfenonce. Stioufd furiher information be desired

orthowd pariimtar probhtns arise which are nof covered suffkimtfy far the purcboser'c purposes, the matter should
be referred la the General Electric Company.

tact surfaces should be clean and have a
smooth finish.
The bus or cable con

Thaie instrvciioM donof pvfpoH lo cover atl defaiU or varialicns in otjurpmenf nor fo provide for every pesiib/e

breakers have guides on their side piates

engagement or engagement of the primary

3. Mount enclosing case to supporting
Breaker

Drawout Breakers

are bolted solidly to the enclosure frame

preparing a suitable

enclosure or cubicle for the various types
of AK breakers are given below. These are
for standard 2 or 3 pole breakers.

sure that it is functioning properly. (See

Installation and Operation of Type AK Air Circuit Breakers
TERMINAL

CIRCUIT BREAKER
FRONT ESCUTCHEON

EXTERNAL
o lOh^;
:^CLOSE SW.

tripping device,

applied between 6 and 9. If the breaker is
FOR

If the breaker has an undervoltage
the voltage for this is

DC breaker and has a reverse current

device, DC voltage is applied between ter

minal 10 and the "a" contact of the second

stage from the right of the auxiliary switch.

<1—n—•-(+)
TO (a) CONTACT

breakers, external control connections are
made to a vertical 10 point terminal board
on stationary dead front and Individualiy
enclosed breakers. Numbering the points
from 1 to 10, from the top to the bottom,
connections are made as follows: Closing
voltage is applied between 3 and 4; tripping
voltage between 6 and 7. An external clos
ing switch may be connected between 1 and

The negative lead is connected to terminal
post 10. If the breaker is a small AK type

(AK-15/25), the terminal board is on the

right side of the breaker and connections

are made to the right side of the t)oard.
Exactly the reverse of this is true if the
breaker is a large AKtype(AK-50/7S/I00).

EXTERNAL CONNECTIONS FOR OPERATION
OF BREAKER CONTROL COMPONENTS AND ACCESSORIES
Figure I

"^'AK-l-lS and AK-1-25 Breakers are
ed by rotating the breaker handle in a
L..jclcwise direction approximately 90
legirees from its normal vertical position.
Mter tripping, the closing mechanism re-

-2-15/25 and AK-50 manually operated

. eakers are closed by turning the handle
to the original position, again throughabout

The initial counterclockwise

In closing an AK-l-lS/25/50 manual

ELECTRICAL CLOSING: Figures 2Aand2b
AK-IS and AK-25 electrically operated
tireakers are closed when a closing solenoid
coil is energized.
The magnetic force
generated by the solenoid moves an armaEure into the solenoid coil. The armature

movement resets the closing mechanism.

lireaker on a load, it is desirable to make
the handle movement with a reasonably
East, snapping action in order to prevent
unnecessary heating of the breaker contacts.

~^s automatically by means of springs.

Eounterclockwise and tlien clockwise back

Jl. • X RELAY COL

W • X RELAY CONTACT

y • Y RELAY CONTACT
• MECHANICALLY OPERATED SWITCHES

sj" • normally open SWITCH CONTACTS

• RELAY COIL
• RELAY CONTACT

FSG • MECHANICALLY OPERATED SWITCHES

t • NORMALLY OPEN SWITCH CONTACTS
f mnormally CLOSED SWITCH CONTACTS

# • NORMALLY CLOSED SWITCH CONTACTS
SIMPLIFIED ELEMENTARY DIAGRAM

INTERNAL WIRING AK-I-I9AND25

SIMPLIFIED ELEMENTARY DIAGRAM

INTERNAL WIRING AK-l-50,75, AND 100

Is linked to the breaker mechanism and its

movement, operating through the mecha
nism, closes the movable contacts against
the stationary contacts of the breaker. The
closing solenoid circuit may be closed by a
push button closing switch on the breaker
nr by a remote switch or relay, depending
nn the individual arrangements desired.

When a closing signal is ^ven, the X relay
coil is energized and it in turn closes its
[our sets of contacts.

solenoid closingcoil. As the breaker closes,
cechanicaiiy operated switch opens one
.r of its contacts (bb) and closes another

The contacts which open cut out the

now seal in the Y coll and hold open the
X relay coil circuit. This prevents another
closing operation if one of the protective
devices operates to trip the breaker before
contact at the closing switch is released.

The electrical control system is com
prised of an X relay, two double contact
mechanically operated switches (F and G),
a push button closing switch and any means
for remote closing which the user may
incorporate into the system. When voltage

Large AK breakers (AK-50/75/100) are
closed by the discharge of a closing spring.
This rotates a crankshaft which, by means
of an attached roller, operates a closing
cam, forcing the movable breaker contacts
against the stationary contacts. The closing
spring is charged through tlie operation of

Is first applied to the breaker, (before any
closing signal is given) the motor is ener
gized through two of the X relay contacts
and the two G switch contacts. The motor

a motor and gear reduction unit.

One of these seals

In the X coll circuit; the other three, which
ire

The contacts which close

^rglze the Y relay coil, whose contacts

then compresses the closing springs to the,
"pre-charged" position at which point the '

mechanicaliy operated F and G switches.,,

Installation and Operation of Type AK Air Circuit Breakers

This (q)ens the C contacts, stopping the
motor, and closes the F contacts, which
rdadies'mrs system for the actual closing
( the breaker. When the push button or
smote switch signals for a closing opera-

uon, the X relay coil Is energized, operating

the X contacts. This seals In the X relay
and energizes the motor once again and the

'^losing operation takes place.
•gain

operates the F and G switches so

(heir contacts again assume their original
position and the motor continues to run

until the "pre-charged" position Is reached.
TBIPPING

The breaker is tripped open by the dis

placement of a mechanism latch, which
allows a toggle linkage supporting the mov
able contacts in the closed position to
collapse. This trip latch Is fastened rigidly
to a trip shaft which runs horizontally from
left to right through the breaker. All of the
means provided for tripping the breaker
operate through striker arms which displace

the mechanism trip latch by movlngagalnst

trip paddles fastened on Ihe trip shaft.
Looking at the breaker from the right,
counterclockwise rotation of the trip shaft
causes the breaker to trip; clockwise
movement resets the mechanism latch. The

manual trip button, overload devices, shunt

trip, undervoltage tripping device, and re
verse current trip all operate In this fashion
to trip the breaker. The movement of the

striker arms of all of these, when activated,
should have at least a perceptible amount
of movement beyond the point at which
tripping occurs. This Is what Is meant by
the expression, "positive tripping".
Most air circuit breakers are equipped
with series overcurrent trip devices either

of the dual magnetic type (Instantaneous
and time delay tripping) or Instantaneous

Breakers are designed to carry up

to 100% of the continuous current rating of
Any attempt to carry

their trip devices.

These instructions have as their pur
pose the imparting of Information of a
general nature concerning the installation
and operation of type AK air circuit

breakers. If more complete and specific
Information is required, such as might be
needed for overhauling the breaker, trouble
shooting, or replacing parts of the breaker.

coll rating. To get best protection and to
avoid nuisance tripping from a fluctuating
load, It Is generally recommended that the

pickup be set at 125% of the actual steady
state load current. For example, a breaker
rated at 1200 amperes continuous current
with a 1000 ampere load should have Its
trip device set to pick w at 1250 amperes.

(Slightly above the 100% calibration mark
on the trip scale plate of the device).
For a more detailed discussion of the

construction, operation, and application of
overcurrent trip devices refer to the follow
ing publications:

1. Instruction Bock (or specific
breaker Involved (see "Maintenance").
2. "Selection and Application of Air

higher currents for a prolonged period will
cause overheating and possible damage.

Circuit Breakers" CET-1113.

Breakers are usually shipped with the
pickups of the trip devices set at 100% of

3. "Overcurrent Trip Device - Type

GEl-50216. This applies only to

trip devices on AK-15/25/50 breakers.

refer to the complete Instruction for the
particular breaker type Involved.

Renewal parts bulletins for the various
types of breakers are:

GEH-1824
GEH-1807
GEH-1799
GEH-1798

Br^er T^e
AK-1-15
AK-1-15
AK-1-50
AK-1-50

or 25 man. oper.
or 25 elec. oper.
man. oper.
elec. oper.

GEH-1831
GEH-1832

AKF-IB man. oper.
AKF-IB elec. pper.

GEH-50210
GEH-50212

GEl-50299
GEl - 57077

AK-2-15/2S
AK-2-75/100

AK-1-15/25 and AKF-IB

•/ ;v Sil' .;•• ^ •

GEH>l6i4.'. ; .:-X

GENERAL^ ELECTRIC
PHILADELI^HIA, PA.

'• '••,• •;•

••• I 'M-

PAGs;^;^|
INTRODUCTION.•••;••
5iV

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••••••••♦•••••••«•••••♦•••9
••••••♦•••••••

m-x:-/; :• ^v'- •.:

BASIC BREAKER COMPONENTS .
ARC QUENCHER

POLE UNIT ASSEMBLY
AiDOLttBY SWITCH

OPERATING MECHANISM.

«
* • * ** * **A

******"* 'I
:;;;: *:;: u

! I I I! *! *****I ****f

PROACTIVE DEVICES

TIME-DELAY UNDERVOLTAGE DEVICE
!!!!!!
' ****12
INSTANTANEOUS UNDERVOLTAGE TRIPPING DEVICE ..... . . . ! *M. . **' ' V{2
OVERCURRENT TRIPPING DEVICES
7. .
' " *" * is

REVERSE CURRENT TRIPPING DEVICE.i I!! .* .*; I];;;; I*:;}?

BREAKER accessories ... . .

^^A^SI^^^ifLoa^uTj:^^
.* **.' *!
MI! III1111 **" **
^fflJjg^AKER;
..
....... I. IIII11 II I1111

. . .19
. . . 19

. , . 19
:«'• • 20 .

. . . 21
> . • 21

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TYPES AK-1-15-3 TO 10 AND AKa-25-3 TO 10
MANUALLY OPERATED
INTRODUCTION
The instructions contained herein provide in
formation for performing maintenance procedures
and for replacing AK-1-15/25 breaker components
and accessories. For information regarding the
receiving, handling, storage and installation of these

breakers, refer to GEH-2021A, furnished with all
AK breakers.

The AK-1-15 and AK-1-25 breakers differ, in

that, the AK-1-25 has an extra contact per pole with
corresponding differences in the upper stud and
interrupter.

improvements and new

features were added, the suffix digit of the breaker
type number was progressively increased.

these models are essentially the same breaker, as

changes were mainly of a minor nature. These are

tabulated below:

AK-1-15/25-6 Stationary primary disconnects and
cable clamp redesigned. (Only en
closed breakers aSected).

AK-1-15/25-7 New type of front escutcheon and
closing handle.

Trip button relo

cated on escutcheon and reset lever

for bell alarm and lockout device
changed.

AK-1-15/25-8 EC-2 overcurrent device used in
stead of the EC-1 device except on
units requiring short-time delay

AK-1-15/25-9 New drawout frame introduced.
NOTE: SuHix digit number changes which do not

1. Arc Quencher
2. Clanp

6. Operating Handle

6. Position Indicator

9. Front Escutcheon

5. Series Overcurrent Device 10. Grounding Strap

appear above do not apply to manual breakers.

Oblique Left View of AK-1-25 Breaker

OPERATION
The breaker may be closed manually byrotating

^tton (7), or automatically by any of the tripping
Mvices with which the breaker may be equipped.

tion. After the breaker closes the operating handle

breaker trips, however, the breaker Is "trip-free"

MANUAL me operating handle (6) 90

FIG. 1
in the clockwise direc

^ returned to its normal position by a springforce.
This breaker may be tripped manually by the trip

mechanism is automatically reset when toe

from the closing mechanism which assures that it
cannot be closed as long as any tripping device is
fxmctionlng.

MAINTENANCE
INSPECTION
INSPECTION OR ANY MAINTENANCE

WORK IS DONE, BE SURE THAT THE BREAKER IS

m THE OPEN POSITION.

POWER, BOTH PRIMARY ANDC0NTR0LS0URCE8.

SHOULD ALSO BE DISCONNECTED.

yariotion, in squ/pmenf ner fo prwid% fc evsrv domAu'
' V'

%BI-74602 Power Circuit Breakers Type AK-l-lS-S To 10And AK-1-25-3 To 10
Periodic inspection of the circuit breaker is

recommended at least once a year. More frequent

inspections are recommended, if severe load condi
tions, dust, moisture, or other unfavorable conditions
exist.

If the breaker remains open or closed for a

long period of time, it is recommendedthatarrangemente be made to open and close it several times in
succession, preferably under load.

At all times it is important not to permit pencil

lines, paint, oil or other foreign materials to remain
on the insulating surfaces of the breaker as they may
cause low resistance between points of different

potential and result in eventual electrical breakdown.
Always inspect the breaker after a short circuit
current has been interrupted.

At the time of periodic inspection, the following

Ratchet Socket Wrench 1/2" Drive

7/16"
1/2" Drive Socket
9/16"
1/2" Drive Socket
5/8"
1/2" Drive Socket
3/4"
1/2" Drive Socket
13/16"
1/2" Drive Socket
15/16"
1/2" Drive Socket
10"
Extension Bar 1/2" Drive
6"
Extension Bar 1/2" Drive
8"

Adjustable End Wrench

5/16" (Blue Point) Open End Wrench

1/2" 5/8" 3/8" 11/32" -

9/16" Open End Wrench
3/4" Open End Wrench
7/16" Open End Wrench
5/16" Open End Wrench

1/16"
5/64"
3/32"

Allen Head Wrench for #6 Screw
Allen Head Wrench for #8 Screw
Allen Head Wrench for #10 Screw

checks should be made after the breaker has been

Allen Head Wrench for 1/4" Screw
Straight Shank Allen Head Wrench for 3/8"
screw, with adapter for 1/2" drive ratchet

1. Manually operate the breaker several times,
check for obstructions or excessive friction.

2. Arc
quencher
Quencher").

3. Contact condition, wipe, and pressure (See
Section on "Pole Unit Assembly").
4. Latch engagement (See Adjustments under
"Operating Mechanism").
5. Overcurrent device tripping (See Adjust
ments under "Series Overcurrent Tripping
Device").

Ball peen hammer

6 point open box wrench

NOTE: Obtain from local hardware, do not order on
General Electric Company.
LUBRICATION

The tools listed below will adequately equip an

In general, the circuit breaker requires moder
Bearing points and latch surfaces
should be lubricated at the regular inspection
periods with a thin film of extreme temperature,
high-pressure, light grease similar to G. E. Spec.
No. D50H15. Hardened grease and dirt should be

operator for any maintenance operation on all Type

ate lubrication.

^-1-15 and 25 Breakers:
#1
#2

PhiUipa Screw Driver
Phillips Screw Driver with 8" shaft

Phillips Screw Driver

removed from latch and bearing surfaces by using

KlOl-1/2 Crescent (Short) Screw Driver

ALL EXCESS LUBRICANT SHOULD BE
REMOVED WITH A CLEAN CLOTH IN ORDER TO
AVOID ANY ACCUMULATION OF DIRT OR DUST.

K505-1/2 Crescent (Long Thin) Screw Driver
K306 Crescent (Standard) Screw Driver
H-28 8" Gas Pliers

At each maintenance period, all silver to silver

654 Pointed Nose Side Cutting 6" Pliers
#2 Waldes Truarc Pliers Straight
#2 Waldes Truarc Pliers 90° Angle

friction points, such as primary disconnects, should
be cleaned and given a fresh coat of G. E. Spec, No.
D50H47 lubricant.
TBOUBLB aHoonwo

THOUB'"
OrtrheaUog

Ceotaets oot allptmL
CoiActa dlrK, (r«UT or coated wllli dark tUsu

Clean eurlacte of eurrenl carrying parts.

Currant In axceta cd breaker rating.

Decrease ica£ rearrange cireuil or

Replace ccelacta.

Tighten, but do not exceed elastic limit ol

boils or liUlngs.

tostaU larger breaker.

Czceealrt amblmt temperature.

Provide adequate ventilation.

poeltive releaee m tripptng latch.

Worn or dama^ trip onll parta.

Blnde in overcurrent device.

Ra-ad]ut or repiaco trip unit.
Replace trip unit.
Replace overcurrenl device.

Overcurrent pick.igi too low.

Change ad]uataenl or repiaco with

Overeurreot time-eetting too ehort.

Change atHusimenl or replace with

Blod In overcurrent device.

Replace device.

Chipped or worn latch.'
lAten out

^icb return epring too weakor broken.

Hardened or gummy Sobrtcant on baarlu and

latch suifacee.

higher rated device.
higher rated device.

Failure
Failure to
to Clooe
Cloea BMing in nttachmente preventing renetting ol iiteh.

and lAteh
•"I

Clean contacte.

Coetaeta badljr burned or pitted.
Current carrrtag surlncee dirty.
Bolte and ooU at terminal eoBoeellco not Ugbt.

Pallnre to Trip. Travel ot tripping device does not provide

Adluet cootacte.

Re-allpi and adjuit allachments.

Replace apring.
Clean bearing and fattoh •uriacaa.

1. Pole Iftiit Bate
2. Ifciffler

3. Inside Barrier

4. Outside Barrier

5> Front Cbp
6. Clamp
7. Strep

•b ; ' , B •' .
' > •.

Power Circuit Breakers Type AK-1-15-3 To 10 And AK-1-25-3 To 10

ARC QUENCHER - FIG. 2
Each arc quencher has several compound inside

barriers (3) containing a large number of per
forations and two

outside barriers (4) without

perorations, as well as a front cap (5) and a rear
support (24) held in place by a fiber strap (23).
mm A clamp (6) is attached to the breaker base by two
bolts. Clamp (6) holds all the arc quencher assem

blies to their ,respective pole units. A muffler (2) is
located on top of the compound barriers. The com
barriers and the muffler, together with the
^V> : pound
slots between the barriers, serve to extinguish the
arc.

COiWPONENTS
stationary contacts are pushed to the rear Iqr tte

movable contacts (see "Measuring Contact Wipe"), , m

must result during the closing operation. Both
contact pressure and contact wipe should be checked
at the regular inspection period.
MEASURING CONTACT PRESSURE - FIG. 3
1.

With the breaker closed, place a push-type:

contact tip (3).
Exert pressure against the push-type scale

scale against the upper front of the staUonai*y

until the contacts just part. When the con-;
tacts first part the scale should read between

If the barriers are

1. Remove clamp (6) by removing two bolts.
Unclasp fiber strap (23).
,
Remove front cap (5), muffler (2), outside
barriers (4), inside barriers (3) and rear
support (24).

indicated, see /'Adjusting Contact Wipe and

4 to 6 pounds. E the proper pressure is not

cracked or eroded to one-half their original thick
ness, they should be replaced.
REPLACEB4ENT, Fia 2

X. Remove arc quencher (see "Replacements"
under Arc Quencher).
2. Measure the dimension between the inside

surface of the pole base and the top edge of

Install hew or disassembled parts in reverse

tohard the top of the pole unit so tlmt that the

clearance in the rear supportiwill accommodate the

screwhead of the back plate.

POLE UNIT ASSEMBLY - FIG. 3

the stationary contact tip (3), (a) with the
breaker open, (b) with the breaker closed.
3. The difference between these two measure

ments should be approximately 7/32".
4. Re-assemble parts in reverse order.

ADJUSTING CONTACT'WIPE AND CONTACT
PRESSURE - FIG. 3
1.

The contact assembly of each pole unit consists

^ a stationary and a movable contact sub-assembly.
?

The stationary contact assembly consists of

parallel contact fingers (3) with silver alloy tips, the

:^pcr stud (20) and pins (4) with compression springs

' (19) which provide conttouous contact pressure
between the contact fingers and the upper stud (20).

A shunt (21) is used to prevent pitting at the pivot
point of the stationary fingers when carrying high

momentary currents. The stationary contactfingers
. are held in place by the vqpper stud cap (6).
The movable contact assembly ; consists of
parallel contact arms (5) with silver Ialloy tips, a

contact carrier (18) with a spring (17) which pro

vides continuous contact between the Icontact arms

Ana^pin (15). A clamp (14) secures pin (15) to the
contact support (16). A flexible connection (12) is
provided to prevent pitting at; the pivot point of the
movable contact arms when carrying high momen
tary currents.

assembly is connected to

; wt^rating
5^^ shaftthe
(16),
Fig, 2,when
by antheinsulating
link (7)
contacts
breaker closes.
contactpressure (see Measuring

be; exerted by the movable
c^tacte ,agai^ the statiohaxy
contacts. Adefinite

Remove arc quenchers (see "Replacements":
under Arc Quencher).

2.
S..' >•'" •"

Re-assemble parts in. reverse order.

MEASURING CONTACT WIPE - FIG. 3

' NOTE: In re-hssembling the rear support (24)
to Uie breaker, be stire and push the rear support

Remove arc quencher (see "Replacements"
under Arc Quencher).

The .arc quenchers should be inspected at the
regular inspection period.

amount of contact wipe, or the distance that the

Remove tru-arc retaining ring from main
shaft (16), Fig. 2, nearest the insulating
link and contact assembly to be adjusted.'
Loosen clamp (9) which secures eccentric
bushing (8).
Turn me eccentric bushing in the insulating

link (7) thereby moving the insulating, link

closer or farther away from the stationary
contacts, as required to obtain proper wipe;
5. Re-assemble parts in the reverse order
after making proper adjustments.
NOTE: To adjust the insulating linkin the center

pole unit, first, push,the;maiin shaft throughthe ri^t
hand insulating link and into the center lihk as

described in items 2 and 3 above. .Opening spring
and cap will drop out. Adjust center insulating liiS

as described in item 4 above. Reassemble parts in, mm

reverse order being careful to replace opening' •V
spring and cap in their proper position.

If any of the contacts are badly corroded or
pitted, thereby, making it impossible to adjust for
proper contact; pressure or wipe, such stationary
contacts and/or movable contact assemblies should
be replaced. A commonly used "rule nf Anmh*-' is
that contact replacement is indicafed if less than
one-half the original thickness ,(apprbx. 1/8 inch) (d
the contact tip material remins.kSee "Replhce
ments" below.

OBI-74602 Power Circuit Breakers Type AK-1-15-3 To 10 And AK-1-25-3 To 10
If the proper contact pressure does not exist
when the wipe is within its limits, the stationary
contact springs must be replaced.
REPLACEMENTS
Movable Contact Assembly, Fig. 3

1. Remove front escutcheon (see "Replace

ments" under Operating Mechanism).
2. Disconnect external wiring to the terminal
board and auxiliary switch.
3. Remove arc quenchers (see "Replacements"

under Arc Quenchers).
4. Remove tru-arc washer from one end of the

main shaft and push main shaft through
insulating link (7).
5. Remove four mounting bolts (26), Fig. 5 and
lift entire operating mechanism from
breaker.

6. Remove four screws which attach braid (12)
to the movable contact arms.

7. Remove two screws and clamp (14).
8. Remove the movable contact assembly.
9. Remove the Insulating link from the old
movable contact assembly and re-assemble
this same link to the new movable contact

10. Remove braid (12) from new movable con
tact assembly.

11. Install new movable contact assembly and
replace clamp (14).
12. Remove screw from left hand coil terminal.
13. Remove old braid.

14. Install new braid by re-assembling coil ter
minal screw and four screws in the movable

contact assembly.

15. Replace parts in reverse order.

16. Adjust contact wipe and contact pressure
(see above).

1. Position Indicator

7. Operating Handle

2. Retaining Ring
3. Trip Button

4. Spring
5. Trip Rod
d. Nameplete

Front Escutcheon and Operating Handle
Assembly

Stationary Contact - Fig. 3

1. Remove arc quencher (see "Replacements"
under Arc Quencher).

2. Remove upper stud cap (6) by removing two
holding screws.

3. Pry the stationary contact (3) from upper
stud (20).
4. Replace the new stationary contact in re
verse order. (It may be necessary to tap
the new stationary contact into place by

a. A pistol grip operating handle (7) attached
to one end of the shaft (10) which extends
throurt the front escutcheon.

end 01 the shaft has a roller (8) attached to it..
b. A trip rod (5) which extends to the front
escutcheon and which has a trip button (3)
mounted to it.

using a rawhide mallet).

The breaker may be locked in the tripped posi
tion by depressing the trip button (3) and inserting a

padlock through the slot in the side of the front

5. Adjust contact wipe and contact pressure
OPERATING

The breaker closing mechanism consists of a

front escutcheon and operating handle assembly and
an operating mechanism. The combination of these

^0 assemblies serve to close the breaker bymeans
of an operating handle.

FRONT ESCUTCHEON ASSEMBLY - FIG. 4
The front escutcheon is mounted on front of the

aerating mechanism framebyfour screws (9) Fig.2.

9. Trip Paddle
10. Shaft

®®?'iicheon and operating handle assembly

BREAKER OPERATING MECHANISM - FIG. 5

The operating mechanism is simported between

two molded side frames in front of the center pole

unit. It consists of a toggle linkage (17), cam (11),
crank (10), latch (13), trip shaft (14),androUer (12).

The breaker is closed by rotating the operating

handle 90° clockwise causi^ roller (5) to engngp
cam (11), thereby strai^tening the toggle linkage,

which closes the breaker. The breaker is held in the

closed position by prop (19) resting against pin (16)
and by latch (13) against roller (12).

Power Circuit Breakers Type AK-1-15-3 To 10 And AK-1-2S-3 To 10 GEI-74602
TOe brewer mechanism is tripped Iw rotating
trip sh^t (14), and releasing trip latch (13) which

causes the toggle linkage to boUapse, thereby allow
ing the opening springs (21) to push the main shaft
aM movable contacts forward to the open position.
Trip latch (13) is automatically reset during the
caning operation providing none of the trip devices
are actuated. Latch adjusttng screw (28) limits the
CQtation of the trip sluut (14) and tous determines
me amount of latch engagement.

ADJUSTMENTS, FIG. 5

There should be 5/64" engagement between the
latch (13) and roller (12). To obtain the atHustment
proceed as follows:
1. Loosen

nut on -adjusting ;
-•.a;
v'.JV.

p.". -r •.' '

0
V-'' ie; V
1. Screw

2. Cam Return ^rln^
3i Handle

4^ Hold In Post

6. Adjusting Screw

7. Cam Supporf
8. Cam Support Pin
9. Crank Pivot Pin
10. Crank

. 11. Cam
12. Roller

13.
14.
15.
16.

Trip Latch
Trip Shaft
Tapered Insert
Toggle Link Pin

17.
18.
19.
20.

Toggle Links
Spring
Prop
Cap

21. Opening Spring
22. Main Shaft

23. Uechanism Frame '
24. Prop Pin

25. Prop Return Spring

26. Mounting Bolts
27. Buffer PaddlA

28. Latch Adjusting Screw
29i Trip Siaft Return
Spring
•

Operating Mechanism (Breaker Closed)

;^^w?4602 Power Circuit Breakers Type AK-1-15-8
2.

To 10 And AK-1-25-3 To 10
a-

hold the breaker contacts in a

position in which the movable contacts are
Just touching the stationary contacts.
Turn down attesting screw (28) until the
breaker trips open. Normally the force

required to rotate the trip shaft is small

eno^h so that the spring on the buffer
paddle (27) is not noticeably deflected. If

any deflection is observed while turning
down the screw, back off screw until spring
returns, then turn down screw again, u
deflection persists, check trip shaftfor binds.

4. Mark position of adjusting screw head when

2. Movable Indicator

Si Mechanism Fraaittv|i|pj|

5. Repeat steps 2 and 3 and check position of

adjusting screw in relation to marked posi
tion.
6.

1. Statimiary Indicator
(Open)

If acQusting screw is in the same position as
it was in the first tripping, back off the ad-

Justing. screw (28) three complete turns and

tij^ten locknut If it is not, rraeat steps 2

and 3 until a constant position of the acjjusting screw is determined before backing off
three turns and locking.
Tkis check is
necessary to avoid a false setting due to
accidental tripping.
7. Latch adjustment should now be correct.

Operate breaker several times to assure
that the mechanism is functioning properly.

; The clearance between .the latch (13) and roller

(12) should be between 1/32'? to 1/16" when the

breaker is open, in order to allow the mechanism
to reset automatically when the breaker opens, and
at the same time, provide the necessary overtravel

for prop (19) to move on toggle link pin (16). R not
enough clearance is provided the niechanism will not
reset. R too much clearance is provided, prop (19).

will not move on pin (16). Thisat^ustmeht us obtained
by turning the Allen Head adjusting screw (6).

Position Indicator With Auxltlhry Switch

Reset Spring (18)

1. Remove operating mechanism (see "Replace- .•
ments" under movable Contact Assembly, '

2. Remove paddles from the trip shaft (hi thO
right side of the breaker.
3. Remove tru-arc from right side of trip shaft.
4. Remove return sprinjg (29).
'
.
5. Remove screw (1).
6. Remove nut from right end of hold-inpkist (4).
7. Remove ri^t hknd mechanism frame.
; ;
8. Remove reset spring (18). Replace parts in :
reverse order.

NOTE: To replace torsion springs (2) and (25)
follow procedure for removing reset spring (18) as
above and, in addition, removethenecessarytra-ard .
washers and pins.
Front Escutcheon Assembly - Tig. 5.
1.
2.

Remove four mounting screws (9), Fig. 2.

turnii^ and tipping the front escutcheon y
slightly until dislodged from the breaker.,

REPLACEMENTS - FIG. 5

To remount the froirt escutcheon assembly,'., y -

position. Then puU the cam suiqiort (7) ;
slightly forward.
>
Insert the shaft (10), Fig. 4 and roller (8),

first, hold the trip shaft in a

Two Opening Springs (21)

Remove arc quencher (see "Replacements"
under Arc Quencher).

removed in order to remove the handle.

Cap (20) and spring (21) wiU

tty using small screwdriver.

.. bstall new springs in reverse order after
assemUing cap (20) to new spring and pushV. ing cap and spring in place.

back iq) into slot occupied by main shaft.
Remove cap (20) and spring (21) from slot

Fig. 4 into, the hole of me cam support so . , ,
that the roller drops behind-cam (11). y't
5. Replace the four mounting screws fotsecuret'
the front escutcheon-assembly to th'emecha-

shaft (16), Fig. 2, nearest the ^ringtobe

Push main shaft to opposite side of operating

The operating handle may be removed simply
removing the set screw tapped in the hole in the •
handle. Some handles are held to the shaft by two:
set screws, which requires bbth set i-'

NOTE: On older model breakers where the trip'-:';
button is moimted in the operating handle, bhe trv
rod and return spring must be removed by pushing /
,

: • • :- 'i; •

Power Clrcutt Breakers Type AK-1-15-3 To 10 And AK-l-^25>3 To 10 QEai-7460a ^

V^»|
ilfil
STAGE OF SWITCH SHOWING
BREAKER IN OPEN POSITION
^ ?-M ^'fr-

•'a
1. Mounting Bolt

9> Contact Spring

2. Tie Bolt
3. Shaft
4. Screw
5. fottoffl Cover
6. End Plate
7. Top Cover
8. "a" Contacts

10. Rocker Arm
11. Pin
12. Cam
.

13. "b" Contacts ^
14. "b" Terminals
15. "a" Terminals
16. Barrier

Rotary Auxiliary Switch

the trip rod forward through the opeirating handle,

m reassembly, sufficient clearance between the long
S6t screw and the trip rod must be provided.
Advance tte long set screw into the tapped hole in

^ operating handle until it just binds the tr^ rod.
TOen back tiff the set screw one turn and lock the

lOTg set screw by inserting short set Screw. Check
trip rod for free movement.

AUXILIARY SWITCH - FIG. 7
The auxiliary switch is mounted on the left side

« the operating mechanism. The main shaft (16),
Fig. 2, of toe breaker causes crank (4), Fig. 6, to
rotate as toe breaker opens and closes. Tlie crank

operates toe^auxiltoy switch shaft (3), which opens

^ contacts of the switch,

iu Jji contacts are open whentoebreaker is open:
r** The
contacts
are and
closed
Whenoftoe
is
orcn).
opening
closing
thebreaker
auxiliary
smtch contacts is determined by toe arrangement
/Sv®^
"ounted on toe auxiliary:switch shaft
top terminals Of toe switch are "a" contacts,
the bottom terminals are "b" contacts.

ADJUSTMENTS - FIG. 7

..o"
may beare
changed
from
a" to "b" or vice^versa.stMe
H changes
desired
in ^
the (deration of the contacts, an approved drawing 'i'""
of the cam (12) arrangement should be obtained oi^> '

careltti sketch made* In order to chanse an "a"
contact to a "b" contact, it is necessary to remove
the four tie bolts (2) and chann the position of the •
puticular cam
in relation to the shaft Ccntacts
should be cleaned occasionally to insure proper
performance.

REPLACEMENTS, FIG. 7

1. Disconnect all leads to, the auxiliary swltehr

2. Remove mounting twit' (l) and screw (4) tb
remove device from br^Ucer.

3. If no approved sketch of toe cam surran^mmit
is avauiable, remove the endplate(6)from

removing toa four tie buts (2)

and draw a sketch of; toe position of toe^
particular cam in relation to the; lAaft.

4. Before installing toe hew devic^i.-8ee< toal
the cams are. in the same positimi ah tntoe

device that is being replac^i :, : ; v.
6. Install the new device inyrBvhyae ortferi.

. • •.••Na/J'

OBt-74602 Power Circuit Breakers Type AK-1-15-3 To 10And AK-1-26-3 To 10

PROTECTIVE
An AK-1-15 or AK>l-25 breaker may be equipped
with any combination of the following protective
devices:

3. Acalibration spring (4) attached toaidjust^#

screw (18) establishes the drop-out value oi^ yoltam'
which results in breaker tripping. This is largeljr a
factory adjustment, the drop-out value being 30 to ,
60% of rated voltage.
A

2. Reverse Current trip
3. Undervoltage trip.

TIME DELAY UNDERVOLTAGE
TRIPPING DEVICE FIG. 8
Hits device is mounted to a bracket on the right

side of the operating mechanism (looking from the
front). The purpose of this device is to trip the

breai^ for undervoltage. For rated voltage, the
armature (3) is attracted by magnet (14). u the
voltage falls below a predetermined value the magnet

(l4) releases the armature (3).

Spring (4) then

ADJUSTMENTS, FIG. 8

REPLACEMENTS, FIG. 8

1. An adjusting screw (20) in the trip paddle (22)
is used to allow from 1/32 to 1/16 inch overtravel

Time Delay Undervoltage Device

such as, G.E. 9981LT40NV or similar, in the
'l

1. Disconnect coil leads.
2. Remove two screws

(Bracket is omitted when Instantaneous
undervoltage device is used).

2. The armature pick-up is a function of the
open air gap of the armature. The air
is factory
set by means of adjusting screw w so that the

order to make uiis adjustment in the field, a variable

remove device.
4. bstall new device in reverse order.

arpiature will pick-tq) at 80% of rated voltage. In

somewhat by changing the relative positions of die::
connecting rod (11) and clevis (7). Thik is:accomplished by loosening the locking nut (8), raiklng
or lowering the plunger (12)by turning the connecting
rod (11) which Is threaded into the clevis (7). When
any time-delay of 3 to 10 seconds exists from loss cf
voltage, the device is considered Satisfoctorily ad

restraining force of the oil the armature engages

screw (20) thus rotating the trip shaft and opening

after tripping the breaker.

4. The time-delay of the device may be varied

5. From 1/4 to 3/8 inch of oil should be main
tained in the cylinder at all times. In order tomakO';
an inspection of the oil, the cylinder (10) may be
unscrewed from the cap (9). Use a silicone oil/

puUs armature (3) upward aralnst the restraining
force of the oil in cylinder (10); this action causes
a time delay. When the spring overcomes the

voltage source is required. The air gap should be
increased if pick-up occurs at less than 80%of rat^
voltage and decreased If pick-up occurs at more
than 80%.

1. Overcurrent trip
1

Remove four mounting screws (21)

oZo
o3o
o4o
olo

o3o
• JZ—- o4o
050
-jl•r.:3-

5. Shading Bing

2. Adjusting Screw

8. Lodcing Mit
9. Cap

10. cylinder
11. Connection'
Bod
12. Plunger
13. PI iktnp

19. Locking Wire

20. Adjusting ^reii

16. Screws
17. Pin

21. Mounting Screwe'"; . .i

18. Adjusting Screw

Tine Delay Undervoltage Tripping Device

22. Trip Paddle

Power Circuit Breakers Type AK-1-15-S To 10And AK-1-25-3 To 10 GEt-746bi
CoU (15)

1. Disconnect leads to coil.

2. Remove two screws (16).
3. Remove magnet and coll assembly.
4. Straighten laminations around shading ring
(5)«
5. Remove shading ring and strai^ten lower

2. Trip Adjustment
Screw

end of coil clamp (13).
6. Remove coil. Install new coil in reverse

3. Opening for Tine
Adjustment

4. Pickup Indicator

& Calib. Plate i

5. Pideup Adjustment
Knob

TRIPPING
DEVICE
This undervoltage tripping device is con

structed similarly to the time delay undervoltage
tripping device with the exception that the cylinder

(10), plunger (12), connecting rod (11), clevis (7),

bracket (1), and locking nut (8), as shown in Fig. 8

EC-2 Overcurrent Trip

The adjustments and replacements for this
device are also the same as those for the time

DUAL OVERCURRENT TRIP, WITH LONGrTIME
DELAY
AND
HIGH - SET
INSTANTANEOUS

delay undervoltage tripping device.

TRIPPING. - FIG. 9

The typical overcurrent trip device consists of
a magnetic structure, a series current coll, and a
pivoted armature. Depending on the tjpe of individual
device, the movement of the armature may
delayed by a timing device, of either the oil dashpot
or escapement gear and pallet type.

An AK-1-15/25 breaker may be equipped with
either the EC-2 or EC-1 overcurrent trip device.
The majority of applications will require tiie use of
the EC-2 device. The EC-1 device is normally used
when the short-time delay feature is required, or
when the trip device is used to operate a special
overcurrent alarm switch.

Most circuit breakers are equipped with series
overcurrent trip devices either of the dual magnetic

type (instantaneous and time delay tripping) or
instantaneous alone.
Breakers are designed to
carry up to 100% of the continuous current rating
of their trip devices. Any attempt to carry higher

By means of the adjustment knob (5), which can.
be manipulated by hand, the current pick-up point
can be varied from 80 to 160 percent of the series

coil rating. The indicator and the calibration plate
(4), on the front of the case, provide a means ^
Indicating the pick-up point setting in terms of
percentage of coil rating. The calibration plate is
indexed at percentage settings of 60, 100, 120, 140
and 160.
«
.
>
The long-time delay tripping feature can be
supplied with any one of three time-current charac

teristics which correspond to the NEMA standards

maximum, Intermediate and minimum long-time
delay operating bands. These are Identified as lA,
IB and IC characteristics, respectively. Appro:dmate tripping time for each of these, in the same

order are 30, 15 and Sseconds at 600% of the pick-up
value of current.

(See time-current characteristic
curves 288B201 A, B and C).

currents for a prolonged period will cause over
heating and possible damage.
EC-2 DEVICE

The EC-2 overcurrent tripping device is avail
able in three forms:

1. Dual overcurrent trip, with long-time delay
and high-set instantaneous tripping.
2. Low-set instantaneous tripping.
3, High-set instantaneous tripping.

1. Instantaneous Calibration S. Time-Delay Adjuatnetit
Spring
Screw
'
2. Movable Nut (Index I^>inter) 6. Oil Daahpot
•
3. Time-Delay Calibration
7. Dashpot Arm
Spring

8. Connecting Link

The dual trip has adjustable long-time and 4. Instantaneous Pickup
9. Instantaneous
instantaneous pick-up settings and adjustable time
Adjustment Screw
Calibration llarifs
settings. Both forms of instantaneous trips have
adjustable pick-up settings.
Fig. 10 EC-2 Overcurrent Trip With Cover Reaoved

! settings and tiiue4}
delay adjustments already described, overcurrent'

the index mark on the connecting link (8) lines up
with tte indicated mark on the .dashpot arm, the
aiQiroKimate' time as shown by the characteristic
curve is indicated. Figure 13 shows typical time-

current curves for the BC-2 and' EC-1 tripping
devices.

The lA and IB characteristic devices are

iisuaJly shipped with the time setting atthe2/3 mark
and the IC characteristic at the 1/3 mark. The
Standard characteristic curves are plotted at the

V same settings.

the one at which dimension "A", Fig. 10, is greatest
The time adjustment screw (S), may be turned by
inserting a Phillips head screwdriver through the
hole in the front of the case, but if it is desired to

relate the linkage setting to uie index marks on the
•linkage it will be necessary to remove the case.
This may be done by removing the two mounting
sicrews, one (m each side of the case, which may be
taken off without disturbing the trip unit itself.
. NOTE: Forcing the adjusting screw to either

trip devices must be adjusted for positiye trlpplhg^f

This adjustment is made at the faotory on new

breakers, but must be made in the field vdien the
breaker mechanism or the overciirrent trip devices
have been replaced.

Positive tripping is achieved when adjustment v:

screw (2), is in such a position that it will alwaysl

carry the trip paddle on the trip' shaft ,beyond we
point of tripping the breaker, when the armature-

closes against the ma^et

Time values are inversely proportional to the
efilective length of the dashpot arm. Therefore, the
linkage setting that gives the shortest time value is

calibration mark, punched slots on operating armg
to obtain the proper instantaneous trip betting'

die time adjustment screw (S).^ Turning in a clock
wise direction increases the tripping time; counter

left to ri^t, as viewed in Figs. (10) and (11). When

The tob edia^ of the .

movable nut (2), serves as an index pqmter Slid.
should be lined up widi the Center (d thbdesixwf

. . v^TME ADJUSTMENT - FIG. 10

As the spr^ is tis^teneoT ^

pick-up point is increased.

TlRie-AdJustRient' Indexing

extreme positicm may cause bindtog of the device
and should be avoided.

fo order to make the adjustment, first unscrew
adjusting screw (2), until it will not trip tiie breaker,

even thou^ the armature is pushed against the
magnet, ^en, holding the armature in the closed

position, advance the screw until it just trips the
breaker. After this point has been reached, advance
the screw two additional full turns. ThiswiU giye as
overtravel of 1/16 of an inch and will make sure that;
activation of the device will always trip tixebreaksr.^

Adjustment screw (2), can best be manipula^
tqr an extended 1/4 inch hex socket wrench.
In order to gain access to the adjustment screw.

Of the center pole overcurrent device, ii will be:
FIG. 9

necessary to remove the operation mechanism and

The low-set instantaneous pick-up point may be
varied by the adjustment knob (5). The calibration

^'Replacement - Movable Cmiiact Assembly" under

INSTANTANEOUS LOW-SET TRIPPING -

in diis case usually ranges from 80% to 250% of the
series coil ratiM, the cuibratibnplatebeingindexed

at values of 80%, 100%, 150%, 200% and 2^ of the
coil rating.
INSTANTANEOUS HIGH-SET TRIPPING - FIG. 10

attached components as a complete unit. To remove
the mechanism, foUow th^ first five steps pf^^^

"Pole Unit Assembly".

Rqilacement of the EC-2 overcurrent trip der:
vice is accomplished by the following prociedure:4

as described in the firstflve steps of"Replimement -:

(9), and the value of these
^libration marks will be indicated by stampings on
- 9XJ or (6X - 9X -

2. Remove the steel clamps which fasten the
cover of the device to the liack of Uiebrei^er.
NOTE: Pickup settings on the cover of each device,
are calibrated for the specific device, . Whm ve*'

turning the instantaneous trip a^usting screw (4).
Three standard calibration marks will appear

REPLACEMENT, EC-2

The high set instantaneous pick-ip value may
have one of the following three ranges: 4 to 9 times
coil rating; 6 to 12 times coU ratingor 9 to 15 times
coil rating. The pick-up setting may be varied by

12X) or (9X r 12X - 16X).

1. Remove the mechanism as a complete unit

Movable Contact Assembly" under "Pole Unit As
sembly".

placing covers, replace on associated de^ce.v;

Power CircTllt Breakers Type AK-1-15-3 To 10 And AK>l-a6-8 ito iO-C CSBM^ ..- ;4*

'\-,'y,'%:
•0<

19
1 V. .'.'•r.'^V'

V* -••-'•

LIfT SIDE VIEB SNMIKG
SHUT T(IC Da«« ffiMMISi

RIGHT SIDt Via SmiRG
lONGTIIC KIAT MECHMia

•1 , . •':.««.• 44#

. - ', »r.•;!.*• v*.

. "i .-- . A vf'J'
FRONT VIEl SHORING

iOMTIHGSIUCKn
• •• •' ,-if...'\ i?

1. Series Ooil
2. Magnet
3. Pallet
4. Pinion

5. Escape Wheel
6. Driving Se09ent
7. S.T.D. Armature

8. StT.O. Calibration Spring
,9. Trip Paddle Adjusting Screw
10. LiT.D. Armature

11. L.T.D. Calibration ^ring

12. Instantaneous Trip ^ring
13. ^ring Holder
14. Calibration Clamp Nut

16. Cylinder
17. Calibration Plate '

18. Trip PadiUe ,
; 19.1 "trip. Arm,'

20. Clamping Bracket

• • • V 'V

Series Overcurrent Tripping Device
J.y'.

'OBt-t4602 Power Circuit Breakers Type AK-1-16-S To 10 And AK-1-25-S To 10
3. Remove the 3/8 inch bolts which fasten

the coil of the overcurrent device to the breaker
cqpper.

2. Long time and short time delay tripping
only.

3. Long time delay and instantaneous tripping.

4. Remove the round head screw which fastens

Rte ff^tne of the overcurrent device to the breaker

4. Short time delay and instantaneous trippingi
5. Short time delay tripping only^

5. After reassembling breaker with new over-

"^'(wrent device, adljustfor "positive trip" as described
' under "Adjustments" of this section.

(a) Adjustable (Low set)

NOTE: When replacing an EC-1 device with an

EC-2, or vice versa, it will be necessary to replace
the trip paddles on the trip shaft. These will be
|>roivided with the replacement trip units.

6. Instantaneous tripping only. . ,

--<;:•<'-t. \

Nonadjustable (Hiidiset)

SHORT TIME DELAY TRIPPING^ FlO. 12
The armature (7) is retained by calibratlhg >"sr ^

the EC-1 device can be provided with the

following tripping combinations:

After the magnetic fprcei produced by

an overcurrent condiiibn, overeomes:thls r.estratnW'/ '''^^^t'i'^
force, the arinature; movenaent lb-fiwUier retard^:'.';>'
by an escapement naechanisioa whichVprdduces

, 1. Long time delay, short time delay and in-

htnntaneous tripping.

inverse time delaychancteristlc. Themeehanlsna;.-Aj.'
is shown in the left sideview of Fig. 12^: ^ r

CUI^NT IN TIMES BREAKER'RATING) 4

CURRENT
URREN1 IN TIMES BREAKER RATING

LONG TIME DELAY PICK-UP AOJUSTABLE
FROMa TO la TIMES BREAKERRATON

LOW TtME OBLAV PtOK-UP AMUSTttUE

. FROM .0 TOLO TIMU ORCAKERRAT1N0

rme ADJUSTABLE IN FAOTORT AT

90,» ORS SECONDS (IA,IB ORtO

RESPGCUvELYl ATSOOX OF LONO
TIME OELAT: PICK-UP

MAXIMUM BREAKER

WORT TIME OELAT PMK-UP

AOJUSTABLE. FRCHriO 10^
TIMES BREAXm
WTHA MAXIMUH RAIW

MAXIMUM BREAKER

OR 10 REBPECrtVCLYl
AT 000% OP Lom ~

TIIKKLAV PiCK>U^
MINWUM
RESET TIME

INSTANTANBOUS PtCK-UP
m
IN mCTORT AT 10
.10 SB TIMES BREAKER

SISTINTANEOUS PIOK-UP
SET IN PACTORTAT 410

e TIMES BREAKER NATHM

TIME AWUSTABLE IN
mOTORT AT 0,m

MAXMUM BREAKER
OPERATmO time

OR 0.I9B SECOWS ISA, ,

SB OR SO HESPECnvEa)

AT SBOa OF SHORT TIME
OELAT PICK-UP

MAXIMUM BREAKER

CURRENT IN TIMES: BREAKER RATING

CURRENT IN TIMES ^EAKER RATING.

'\C • ''•'•••.

Figi 13: Typical Tlni^urrent Characteristic of .Series oVercurrent trip DaviM In l8°C ABhieht'
18

Power Circuit Breakers Type AK-1-15-3 To 10 And AK-1-25-3 To
The plckiq) for this device can be field set

between limits having a ratio of 2-1/2 to 1 In the

pick-up when a reversad of current occurs.

;toy the flow of slllcone oil In a dashpot, which pro-

educes an Inverse time delay characteristic.

mechanism Is shown In the right side view of Fig. 12.

INSTANTANEOUS TRIPPING, FIG. 12

(a) Adjustable Instantaneous tripping takes
: place after the magnetic force produced by an
overcurrent condition, overcomes the restraining
force of the adjustable calibration spring (11).
(b) Nonadjustable Instantaneous tripping takes

place after the magnetic force prodhiced
an
>overcurrent condition overcomes the restraining
force of a nonadjustable spring (12).
SELECTIVE TRIPPING

Selective overcurrent tripping Is the application
of circuit breakers In series so that only the circuit
.breaker nearest the fault opens. Any one or com
bination of two or more ofthepreceding over-current
devices may be used In a selective system. The
breaker having the shorter time setting and lower
pickup will trip before the breaker having the

longer setting and higher pickup, provided the fault
-fs on the part of the line protected by the breaker
having the lower settings.

For the exact characterUtlcs and setting of
each breaker In a selective system, reference
Should be made to a coordination chart for the
particular system.

ADJUSTMENTS, EC-1 - FIG. 12

The EC-l device may be adjusted for positive

tripping by following the same procedure described

m^e for the EC-2 device and using adjusting screw
(9)»

(4) connected across a constanti^oorce of voltake

LONG TIME DEIjAY TRIPPING, FIG. 12

spring (11). After the magnetic force, produced by

between two pole pieces (7), alsta^^^dtentlal codl 3.^
and mounted around a roluy-^e a^niature (6);;
Calibration spring (3) determines the

an overcurrent condition, overcomes this restraining
force, the armature movement Is further retarded

range of 200 to 1000% of the coll rating.

The armature (10), Is retained by the calibration

REPLACEMENT - EC-1
The EC-1 device may be replaced by following

the same procedure describedunder "Replacement -

As long as the flow of current through the :
breaker Is In the normal direction, the magnetic
flux of the series coll and the magnetic flux of tte l

potential coll produce a torque' which ten^.
roiate the armature counter-clockwise.

bratlon spring also tends to rotaite the arihaturcip Vr

the same direction. This torque cauSes tbetu'ixta-i':^:T^ii|
ture to rest against the stop screw (9) attached3td »;;>;ii,ii^j

bearing plate on the rl^t side of the devlw^

If the current tturouA the series coll (l) t^l|^^^

reversed, the armature (6) tends to move in the.

clockwise direction against; the restraint of the";^/;-/<}f'.:

calibration spring. (3).

Wheni the current reversal

exceeds the calibration setting, the armatih'e re^.'^

volves clockwise causing the iS-'lp rod (2) to
iq)ward engaging thef:ta'lppaddle (14), thereby
the breaker.

ADJUSTMENTS - FIG. 14

The only field adjustment thatshould berequli^eilP'^^

on the reverse current device la that of "posliiy*'!
tripping", which Is the amount of overtravel

trip rod (2) beyond the point of tripping the br^Sri

Proper overtravel Is provided. If the trip: rdcK$2)
•n

advances the trip paddle (14) 1/32" to 3/64" b^Mdl t
the point of tripping the breaker. To adjust for a

"positive tripping", proceed as follows:

NOTE: Be extremely ; cautious not to lave hand#'WjfiF"
liwte
near moving breaker parts ivhen making thlsa^ust^' '^ -^
) V.l'

1. Manually lift the i^lp rod (2) as hlBb3-^^J|l|^
possible and turn the adjusting screw^ (15) into
—-

I • —I • 1

trip paddle (14) until It wlU not touch toe trlprbd^':

and trip the breaker.

®eck-out the adjustlnjg screw (itS) to apdiii^S^.3
the'ttv
rod Is lifted as far as It will go.trlppitkl whenr r."'•'

3. Back-out
—-My-* w— the;
Maw. a^ustlng screw
OVABW (IS);
\4V/; Hft-Oimitr. '
k'H

tlonal 1-1/2 turns from the position eat^httaiiiadiiv
step 2 and the proper overtevel should,be.bbtalhed.;

4. Be sure to tlfditen the locking nut on the/'.^,

CURRENT ITRIPPING

DEVICE - FIG.I14
The device Is enclosed In a imolded case and

Is mounted on the rl^t pole base similarly to the

series overcurrent tripplnig device.
Of

The reverse current tripping device consists
a series coll (1) with an Iron core mounted

adjusting screw.

' : ' •'•ftr-.

After removing the wiring foir the '^tentlal COU f

the reverse current device can be ninoved and'V

replaced by foUowlng the'procedure imtlbied for i-ll

replacing, the series overcurrent;.devlCel'
wiring, see Fig. 14.*
•^

•
i
•
Power Circuit Breakers Type AK-1-15-3 To 10And AK-1-25-3 To 10

•- • : .•.U%S '-M

NLARITT emiHEMt RM

t- < • v:- >.

TCtT-MUSI*: HUKM

•o ••C3}""^
^

R)TINTML COIL «IIIIH«

TYPICAL COMNeCTlCN OIAMAM

1. Series Coil
2. Trip Sod

3. Spring (Calib.)

4. Potential Coil

Calibration Niit

8. Counterwei^t

9. Stop Screw
10. Mom ting Screw

13. •SereiK'-'.

Fi^« 14 Reverse Current Tripping Device*.

'I iK'iJ < •;

Power Circuit Breakers Type AK-1-15-3 To 10 And AK-1<
BREAKER
SHUNT

The shunt tripping device is . mounted on a
bracket attached to the right side of the operating
mechanism (looking from the front).

'A remote switch or relay contact is used to
close the circuit of the device causihg the armature

(9) to engage the trip paddle (11) thereby tripping

The spring (2) is used to return the

armature to the neutral posltloji after the breaker
-'trips.

To prevent overheating, the coil (7) is cutoff

by contacts of the auxiliary switch which are open

when the breaker is open.

A bell alarm device is available which operate ^

From 1/32" to 1/16" overhravel of the arma

when an overcurrent trips the breaker. It tohslji^; ^
prin^ily
aaaiAA ujr vx a
«x leyw
X9WX (p^and
\ s / cu«\a hanj^r
ii«iii|^^x (U
\ a a / xxwxWv*W,

auxiliary shaft (6), latch (12)^ catch (16): switch (1)>
reset lever (3), and mouhtli^ bracket .(4); '

When the breaker is tripped by an oveTCimrSht^

the overcurrent device, trip arm (8) causes lever'

(7), hanger (11), and latch (12) to rotate counter
clockwise as a single member about pin (9); Ais '

disengages the latch from die catch (16). When die

breaker opens, link (17) also releases die catch, ^: vv :

allowing , its spring to rotate it couhterclockwiTO H

This in turn permits plunger

switch (1) to move downward, ctosihg the lower v.
contact of the switch and thereby completing the

ture is retired when the breaker is tripped. If any

overtravel, the trip lever is formed in or out
accordingly.

If the breaker is opened by means other t ^ V^i
the overcurrent device, the latch (12) remains to -

acQustment is nececessary to provide this amount of
>

BELL ALARM DEVICE - FIG. 16

about pin (15).

LOCKOUT DEVICE^

position and does not auow the catch to rotate even

thouj^ it is released by link (17).

Cott (7)
1. Disconnect leads to coil.
2. Remove magnet (6) and coil from frame
3. Bend lower end of clamp (8) straight
remove.

Alteration of the reset lever (3) retuihk mb i <
^fl and
QfflH switch contacts to their original position.'. V ' - f t ? /
catch

Remove coil and install new coil in reverse
order.

K, for some reason, the entire device is to be

replaced, this is accomplish^ by removing the
fasteners between the shunt trip device frame (3)
and supporting bracket (13).

At the same time, spring (5) resets latch (12).'
LOCKOUT DEVICE - FIG. 16

The lockout device consists of the samemeclto--

5.SP
except
a scr^
(18) secures bell
the ktomn
hangerdevice
(11) to
totchthat
(12).
This ' ir,/.
^
causes these two parts to function as a unit. When-v
ever the breaker is opened due to an overcurreht,i^i?7^^^ii.<

the trip paddle (10) will be held to the trtep^^'77^
xnereDy
locKingthBtoBatotN,,!
thereby lockingthehreaJmb
'
shunt trip device, 'the overtravel adjustment should in the open position (7),
imtil the tockbut mechtoiism^is't^'
beohecked.
i
reset manually by,jinj|a^
reset leyerr(8)iF'
After replacing either the' coil or the entire

puB&uun
%jy the
uie lever
lever
position by

2. Spring
3. Frame
4. Fin

2o ' 0
30 ••{;:>
o4o
050
060

5. Screws
.6. Magiet
7. Coil
8. Clomp

Shunt Tripping Device

Armature
Armature Ann

' / ^il'-*74602 Power Circuit Breakers Type AK-l-lS-3 To 10 And AK-1-25-3 To 10
This bracket may be shifted vertically by
dismounting the switch and loosening the

> ABJBSTBCENTS - FIG. 16

hardware which fastens the bracket to the
mechanism side frame.

ki order lor the bell alarm and lockout deyice

'to function properly the following conditions must
exist:
••

1. The auxiliary trip sludft (6) must swing
freely from its points of suspension and

comprises the drawout mechanism.

parted. In this position the breaker maybe operated
for test purposes without energizing the primary

the shaft and contacts the

When the breaker is closed, lever (7) must
hang in a position such that it touches neither

<,-•. »•./*V

in place of guides on the bre^r side framei^

otherwise the drawout mechanism are similar.

is an equidistant position.

Older model breakers were equippedwithrollers

the trip paddle .(10). The optimum condition

It is recommended that a fresh coat (d G;v^.

The latch (12) and the catch (16) must be so

Lubricant D50H47 be applied to the primhiy d^^

positioned relative to onh anotiier that when

connects at each inspection
period.
sttonii

the breaker is closed and reset, the latch

For a complete depcription of ^e inserti^.

will clear the catch when the latch is rotated
counterclockwise.

position stop, where the secondary disconneets are
engaged but the primary disconnects are safely.

the. trip arm (8) or the adjusting screw in

racking handle (5), interlock lever (7) and an intei^f
lock arrangement which prevents the inser^n (;|W^
withdrawalof the breakerwheninthecldsedpositijDU; '
The drawout carriage is also equipped with ,a iiest

shaft only at lever (7).
3.

mechanism consists of guides (2)» racking pins (1),

2. The auxiliary shaft must be positioned so
that bhCh of its clearance cut-outs has such
a position relative to its respective overcivrent device trip arin! that the trip arm
can (^erate without encountering inter
from

cuit breaker mounted in a drawout carriage whi<^

hang perfectly level with respect to the
breaker parts.
I

The drawout circuit breaker consists of a cir

and withdrawing operations, refer tdvGEH-202

The catch is mounted on

the same supporting bracket as switch (1).

furnished with all AK breakers.

•wr
3hh>4
TYPICAL CONNECTION
DIAGRAM

• •, > - . t : . . . f

If;'.:-'. •
KcU<.:' t

4. Mounting Bracket:
5. Spring

6. Auxiiiaiy Shaft !
Fig, 16

13. Trip Shaft
14. Main Shaft

10. Trip Paddle
11. Hanger

15. Pin
16. Catdt
17. Link

16. Screw (Lodkbut)

Bell Alarm and Lockout Device

V • •• •

Power Circuit Breakers Type AK-1-15-S To 10 And AK-1-26-8 To 16 OEI-746ffi /. ;.
contact;-.ii:

y
HOLLOW
M. TUBE. .

5. Recking Handle

?• Interlock Lever

Movable Secondary Disconnects

4. Handle Socket

AK-l-25 Drawout Breaker

1. Unfasten disconnect body from breaker back
frame.

PRIMARY DISCONNECTS

The primary disconnects are attached to the ends
m the breaker studs on the rear side of the breaker

base. Each disconnect assembly consists oftwo pair

• of opposed contact fingers. These are secured to
the breaker stud by a bolt which passes through the

^sembly and the stud.

REPLACEMENT OF MOVABLE SECONARY

When engaged with the

ratlonary stud of the enclosure, the disconnect
fmgers exert a set amount of force against the

2. Open tabs which hold wires on inner side.

3. Pull contact tip loose from hollow tube.
4. Remove contact tip by cutting wire at its,
base.

5. Push wire through hollow tube of new dU- ^
connect assembly.

toip Insulation off end of wire to about 1/4 stationary stud through the actionofthecompression ot an6.inch
from end.
^rings. Retainers and spacers hold the contact
7.
Place
new contact tip on end of wire and - ,
fmgers in correct alignment for engagement with
the stud. The amount of force which the fingers crimp.
exert against the stud is determined by degree to
through hollow tube until contact
which the springs are compressed by the bolt and tip fits snugly against
end of hollow tube.
nut which hold the assembly together. If, for any
reason, the disconnects must be taken apart, the
position of the nut on the bolt should be carefully wirepin
assembly to hold
noted, so that in reassemblying, the original amount
of compression can be restored by replacing the
10, Any hollow tubes which are not used should
nut at Its former position on the bolt.
be imshed into the disconnect body and held In that
position by placing fibre spacers over inner ends ot
SECONDARY DISCONNECT, FIG, 18
tubes and spreading tabs.

secondary disconnects serve as connections

between breaker control circuit elements and ex
11. When all wires have been connected, reternal control circuits. They are used only on fasten the body of the assembly to the breaker back
^wout type breakers. A terminal board serves frame.
the same purpose on stationary mounted andgeneral

purpose enclosure mountedbreakers. The secondary
disconnects allow removal of the breaker without
the necessity ofhavingto detachexternal connections
The movable part of the secondary disconnect
consists of an Insulating body which holds a conspring loaded plunger to which a flexible

lead Is attached.

As the breaker moves into its

Power Circuit Breakers Type AK-1-15-3 To 10 And AK-1-2S-3 To 10

! standard calibration ranges for Type AK-1-15Y1,

Fig. 19, are as follows:

Other ranges can be provided within reasonable

limits where the highest calibration settings will not
exceed approximately 2-1/2 times the lowest calt-

a. 300 to 800 amperes

bration setting.

b. 600 to 1500 amperes
.

,.;.'yv, : • '.: iAK^ {

These breakers are not given a continuous

S^dardcalibri^on ranges, for
TypeAK-1-25Y1,
'
19, are as follows:

current rating since the duty impost is infer-

mittent and quite variable depending
upon variods
The breakers iare

types of welding to be done.

designed to safely carry *'during-weld iuuperes'* °o<'v; ^i!' F;i
"during-weld KVA" at welding perloda hot wtoeed-^
tog the corresponding f'daty cycle'V as fitottlatefd;^^

;. i a. 600 to 1500 amperes;
b. 1400 to 4000 amperes
c. 2000 to 5000 amperes

("Duty cycle*'is the per cent oi time

current flows to any (me minute.

i-.'r VXVi.v"
>9000

;• --''.aV/.v'
s

t «
to
to 40 90to
OUTY CYCLE IM KKCnTAMI

.vV'-VV . P ' r'

DUTY CYCLE (M KBCtNTAUl

AK-1-15Y1 Breaker

During-weld Kva

484
419
375
342

Duty
Cycle
m
3
4
5

AK-1-25Y1 Breaker

During-weld Kva

388
370
327
266
231
206
188

1278
1107
990
903

562
487
436
398

Current and Duty Cycle Limits of Types AK-I-IBYI and Ay-|-2571 Breakers
i:vj "fiA'i

RENEWAL PARTS
,°'5Sr.^8address the

*^®General
Electric
Company,
required and
describ^
tfie

complete nameplate data of toe cirtfatt hrBwiiMit.dr'i .
accessory.

«
.»—
wthe
h ioriginal
c h areparts,
furnished
hot be
identical
with
sincemay
improve-*'
tUhe to ttaie. Parts whicl^^ >

n' a Renewal
PartsbyBulletin,
the are furnished will be,totorchangeaUe.
'rtbed pe^ fdiq^d
be identified
giving the
"

.1 . -. , '^ *-:»' V-/^•~*'^-N*'.v

GENERAl EUCmiC SAUS OmCES

ifj^r-^At.-;?^'""-

TO aAIST you .. . Wlwn Ym Hav*ClacMMt rtoblaim'... Nn4 Tw^i t»i»tm»oitNavri^P.OAox 10SANawparlNawiLVa.

.5001 W. Sro^ St

....930AJaffartaaSt.

Rdaneka 14.
WASH(NOTON

Fasca....,
SaaMa 4..
{ Saallla4...

.824 W. Uwls St.
..710 Sacaad Ava.
.550 W. Maha St
AIM Fast St

WEST VitOOtlA
*
Bluaflald

.304 MacCatUa Ava, AE.

Fainaext
Whaallog....

.......40 FourtaaMh St,

' i AppUton. a•,

. .445 W. MaAal St.

Altrop 3 a a s .
COAfOA4...

...310 Jacebp^.

.. .510 W. Cellaga Ava.

H
HAWAlli Amgikan Foclart, M., P.O. Box 3330, HmoMb 1

1224 Maikal Ava, F1
, .2421 Vielary FInvy.

MfiKttlGfl 5 a a s

5317 Old MIddlaton Rd.
, >.940 W. St. Paul Ava.

GENERAL ELECTRIC SERVICE SHOPS

at your agalpiiiant. Par lull IMarnsallaa abaol Rtaaaaacv1caa, caalaalyaor aaataal'
aasvica
* • ahap
'
or aalaa affka.

.3900 Crittandan Driva

. .403 Daaiborn Ava
. 272 A Indlanala Ava.

Fortland 10....

2727 HW.21i|h Ava.

..3S15RRebartianSt

Now Orlaant..
MARYLAND.
Balttmera 30...
MASSACHtlSCnS

920 A Fart Ava.

....;S4 RHarrltan St

Cainii Chrlstl,
DalutSS...;.

......115 Waco St

.3525 Gardhar Ava.

HeuttanSO...
MIdknd

.5534 HoiYay WtlibBOrtva -.s.:.u-

St louli 1 0 ..1II5 Eait Rood
NEW YORK

1097 Caatrai Ava.

Sab lake City 4.

4001 TontiaDa Ava.

Sdwnactady (liiitraiiiantetlan Sarvfca)

3S2S'Thfiri Rood

. Oodnnall 2
444 W. Third St
-••anchwaM 32;
240 W. MRchan Ava.
' Oavaland 4 .
4964 Woodland Ava.
Calambttc23. .F.a Box 4193,3120 Eokln Rd.

..3201 Manor Way

..704 8. Jahottaa St-V -

.;30l A7lh WaitSt

(Haw Yeik) North lafgan,R J..

2025—49fh Ava, R

.448 AHtaMand St
.......841 Oak St.
. .1040 A Ma Ava.

(Fntdrargbl Haa
.Sax sot, ED 1, RoHanxak HaOacr Rd.

.3940 Myrtle Vallay Fatkway
MICNIOAN

mrfnesoYa
Mlnhaapalltl2

AOanlewn
Joboitawn....

(Batlaal Madferd 55

•FOaootaa Aircraft Sarvica Shopa

ToMe 5 . . . . .

itialliada ood oaiialaa 04 raaavnt paria ara oaad la atalnlnln pasA Fatlatanaata

WASHMOTON
Saoltla 4....,
•Sbonln 8... ...
SpokonaS.
Win vmmA
ChetlaiMa 28.
WttCONSRt

6EMnAl ElEailC COMPAiiy. PHILADELPHIA, PA.

305 R Chaparral
.8101 Stammon* Fraaproy

LnUtack......... ........3302 Avanaa'A"
Midland
704 S. Jahasaa St
434 S. Main Ava.
SaaAalonlaS,....

...1411 W. Bhabalh Ava.

*lftatkar|Aikaocaaaiy.6.ACo,FAiax797

303FalhSt.
.......ISBSCaMarAva.

Corpus Chrlstl.....

..........442CadarSt:

Abflana
AaMtlllo
Saaamant

r^,^Chteaao=32... ..a...,,.b.4360 W.47HiSf.
rr5?tYi^iU»6»S"

570 laxington Ava.

Niagara Fotls....

• a • a • • • .6035 7«oAtrGP MmMoI fiM.

t0eva4M> Battandeif,

.633 Oaergla Ava,
.322 Caomaraa St '
nogapett..
Kaaxviaal4.......1301 Haaaoh Ava. RW.
.1420 Unlaa Ara.
Mamphli 4. ^
...1717 W. bdAva,
2
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.. .353 Mala St, Cnl
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a I 2 { Chaltoiieoga 2..

. . . . . .425 Dalawora Ava.
Main oad Woodland Ava.

Ebnlra
|NawYaA23

•(Now York) lindan, R J..

ia^alli 22........ 1740 W.Votment St

1310 lady St;
.108 W. Wathlnaloa St

19 Chaoaago St.

Btnghamtoo
BuHalo2

gall yaboM.yagr Nastric opiioralin. Tha (acWIIaa an dvalhiklo day and alghl,

tr'f i . -*,las Axgalaal Ontario

SOUTH CAtOUNA
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Cobnhia 1..
*
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navao. day, a graalt Far wock la tha ahapa ar|aa yaar pratalaaa. lataat laclary

iBRm YOU MEDTBRVKE ... Tbaaa M aarvko a^ wm rapolr, tasaadMaa,

'T ' ' LbsAngblaaT . . 4 9 0 0 Stanford Ava.

732 North 14th St
1001 Slal»5t
..841 Oak St
I niltsdalpMa2..
3 Faaa Canlar Ftm
. nttib«gh23... .Tha ORvar Bldg« MaOon So.
733 WmhlaolonM.
I nttibnghZS...
50-44 a Harrhaa St_>>t
V»A....
W.2

......107 A Main St
.2929aW.29tkAva.

il:
'CAMAOAi ORMciiatt Oatnatal ClacMaCompaity, iNluTofoalo

'.^'.4:'L'ihr't'*

.......iizorMtist

..1711 S.8th St.

....Zn tWhiiielaAra.

306 SMk eWg.
I a .701 H. S«f«nih $1,

Blrmlaghaai. ,F.O. Box 3487,7—TSlh St, AW.

.409 S. Savanlaanth St.

..... ^..AM'Madtmi Av*.

119 H. Rebknoa St
OUohone Citr 2
ToIm 4
. .'Cohnibta SMg., 2451 E. 21(t St.

12 S. Sixth St.

Joduan
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Son JM*.
•'COIORAOO

........iW W.MfNSt..
.:. .I3T nik Avtw VYnl'

Sa«l«nMr4lM;337N.RIyariMaAvavRla1io,Co1.

120 M«pU St
,.. .218 CtDva St.
. .700 AaloInaHa St
453 S. Saalnow
,453
Saglnow St.

,..11 W. IMihriIotI

.31 St. Jofliat Ava.

,.3t5C.RrwM St.

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....;34^PlralAvaa5.
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•S^th' 1*55 Shtrmop Si

.... .MidwayladaitiM Araa .7''' 7-.
P.O. Baxn CaaiM.Tracfe P

llfl 118^ • • G

940 W,Sb'PcMl Ava,'

POWi^ CIRCUIT BREAKERS

Types
AK-1-15and AK-l-25

Electrically Operated
I ••• J '

GENERAL^ELECTRIC
PHILADELPHIA. PA.

MANUAL
ELECTRICAL

ELECTRICAL CONTROL CIRCUIT

TOOLS
LUBRICATION
TROUBLE SHOOTING
BASIC BREAKER COMPONENTS

POLE UNIT ASSEMBLY
OPERATING MECHANISM
Without Closing Handle
With Closing Handle

Addition of Closing Han^e

15
16
16
16
17
17

Prop Switch (Cutoff)

Closing Solenoid

PROTECTIVE DEVICES
TIME-DELAY UNDERVOLTAGE DEVICE
INSTANTANEOUS UNDERVOLTAGE DEVICE
OyERCURRENT TRIPPING DEVICES
EC-2 Device

Dual Overcurrent Tripping, Long Time Delay and High-Set Lut
Time Adjustment

Instantaneous - High Set
EC-1 Device

AUXILIARY SWITCH
ELECTRICAL CLOSING DEVICES AND CONTROLS
Closing Switch
Solenoid Control System
Y Relay and Coil
X Contactor and Coil

Instantaneous - Low Set

Short-Time Delay

Selective Tripping

Long-Time Delay
Instantaneous Tripping

REVERSE CURRENT DEVICE
BREAKER ACCESSORIES

SHUNT TRIPPING DEVICE
BELL ALARM AND LOCKOUT DEVICE
DRAWOUT BREAKER

WELDING BREAKERS

! ! ! !!! ! ! ! ! !!!! ! ! .28
28

AIR CIRCUIT BREAKERS
ELECTRICALLY OPERATED
TYPES AK-l-lS-3 THROUGH AK-l-lS-10
AND AK-1-25-3 THROUGH AK-1-25-10
INTRODUCTION
The instructions contained herein provide in
formation for performing maintenance procedures
and for replacing AK-1-15/25 breaker components
and accessories. For information regarding the
receiving, handling, storage and installation of
these breakers, refer to GEH-2021A, furnished

AK-1-15/25-4
AK-1-15/25-6

Stationary primary disconnect
and cable clamp redesigned.

(Only enclosed breakers af
fected.)

with all AK breakers.

The AK-1-15 and AK-1-25 breakers differ, in
that, the AK-1-25 has an extra contact per pole
with corresponding differences in the upper stud

Improved "Y" relay in sole
noid control system.

New type of front escutcheon
and closing handle. Trip but
ton relocated on escutcheon and
reset lever of bell alarm and

and interrupter.

lockout breakers changed.

As various design improvements and new fea
tures were added, the su£tix digit of the breaker
troe number was progressively Increased. All of

instead of the EC-1 device ex

cept on units requiring the short
time delay feature.

these models are essentially the same breaker, as

changes were largely of a minor nature. These are
tabulated as follows:

EC-2 overload trip device used

New drawout frame introduced.

AK-1-15/25-10 Improved "Y" relay in sole

AK-1-15/25-3 Basic model.

noid control system.

OPERATION
(older model breakers in the manual operating

An electrical breaker may be equipped with
a manual operating handle, thus providing both
manual and electrical closing features.

which are equipped with manual han^es may be
closed by routing the handle 90° in the clockwise

Electrical breakers which do not have

a manual operating handle may be closed by means
of the manual maintenance handle furnished with

the breaker. The closing mechanism automatic
ally resets when the breaker trips, regardless
of the type of breaker closing.

If the front escutcheon (9) Fig. 2 has been
removed from the breaker, the maintenance han

dle can no longer be used.

However, the breaker

may still be closed manually by inserting a screw

driver in the cam support as shown in Fig. 9,

and then rotating its handle upwards and toward
the top rear of the breaker.

The breaker may be tripped manually by means
of the manual trip button in the front escutcheon

handle), or automatically by any of the tripping
devices with which it is equipped.
ELECTRICAL

The breaker is closed electrically by means

of a push button, located on the front of the breaker,

or by a remote switch. When the closing contact is
made the x contactor, becomes energized, thereby

closing the x contacts and energizing the breaker
closing solenoid, which causes the breaker to close.

When the breaker closes, the prop switch causes the
breaker closing solenoid to be de-energized.
The breaker may be tripped manually by push
ing the manual trip button, which is located on the
front escutcheon or automatically by any of the trip
devices with which the breaker is equipped. The
breaker mechanism will automatically reset when
the breaker is tripped. The breaker is "trip free"
from the closing mechanism, which assures that it
cannot be closed as long as any trip device is
functioning.

Tktt* iiutmctiom do not purport to cover all dotaih or variations in oquipmont nor to prevido for every posdblo
contingoney to bomot in eomoetion with indallation, oporalim or mabitonaneo. Sheuki turSior informatton bo decree/
or should particular probloms ariso which an not covered suffkiontly for tho purthasor's purposos, tho mattor should
be referred to tho Gonoral Boctrk Company.

GEI-74603 Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10
ELECTRICAL CONTROL CIRCUIT - Fig. 1

Figure 1 shows a typical elementary and con
nection diagram for the AK-1-15 and 25 breakers,
with the breaker in the open position.

Prop switch contact BB (1-2) opens the circuit to

the X contactor coil (9-10). thus de-energizing

the breaker closing coil CC (1-2) by opening con
tacts X (3-4), X (6-5), and X (7-8). Prop switch
contact AA (3-4) will also energize the permissive

relay Y (6-5), providing contact is maintained at

When normal voltage is supplied to the control
curcuit, either by closing a remote switch or relay,

the closing switch. The Y relay will in turn open
its contact Y (4-3), thus holding open the X con
tactor coil circuit and providing the circuits anti-

or by ^e push button PB, the closing contactor coil

pump feature, as long as contact is maintained at

sealing in the X coil through contact X (1-2) and

The breaker may be tripped electrically by a
remote switch or relay which will energize the
shunt trip coil TC (1-2) and trip the breaker.

X (9-10) will become energized through contacts
BE (1-2) and Y (4-3). The Xcontacts will then close,

energizing the breaker closing coil CC (1-2)through
contacts X (3-4), X (6-5), and X (7-8). This causes

the armature to move downward and the breaker to

close, thereby opening the BB (1-2) contact and
closing the BB (3-4) contact of the prop switch.

the closing switch.

I^e trip impulse is internmted i^ an "A" aux
iliary switch contact (1-lC) which is connected
in the shunt trip circuit.

MAINTENANCE
TOOLS

INSPECTION
BEFORE INSPECTION OR ANY MAINTENANCE
WORK IS DONE'.' BE SURE THAT THE BREAKER
IS IN THE OPEN POSITION. ALL ELECTRICAL

POWER, BOTH PRIMARYANDCONTROLSOURCES,
SHOULD ALSO BE DISCONNECTED.

The tools listed below will adequately equip an

operator for any maintenance operation on AK-1-15
and AK-1-25 breakers.

#1 Phillips Screw Driver

#2 Phillips Screw Driver with 8" shaft

inspections are recommended, if severe load con
ditions, dust, moisture, or other unfavorable con

#3 Phillips Screw Driver
KlOl-1/2 Crescent (Short) Screw Driver
K505-1/2 Crescent (Long Thin) Screw Driver
K306 Crescent (Standard) Screw Driver

H-28 8" Gas Pliers

If the breaker remains open or closed ,for a
long period of time, it is recommended that ar

654 Pointed Nose Side Cutting 6" Pliers
#2 Waldes Truarc Pliers Straic^t

rangements be made to open and close it several

#2 Waldes Truarc Pliers 90° Angle

times in succession, preferably under load.
At all times it is important not to permit pen
cil lines, paint, oil or other foreign materials to
remain on the insulating surfaces of the breaker

Ratchet
7/16" 9/16" 5/8" -

Periodic inspection of the circuit breaker is
recommended at least once a year. More frequent

as they may cause low resistance between points
of different potential and result in eventual elec
trical breakdown.

Always inspect the breaker after a short circuit
current has been interrupted.

At the time of periodic inspection, the following
checks should be made after the breaker has been
de-energized.

1. Manually operate the breaker several times,
check for obstructions or excessive friction.
2.

Electrically operate the breaker several
times to ascertain whether the electrical

attachments are functioning properly.

Arc quencher (See Section on "Arc Quen
cher").

Contact condition, wipe, and pressure (See
Section on "Pole Unit Assembly").

Latch engagement (See Adjustments under
"Operating Mechanism").
Overcurrent device tripping (See Adjust
ments under "Series Overcurrent Tripping
Device").

Socket Wrench 1/2" Drive
1/2" Drive Socket
1/2" Drive Socket
1/2" Drive Socket

3/4" - l/2" Drive Socket
13/16" - 1/2"
15/16" - 1/2"
10" Extension
6" Extension
8

Drive Socket
Drive Socket
Bar 1/2" Drive
Bar 1/2" Drive

Adjustable End Wrench

1/4" - 5/16" (Blue Point) Open End Wrench
1/2" - 9/16" Open End Wrench
3/4" Open End Wrench
5/8"
7/16" Open End Wrench
3/8"
11/32" 5/16" Open End Wrench
1/16" Allen Head Wrench for #6 Screw
5/64" Allen Head Wrench for #8 Screw
3/32" Allen Head Wrench for #10 Screw
1/8" Allen Head Wrench for 1/4" Screw
5/16" StraightShank Allen Head Wrench for 3/8"

screw, with adapter for 1/2" drive ratchet

8 oz. Ball peen hammer

5/8" 6 point open box wrench
3/8" ^intite
NOTE: Obtain from local hardware, do not order
on General Electric Company.

r
Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

NOTE-WHEN SEMRATE POWER SOURCE FOR CLOSING

COL B USEDlOMrr iWMPERS A1-A3 a AS-A4 THEN
CONNECT CLOSING POWER TO A3 S A4 AND
CONTROL POWER TO Al 8 A2.

-|c3—y-SOURCE

-63- -o I o- •
10 B

T^^ ^CLOSE
{c;:>—X-CLOSING

-K3--«3<^•' tT--

s:5—Y- SOURCE

X- TRIP
..Y SOURCE

—oCUSTOMER WIRING
—ofactory wiring

—oRGTORY WIRING FOR ENCLOSED BKR

CUSTOMER WIRING FOR STATIONARY BKR.
ALTEmUTE WRN6 FOR USE WITH
FOLLOWING CONTROL VOLTAGE RATING

575 V AC.
575 V AC

A-TERMINAL BOARD LOCATED TOP RIGHT
FRONT VIEW

B-TERMINAL BOARD-LOCATED UNDER-A.

F-ANThPUMI> PERMISSIVE RELAY.

G-(oa-bb)-MECHANISM SWITCH
K-IXI- CLOSING CONTACTOR-3 SETS OF CON

TACTS IN SERIES (MAIN) 8 I SET
na,

6TD) OR 5%" 8 SB (SPECIAL).

M-ITCl-SHUNT TRIP DEVICE.

N-(c.ft)-SOLENOID CLOSING COIL.
p-iri.)-closin6 switch on breaker.

L-I*U]ISWHAU)L SW-2%"8 A" CONTACTS

GEI-74603 Power Circuit Breaker Types AK-1-15-3 to 10 and AK-1-25-3 to 10
LUBRICATION

At each inspection period, all silver to silver

friction points, such as primary disconnects should

— c ^ c u i t breaker requires mod-

f? li?.
Searing points and latch surfaces
♦iJ' film of extreme
*"«P»lar
Inspectionperiods
Witt a» thin
temperature,
highSbohi?®'
m
^®®®®
similar
to G.E.
Spec.
No.
D&OHIS. Hardened
grease
and dirt
should
be re
moved from latch and bearing surfaces by using
EXCESS LUBRICANT SHOULD BE
A CLEAN CLOTH IN ORDER TO

AVOID ANY ACCUMU^TION OF DIRT OR DUST.

No.te'7 uSiS™ •
TROUBLE SHOOTING
following table lists several typical symp
toms of breaker malfunctions together with their
causes and remedies. If, at any time, these
symptoms are observed, their cause should be

determtted and the necessary corrective action
should be taken.

Contacts not aligned.

Contacts dirty, greasy or coated with dark film.
Contacts badly burned or pitted.
Current carrying surfaces dirty.

Adjust contacts.
Clean contacts.

Bolts and nuts at terminal connections not tight.

Replace contacts.
Clean surfaces of current
carrying parts.
Tighten, but do not exceed elastic

Current in excess of breaker rating.

limit of bolts or fittings.
Decrease load, rearrange circuit

or Install larger breaker.

Failure to Trip

Excsaslve ambient temperaturei

Provide adequate ventilation.

Travel of tripping device does not provide
positive release of tripping latch.
Worn or damaged trip unit parts

Re-adjust or replace trip unit
Replace trip unit

Binds in overcurrent device.

Replace overcurrent device.

Overcurrent pick-up too low.

Change adjustment or replace

with higher rated device.

Overcurrent time-setting too short.

Change adjustment or replace
with higher rated devtce.

Failure to Close
and Latch

Bind in overcurrent device.

Replace device.

Binding in attachments preventing resetting

Re-align and adjust attachments.

Chipped or worn latch.

Latch out of adjustment.
Latch return spring too weak or broken.

Hardened or gummy lubrication on bearing
and latch surfaces.

Replace latch.
Adjust latch.

Replace spring.
Clean bearing and latch
surfaces.

Closing solenoid burned out.

Replace solenoid coll.

Solenoidcontrol device not functioning properly.

Re-adJust or replace device.

BASIC BREAKER COMPONENTS
ARC QUENCHER • FIG. 2
^) is located on top of the compound barriers.
The
compound barriers and the muffler, together
Each arc quencher has several compound in with tte
slott between the barriers and the muffler,
side barriers (2) containing a large number of
with tte slots lietween tte barters, serve
perorations and two outside barriers (3) without together
to extinguish tte arc.
mpport (24) held in place by a fiber strap (23).
The arc quenchers should be inspected at tte
attached to the breaker base by regular
inspection period. If tte barriers are
Z^^two
Cl^p (5) holds all the arc quencher cracked or
eroded to one-half their original thick
assemblies to their respective pole unit A muffler ness,
they should be replaced.
6

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10 OEI-74603

1. Muffler
2> Inside Barrier
3. Outside Barrier

4. Front Cap
5< Clamp
6. Strap

7. Operating
Mechanism

8. Mounting Scree

11. Trip Shaft
12. Stop Nut
13. Overcurrent

9. Front Escutcheon
10. Hub

14. Lower Stud
15. Series Coil

17.
18.
19.
20.

22. Movable Contact

cap
Opening Spring
Insulating LiiA
Stationary
Contact

Right Side View of Breaker

23. Fiber Strap
24. Rear Support
25. Steel Base

26. IV)ie Unit Base

OEI-74603 Power Circutt Breakers Tyoe AK-l-lS-3 to 10 and AK-1-25-3 to 10

£art the scale should read between 4 to 6pounds.

REPLACEMENT, FIG. 2

1. Remove clamp (5) lay removing two traits.
2. Unclasp fiber strap (23).

4. Re-assemble parts in reverse order.

3. Remove front cap (4), muffler (1), outside
taarriers (3), inside terriers (2) and rear
support (24).

4. Install new or disassembled parts in re
verse order.

toward the top of the pole unit so that the clearance
in the rear support will accommodate the screwhead of the back plate,

MEASURING CONTACT WIPE, FIG. 6
1. Remove arc quencher (see "Replacement"
under Arc Quencher).
2. Measure the dimension between the inside

NOTE: In re-assembling the rear support (24)
to the breaker, be sure and push the rear support

[ the proper pressure is not indicated, (see "Ad
justing Contact Wipe and Pressure").

The contact assembly of each pole unit consists

of a stationary and a movable contact subassemUy.

The stationary contact assembly consists of

parallel contact fingers (3) with silver aUoy tips,
the upper stud (20) and pins (4) with compression
springs (19) which provide continuous contact pres
sure between the contact fingers and the upper stud

(20). A shunt (21) is used to prevent pitting at the
pivot point of the stationary fingers when carrying

high momentary currents. The stationary contact
fingers are held in place by the upper stud cap (6).

The movable contact assembly consists of par-

lel contact arms (5) with silver alloy tips, a contact

..arrier (18) with a spring (17) which provides con
tinuous contact between the contact arms and pin
(15). A clamp (14) secures pin (15) to the contact

support (16). A flexible connection (12) is provided

to prevent pitting at the pivot point of the movable
contact arms when carrying high momentary currents.

The movable contact assembly is connected to

the main shaft (16), Fig. 2, liy an insulating link (7)
which causes the contacts to move when the breaker

is operated. Each movable contact assembly must
exert a definite amount of contact pressure (see
"Measuring Contact Pressure") against the station
ary contacts when the breaker closes. During a
closing operation, a definite amount of contact wipe
must result, the distance which the stationary con
tacts are forced to the rear by the. movable contact.

(See "Measuring Contact Wipe"). At regular in

spection periods both contact pressure and contact
wipe should be checked.

MEASURING CONTACT PRESSURE - Fig. 6
1. Remove arc quencher (see "Replacement"
under arc quencher).

2. With the breaker closed, place a push-type
scale against the upper front end of the stationary
contact tip (3).

3. Exert pressure against the push-type scale
itil the contacts just part. When the contacts first

surface of the pole base and top edge of the
stationary contact tip (3), (a) with the breaker
open, (b) with the breaker closed.
3. The difference between these two measure

ments should be within the limits of 3/32"
and 1/4". If not within this range, the con
tact wipe must be adjusted.

4. With the breaker closed, the stationary con^
tacts should have a minimum of 1/16" over-

travel^ measured at the contact tips, before
reachmg the limit of their movement in the

direction of closing.

5. Replace arc quencher.
ADJUSTING CONTACT WIPE AND CONTACT
PRESSURE" FIG. 6

1. Remove arc quenchers (see "Replacements"
under Arc Quencher).
2. Remove tru-arc retaining ring from madn
shaft (16), Fig. 2, nearest the insulating
link and contact assembly to be adjusted.

3. Loosen clamp (9) which secures eccentric
bushing (8).
4. Turn the eccentric bushing in the insulating

link (7) thereby moving the insulating link

closer or farther away from the stationary
contacts, as required to obtain proper wipe.
5. Reassemble parts in the reverse order
after making adjustments.

NOTE: To adjust the insulating link in the center
pole unit, first, push the main shaft through the
right hand Insulating link (7) and into the center
insulating link as described in item 2 and 3 above.

Opening spring (18), Fig. 2 and cap (17) Fig. 2, will
drop out. Adjust center insulating link as' described

in step 4 above. Re-assemble parts in reverse
order being careful to replace the opening spring and
cap to their proper position.

If any of the contacts are badly corroded or
pitted, thereby making it impossible to adjust for
proper contact pressure or wipe, such stationary
contacts or movable contact assemblies should be

replaced, A commonly used "rule of thumb" is
that contact replacement is indicated if less than

one-half the original thickness (approx. 1/8 of an
inch) of the contact tip material remains.

"Replacements" below.

1
Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

If the proper contact pressure does not exist

when the wipe is within its limits, the stationary
contact springs (19) must be replaced.
REPLACEMENTS

MECHANiSM
MOUNTING
SCREWS

Movable Contact Assembly, Fig. 6

Remove arc quenchers (see "Replacement"
under "Arc Quencher").
2. Remove main shaft from breaker by re
moving tru-arc retainer from one end and
1.

Flushing shaft through insulating links (7).

INTERLOCK
LEVER

See Figs. 3 and 4.) As shaft clears the
mechanism side frames, the opening springs
and caps, (18) and (17) Fig. 2, will probably
drop out of. their
frames.

If the breaker is of the drawout

type, handle socket, interlock lever, bush
ing and nut must be removed on the side
o>
00

from which the main shaft is to be removed.
3. Remove the upper mechanism
mounting

screws (Refer to Fig. 3).
4.

Loosen lower mech^ism mounting screws

the mechanism will be somewhat re

stricted by control wires. There will be
enough freedom, however, to allow the mech
anism to be lifted to the top of the drawout
frame, or on later model breakers, to the
top of the pole base, where it should be
secured by tying.
'
6.
7.

Arc Quenchers and Handle Socket
Reffloved from Drawout Breaker

by using screw driver in slot provided on
tpreaded end of screw which projects through
back frame of breaker. (See Fig. 5.)
5. Mechanism and attached components may
now be lifted clear of the breaker,
u
breaker is of the drawout type, movement

Remove insulating link (7) t)y removing
tru-arc and drifting out pin (11).
Remove clamps (14) by removing fastening

hardware.
8. Remove series coil terminals bolts. Mov

able contact unit is now free and may be
removed.

9. Breaker may now be reassembled with new

contact assembly by reversing the above
described procedure. In remounting mech
anism, be sure that dowels in mechanism

side frames are well seated in dowel holes

in the pole unit base. (See Fig. 7.) It will
also be necessary to compress the opening
spring and cap in the recess in the mech

Removal of Main Shaft from
Drawout Breaker

anism side frame in order to obtain clear

ance for replacement of the main shaft.
10. Check contact wipe and pressure and adjust

U necessary.
CO

Stationary Contact (3) Fig. 6
1.

Remove arc quencher (see Replacements"
under Arc Quencher).

Remove upper stud cap (6) by removing two
holding screws threaded through the top of
the cap.

Pry the stationary contacts (3) from upper

stud ^0) with a screw driver as shown in
Fig. 7.
Stationary contacts of the outer
poles are readily accessible. On the center
pole, it is recommended that the mech-

Loosening Lower Mechanisn Mounting Bolts

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

1* Pole Uhit Base

2. Fiber Strap
3. Stationary Omtact
4. Contact Pin

5. Movable Contact
Arm

6. Upper Stud Cap
7. Insuiating Link

8. Eccentric Bushing
9. Clamp
10. Screw
11. Pin

12. Flexible Connection

and Terminal
13. Lower Stud

18. Contact Carrier

20. Uijper Stud

21. awnt
22. Steel Plate

16 Contact Support

Pole Unit Assmibly

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-l-25-'3 to 10

anism be removed tofacilitate removal of the

stationary contacts. Refer to steps 1 to 5 of
the procedure for "Replacing Movable Con

4. Replace the new stationary contact in re
verse order. (It may be necessary to tap the
new stationary contact into place by using a
rawhide mallet).

5. Adjust contact wipe and contact pressure
(see above).
OPERATING

WITHOUT CLOSING HANDLE - Fig. 9
The operating mechanism is supported between
two molded side frames in front of the center pole

unit. It consists of a toggle linkage (19), crank (5),
latch (15), trip shaft (12), roller (6), closing links
(1), and armature (14).
When the coil (8) is energized it pulls armature
(14) downward, which through closing links (1), causes
the toggle linkage (19) to straighten. This motion

Removal of Stationary Contacts

causes the main shaft (18) and movable contacts to

move to the closed position. As soon as the toggle
linkage is straightened the prop (23) moves on top of
prop piii (20) and roller (6) moves on latch (1^)
thereby holding the mechanism in theclosedposition.
The motion of the prop (23) causes switch (25) to
operate, thus de-energizing the closing coil.
The breaker mechanism is t -ipped by rotating

the trip shaft (12), and releasing latch (15) which
causes the toggle linkage to collapse, thereby al
lowing the opening springs (17) to push the main
shaft and movable contacts forward to the open

position.
Trip latch (15) is automatically rOset
during the opening operating providing none of the

trip devices are act^ted.

Latch adjusting screw

(9) limits the rotation of the trip shaft (12) and thus
O)
CO

determines the amount of latch engagement.
To operate the breaker manually see section

titled "Manual" under "Operation".
Adjustments, Fig. 9
Latch (15) is adjusted to provide approximately

5/64" engagement between latch and roller (6). To
adjust for proper latch engagement, follow the pro

Dismounting Upper Section of Magnet

cedure described below:
1.
2.

Loosen locknut on adjusting screw (9).
Hold breaker contacts in a position in which

the movable contacts are just touching the
stationary contacts. This may be done by any
of the provided means of manual closing.
3.

Turn down adjusting screw (9) until breaker
trips open.

Normally the force required to

rotate the trip shaft is small enough so that

the spring on the buffer paddle (10) is not
noticeably deflected.

If any deflection is

observed while turning down the screw,back
off screw until spring returns, then turn
down screw again. If deflection persists,
check trip shaft for binds.
4. Mark position of adjusting screw head.
5. Repeat steps 2 andSand check position of ad

justing screw in relation to markedposition.

6. If adjusting screw is in the same position as it
was in the first tripping, back off the screw
3 full turns and tighten locknut. If it is not,

repeat steps 2 and 3 until a constant tripping
position is determined before backing off the
three

turns and locking.

necessary to avoid a false setting due to
accidental tripping.

7. Operate the breaker electrically several
times

functions correctly.

With the breaker open, the stop nut (13) should be

adjusted so that there is approximately l/l6" clear

ance between the bottom of the magnet and the upper

stop nut. This will restrict linage movement in
tripping but allow enough movement for the mech
anism to reset.
11

Power Circuit Breakers Type AK-1-15-3 to 10and AK-1-25-3 to 10

Replacements. Fig. 9

Remove shunt trip supporting bracket by

taking out the two screws which fasten it to

the mechanism side frame. The nuts for

these screws are loosely held in the recess

;OT£: If a reasonable amount of care is exercised

on the inner side of the frame. If breaker

nections will not be overstressed and need not be

this also will be dismounted since it is held

when replacing the mechanism, wiring lead con

is supplied with an undervoltage device,

disconnected during the disassembly procedure.
The electrical accessories may be tied up out of

the way of the operator. If leads are disconnected,

they should be marked to avoid incorrect connection.

by the same supporting bracket.
If breaker is supplied with a closing switch,
dismount switch base by
removing two
screws (10), Fig. 13.

6. Remove solenoid control device cover.
7. Remove X contactor and Y relay together,

1. Remove arc quenchers (see "Replacement"

first removing two screws securing Y relay
to arm which projects from magnet, then

under "Arc Quencher").
2. Remove escutcheon (4).

loosening the three screws which fasten the

3. If breaker is supplied with a terminal block,

X contactor to the supporting arms. Both

dismount block by removing two screws in
back which fasten it to the supporting bracket.

devices can then be removed by lifting
slightly and moving towards front of breaker.

1. Closing Link
2. Cam Return Spring
3. Hold in Post

10. Buffer Paddle
11. Trip Shaft

8. Coil (Solenoid)
9. Trip Shaft
Adj. Screw

13. Stop Mit
14. Armature
15. Latch

21. Reset Spring

16. Mech. Frame

22. Prop Pin
23. Prop

17. Opening ^ring

25. Switch (Prop)
26. Screw

Operating Mechanian Without Operating Handle

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

8. Remove stop nuts (13) from armature plun

9. Remove lower section of magnet and closing
coil by taking out four screws (7).

10. Remove upper section of magnet by taking
out two screws which fasten it to mech

anism side frames. (See Fig. 8).
11. Remove auxiliary switch liy taking out bolt
(1) and screw (4), Fig. 12.
12. Remove cutoff smtch (25) by removing locknuts (24).

13. Remove tru-arc and take out main shaft(18),

being careful not to lose opening spring (17)

and cap which may pop out when main shaft
is removed.

14. Take off mechanism by removing mounting
screws from mechanism frame.

15. Mechanism may now be replaced as a unit

latch (13) resting on roller (8) will hold the contacts
in the closed position. Rotating the tripshaft (14) in
the

counter-clockwise direction will release the

roller (8) which causes the toggle linkage to collapse
thereby allowing the opening springs (16) to push the
main shaft and movable contacts forward to the open

position. Trip latch (13) is automatically reset during
the opening operation, providing none of the trip
devices are actuated.

Adjustments - Fig. 10

In addition to the adjustments shown for mech
anisms furnished without an operating handle, ad

justment screw (26) must be set for proper opera
tion. This adjustment is satisfactory if the screw is
set in such a position that the following two con
ditions exist

or disassembled and then reassembled with

new parts as needed.

16. Reassembly of the breaker is accomplished
by reversing the procedure described. In
replacing the mechanism, make sure that

the dowels on the mechanism side frames

are properly seated in the dowel holes in the

pole unit base; (see Fig. 7) also that the
dpening springs and caps are positioned
properly when, replacing the main shaft.
17. Adjust prop switch as described under "Ad
justments" in "Solenoid Control System" and
check operation of breaker manually and
electrically.

Opening Springs (17) Fig. 9 or (16) Fig. 10
Opening springs may be replaced by following
the first two steps of the procedure for replacing
the "Movable Contact Assembly."

In closing, there must be enough overtravel
of the mechanism to easily allow prop (22)
to move on pin (19).
When the breaker is open, roller (8) must
clearly be free of contact with latch (13).

Replacements - Fig. 10

The replacement of parts in the operating
mechanism

manual handle are

similar to those for the mechanism furnished with- •

out a handle, with the following additions:
Front Escutcheon Assembly
1.
2.

Remove four mounting screws (8), Fig. 2.
Now pull forward on'the operating handle
turning and tipping the front escutcheon
slightly tmtil dislodged from the breaker.

3. To remoimt the front escutcheon assembly,

WITH CLOSING HANDLE, FIG. 10

first, hold the trip shaft in a trip free posi

The electrically operated mechanism equipped
with a manual operating handle is shown in Fig. 10.

tion. Then pull the cam support, (7) slightly
This mechanism is similar to the one furnished

without an operating handle with the following ex
ceptions:

- a. There is only one stop nut (11) on the lower
end of the rod extending from the armature

(12) since there is no need to provide for
operation by the maintenance handle.
b.

The mechanism which is furnished with an

operating handle contains a cam support (7)
and cam (6), whereas the mechanism furn
ished without an operating handle contains
neither of these parts.
The sequence for electrical operation is the
same as given for the mechanism furnished without

an operating handle. (Refer to the second paragraph
under, "Operating Mechanism - Without Closing
Handle").

Turning the aerating handle (5) in the clock
wise direction 90° causes a roller attached to the

operating shaft to engage cam (6) thereby moving
I

the cam support (7) toward link (4). This motion
straightens the operating linkage, thereby moving

^the main shaft (17) and movable contacts to the
closed position. Prqp (22) engaging pin (19) and

Insert the operating shaft and roller into the
hole of the cam support so that the roller

drops behind cam (^.

5. Replace the four mounting screws to secure

the front escutcheon assembly to the mech
anism frame.

Replacing the Operating Handle
1. Remove the short set screw from the tapped.
hole in the operating handle.
2. Back off a second longer set screw from

the same tapped hole until it is moved clear
of the shaft.

3. Pull forward on operating handle until it is
released

operating shaft.
4. Re-assemble operating handle to front es
cutcheon and operating shaft in reverse order.
NOTE: On older model breakers where the trip but

ton is mounted in the operating handle, the trip rod
and return spring must be removed by pushing the
trip rod forward through the operating handle.

reassembly, sufficient clearance between the long
set screw and the trip rod must be provided. Advance
the long set screw into the tapped hole in the operating
13

GEI-74603 Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10
handle until it Just binds the trip rod. Then back off
on set screw one turn and lock the lone set screw by

anism, and the trip shaft retaining ring.
3. The toggle linkage and armature, now free
of the mechanism side frames, may be

inserting short set screw. Check tr5> rod for free
/"^ipovement.

disassembled and reassembled with the parts
required for manual operation.
Return

ADDITION OF CLOSING HANDLE - FIG. 10

spring, (2) Fig. 10, replaces (2) Fig. 9, and
cam support (7), is added to the linkage as

If it is desired to add a manual closing handle
to a

breaker which was not furnished with one

Fig. 10 shows how the linkage

should be reassembled.

originally, the conversion may be made by following
the procedure below. Required parts catalog num

4. Reassemble mechanism and breaker parts
with exception of escutcheon.
5. Mount new escutcheon assembly, which will
include a manual operating handle, accord

bers may be obtained by reference to Renewal Parts
Bulletin GEF-3506.

ing to the directions in the section titled

1. Follow steps 1 to 14 of procedure for re

"WITH CLOSING HANDLE" under "Replace

placement of the mechanism.

2. After mechanism has been removed, remove

6. Adjust screw (26) as described in "Adjust

right mechanism side frame by removing

ments" under "WITH CLOSING HANDLE."

hardware at (3) and (26), Fig. 6, all trip

7. Check manual and electrical operation of

shaft attachments to the right of tne mech

1. Closing Link
2. Cam Return

^ring
3. Hold in Pbst
4. Link
5. Handle
6. Com

7.
8.
9.
10.
11.
12.
13.

Roller
Screw
Coil

15. Cam Roller
16. Opening Spring
17. Main Shaft

19. Pin
20. Reset

21.
22.
23.
24.
25.
26.

Operating Kechanisn with Closing Handle

Prop Pin
Prop
Locknuts
Switch
Screw

Adjusting
Screw

Power Circuit Breakers Type AK-l-lS-S to 10 and AK-1-25-3 to 10

AUXILIARY SWITCH - FIG.

The auxiliary switch Is mounted on the left side

of the operating mechanism. The main shaft (17),
Fig. 10, of the breaker causes crank (4), Fig. 11; to
rotate as the breaker opens and closes. Hie crank

operates the auxiliary switch shaft (3) which opens

a^ closes the "a" and "b" contacts of the switch.
(The a" contacts are open when the breaker is open;
the "b" contacts are closed when the breaker is

The opening and closing of the auxiliary

switch contacts is determined by an arrangement of
cams (12), mounted on the auxiliary switch shaft
(3). The topterminals oftheswitch are "a" contacts,

the bottom terminals are "b" contacts.
ADJUSTMENTS, FIG. 12
o
CM
CD
ID
iO
CM

The contacts of any stage may be changed from
"a" to "b" or vice versa. If changes are desired in.

the operation of the contacts, an approved drawing

of the cam (12) arrangement should be obtained or
a careful sketch made. In order to change a "a"
contact to a "b" contact, it is necessary to remove
the four tie bolts (2) and change the position of the
particular cam 90° in relation to the shaft. Con
tacts should be cleaned occasionally to insure
proper perforinancei

1. Stationary Indicator
(Open)

REPLACEMENTS, FIG. 12

1. Disconnect all leads to the auxiliary switch.
2. Remove mounting bolt (1) and screw (4) to

2. Movable Indicator

3. Unk
4. Crank
5. Mechanism

remove device from breaker.

Position Indicator

STAGE OF SWITCH SHOWING
BREAKER IN OPEN POSITION

1. Mounting Bolt

5. Bottom Cover

2. Tie Bait
3. Shaft
4. Screw

7. Top Cover
8. 'a* Contacts

9. Contact Spring
10. Rocker Arm
11. Pin
12. Cam

13. 'b' Contacts

14. 'b' Terminals
15. 'a' Terminals
16. Barrier

Auxiliary Switch
15

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

3. If no
ment
from
bolts

approved sketch of the cam arrange
is available, remove the end plate (6)
the device by removing the four tie
(2) and draw a sketch of the position

of the particular cam in relation to the shaft.

4. Before installing the new device, see that
the cams are in the same position as in the
device that is being replaced.
5.

Install the new device in reverse order.

The electrical closing devices and controls
consist of the following:

a. Closing Switch
b. Solenoid Control System

c. Closing Solenoid
6. Movable Contact

1. Front Escut^eon

CLOSING SWITCH,

The closing switch is located in the lower right
hand corner of &e front escutcheon (1).

11. Closing Solenoid

12. Stationary
Contact

A push button extends through the front escutch
eon and is supported by bracket (3). Spring (6) re
turns the push button to a neutral position after the

13. Insulation Strip

movable contact (8) has momentarily engaged the

stationary contacts (12). Two retainers (2) and spac
er (7) are used to hold the movable contact in place.

The stationary contacts (12) and insulation strip
(13) are attached to the closing solenoid by bracket
(9) and screws (10). A remote closing switch may
be used to close the circuit of the solenoid control

system, thereby ener^zing the closing solenoid.
Adjustments

The closing switch requires no attention, other
than cleaning of contact occasionally.
SOLENOID CONTROL SYSTEM - FIG. 14

This system consists of an X contactor and Y
relay which are located on the left side of the
operating mechanism. It also contains aprop switch
(25), Fig. 9, which is located in the top front of the
operating mechanism (looking from the front). The

sequence of operation is as follows:

a. When the closing switch is closed, the coll
of the X contactor becomes energized.

b. The contacts of the X contactor close, seal

ing its coll in andalsoenergizlngthebreaker

closing coil.
c. The breaker then closes and latches causing

the bb contact of the prop switch (25), Fig. 9,
to open thereby de-energizlng the X con
tactor coil and the breaker closing coil.

1. Mtg. Screws, Y Relay
2. Frame, Y Relay

NOTE: If the closing switch is closed while the
breaker is in the closed position, or If it remains
' closed after the breaker closes, the coil of the Y

relay will become energized through the aa contact
of the prop switch (25), Fig. 9. This will open the

circuit to the X contactor coll, thereby preventing

3. Mtg. Screws, X Contactor
4i Hex. Posts

S. Tern. Screws. X Contactor

6. X Contactor
7. Armature Screw

8. Y Relay
9. Mtg. Screw, Y
Relay Coil

X Contactor and Y Relay
(AK-l-15/25-0)

waiWTiBWMimrsiaaiaiiBagBaiiii

T
Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10 GEI-74603

the X contactor from operating. This feature makes
it impossible to operate the closing solenoid when
the breaker is already closed. It also provides for
cut-off of the closing solenoid and anti-pump opera
tion.

ADJUSTMENTS - FIG. 9

X Contactor - Fig. 14

1. Perform steps 1 and 2 of "Replacing YRelay
and Coil".

2. Remove three mounting screws (3) which
fasten the X contactor to magnet frame extensions.

TTie only adjustment required for this system is
on the prop switch (25). To make this adjustment

3. The X contactor is now free frobi the breaker.
Install new X contactor in reverse order.

proceed as follows:

X Contactor Coil

1. Press the trip button in the front of the
breaker.

2. Maintain pressure on the trip button and at
the same time close the breaker with the
maintenance operating handle.

3. The prop switch (25) should operate just

before the armature (14) reaches the end of

its stroke. To obtain this adjustment move
the prop switch toward or away from the
prop (23). Moving the switch too close to
the prop can result in damage to the switch
if its operating button is forced to travel
beyond the limit of its movement. It is
also possible, in this case, for the switch
• not to toggle when the breaker closes. (When
the breaker closes, the prop moves away

from the switch and the button is extended).

1. The X contactor coil may be removed with
out removing the X contactor by first disconnecting
wiring from X contactor terminal screws (S).
2. Remove two hex. shaped posts (4). The coil
is now free of its mounting.
3. Remove screw (7) which fastens the armature

to the movable contacts. The coil is now completely
removed.

4. Install new coil in reverse order.

Prop Switch (25). Fig. 9

1. Remove wiring.
2. Remove locknuts (24) from switch.
3. Replace switch in reverse order.

This would leave the bb contacts closed
with the breaker closed, and burn out the

contactor and closing solenoid coils. If, on
the other hand, the switch is too far away

from the prop, it is possible for the bb con
tacts to remain open when the breaker is
open. This would make it impossible to close
the breaker electrically. This condition

could also result in false tripping even
though the switch may operate, since the
thrust of the switch button is depended iqion

to move the prop into position and hold It in
place on breaker closing operations.
REPLACEMENTS - FIG. 14

Y Relay and Coil - Fig. 14

1. Remove relay cover by removing two cover
screws.

2. Disconnect wiring from front of relay (8) by
loosening terminal screws.

3. Remove two screws (1) which fasten relay
frame (2) to upper extension of magnet frame.
4. The relay and its frame are now free of the
breaker.

5. With the relay (8) removed, the coil maynow
be removed by removing two small cotter keys at
rear of relay frame.

CLOSING SOLENOID, FIG. 9
The closing solenoid is located directly below

the operating mechanism. It consists of a coil (8),

a magnet, an armature (14), andfourclosinglinks (1).

The closing solenoid .is connected in series with
the main contacts on the X contactor and is ener
gized or de-energized when these contacts are

closed or opened, respectively. When the closing

solenoid is energized, its armature (14) is drawn

downward into the coU (8) pulling the four closing
links (1) in the same direction. This action straight

ens the toggle linkage (19), of the operating mech
anism, thereby closing the breaker. As the operating
mechanism moves into the closed position, the prop
switch (25) operates, causing the X contactor coU
and breaker closing coil (8) to be de-energized.
ADJUSTMENT - FIG. 9

The stop nut (13) should be set so that there is
approximately 1/16" clearance between the nut and

the magnet when the breaker is in thq open position.
This adjustment is required in order to ^ow the
mechanism linkage to reset.

REPLACEMENTS, FIG. 9
Closing Solenoid
1.

6. Remove small spring at rear-center ofrelay
frame.

7. Remove coil mounting screw (9) from center
of coil. The coil may now be removed.

8. Install new coll or relay in reverse order.

Remove the X contactor and Y relay (see

"Replacements" under Solenoid Control Sys

tem).
Remove stop nut (13).
Remove four screws (7) which attach lower

part of magnet to upper part of magnet.
Remove two screws (see Fig. 8) which attach

upper part of magnet to the two side frames of
the operating mechanism.
17

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

5. Install new closing solenoid in reverse

2. Remove wiring to coil (8) by disconnecting

one lead at the X contactor and cutting the other
lead three to four inches from coil.

CoU (8) - Fig. 9
1. Remove lower member of magnet as des
cribed in steps 1 to 3 of "Closing Solenoid Re

3. Remove brass coil guides and the coil may
now be removed.

4. Install new coil in reverse order.

An AK-1-15 or AK-1-25 breaker may be equip
ped with any combination of the following protective

armature (3) upward against the restraining force
of the oil in cylinder (10); this action causes a min

imum time delay of 3 seconds. When the spring
overcomes the restraining force of the oil the arm

1. Overcurrent trip
2. Reverse Current trip
3. Undervoltage trip

ature engages screw (20) thus rotating the trip shaft
and opening the breaker.
ADJUSTMENTS - Fig. 15

TIME DELAY UNDERVOLTAGE
TRIPPING

1. An adjusting screw (20) in the trip paddle (22)

This device is mounted, to a bracket on the right
side of the operating mechanism (looking from the
front).
The purpose of this device is to trip the
breaker for undervoltage. For rated voltage, the

armature (3) is attracted by magnet (14). u the
oltage falls below a predetermined value the magnet
14) releases the armature (3). Spring (4) then pulls

is used to adjust for "positive tripping". The overtravel of the trip paddle from the point of tripping

the breaker should be 1/32 to 1/16 inch, which may
be visually observed when making this adjustment.
2. The armature pick-up is a function of the

open air gap of the armature. Theair jap is factory
set by means of adjusting screw (8) so that the

O 10
o2o
o3o
o4o
o 1o

o2o
o3o
o4c>050 -•g:
060

S. Shading Ring

19. Locking Wire

2. Adjuating Screw

and Nut
3. Armature

6. Pin
7. aevis

20. Adjusting Screws
21. Mounting Screws
22. Trip Paddle A Clamp

12. Plunger
13. Cianp

15. Cbil
16. Screws
17. Pin

18. Adjusting Screw

23. Supporting Bracket

Tine Delay Undervoltage Tripping Device

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10 GEI-74603

armature will pick-up at 80% of rated voltage. In

order to make this adjustment in the fieldavariable

voltage source is required. The air gap should be
^ increased if pick-up occurs at less than 80% of
.rated voltage and decreased if pick-up occurs at more
than 80%.

similarly to the time deUy undervoltage tripping
device with the exception that the cylinder (10),

3. A calibration spring (4) attached to adjusting
screw (18) extablishes the drop-out value of voltage
which results in breaker tripping. This is largely
a foctory adjustment, the drop-out value being 30 to
60% of rated voltage.

INSTANTANEOUS UNDERVOLTAGE
TRIPPING DEVICE
This undervoltage tripping device is constructed

plunger (12), connecting rod (11). clevis (7), bracket
(1), and locking nut (8), as shown in Fig. 15 are
omitted.

The adjustments and replacements for this
device are also the same as those for the time

4. The time-delay of the device may be varied

somewhat by changing the relative positions of the
connecting rod (11) and clevis (7). This is accom

plished by loosening the locking nut (8) then raising

or lowering the plunger (12) by turning the connect
ing rod (11) which is threaded into the clevis (7).

When any time-delay of 3 to 10 seconds exists from
loss of voltage, the device is considered satis
factorily adjusted.
5. From 1/4 to 3/8 inch of oil should be main
tained in the cylinder (10) at all times. In order

to make an inspection of &e oil, the cylinder may
be unscrewed from the cap (9). Use a silicone oil,

such as, G.E. 9981LT40NV or similar, in the
cylinder.

delay undervoltage tripping device.

OVERCURRENT TRIPPING DEVICES
The typical overcurrent trip device consists of
a magnetic structure, a series current coil, and a
pivoted armature.
Depending on the type of in
dividual device, the movement of the armature may
be delayed by a timing device, of either the oil
dashpot or escapement gear and pallet type.

An AK-1-15/25 breaker may be equipped with
either the EC-2 or EC-1 overcurrent trip device.
The majority of applications will require the use of
the EC-2 device. The EC-1 device is normally used
when the short-time delay feature is required, or
when the trip device is used to operate a special
overcurrent alarm switch.

REPLACEMENTS, FIG. 15

Most circuit breakers are equipped with series
overcurrent trip devices either of the dual magnetic

The only part of the undervoltage device that is
likely to require replacement during the life of the
breaker is the coil (15). The replacement procedure
follows:

(Note:- It is advisable to replace the magnet and

type (instantaneous and time delay tripping) or
instantaneous alone.. Breakers are designed to carry
up to 100% of the continuous current rating of their
trip devices. Any attempt to carry higher currents
for a prolonged period will .cause overheating and
possible damage.

coil assembly as nearly as possible in its exact

original position in relation to the device frame.

Doing this will result in having the same open
air gap between armature and magnet and wiU
Insure the device's picking up at the same voltage
value).

1. Dual overcurrent trip, with long-time delay

1. Disconect coil leads.
2.

Remove two screws (16), freeing magnet

(14) and coil (15) from device.

more convenient to remove the entire de

vice from its supporting bracket (23) before
removing the magnet and coil. If the device

is of the time-delay type, bracket (1) will
also have to be removed from bracket (23).
3. Straighten laminations which were bent to

hold shading ring (5) in place.

Removing shading ring (5).
Straighten end of coil clamp (13).

Remove coil, install new coil, and reas
semble device by reversing disassembly
procedure.

The EC-2 overcurrent tripping device is avail
able in three forms:

If the entire device is replaced, simply remove

/^vthe hardware fastening the frame of the device to
supporting bracket (23). If a time-delay .device,
bracket (i) must also be removed from bracket (23).

and high-set instantaneous tripping.
2. Low-set instantaneous tripping.

3. High-set instantaneous tripping.

The dual trip has adjustable long-time and
instantaneous pick-up setting and adjustable time
settings. Botti forms of instantaneous trips have
adjustable pick-up settings.
DUAL OVERCURRENT TRIP, WITH LONG-TIME
DELAY AND HIGH-SET INSTANTANEOUS
TRIPPING.

By means of the adjustment knob (5), Fig. 16,
which can be manipulated by hand, the current
pickup point may be varied from 80 to 160 percent
of the series coil rating.
The indicator and a
calibration plate (4), Fig. 16, on the front of the
case provide a means m indicating the pick-iqp
point setting in terms of percentage of coil rating.
The calibration plate is Indexed at percentege
settings of 80, 100, 120, 140 and 160.
19

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

The long-time delay tripping feature can be
supplied with any one of three time-current char
acteristics which correspond to the NEMA standards

maximum, intermediate and minimum long-time
delay operating bands. These are identified as lA,
IB and IC characteristics, respectively. Approx

imate tripping time for each of thes^ in the same

order are 30, 15 and 5 seconds at 600% of the pick

up value of current. (See time-current character
istic curves 286B201A. B and C).

2. Trip Adjustment
Screw

3. Qpeninf! for Time

TIME ADJUSTMENT - Fig. 17

4. Pickup Indicator

The tripping time may be varied within the

Bi Caiibr Plate

limits shown on the characteristic curves (Fig. 19)
by turning the time adjustment screw (5). Turn
ing in a clockwise direction increases the tripping
time; counterclockwise decreases it. The dashpot
arm (7) is indexed at four points, max. - 2/3 - 1/3 min. from left to right, as viewed in Figs. 17 and
18. When the index mark on the connecting link
(8) lines up with the indicated mark on the dash-

5. Pickup Adjustment
f&iob

pot arm, the approximate time as shown by the

characteristic curve is indicated.
typical

time-current curves

EC-1 tripping devices.

Fig. 19 shows
the

The lA and IB character

istic devices are usually shipped with the time
setting at the 2/3 mark and Uie IC characteristic
at the 1/3 mark.
The standard characteristic
curves are plotted at the same setting.

EC-2.Overcurrent Trip

calibration marks will be indicated by stampings
on the arm as follows;

inversely proportional

the effective length of the
fore, the linkage setting
time value is the one at
Fig. 17, is greatest. The

dashpot arm. There
that give the shortest
which dimension "A",
time adjustment screw

At the factory,
set at

the pick-up point has been

nameplate value of the instantaneous

(5), may be turned by inserting a Phillips head

screwdriver through the hole In the front of the

ampere rating of the trip coil.) The variations
in pick-up setting is accomplished by varying the

case, but if it is desired to relate the linkage
setting to the index marks on the linkage it will

be necessary to remove the case. This may be
done by removing the two mounting screws, one
on each side of the case, which may be taken off
without disturbing the trip unit itself.
NOTE:

(Usually expressed in times the

tensil force on the instantaneous spring (I), Turn

ing the adjustment screw (4) change the position
of the movable nut (2), on the screw. The spring

Forcing the adjusting screw to either

extreme positon may cause binding of the device
and should be avoided.

INSTANTANEOUS-LOW-SET TRIPPING - FIG. 16

The low-set instantaneous pick-up point may
be varied by the adjustment knob (5). The calibra

tion in this case usually ranges from 80% to 250%
of

coil rating, the calibration plate

being indexed at values of 80%, 100%, 150%, 200%
and 250% of the coil rating.
INSTANTANEOUS-HIGH-SET TRIPPING - FIG. 17

The high set instantaneous pick-up value may
have one of the following three ranges: 4 to 9

times coil rating; 6 to 12 times coll rating or 9
to 15 times coil rating. The pick-up setting may
be varied by turning the instantaneous trip ad
justing screw (4).
Three standard calibration marks will appear

on the operating arm at (9), and the value of these
20

Instantaneous Calibration Spring
Movable Nut (Index Pointer)

Time-Delay CBlibratinn Spring
Instantaneous Pickup Adjustment Screw
Time-Delay Adjustment Screw

6. Oil Dashpot
7. Dashpot Arm

8. Connecting Link

9. Instantaneous Pickup Calibration Marks

Flfli 17 EC-2 Overcurrent Trip with Cover Removed

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10 GEI-74603
is anchored to this movable nut so that when the

position of the nut is changed, there is a corres
ponding change in the spring load. As the spring
is tightened, the pick-up point is increased. The
top edge of the movable nut (2), serves as an index
pointer and should be lined up with the center of
the desired calibration mark, punched slots on
operating arm, to obtain the proper instantaneous
trip setting.

adjustments, EC-2 - FIG. 16

In addition to the pick-up settings and timedelay adjustments already described, overcurrent
trip devices must be adjusted for positive tripping.
This adjustment is made at the factory on new
breakers, but must be made in the field when the

breaker mechanism or the overcurrent trip devices

have been replaced.

Positive tripping is achieved when adjustment

screw (2), is in such a position that it will always
carry the trip paddle on the trip shaft beyond the

point of tripping the breaker when the device arma

ture closes against the magnet.
In order to make the adjustment, first unscrew

trip adjustment screw (2), until it will not trip
the breaker even thou^ the armature is push^

TinerAdJustment Indexing

CURRENT IN TIMES BREAKER RATING
I

CURfiENT IN TIMES BREAKER RATING

LOM TtU OCLAV PICK-UP AUUCTULC
FROM .a TO LS TIKES BIEMIER RATIM

LCWO TIME DELAY PICK-UP ADJUSTABLE
FROMS TO I.S TIMES BREAKER RATDK

TIME ADJUSTABLE IN FACTORY AT

30,a OR 9 SECONDS (lA,ia OR 10
RESPECTIVELY) AT 800 S OF LONO
TIME DELAY PICK-UP

MAXIHUM BREAKER
OLE ARINO-TIME

SHORT TIME DELAY PICK-UP
HDJUSTASLE FROM2 TO 10
TIMES breaker RATKRT
WITHA MAXIMUM RATIO

TIME ADJUSTABLE'^ N

M FACTORT AT 30,13

MAXIMUM BREAKER

OR 9 SECONOSlULtB
OR IC RCSPEaiVELT)
AT eOOX OF LONO

TIKE DELAY PICK-UP,
MINIMUM
RESET TIME
RESET TIME

INSTANTAKEDUS PICK-UP
SET IN mOTOflV AT 10

TO 29 TIMES BREAKER
RATIN6

MSTANTXHECVS PICK-UP
SET IN FACTORY AT 4T0

19 TIMES BREAKER RATINfl

TIME ADJUSTABLE
MAXIMUM BREAKER
OPERATINS TIME "

FACTORY AT 0.999, 0.266
CR 0.133 SECOMCS IZA,

MAXIMUM BREAKER
OPERATINO TIME

2B OR EC RESPECriVElY)

AT 290X OP SHORT TIME
DELAT PICK-UP

CURRENT IN TIMES BREAKER RATING

CURRENT IN TIMES BREAKER RATING

lyplcal Time-Current Characteristic of Series Overcurrent Trip Device in 25® C Ambient21

GEI-74603 Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10
against the magnet. Then, holding the armature In
the closed position, advance the screw until It just
trips the breaker. After this point has been reached,
advance the screw two additional full turns.

ment - Movable Contact Assembly" under "Pole
Unit Assembly".

will give an overtravel of 1/16 of an Inch and will
make sure that activation of the device will always
trip the breaker.

Adjustment screw (2), can best be manipulated
by an extended 1/4 Inch hex socket wrench.
In order to gain access to the adjustment screw
of the center pole overcurrent device. It will be
necessary to remove the operating mechanism and
attached components as a complete unit. To remove
the mechanism, follow the first five steps of "Re
placement - Movable Contact Assembly" under
Pole Unit Assembly".

cover of the device to the back of the breaker.

NOTE: Pickup settings on the cover of each device
are calibrated for tiie specific device. When re
placing covers, replace on associated device.
3. Using a 5/16 Inch Allen Head Wrench, re
move the 3/8 Inch bolts which fasten the coll of
the

breaker copper.

4. Remove the round head screw which fastens
the frame of the overcurrent device to the breaker
base.

REPLACEMENT, EC-2

5. After reassembling breaker with new overcurrent device, adjust for "positive trip" as des
cribed under "Adjustments" of this section.

Replacement (rf the EC-2 overcurrent trip
device Is accomplished by the following procedure:

1. Remove the mechanism as a complete unit
described In the first five steps of "Replace-

2. Remove the steel clamps which fasten the

When replacing an EC-1 device with an

EC-2, or vice versa. It will be necessary to replace
the trip paddles on the trip shaft. These will be

provld^ with the replacement trip units.

natt fill ii«n«

1. Series Coil
2. Mapiet

6. Driving Segment

8. S.T.D. Calibration Spring
9. Trip Paddle Adjusting Screw

5. Escape Wheel

7. S.T.D. Armature

10. L.T.D. Armature

11.
12.
13.
14.

L.T.D. Calibration Spring
Instantaneous Trip Spring
Spring Holder
Calibration Clamp.Mit

Type EC-I Series Overcurrent Tripping Device

16. cylinder
17. Calibration Plate

18. Trip Paddle
19. Trip Arm
20. Clamping Bracket

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10
EC-1 DEVICE

The EC-1 device can be provided with the fol
lowing tripping combinations:

1. Long time delay, short time delay and in
stantaneous tripping.

Long time and short time delay tripping only.
Long time delay and instantaneous tripping.
Short time delay and instantaneous tripping.
Short time delay tripping only.
Instantaneous tripping only.
(a) Adjustable (Low set)
Or

Nonadjustable (High set)

SHORT TIME DELAY TRIPPING, FIG. 20

The armature (7) is retained by calibrating

spring (8). After the magnetic force, produced by
an overcurrent condition, overcomes ttis restrain
ing force, the armature movement is further re

tarded by an escapement mechanism which pro

duces an Inverse time delay characteristic. The
mechanism is shown in the left aide view of Fig. 20.
The pickup for this device can be field set
between limits having a ratio of 2-1/2 to 1 in the

range of 200 to 1000% of the coil rating.

LONG TIME DELAY TRIPPING, FIG. 20

The armature (10) is retained by the cali£>ration spring (11). After the magnetic force, produced

by an overcurrent condition, overcomes this re

straining force, the armature movement is further

retarded by a flow of silicone oil in a dashpot, which
produces an inverse time delay ciraracteristic.
The mechanism is shown in the right side view of
Fig. 20.

INSTANTANEOUS TRIPPING, FIG. 20

(a) Adjustable instantaneous tripping takes place
after the magnetic force produced by an overcurrent
condition, overcomes the restraining force of the
adjustable calibration spring (11),

(b) Nonadjustable instantaneous tripping takes
place after the magnetic force produced
an overcurrent condition overcomes Uie restraining force

of a nonadjustable calibration spring (12).

SELECTIVE TRIPPING

Selective overcurrent tripping is the applica
tion of circuit breakers in series so that only the
circuit breaker nearest the fault opens. Any one
or combination of two or more of the preceding
over-current devices may be used in a selective
system.
The breaker having the shorter time
setting and lower pickup will trip before the breaker

^having the longer setting and higher pickup, pro

vided the faiilt is on the part of the line protected
by the breaker having the lower setting.

For the exact characteristics and setting of
each breaker in a selective system, reference
should be made to a

coordination chart for the

particular system.

ADJUSTMENTS - EC-1 - Fig. 20
The EC-1 device may be adjusted for positive
tripping by following the same procedure described
above for the EC-2 device and using adjusting
screw (9).
REPLACEMENT - EC-1

When replacing the EC-1 device, refer to the
section entitled "Replacement" under EC-2 device.

REVERSE CURRENT TRIPPING
DEVICE -

The device is enclosed in a molded case and

is mounted on the right pole base similarly to the
series overcurrent tripping device.
The reverse current tripping device consists
of a series coil (1) with an iron core mounted

between two pole pieces (7), also a potential coil

(4) connected across a constant source of voltage
and mounted around a rotary-tj^e armature (6),
Calibration spring (3) determines the armature
pick-up when a reversal of ciurrent occurs.
As long as the flow of current through the
breaker is In the normal direction, the magnetic
flux of the series coil and the magnetic flux of the
potential coil produce a torque which tends to ro
tate the armature counter-clockwise.

bration spring also tends to rotate the armature
in the same direction.
This torque causes the
armature to rest against the stop screw (9) attached
to a bearing plate on the right side of the device.

If the current through the series coil (1) is
reversed, the armature (6) tends to move in the
clockwise direction against the restraint of the
calibration spring (3). When the current reversal
exceeds the calibration setting, the armature re

volves clockwise causing the trip rod (2) to move
upward engaging the trip paddle adjusting screw
(15) thereby tripping the breaker.
ADJUSTMENTS - Fig. 21
The only field adjustment that should be re
quired on the reverse current device is that of

"positive tripping", which is the amount of over-

travel of the trip rod (2) beyond the point of tripping
the breaker. Proper overtravel is provided. If the
trip rod (2) advances the trip paddle (14) 1/32 to
3/64 inch beyond the point of tripping the breaker.
To adjust for "positive tripping", proceed as follows:
NOTE: Be extremely cautious not to have hands near
moving breaker parts when making this adjustment.

1. Manually lift the trip rod (2) as high as

possible and turn the adjusting screw (15) into

the trip paddle (14) until it will not touch the trip

rod and trip the breaker.
23

Power Circuit Breakers Type AK-1-15-3 to 10 and AK-1-25-3 to 10

2. Back-out the adjusting screw (15) to a
Sosition
where the brewer is just tripped when
ie tr^ rod is lifted as far as it will go.

3. Back-out the adjusting screw (15) an addi
tional 1-1/2 turns from the position established in
step 2 and the proper overtravel should be obtained.

4. Be sure to tighten the locking nut on the

adjusting screw.

After removing the wiring for the potential
coil the reverse current device can be removed

and replaced by following the procedure outlined
for replacing the series overcurrent device. For
wiring, see Fig. 21.

«.t. OP I POU ORIAKCII
I 4-

moiiiTY RCPtJiEaef ran

ttPT-CMIttt MCMCR
ro mm

1. Mtg. Screws (3)
2. Spring

4. Pin
5. Screws

10. Armature Arm

11. Trip Paddle
12. Clamp

13. Supporting Bracket

Shunt Tripping Device
25

GEI-74603 Power Circuit Breakers Type AK-i-15-3 to 10 and AK-1-25-3 to 10
ADJUSTMENTS

positioned relative to one another that when

the breaker Is closed and reset, the latch

In order for the bell alarm and lockout device

will clear the catch when the latch Is rotated
cotmterclockwlse. The catch is mounted on

/"^to function properly the following conditions must
ixlst:

the same supporting bracket as switch (1).
This bracket may be shifted vertically
dismounting the switch and loosening the

1. The auxiliary trip shaft (6) must swing
freely from Its points of suspension and
hang perfectly level with respect to the

hardware which fastens Uie bracket to the
mechanism side frame.

2. The auxiliary shaft must be positioned so

DRAWOUT BREAKER - FIG. 24

that each of Its clearance cut-outs has such

a position relative to Its respective overcurrent device trip arm that the trip arm
can operate without encountering Interfer
ence from the shaft and contacts the shaft
only at lever (7).

3. When the breaker Is closed, lever (7) must
hang In a position such that It touches

neither the trip arm (8) or the adjusting

screw In the trip paddle (lO). The optimum
condition Is an equidistant position.

4. The latch (12) and the catch (16) must be so

The drawout circuit breaker consists of a cir

cuit breaker mounted In a drawout carriage which
comprises the drawout mechanism.

mechanism consists of guides (5), racking pins (3),

racking handle (7), Interlock lever (2) and an inter
lock arrangement which prevents the Insertion

and withdrawal of the breaker In tee closed posi
tion. The drawout carriage Is also equipped with
a "test position" stop, where the secondary dis
connects are engaged but the primary disconnects
ve safely parted. In this position the breaker may

be operated for test purposes without energizing

the primary circuit.

the complete nameplate data of the circuit breaker
or accessory.

Renewal parts which' are furnished may not be

identical with the original parts, since improve
ments are made from time to time.

are furnished will be interchangeable.

GENERAL ELECTRIC COMPANY, PHILADELPHIA, PA.

INSTRUCTIONS GEI-23989

TYPE AK-1-15, 225 AMP
TYPE AK-1-25, 600 AMP

GENERAL ® ELECTRIC
SWITCHGEAR

GENERAL INFORMATION

1. Similarity in Construction of AK—1-15 and AK-1-25 Air Circuit Breakers . . .
2. Application
SHIPPING—UNPACKING—STORAGE

1. Transportation Damage
2. Unpacking
3. Storage
INSTALLATION
1.

2. Dead Front Breakers
3. Enclosed Breakers . .

OPERATION AND MAINTENANCE
1. Operation . .
2. Maintenance

3. Lubrication
SAFETY PRECAUTIONS

BASIC BREAKER COMPONENTS

1. Arc Quencher

2. Contact Assembly
3. Operating Mechanism
4. Front Escutcheon and Operating Handle Assembly
5. Position Indicator

6. Rotary Auxiliary Switch
Vn.

ELECTRICAL CLOSING COMPONENTS

1. Closing Switch
2. Closing Solenoid
3.

Solenoid Control Device

Vm. PROTECTIVE DEVICES

2. Instantaneous Undervoltage Tripping Device
3. Series Overcurrent Tripping Device
4. Reverse Current Tripping Device
MISCELLANEOUS

1. Shunt Tripping Device
2. Bell Alarm Device
3. Lockout Device

4. Enclosing Case and Interlock . . .
5. Extension for Recessed Breakers
6. Disconnects

7. Terminal Board
TYPE AKF-1 FIELD SWITCH
1. General

2. Field Discharge Contacts
RENEWALS

CONNECTION DUGRAMS

Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.

Type AK'-l-25 Manually-operated Breaker
Type AK-1-15 Breaker with Electrical Attachments
Rear View of Breaker with Disconnects
Enclosing Case with Breaker
Attaching Cables to Solderless Connectors
Mounting Breaker in Enclosing Case
Type AK-1-15 showing Arc Quencher with Outside Barrier and Side of

Muffler Removed

Right Side View of Breaker Assembly
Type AK-1-15 showmg Contact Arrangement with Arc Quencher and

Contact Assembly

Fig. 11
Fig. 12
Fig. 13

Fig. 14
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.

15
16
17
18
19
20A
20B
21
22A
22B
22C
22D
22E
22F
22G
22H
23

Amdliary Switch Removed

OperatRig Mecha^sm

Partial View of Operating Mechanism
Front Escutcheon and Operating Handle Assembly

Linkage for Position Indicator and Auxiliary Switch

Position Indicator
Rotary Auxiliary Switch
Attachments and Their Location on Electrically-operated Breakers
Closing Solenoid
Closing Switch
Solenoid Control Device
Internal View of Solenoid Control Device Showing Wiring
Time Delay Undervoltage Tripping Device
Short-time Delay (Left Side View)
Short-time and Long-time Delay (Front View)
Long-time Delay (Right Side View)
histantaneous Mon-adjustable) Tripping Device
Instantaneous (Adjustable) Tripping Device
Instantaneous and Short-time Tripping Device
Instantaneous and Long-time Tripping Device
Instantaneous, Short-time and Long-time Tripping Device
Schematic View Showing Overcurrent Short-time, Long-time and Instan
taneous Tripping Mechanism

11
12
. 13
14
15
16
17
18
20
20
20
21
21
21
21
21
22

Fig. 24
Adjusting Overcurrent Device for Positive Tripping
Fig. 2SA Long-time and histantaneous Tripping Characteristic

Fig. 25B Long-time, Short-time and Instantaneous Tripping Characteristic
Fig. 26 Reverse Current Tripping Device Located on Breaker

Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.

Reverse Current Tripping Device
Shimt Tripping Device
Bell Alarm Device
Lockout Device
Enclosing Case and biterlock
Extension for Recessed Breakers
Disconnects Engaging Stationary Studs
Disconnect for Mounting Type AK-1-15 Breaker
Disconnect for Mounting Type AK-1-25 Breaker

25
26
27
27
28
29
30
30
30

Fig. 35
Fig. 36
Fig. 37

Terminal Board with Cover Renio"«»d
Field Discharge Contacts
Typical Elementary Diagram

Typical Connection Diagram

27
28
29A
29B
30
31
32
33
34

t
ryPE AK-l-25 MANUALLY-OPERATED BREAKER

TYPE AK-l-15 BREAKER WITH ELECTRICAL
ATTACHMENTS

FIG. 3
REAR VIEW OF BREAKER WITH DISCONNECTS

ENCLOSING CASE WITH BREAKER

'II
FIG. 6
ATTACHING CABLES TO SOLDERLESS CONNECTORS

MOUNTING BREAKER IN ENCLOSING CASE

AIR CIRCUIT BREAKERS
TYPES AK-M5 AND AK-IOS

These instructions do not purport to cover
all details or variations' in equipment nor to
provide for every possible contingency to he
met in connection with installation, operation
or maintenance. Should further information
be desired or should particular problems arise
which are not covered sufficiently for the pur
chaser's purposes, the matter should be re
ferred to the General Electric Company.
I

1. SnmLARITY IN CONSTRUCTION

TypesAK-1-15 and AK-1-25 air circuit break
ers are essentially similar in construction with the

exception that the AK-1-25 is built for higher con
tinuous and interrupting ratings. This instruction

book, is based on Type AK-1-15 air circuit breaker,
but it applies equally to type AK-1-25 after making
the following allowances for ratings and construc
tion:

g. A compound re-enforcing plate has been
added to both sides of the two outside arc
quenchers.

h. The main shaft has been lengthened in ac
cordance with an increase in the width of

the pole bases due to an increase in the
number of contacts.

The flexible connection is attached with
four screws instead of three screws.

]. The overcurrent and the reverse current
tripping devices of the AK-1-25 breakers

may have series coils
to 600 amperes
(AK-1-15 breakers may have series coils
up to 225 amperes).

These circiiit breakers are generally used for
the protection and control of apparatus and branch
circuits, including eq\iipment in buildings, indus
tries, power stations and for marine application
within the ratings designated above.
The circuit breakers are furnished with two or

three-pole units and are available with various auto
matic tripping devices and accessories for overcurrent, undervoltage and reverse current protec

tion. The center pole of the two-pole breaker is pro
Ratings

a. AK-1-25 current rating- 600 amperes (AK1-15 current rating- 225 amperes).
b. Voltage rating is similar for both break
ers; namely 600 volts a-c and 250 volts

vided for mechanical construction and may be uti
lized for electrical connections and a series over-

current tripping device, when needed. No contacts
or stud connections are located in the center pole of
a two-pole breaker.
n

SHIPPING • UNPACKING • STORAGE

c. AK-1-25 interrupting capacity - 2 5,000
amperes {AK-1-15 interrupting c^icity 15,000 amperes).

1. TRANSPORTATION DAMAGE

Immediately upon receipt of the circuit break
Construction—Type AK-1-25 Compared with
Type AK-1-15
a. The metal base is wider and longer.
b. The studs have been increased in width

er, an examination should be made for any damage
or loss sustained in transit. If injury or rough hand

ling is evident, a damage claim should be filed at
once with the transportation company and the near
est General Electric Sales Office should be prompt
ly notified.

and thickness.
2. UNPACKING

c. The pole units are wider and longer to

provide for an additional movable and a
stationary contact arm.

d. The insulating link for each pole unit has
been increased in size to provide insula
tion for the additional contact arm$.

e. The shunt has been increased in length and
width.

The circuit breaker should be unpacked as soon
as possible after being received as difficulty may

be experienced in making claim for damage, not
evident upon receipt, if delayed. Care should be
used in unpacking to avoid damaging any of the
breaker parts. Be sure that no loose parts are
missing or left in the packing material. Blow out
any dirt or particles of packing material that may
have accumulated on the breaker parts..

An interior barrier has been added. Also,
the interior and exterior barriers, as well

as muffler, front cap, rear support and
fiber straps for each pole unit nave been
increased in size to dissipate any increase
in arcing.

If the circuit breaker is not installed at once,
it should be stored in a clean dry place and prefer

ably placed in a vertical position. It should be sup
ported to prevent bending of studs or damage to the

breaker parts. It Is advisable not to cover the
breaker with any packing of other material that ab
sorbs moisture wMch may cause corrosion of breaker parts. A covering of paper wiUprevent dust from

^ settling on the breaker parts.
m

disconnects fit over the stationary studs to which

the power circuits are connected. Four 1/Z'mount

ing bolts are then inserted into the holes for bolt
ing the breaker to the panel. When the disconnects

are not used, the power circuits are bolted to the
breaker studs after bolting the breaker to the panel
by using the four 1/2" mounting bolts. Breakers

mounted in drawouts or an enclosing case (see be
low) are equipped with disconnects.

The air circuit breaker should be installed in

a clean dry placewhere it is readily accessible for
operation, inspection and proper maintenance.
Special enclosures are available for the installation
of circuit breakers which may be subjected to dust
and moisture or other unfavorable locations.
2. BREAKER CONNECTIONS

The connections to the circuit breaker studs

should be firnoly clamped or bolted in place to pre
vent excessive heating. The connecting cables or

4. ENCLOSED BREAKER

The enclosed air circuit breaker is shipped in

an enclosing case. Before the enclosed breaker is
installed, first, remove the cover of the enclosure
and the four moimting screws in the breaker base
(Fig. 6). The breaker unit is then pulled forward to

^sengage disconnects and to remove it from the en

closing case. Knockouts at the top and bottom of the
enclosing case must be removed in order that con

nections can be made with power cables and control

equipment. Next, mount the enclosing case in the

desired location and secure the cables in the solder-

bus bars should have a current-carrying capacity

less connectors of the enclosing case, and connect

specified for the breakers. If these connecting ca

the control circuits (Fig. 5). Finally, return the re
movable breaker unit to the enclosing case and re
place the four mounting screws and the cover to

sufficient to limit their temperature rise to that

bles or bus bars are not of sufficient size, heat will
be conducted from them to the breaker so that the

breaker cannot carry normal rated current without
exceeding the specified temperature rise. Connect
ing cables or bus bars should be siipported so that
the breaker studs will not be subjected to unneces
sary strains.
3. DEAD FRONT BREAKERS

Dead front circuit breakers are designed for
mounting in a switchboard or an enclosing case.
The mounting of dead front breakers consists in

placing the breakers within the enclosed structure
and connecting the power buses or cables and mak
ing the necessary control connections. The stand
ard moimting depth from the back surface of the
breaker base to the back side of the front panel is

8-3/4". Provision is made, when specified, for re

cessingbreakers to a depth of 17-1/4" (see Fig. 31).

The front cover of dead front breakers consists ei

ther of a hinged door with cut-out or a plate bolted
to the panel. An adapter plate is used in addition
to fte front cover when the breaker is recessed.

This plate is bolted to two angle irons furnished by
the switchboard builder.

A terminal board on the right side of the break

er, Fig. 35, is \ised for making various control con
nections with breaker devices. An auxiliary switch
on the left side of the breaker Fig. 16, is used for
some control connections and for connecting various
auxiliary accessories.
The structural surface to which the breaker is

bolted must be flat through-out and the supporting
structure must be of sufficient strength to hold the
breaker firmly in place. Minimum cut-out dimen
sions must be maintained in order to have proper
electrical clearance.

When disconnects. Figs. 32,33 and 34 are used,

r ^ the breaker is placed against the panel so that the

complete the installation.
IV

The circuit breaker may be closed manually
with a pistol grip operating handle. Breakers equip
ped with a closing solenoid may be closed manu

ally by using the operating handle, or electrically by
means of a closing switch. To close the breaker
manually, the operating handle must be moved ap

proximately 90° in a clockwise direction (looking
from the front). The handle will drop back auto
matically to the "Down" position after closing the

breaker. The breaker may be tripped manually by
pushing a trip button located in the front part of the
operating handle, or automatically by any trip devicewith which the breaker is equipped. Thebreaker is automatically reset when tripped either man
ually or electrically. The breaker is "trip free"
from the closing mechanism which assures that it
cannot be closed as long as any trip device is func
tioning.
2. MAINTENANCE
BEFORE INSPECTION OR ANY MAINTE

NANCE WORK IS DONE, BE SURE THAT THE
BREAKER IS IN THE OPEN POSITION. ALL ELEC

TRICAL POWER, BOTH PRIMARY AND CONTROL
SOURCES, SHOULD ALSO BE DISCONNECTED.

Periodic inspection of the circuit breaker is
recommended at least once a year. More frequent
inspections are recommended, if severe load con
ditions, dust, moisture, or other unfavorable con
ditions exist. A complete inspection of the breaker,
including contacts and arc quenchers, should always

be made after the breaker has opened a severe short
circuit.

After the breaker has been installed, as well

as at the regular inspection periods, slowly oper

ate it manually several times as described above
and observe whether the contacts line up properly
and make sure that all parts move freely without

binding or excessive friction.
If the breaker remains open or closed for a
long period of time, it is recommended that arrange
ments be made to open and close it several times
in succession, preferably under load.

If overheating, not caused by overcurrent, is
observed, a complete inspection of the breaker
should be made including connections, contacts and
flexible connectors.

At all times it is Important not to allow pencil

lines, paint, oil or other foreign materials on the in
sulating surfaces of the breaker as they may cause
low resistance between points of different potential
and result in eventual electrical breakdown.

The electrically operated breaker should be

opened and closed at rated voltage, to make sure
that all control circuits areproperly connected and
that all electrical attachments arefunctioningprop-

erly. Itshouldberemembered thattheclosingsole
noid is rated for intermittent service only. Reason

able care, therefore, should be exercisedwhen test

ing to avoid overheating of the closing solenoid by
repeated operations.
FIG. 7

The contacts should be inspected at the regular

mspection periods and always after a known severe
short circuit has been opened to ascertain whether
the contacts are badly worn or pitted, in which case

TYPE AK-l-15 SHOWING ARC QUENCHER WITH
OUTSIDE BARRIER AND SIDE OF MUFFLER
REMOVED

they should be dressed or replaced. It is necessary
to remove the arc quenchers in order to properly

inspect the contacts (see "Replacements" under Arc
Quencher). For a more comprehensive discussion
of contacts, see Contact Assembly.
3.

In general, the circuit breaker requires little
lubrication. Bearing points and latch surfaces
should be lubricated at the regular inspection per

iods with a thin film of extreme temperature, high-

pressure, light grease similar to Royco #20 (Royal
Engineering Company, Hanover, N. J.) Hardened
grease and dirt should be removed from latch and
bearing surfaces by using kerosene. ALL EXCESS
LUBRICANT SHOULD BE REMOVED WITH A
CLEAN CLOTH IN ORDER TO AVOID ANY AC
CUMULATION OF DERT OR DUST.

BASIC BREAKER COMPONENTS
1. ARC QUENCHER FIGS. 7 AND 8

Each arc quencher has two compound inside

barriers (3) containing a large number of perfora

tions and two outside barriers (4) without perfora

tions, as well as a front cap (5) and a rear support

(24) held inplace by a fiber strap (23). Aclamp (6)

is attached to the breaker base by two bolts (7).
Clamp (6) holds all the arc quencher assemblies to

their respectivepole units. A muffler (2) is located
on top of the compound barriers. The compound
barriers and the muffler, together with the slots be
tween the barriers, serve to e.xtingulsh the arc.

The arc quenchers should be inspected at the

regular inspection period and parts replaced, if
badly burned or corroded.
SAFETY PRECAUTIONS
CARE MUST BE TAKENWHEN THE CIRCUIT
BREAKER IS BEING INSTALLED ANT WHEN ANY
INSPECTION OR MAINTENANCE WORK IS BEING
DONE THAT THE BREAKER IS IN THE TRIPPED
OR OPEN POSITION. ALL CONTROL AND POWER
CIRCUITS ATTACHED TO THE BREAKERS,
SHOULD ALSO BE DE-ENERGIZED.

REPLACEMENTS--Arc Quencher, Fig. 8

1. Remove clamp (6)by removing two bolts (7).
2. Unclasp fiber strap (23).
3. Remove front cap (5), muffler (2), outside

barriers (4), interior barriers (3) and rear
support (24).

MOUNTING SCREW BNUT

OPERATING HANDLE

STATIONARY CONTACT

OPENING SPRING
LINK

OUTSIDE BARRIER

OVERCURRENTTRIP DEVICE

MOVABLE CONTACT

OPERATING MECHANISM

FIG. 9
TYPE AK-l-15 SHOWING CONTACT ARRAHGEHENT

WITH ARC QUENCHER AND AUXILIARY SWITCH
REMOVED

In re-assembling the rear support (24) to the

The movable contact assembly is connected to
the main shaft (16), Fig. 8, by an insulating link (8)
for operating the contacts when the contacts close.
A definite amount of contact pressure (see "Meas

clearance in the rear support will accom
modate the screw-head of the back olate.

movable contacts against the stationary contacts.
A definite amount of contact wipe, or the distance
that the stationary contacts are pushed to the rear

4. Install new or disassembled parts in re
verse order.
NOTE:

breaker, be sure and push the rear si^port
toward the top of the pole unit so that the

uring Contact Pressure") must be exerted by the

by the movable contacts (see "Measuring Contact
2. CONTACT ASSEMBLY FIGS. 9 AND 10

The contact assembly of each pole unit consists

Wipe"), must result during the closing operation.

Both contact pressure and contact wipe should be
checked at the regular inspection period.

of a stationary and amovable contact sub-assembly.
The stationary contact assembly consists of
three parallel contact fingers (25) with silver alloy

tips, the upper stud (24) and three pins (22) with

compression springs (23) which provide continuous
contact pressure between the contact fingers and
the upper stud (24). A shunt (26) is used to prevent
pitting at the pivot point of the stationary fingers
when carrying high momentary currents. The sta
tionary contact fingers are held in place by the up-,
per stud cap (6).
The movable contact assembly consists of three

parallel contact arms (4) with silver alloy tips, a
contact carrier (21) with a spring (20) which pro

MEASURING CONTACT PRESSURE

1. Remove arc quencher (see'Replacements"
under Arc Quencher).

2. Place a push-type scale against the upper

end of the stationary contact tip (3) with the
breaker closed.

3. Exert pressure against thepush-type scale
until the contacts just part. When the con

tacts part, the scale should register between
4 and 6 pounds.

vides continuous contact between the contact arms

4. Re-assemble parts in reverse order.

and pin (17). A clamp (16) secures pin (17) to the
contact svq}port (18). A flexible connection (14) is
provided to prevent pitting at the pivot point of the

MEASURING CONTACT WIPE

movable contact arms when carrying high momen
tary currents.

1. Remove arc quencher (see "Replacements"
under Arc Quencher).

1 POLE UNIT BASE
2 FIBER STRAP
3 CONTACTS

4 MOVABLE CONTACT ARM
5 SCREW
6 UPPER STUD GAP
7 PIN
8 INSULATING LINK

ECCENTRIC BUSHING
CLAMP
SCREW
TRUARC RETAINER
SCREW
FLEXIBLE CONNECTION
a TERMINAL

I 5 LOWER STUD
I 6 CLAMP
I
I
1
2
2
2
2

PIN
CONTACT SUPPORT
SCREW
SPRING
CONTACT CARRIER
CONTACT PIN
SPRING

2 4 UPPER STUD
2 5 STATIONARY CONTACT FINGER
2 6 SHUNT

2 7 SCREW
2 8 STEEL PLATE

CONTACT ASSEMBLY

2. Ascertain the dimension between the inside

surface of the pole base and the top edge of
the stationary contact tip (3), (a) with the
breaker open, (b) with the breaker closed.

5. Removefour mounting bolts (2), Fig. 11,and
lift entire operating mechanism from break
er.

!fote: To remove the two lower mounting bolts
3. Now ascertain the difference between the two

measxirements which should be approxi

(2), Fig. 11, on electrically-operated

breakers proceed as follows.

mately 7/32".
4. Re-assemble parts in reverse order.

a. Move left hand trip paddle to the
extreme left on the trip shaft. Also
remove right hand trip paddles.

ADJUSTING CONTACT WIPE AND CONTACT
PRESSURE

b. Remove lower mounting bolts with
off-set screwdriver and lift entire

1. Remove truarc washer from main shaft (16),
Fig. 8, nearest the insulating link and con
tact assembly to be adjusted.

2. Loosen screw (11), Fig. 10, which secures
the eccentric bushdng to the insulating link
to be adjusted.

3. Push the main shaft (16), Fig. 8, approxi
mately half-way through the insulating link
to be adjusted.
4. Apply an adjustable e:q)ansion tool to the
bushing in the insulating link and turn the

bushing, thereby moving the insulating link
closer or farther away from the stationary
contacts, as required.

5. Re-assemble parts in reverse order and
make proper adjustments.

NOTE: To adjust the insulating link in the center
pole unit, first, push the main shaft through the
right hand insidating link and into the center
link as described in items, 2 and 3 below.

(Caution: Opening spring and cap will drop

out). Adjust center insulating link as described
in item 4 above. Re-assemble parts in reverse

operating mechanism from the
breaker.

6. Remove four screws (13) attaching the braid
(14) to the movable contact arms.
7. Remove two screws and clamp (16).

8. Remove the movable contact assembly from
the operating mechanism.
9. Remove the insulating link from the old

movable contact assembly and reassemble
this same link to the new movable contact

10. Remove braid (14) from new movable con
tact assembly.

11. Install new movable contact assembly and
replace clamp (16).
12. Remove screw from left hand coil terminal.

13. Remove old braid,

14. Install new braid by re-assembling coil ter
minal screw and four screws (13) in mov
able contact assembly.

order being careful to replace opening spring
and cap in their proper position.

15. Replace items 3 and 4 in reverse order.

If any of the contacts are badly corroded or pit

16. Adjust contact wipe and contact pressure
(see above).

ted, thereby making it impossible to adjust for prop
er contact pressure or contact wipe, such station
ary contacts or movable contact assemblies should
be replaced. See "Replacements" below.
REPLACEMENTS" Movable Contact Assem

1. Remove front escutcheon (see "Replace
ments" under Front Escutcheon).

2. Disconnect external wiring to terminal
board and auxiliary switch.

3. Remove arc quencher (see "Replacements"
\mder Arc Quencher).
4. Remove truarc washer from one end of the

main shaft and push main shaft through in
sulating link.

17. Replace items 1 and 2 in reverse order.

Stationary Contact (25)

1. Remove arc quencher (see "Replacements"
under Arc Quencher).

2. Remove the unper stud cap (6) by removing
two screws (5).

3. Pry the stationary contact (25) from upper

4. Replace the new stationary contact in re

verse order. (It may be necessary to tap
the new stationary contact into place by us
ing a mallet).
5. Adjust contact wipe and contact pressiu-e
(see above).

ASSEMBLY
RbRTIAL SECTION A-A

TOGGLE
LINKAGE ASSEMBLY

1 MECHANISM FRAME

2 MOUNTING BOLT

ADJUSTING SCREW

5 SPRING
6 MAIN SHAFT

7 SLOT IN FRAME

22 POSITION INDICATOR

23 RECESS FOR MOUNTING SCREW (SEE R6 B)

24 TORSION SPRING

25 TOGGLE LINKS

11 BUFFER PADDLE

29 NUT AND WASHERS

3. OPERATING MECHANISM FIGS. 11 AND 12

The operating mechanism, Fig. 11, is support
ed between two molded side frames in front of the

middle pole unit. It consists primarily of a toggle
linkage (25), cam (19), crank (16), latch (13), trip
shaft (10) and roller (15). The mechanism is con
nected with insulating link (8), Fie. 10, which, in

turn, is attached to the main shaft (6).

The breaker is closed manuaily by moving the

operating handle approximately 90°clockwise (look
ing from thefront), thereby straightening the toggle

linkage andpushing back main shaft (6) and movable

contacts to theclosedposition. Asimilar action re
sults when the breaker is closed electrically by
means of the closing solenoid (see Fig. 18). The
breaker is held in the closed position by prop (28)

supported on pin (3) and by latch (13) against roller
(lofattached to crank (16).

The breaker mechanism is tripped by rotating

trip shaft (10) and releasing trip latch (13) which
causes the toggle linkage to collapse,thereby allow

ing theopening springs (21)topushforward thernain

shaft and movable contacts to the open position.

Trip latch (13) is automatically reset during the
opening operation. Stop (14) limits the rotation of
trip shaft (10) and thus determines the amount of
latch engagement.

ADJUSTMENTS—Latch (13) is adjusted at the

factory to provide approximately 1/16"engagement

between latch (13) and roller (15) when the breaker
is closed. To adjust for proper latch engagement,

first, loosen lock nut of adjusting screw (18) on the
buffer paddle, to the left of the mechanism frame,
and back off several turns on this same adjusting
screw. Then close breaker and place 1/16" shim
between end of adjusting screw (18) and buffer pad

dle (11). Now advance adjusting screw (18) until
the breaker just trips. Tighten lock nut.

The adjusting screw on top of cam support (20)

PARTIAL VIEW OF OPERATING MECHANISM

Two Opening Springs (5)

1. Remove arc quencher (see "Replacements"
under Arc Quencher).

2. Remove truarc washer from end of main

shaft (16), Fig. 8, nearest to spring to be
installed.

is used to provide between 1/32" and 1/16" clear
ance between latch (13) and roller (15) with the
breaker in the open position. With this amount of
clearance, the breaker mechanism will reset auto

3. Push main shaft to opposite side of operating
mechanism. (Cap (4) and spring (5)will back

same time, provide the necessary overtravel for
prop (28)to moveon pin (3). If not enough clearance

4. Remove cap (4) and spring (5) from slot by
using small screwdriver.

breaker mechanism will not reset. If too much
clearance is provided, prop (28) will not move on
too of pin (3) and the breaker will not reclose be
cause cam support (20)will move against the inner

5 Install new springs in reverse order after
assembling c^ (4) to new spring and push-,
ing cap and spring in place.

matically during the closing operation, and, at the

is provided between latch (13) and roller (15), the

surface of the front escutcheon during the closing
operating. By applying anallen wrench to screw on

top of the cam support (20), and either advancing or
backing off on this same screw, as required, the
proper adjustment can be made.
REPLACEMENTS-'Operating Mechanism,
Fig. 11.

1. See "Replacements" under Movable Contact
Assembly, items 1 to 5.

2. Replace operating mechanism in reverse
order.

up into slot occupied by main shaft.)

Tension Spring (21)

1. Remove operating mechanism (see "Re

placements" under Movable ContactAssem

bly, items 1 to 5).

2. Remove paddles from the trip shaft on the
right side of the breaker.

3. Remove truarc washer from right side of
trip shaft.

4. Remove return spring (12).

POSITION INDICATOR
RETAINING RING
SPRING
SLOT
TRIP BUTTON
TRIP ROD

SPLIT WASHER
NAME PLATE

OPERATING HANDLE
ROLLER
TRIP PADDLE
SHAFT

FRONT ESCUTCHEON AND

OPERATING HANDLE ASSEMBLY
5. Remove top bolt (26).
6. Remove nut from right end of bottom bolt

(26).
7. Remove right hand mechanism frame.
8. Remove tension spring (21).

9. Replace new tension spring in reverse or
der.

NOTE: To replace torsion springs (24 and 27), fol
low procedures for removing tension spring (21)
as above and, in addition, remove the necessary truarc washers and pins.
4. FRONT ESCUTCHEON AND OPERATING HAN

The breaker is closed manually by turning the
operating handle clockwise approximately 90° caus-

i% roller (10) to engage cam(13), therebystraight

ening a toggle linkage (25), Fig. 11, and closing the
breaker. After closing the breaker, the operating
handle will return automatically to the 'Down"position. The trip button (5), in the front part of the
operating handle, is pushed to the rear to trip the
breaker manually.
The breaker may be locked in the tripped posi
tion by pushing the trip button to the rear and in

serting a padlock throi^ slot (4) in the metal fer
rule.

REPLACEMENTS- - Front Escutcheon Assembly

1. Remove four mounting screws (9), Fig. 8.

DLE ASSEMBLY FIG. 13

2. Now pull forward on the operating handle
The front escutcheon is mounted on front of the

operating mechanism frame by four screws (9), Fig.
8. The front escutcheon and operating handle as
sembly consists of:

a. A pistol grip operating handle (9) attached
to one end of the shait (12) which extends
through the front escutcheon.

b. A roller (10) attached to the other end of the
shaft.

c. A trip button (5) screwed to the front end of
trip rod (6) which is centered in the shaft.

turning and tipping the front escutcheon

slightly until dislodged from the breaker.
3. To remount the front escutcheon assembly,
first, hold the trip shaft in a trip free posi
tion. Then pull the cam support (20), Fig.
11, slightly forward.
4. Insert the shaft (12) androller (10) into the
hole of the cam support so that the roller

(10) drops behind cam (13).
5. Replace the four mounting screws to secure
the front escutcheon assembly to the mech
anism frame.

eon andshaft (12). Remove the tnprod and
returning spring (3) from theoperating han

dle by pushing the trip rod forward through
the operating handle. (For removing shaft
(12) see "Recessing the Standard Breaker

under Extension for Recessed Breakers,
items 3 and 4.)

4 Re-assemble operating handle to front es
cutcheon and shaft (12) in reverse order.

Note: Inrepiacingsetscrews inoperating han
dle.it is important that the shortset screw in item
(1) above, is replaced after the long set screw in
item (2) has been replaced.

Toprovide forsufficient clearance between the
lone set screw and trip rod (6), the long set screw
is advanced until it just binds the trip rod. Then

back off on set screw one turn. After lockii^ the
long set screw with the short set screw, check trip
rod (6) to see that it moves freely.

5. POSITION INDICATOR FIGS. 14 AND 15
The mechanism of the position indicator is
mounted on the leftside of the operating mechanism

frame (looking from the front). It consists of a link
(5) connected with the main shaft (6), crank (3) and

shaft (4).
FIG.

The stationary green target (9) is mounted be
hind a window (10) in the front escutcheon (15) and
indicates when the breaker is in the open position.
The red target (ll)which indicates when the break
er is in the closed position, is actmted by the mam

LIHKAGE FOR P0S1T10H INDICATOR AND
AUXILIARY SWITCH

REPLACING THE OPERATING HANDLE
1. Remove the short set screw from the tap

ped hole In the operating handle. (See Sec
tion A-A).

2. Back off a second longer set screw from
the sametJ^ped holeuntil it is moved clear
of the shaft.

3 Pull forward on operating handle until trip
rod (6) is released from the front escutch

shaft (6) through link(5) and crank (3), thereby mov
ing the red target in front of the mdicator
Shaft (4) serves as a pivot for cr^ (3)
turn, also operates the rotaryauxiliary switch (see

"Rotary Auxiliary Switch'Tig. 16). When the brew
er opens,
ooens, the
tne main
mam shaft
snaii. liiuvco
moves the
..... crar^
v,.-.-. upward
-r---er
^
wmHmy which
causing
the red»Itarget to drop belcm theA window
which

allowsthe stationary green target to become visible.
REPLACEMENTS—The position indicator is a

sub-assembly of the operating mechanism ^d is

replacedwhen theoperating mechanism is replaced.
I OPERATINO MECHANISM
FRAhC

Z SUIT IN CRANK
3

4 SHAFT OFAUXIUARY

SWITCH (SEE FIG. IS)

6 MAIN SHAFT
7 PIN IN CRANK

8 PIN IN INDICATOR ARM

8 GREEN TARGET (SEE
FI6.I3]
I 0

I I RED TARGET AND
INDICATOR ARM

I Z PIVOT-INDICATOR ARM

9)13 RIVET
I 4 SLOT IN MECHANISM
FRAME

I 9 FRONT ESCUTCHEON
(SEE FIG. 13]

POSITION INDICATOR

6. ROTARY AUXILIARY SWITCH FIGS. 16 AND 17

The auxiliary switch is mounted on the left
ae of the operating mechanism frame (looking

iTom the front). The main shaft of the breaker

position of the particular cam 90^ inrelation to the
shaft. Contacts should be cleaned occasionally to
insure proper performance.

REPLACEMENTS"Rotary Auxiliary Switch, Fig. 16

operates a crank (3) when the breaker opens or

1. Disconnect all leads to the auxiliary switch.

closes which, in turn, actuates a shaft (4) extend
ing through the various stages of the device, there

2. Remove mounting bolt (1) and screw (6)re
moving device from brewer.

by opening and closing the "a" and 'V contacts of

the atixiliary switch (the "a" contacts open when the
breaker opens and the "b" contacts open when the
breaker closes). The opening and closing operation
of the contacts is determined by the arrangement of

If no approved sketch of the cam (16) ar

rangement is available, remove the endplate
(9) from the device by removing the four
tie bolts (2) and draw a sketch of the posi
tion of the particular cam in relation to the

STAGE OF SWITCH SHOWING

BREAKER IN OPEN
1
2
3
4
5
6
7
e
9
10

MOUNTING
TIE BOLT
CRANK
SHAFT

LINK(SEE FIG.15)
B0TT(»4 COVER
END PLATE

SLOT (SEE FIG. 15 )

1 1
12
13
14
15
16
17
18
19
20

TOP COVER
"a" CONTACTS
CONTACT SPRING
ROCKER ARM

CAM
"b" CONTACTS

RECESSED BREAKERS

6. DISCONNECTS FIGS. 32, 33 AND 34
The disconnects are attached to t h e

;^«>^breaker studs on the rear side of the breaker.
Each disconnect consists of four contact fin

gers (3) secured to each breaker stud (7) by screw

0) and retainers (6 and 8). A pair of springs (2)
exert pressure on the contact fingers when engag
ing the stationary studs (4). Stop (5) and retainers
(6 and 6) serve to maintain the proper alignment of
the fingers when engaging the breaker studs.
Note: For Instructions on mounting the break
ers by means of disconnects, see"Dead Front Break
ers" under Installation, Section m.
ADJUSTMENTS—When the proper amount of

contact pressure is exerted against the stationary
stud, the dimension from the top side of the iq)per
washer to the bottom side of the lower washer on

screw (1) should be approximately 3-1/32" using
5/8" springs, or 4-1/32" using 1-1/8'springs. (The

corresponding dimension on Type AK-1-25 break

ers should be approximately 3-29/32"). To adjust
for proper contact pressure, the adjusting nut of
any particular contact finger should be backed off
or advanced, as required.
FIG. 32

The disconnects are checked for the proper

amount of spring pressure before leaving the fac

DISCOHHECTS ENGAGING STATIONARY STUDt

A STATIONARY STUD

DISCONNECT FOR MOUNTING TYPE AK-l-15 BREAKER

CONTACT TINOCNi

DISCONNECT FOR MOUNTING TYPE AK-l-25 BREAKER

2. Disconnect wiring to Terminal board.

7. TERMINAL BOARD FIG. 35

The terminal board is attached to the right

3. Remove two screws attaching terminal

side of the breaker (looking from the front) by a

board to bracket and remove terminal board.

bracket and two screws. It consists of a molded

contact strip on which are arranged a number of

4. Install terminal board in reverse order.

binding screws for making connections with the

various breaker devices which are externally con

trolled. It has a front cover to prevent dust and

dirt from collecting on the terminal connections.

1. Remove terminal board (see above).

REPLACEMENTS'-Terminal Board

2. Remove two screws from bracket and re
move bracket.

1. Remove cover of terminal board by re
moving two screws.

3. Install bracket in reverse order.

WftSffWt• l i

TERMINAL BOARD WITH COVER REMOVED

FIELD
SWITCH
FIELD

DISCHARGE
CONTACTS

RESISTOR
FIELD
WINDING

2. MOVABLE CONTACT
3. SHAFT
4. LINK

5. LINK
6. PIN
r

8. CRANK
9. SPRING

IL SCREW
12. SCREW

iioisie
B3M2|^3 »
4

FOR CLOSmO COIL IS USED OMIT
JUMPERS AI-3 a A2-4 a CONNECT
CLOSING COIL POWER TO A3aA4

\
•• ''v' ••:

• '••'r-fT'

7yp>© AiCP-^B-3
iSeetneesily Og»erG&@clI

r;: .....
• >'•.

;• •••.• 'u'.; v4i

'•''.•••i-SISI
.Vj.;-.

ni.ijiin.< n 'liitmipaniaaaaq

ISfi:©
PHILADELPHIA, PA.

GEI-74624 Power Circuit Breakers Type AKF-lB-3 to 10'
.

TO POWER SOURCE

FIELD OlSCHAROe

DISCHARGE
RESISTOR

-AAAAA/^
vv VVV

TYPICAL CONNECTION
DIAGRAM

1. Stationary Contact
2. (iSovable Contact
3. Breaker Contacts
4. link

5. Main Shaft
6.
7.
8.
9.

Crank
10. Eccentric Pin
11.
12.
13.
14.
15.
16.
17.
18.

Holding Screw and I6it
Screw

Clamp
Pin
Screw

Field Discharge Contacts (AKF-iB-3 to. 5}.
Y.

POWER CIRCUIT BREAKERS
TYPE AKF-lB-3 TO 10

ELECTRICALLY OPERATED

The instructions contained herein are a supplement to instruction book GEI-74603
to be used in conjunction with GEI-74603.

The AXF breaker is a special type of AK breaker designed especially for use in
controlling the shunt field circuits of synchronous generators and synchronous motors.

These breal:crs are usually furnished jwithout series overcurrent tripping devices and
have a continuous rating of 600 amperes. The AKF is a two pole air circuit breaker '
with field discharge contacts placed in the center pole base.

The closing of the field dischargeIcontacts connects a discharge resistor across

the field of the generator or motor, l^is makes it possible to open the field switch

without inducing a high voltage in the field.
S%i :•

The AKF breakers differ as follows:
I

1. The AKF-lB-4 is the same as the AKF-lB-3 except for the "T* relay of the
solenoid control system.
2.

The AKF-lB-5 differs from the AKF-lB-3 in that it has a plastic front
escutcheon and the same "Y»'relay as the AKP-lB-4 breaker.
The AKF-lB-6 is the same as the AKF-lB-3 except that it has a different
field discharge mechanism. It also has the same "Y** relay as the AKF-lB-4
breaker.

4. The AKF-lB-6 to 10 have same field discharge mechanism. (For a complete
tabulation of nomenclature changes, see Page 3 of GEI-74803.)
AKF-lB-3, AKF-lB-4 AND AKF-lB-5
FIELD DISCHARGE MECHANISM
FIGURE lA

When an AKF-lB-3, AKF-lB-4 or AKF-lB-5 field breaker is operated, the field
discharge contacts close before the main contacts of the breaker open; the field

discharge contacts open after the main breaker contacts close. This overlap prevents
an open circuited field.

Smficient clearance between the upper stud and the upper part of the stationary
f

is provided.so that a contact wipe of approximately one-half inch on
discharge and the main contacts may be established. The main shaft

4 bracket (12). Link (4) is coupled
hole to
in crank
compound
link (4)
which ison
pivoted
on pin (7) in
(9) which
is. pivoted
pin (8)

These instructions do not purport to cover all details or variations in
provide for every possible contingency to be met in connection

.Vitil installation, operation or
maintennr>r«
or maintenance.

.Qfirti.lH further
fi.'nfKA.. information be
Should

ao.>ired
ed or
or should
shoulc particular problems arise which are not covered sufficiently

ior the purchaser's

El'ecSfc CompSy^ ^ purposes, the matter should be referred to the General
'wm
. '.Vv

- GEi-74624 P0T7er Circuit Breakers Type AKP-lB-3 to 10

in bracket (12) by means of an eccentric pin (10). Compound Unit fS^ u

cranii (9) and discharge con^oict (2). Bracket (12) is securely fasteSd to &e oole
holding screwsnurs (13) and is dowelled in place fay dowel
attempt ^i^fuldhe made to move the supporting brackeT(12riS the

main sliaft (5) moves backward, away from the oole
tmo
tothestraighten
the toggle ttnhage (6 and 9) tlias forcing the disihar^
rontelm cl&

towa?d"h?e®poir4°IJf®TSs''c^^^^^

wthtc&X^on^n'tayfLT'®®

bettrSfth^to?^f„dT^o^®/?onlct®''a^^^

»PSf°^teIy one Inch

sroiss-^^s-SS-srSs?
b.

SW.tJSSS SSZV^SS^p»i. «».B

As8e^M^l^li°7^a°fetoe»s should be approjdinately 1/2". See "Pole Unit

»®tood of obtaining desire/w4>e and pres^ router

REPLACEkSSNTS
".I

Movable Contacts (2)

<®®® "Replacements" under "Arc Quencher'', page 6of

'• lasffv ^a|e"u'r^^W
*"

3. Remove pin (17).

4. gemove two screws (13) and remove field discharge mechanism
5. Remove two screws 15) and two clamps
"lecnamsm.

6. Remove movable contacts.
v-ioA
7. Replace new contacts in reverse order,
Q

contact pressure (see above)

gepiace operating mechanism.
Replace arc quencher.

Stationary Contacts (1)

v®®® aoove;.

gI?.?4S^.^ quencher (see "Replacements" under "Arc Quencher", Page 6of

2. gsuiovG the upper stud cap by removing two screws (18)

a may be necessary

Power Circuit Breaicers Type AKF-lB-3 to 10 GBI-74624

•''^-lB-6 "O 10 ^^^I^O'SOlAEGa I4ECHANISM
moves forward causing arm (7) to dwoTahnnt ni«

av/2y from tiie breaker base. Tris moition ciuSii?2v?i

causing link (16) to move

^^CtsmwMchpivoi^L^^
SO tlat'tte^eW^dUctoll^M^^

described above is reversed, ';;

tl.e ott^f
•y ;• •

discharge
contactstheshould
between'l-l/Pftid^
♦ movement
stationary
& .M^c^ding
to reduce
gap. beThis
adiufitnid»n?4^5^f "3/^"^
• side of the eccentric
and rotatlnff^n^m«i^fc^"^® ^ loosening the huts on either

h. 1- nuts securely after n^ti^ rota.tijig pin until the proper opening exlste. Ti^t^ the

!^s^£rtd?eWeaV?6°'^d
;;
Close betwee.il/4^i^8;.2^^^2:^^^
1/16" overtravel^hen''ttOT°5e^!ai^wSed'hf

1/2". However, this dimlLtou i^ot^?ftl?i'

should be
' ® adjusted to provide

^''c'dd be approxb^teS

-nethod 01 adiustin|^»^Sj&y«^^™^t Unot
: '

Movable Contacts (2)

^ "Replacement" under "Arc Quencher", Page 6of '

4.. now
EoSove
claS'1:M) and^twJsciews aUo}.
.tree to be removed.

niovable contacts (2)

The field discharge mechanism is

Powsr Circuit Breakers Type AKF-lB-3 to 10

Stationary Ccncacts (1)
1, Remove movable contacts as described above.

2. Remove upper
(25) by removing three screws (26).
Re-move upper stud cap (5) by removing screws (4).
4. R-emove pin (3) and stationary contacts (1).
5.

Keplace parts in reverse order.

NOTE: The stationary contacts on the outside pole units of the AKF-lB-6 to 10
are eimilar to the stationary contacts of the field discharge mechanism.
When replacing the stationary contacts on the outside pole units, remove
the movable contact assembly as described in GEH-74603 and then
remove the stationary contacts as described above.

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.

Oontact Finger (Sta.)
Cbntact Arm (Mov. )
Pin (Contact Pivot)
Screw FL. PH. HD.

Up?er Stud Cap
Coupling

Buffer
Biain Shaft
Link
Pin
Link
Bracket
Link
Pin
Link
Eccentric

17.
18. .Screw RD. PH. HD.
19. Fie:tible Lead
20. Clamp
21. Pin (i.!ov. Cont. Pivot)
22. Pin (Insul.To.Mov.Cont.

23. Screw RO. PH. HD.
24. Spring (Stat. Cont.)

25. Upper Stud
26. Screw RD. PH. HD.

Field Discharge Contacts (AXF-IB-6 to 10)

Types AKf-lB-S, AKf-lB-4, ASCF-1B-5,
and AKF-1B-6, llectricoliy 0|jeret8d
Kf?a

SWiTCNOEAR
fir. .

Air Circuit Breakers Type AKF
TO POWER SOURCE

field discharge
CONTACTS

-discharge
RESISTOR

-i field
WINDING

TYPICAL CONNECTION
DIAGRAM

Stationary Contact

2. Movable Contact
3. Breaker Cbntacts
4. Link
5. Main Shaft
6. Link
7. Pin
8. Pin
9. Crank
10. Eccentric Pin
11. Spring
12. Bracket
13. Holding Screw and

14. Screw
15. Screw
16. Clamp
17. Pin
18. Screw

Field Discharge Contacts

AIR CIRCUIT BREAKERS

TYPES AKF-lB-3, AKF-lB-4, AKF-lB-5 AND AKF-lB-6
ELECTRICALLY OPERATED

The instructions contained herein are a supplement to instruction book
GEH"18G7 and are to be used in conjunction with GEH-1807.

The AKF breaker is a special type of AK breaker designed especially for use
in controlling the shunt field circuits of synchronous generators and synchronous

motors. These breakers are usually furnished without series overcurrent tripping
devices* and have a continuous rating of 600 amperes. The AKF is a two pole air

circuit breaker with field discharge contacts placed in the center pole base.

The closing of the field discharge contacts connects a discharge resistor
across the field of the generator or motor. This makes it possible to open the
field switch without inducing a high voltage in the field.
.

The AKF breakers differ as follows:

1. The AKF-lB-4 is the same as the AKF~lB-3 except for the "Y" relay of
the solenoid control system.

2 The AKF-lB-5 differs from the AKF-lB-3 in that it has a plastic front
escutcheon and the same"Y" relay as

3. field
The AKF.-1B-6
is the, same as the AKF-lB-3 except that it has a dif^rent
discharge mechanism. It also has the same Y relay as the AKF
lB-4 breaker.

AKF-1B"3, AKF-lB-4 AND AKF-lB-5
FIELD DISCHARGE MECHANISM
FIGURE lA

When an AKF-lB-3. AKF-lB-4 or AKF-lB-5 field brewer is operated, the

field discharge contacts close before the main contacts

Yield discharge contacts open after the main breaker contacts close. This over p
prevents an open circuited field.

Sufficient clearance between the upper stud and the upper part of
contact support is provided so that a contact wipe of

on both the field discharge and the mam contacts may be established. T^
ic nfvoted
pivoted on pin (7) in bracket (12). Link (4) is coupled to crank (9) which is pivoted

shaft (5) of the breaker passes through a large hole

These instructions do not purport to cover all details or variations in equyinstallation, operation or maintenance. Should further information be desired or
should particular problems arise which are not covered sufficienUy
P"^_
chaser's purposes, the matter should be referred to the General Electric Com
ment nor to provide for every possible contingency to be met in connection witn
pany.

Air Circuit Breakers

i
. <>. r>in (8) in bracket (12) by means of an eccentric pin (10). Compound link (6) is
' coupled between crank (9) and discharge contact (2). Bracket (12) is securely
fastened to the pole unit by holding screws and nuts (13) and is dowelled in place

^by dowel screw (14). (Caution: No attempt should be made to move the supporting
bracket (12) ). When the breaker trips, the main shaft (5) moves backward, away
from the pole base. This allows the spring fll) to straighten the toggle linkage

(6 and 9) thus forcing the discharge contact (2) closed.

During the closing operation of the breaker, the main shaft (5) moves forward
toward the pole base. This causes link (4) which pivots on pin (7) to force crank (9)
to pivot about pin (8) causing the toggle linkage (6 and 9) to collapse allowing the
discharge contact (2) to open.
ADJUSTMENTS

With the discharge contacts open there should be a gap of approximately one
inch between the movable and stationary contacts. This gap may be adjusted by
loosening the nuts on either side of the eccentric pin (10) and rotating the pin until
the desired gap is obtained. Be sure to tighten nuts securely after adjusting.
The overlap between the discharge contacts and the outside pole contacts

should be between 1/8" and 1/4", measured at the point of contact.

Contact wipe on-alLcontacts should be approximately 1/2". See "Poie Unit

j^iWi^mbIy"in GEH-1807 for method of obtaining desired wipe on outer pole contacts.
Rx:.PLACEMENTS

Movable Contacts (2)

1. Remove arc quencher (see "Replacements" under "Arc Quencher",
.GEH-1807).

2. Remove operating mechanism (see "Replacements" under "Operating
Mechanism", GEH-1807).
3. Remove pin (17).
4. Remove two screws (13) and remove field discharge mechanism.

5. Remove two screws (l5) and two clamps (16).

6. Remove movable contacts.
7. Replace new contacts in reverse order.

8. Adjust contact wipe and contact pressure (see above).
9. Replace operating mechanism.
10. Replace arc quencher.

Stationary Contacts (1)
1. Remove arc quencher (see "Replacements" under "Arc Quencher").
2. Remove the upper stud cap by removing two screws (18).
3. Pry stationary contact (1) from the upper stud.
4. Replace the new stationary contact in reverse order.

5. Adjust contact wipe and contact pressure (see above). It may be necessary
to tap the new stationary contacts in place.

Air Circuit Breakers

AKF-lB-6 FIELD DISCHARGE MECHANISM
FIGURE IB
•

The main shaft (9) of the breaker passes through a large hole in arm (7),
which is pivoted on pin (11) in bracket (13). When the breaker is closed, the main
shaft (9) moves forward causing arm (7) to pivot about pin (11), thereby causing
link (16) to move away from the breaker base. This motion causes link (14) to
move downward pivoting about eccentric (17). The downward motion of link (14)
is transmitted through link (12) to coupling (10) and link (6), thus causing the

linkage to collapse. The field discharge contacts (27), which pivot about pin (21),

open when the coupling (10) and link (6) collapse.

When the breaker is opened, the mechanism motion described above is
reversed, so that the field discharge contacts close.
The contacts of the discharge mechanism are set so that one contact makes
before the other. This is done to minimize wearing of the contacts due to arcing.
ADJUSTMENTS

With the discharge contacts open, the gap between the movable and stationary

discharge contacts should be between l"l/8" and 1-3/8", with the free movement

tending to reduce the gap. This adjustment is obtained by loosening the nuts on
either side of the eccentric (17) and rotating the pin until^the proper opening exists.
Tighten the nuts securely after adjusting.

The extended stationary contact and the standard stationary contact should be

staggered between 1/16" and 1/8". The extended contact finger on the center pole

should close between 1/4" and 3/8" before the contacts on the outer poles break.
Both the breaker contacts and the discharge contacts should be adjusted to

provide 1/16" overtravel when they are fully wiped in. Contact wipe should be
approximately 1/2". However, this dimension is not critical, and wipe in excess
- of this amount.is not significant. For method of adjusting wipe see "Pole Unit
Assembly" in GEH-1807.
REPLACEMENTS

Movable Contacts (2)

1. Remove arc quencher (see "Replacements" under "Arc Quencher" in
GEH-1807).

2.- Remove operating mechanism (see "Replacements" under "Operating
Mechanism" in GEH-1807).
3. Remove screws which attach flexible lead (19) to the movable contact arms.

4. Remove clamp (20) and two screws (18). The field discharge mechanism is
now free to be removed.

5. Remove pin (22) and movable contacts (2).
6. Replace contacts and re-assemble field discharge mechanism in reverse
order.

7. Adjust contact wipe and pressure (see above).
8. Replace arc quenchers.

^^ir Circuit Breakers Type AKF
Stationary Contacts (1)

1 Remove movable contacts as described above.

2* Remove upper stud (25) by removing three screws ( ).
3*. Remove upper stud cap (5) by removing screws (4).
4i Remove pin (3) and stationary contacts (1/.
5*. Replace parts in reverse order.

When replacing the stationary contacts on the

remSve the movable contact assembly as described in GEH 1807 and

[heTremove the stationary contacts as described above.

Contact Finger (Sta.)
Contact Arm (Mov.)

Pin (Contact Pivot)

Screw FL.. PH. HD.

7. Ann
8. Buffer
9. Main Shaft
10. Link
11. Pin
12. Link
13. Bradcet..
14. Link
15. Pin
16. Link
17. Eccentric
18. Screw RD. PH. HD.
19. Flexible Lead
20. Clamp
21. Pin (Mov.Cont.Pivot)
22. Pin (Insul.To Mov.Cont.)
23. Screw RDr PH. HD.
24. Spring (Stat. Cont.)
25. Upper Stud
26. Screw RD. PH. HD.

Field Discharge Contacts
adb

GENERAL ELECTRIC APPARATUS SALES OFFICES
R«otiy lo Asfitt You wllU Your Preblons

P.O. Bo* 58,
229Thtrleenth
W. Bgto St.
409
S».

Flln. 2. M.ch
653 S- Soglncw S,. OKahomc CUy 2, OLIo.. 119 N. Robtn.on S.
A*e fort Wo/ne 6,, hd
3606 So. Co'houn St. Oir.oho 2. Nebr. p^
409
S. Sevonteenth
-.. 8 Col'in
Colrin A«.
,7,_3^4
W. lo-i. St.
St.
323^^r^St., S.W. fo.t
^^ 3^^ „,g
3
309 Jeflcr.on
BUfl.

Milonc, rexai
Ilk . 3,
t KlN. Y..
y
^totiy
Wbu,««q«.
N. Mo*
Ao*andfio, lo

AI1enlown,Fo
^""1 , Wi«

SohlTr'e
Baltimore 1'Md
1, Md.... ._

Bottle Creek, Mich
Btllings, Mont

Biaahamlan N Y
Y
B.nahomten,N.

Fernui Fotlt MInrt.

i132 Hamlllon St

1132 Horn Ho 5t.
Sib w College Ave

Box A»b.
197 Collond
NorfoH«l,Ya
lOB P.O.
N. Co..r1
12, Colil

" 6200 Conp Bowie Bl.d.

407 FoHerton BIdg.
Telore end felton St.

H.W. G,,...b..,N.C

Ill
_ , Pork, Ave!
, 5, Greenville, S. C

P.O. Bo* 1408
108 W. Wothinglon
St.

:.•.....3170 Florida BUd! Gel(port, Mi.k^

PO. Bo*
ibbi Seventh
Ave.,2602N.

Jock.on 1, Milk
2, Flo.

.Vl40 Federol St! IColomaioo, Michigon

k25Del^o«A.e
Sllnr Monl?: P.O. Bo* 836,103
N. Wyoming St! Kon.o. City 5, Mo

1226 Morket Ave., N. ICno*.ille 16, Tenn

e " ei.?
..626^^^^^^^

*" '".110
Vin S.
c f.r.
e- »<•*
S.

203 W.G-Bo*
Copitol 48
St. Socr°mento
Rutlond, Vt. 14, Colif..
Stotion
700 E. Union St.

3750
Mef'dionAve.
St. Rochester
120
W.N.Michigan
Rock(ord III4, N. Y

Alft e#»q.-r A^d.

B^'on""mo.'.!
i^JroMV

Roleigh, N.PoC... P.O. Bo* 2507,
Reoding,

.'"..rdd
A.ylvm AvS. Roonoke 5,aVou v
l312Xi*e OcV Si,

P.O. Box 931
,Vae„ongo
L Indianopolts
Jock.cn: Mich8, Ind

p;,^;;,oL°"Art. BWg River.ide, Colif

l-isTbold^r a:° Hortlord 5, Conn.
Rm. 815, 303 No. Broadwoy Hootton 1, Texas

3Penn Center Plato

Phooni*. Arit.. .P.O. Bo* 4037. 220 lehr. Tower
Pituburgh 22. Po.. .The Oliver BIdg, Mellon Sq.

25 W. Mieh^on Ave Hoger.tovrn, Md

Blneinnham}
Birmingho 2, Ala

Philodelphio 2, Po

Second Nohonol Book BIdg.

P.O. Bo* 447 Son^tonio
5, Te*a.
Son Diego 1, Calif

927 South Burdick St.
106
W. Fourteenth St.

1301 Honnoh Ave., N.W. Son Fronceo 6, Colif.

434 So. "o'" *«•

P.O.Bo*1222
235^MontVomlrv
St"

235 '*?2J?p™Va,V

Cedyreiton , ' *•-jqj_
2'° .V.01o*'h5g
Yi lon.ing 8, Mteh.. .814 Michigon i2fse®v.Mh
i?. t'Seotlle
onnoh.11,GoWo.h !!'.!!!!!!!io
Eo.t BoyAve'St!
National Tower
710^«ond'
1 u r

112 S. Tryon St.

Chicago 80, III

Lexinqlon* Ky.. .. d02 First Notioncl BanV Bldg.

Lincoln 8, Nebr... .Shorpe BIdg., 206 S. 13th St.

840 S. Conol St. lo Angele 54,^Col.f.. ...... ^N.

Ortcinnati 6, Ohio

.2621 Victory Pkwy.

Oovelond 4,Ohio
4966 Woodland Ave.
Celumblo I. S. C.P.O. Bo* 1434, 1420 lody St.

Colurabin 15, Ohior

40 S. Third St.

3325 Wilthire Blvd.

2 Ky
i„i,bock Te*a.

455 S. Fourth St.
P.O. Bo* 1464

• 3302 Avenue "A"

/lu oeeono a e.

Seattle 8, Wash... Avla. 8k Oef., 2^0 Daw^n

Spokone 4, Wash

Springfield, Ul
Springfield 3,Mo.k

S. 162 Post St.

607 E. Adorn. St.
1387 Main St.

SlocHon, Calif.. ..... - 11 So. Son Jooqum St.

Corpu. Chriiti, Te*ot
205 N. Choporrol Macon, Go..... P.O. Bo* 1506, 682 Cherry St. Syr«u.e 1,N. Y P.O. 80* 'O'l. 3M2W« Sk
OoZ.
2,
Te*o.
1801
N. Lomcr Sk Madi.on 3, Wire"p^" Bo*"lii9,.6107N. EMain
Corr^ St.St! Tocomo
1, Wod.
J" J.-^lSng^o; Z
Dovenport-Bettendorf, lowo
.P.O. Bo* 630
Tompa 1, Flo... P.O. Bo* 3092,1206 North ASt.

" W. Monumeiil BIdg.

Ocylon 19. Ohio, Avfa.&DoF..2600 For Hill. Avo.
Denver 1, Colo

••-P.O. Bo* 2331

650 Seventeenth St.

Dei Molnei 9, lowo

505 W. Fifth Ave.

Detroit 2, Mich.
Dvluth 2,Minn.
El Po.o, Texoi

-Erio 2. Po.
eugono,
Eugene, Ore
k/ro..

700 Antoinette St.

14W. Superior St.
215 No. Stonton

'. ' ^ Gty bvio.......
-

Noihville 4, Tenn
N,work 2, N. J

Howoll, Am.rl.on Fodor., Ltd., P.O. Box 3230, Honolulu 1

125. Si«th St.

704 Government St.

1717 W. End Building
520 Brood St.

T^^frn's, n!T.' .V.V.V.:V214 E. Hon"^^

Tuc.on, Arii.. ..P.O. Bo* 710, 650 N. Si*th Ave.
3^ ohIo

Woihinglon 5, D. C

320 S. Bo.ton Ave.
258 Gene.ee St.

Wenotchoo, Woih.. ........... P.O. Bo* 676
328 N. Wenotchoo Ave.

Thoie O-E lorvlee ihopi will ropoir,

y;uV.UcVr:.° pp"ct„i. The'lcCitie. at.

available doy ond night, .oven doyi o week, for work in the ihopi

or on your premliei. loteil foetory roothedt ond genuine O-E renewal

Allanla-Chambloo, Go

4639Indui.
Peochlree
Ft. Woyne, Ind
Blvd. Hoution 20, Texas.

•Arkonsoi Otv Kon

Indianopoli. 22, Ind

318 Urbon St. loulsv.lle, Ky
MWlond, Te*
e'^' Mllwoukee 3, Wise.
'tJ'!! el' Minneapolis 12. Minn
4W W. Third 5.
Orleons, lo

Charleston 28, W. Vo... 306 MocCorkle Ave, S.E.

•Gnpnnoti 3, Ohio

Conodei Canadion G.norol Eluctrlc Company. Ltd., Toronto

GENERAL ELECTRIC SERVICE SHOPS

WHFM YOU NEED SERVICE

Buffalo 11, N. Y
Charlotte, N. C.'
Chlcogo 32, ilk.
Onelnnoti 2, Ohio

1001 Store St. New Haven 6, Conn
129 Church St. Wheeling, W. Vo
2OO e""/.! S"
P.O. Bo* 352, 1170
pob<.*157
Peorl St. Now Orleon.
York 22,12,
N. Y
lo.. ........837
570 le*lngton
GrovierAve.
St. Williom.ten,
f'''"V
N. C, »q
P.O. Box748, 115t. Mom St.

port, ore utod lo molnloin peok performance of your equipment. For

full informetion cbou. the., i.tvic.., ..ntod your nuorui. .ervl.e

Oenotei A.rcroft Sorvico Shop.

606 W. Sj^erior St. Roonoke
Richmond 7,24Vo..
Vo .

5534 Harvey Wikoo Dr.

1740 W. Vermont St.

Sacromento, Col.f

j'OO Cmien Dt.
3404 Bonkheod Hwy.
940 W. St. Poul Ave.
2025 49th Avo, N.
2815 N. Robertson St.

.5 ,„g 4 wo,h
« ,hi„g,o'„ Conn
SpoVgne 3. 'wosh
po„pp j, f,o..
Tdedo 4, Ohio

yprt-N. Bergen, N. J.. 6001 Tonnelle Ave. York,

Wumt"f23. o^te."loMn«: Ooklond, Colif

1525 Pero.to Sk Youngstown 7, Ohio

i,s V,kl™ori"®Avr
SE
Sot. 17,'k st'
99 N. 17th St.

3422 First Ave, S.
45 Roilrood Ave.
S. 155 Shormon St.
P.O. 80* 1245
405 Deorborn St.

54 N- Hot!'"" St.

272 E. Ind.onolo Av^

GENERAL ELECTRIC COMPANY^ PHILADELPHIA, PA.
Hoadboak fttf«r«Aca No. 6735

SvpofBodat CfN.)833A

G£F'350^C
i'•"•I!

RENEWAL PARTS
TYPES AK-1-15 AND AK-1-25
POWER CIRCUIT BREAKERS AND
TYPE AKF-1B FIELD BREAKERS

(PnOTO e02028Jl

Fig. 1. Type AK-1-25-8 air circuit
breaker, monuaiiy operated

NOTE: All reference to "right'' and "left" designate the location of the part when facing the operaHng
mechanism end of the breaker.

ORDERING INSTRUCTIONS

Always specify the complete nameplale data of ilic breaker.

2. Specify the quantity, catalog number (if listed), reference number (if listed), description, and this
bulletin number.

3 CAUTION- When local facilities for breaker recalibration are not available, the breaker should tie
forwarded to the nearest G-E Service Shop, or to the General Electric Company, 6901 Elmwood Ave.,

4. SUindard^hardware, such .is screws, bolts, nuts, washers, etc., is not listed in this bulletin. Such
items should be purchased locally.

5. For prices, refer to the nearest office of the General Eiectric Company.
Wh«n erdpring i«nev.al potU, give qgonlltv. cotoiog numb.r, daicriplisn of eeith Ham reqoiiad. ond compiala nomaplola taoding.

GENERAL
Oefe tubive* >t»

•ithOMf noliuc

TYPES AK-M5 AND AK-1-25 POWER CIRCUIT BREAKERS

-23 4124
4 2
-25 45

Fig. 3. O
for Type

TYPES AK-1-15 AND AK-1-25 POWER CIRCUIT BREAKERS

N'jmliof Roquired tor 3-i)Olo DriMkur

Description
7 -8 -9

For Tyiic AK- 1-25

For Typr AK 1-15

6357045P3
6357059P3
6403453P2

6414297P]
6414299P1

' 9 ;9
!I 2. 13
I-

Trip paddle for EC-1 trip
Trip paddle for EC-2 trip

64031U9G3
6372777G1
6317569P5
6317613P5
631799501
6317995G2
63n551P4

6317719P4
C3neilP4

Upper stud
Stationary contact
Upper stud cap

Upper stud cap
Moving contact
Moving contact
Insulating link

Insulating link, outsidepoles
Insulating link, center pole

Eccentric bushing

644406CP1
6555759P1
6555759P3
6372794G1
6372794C2

Clnmp
Contact support
Contact support

6444378P1
()444195P2

Insulating tube
Insulating cap

Flexible connection
Flexible connccUoii

640313r)G2
6403fi5LPl

Stationary contact pin

Stationary contact spring
Stationary contact pin

6372917
624a887PI
6248887P2
0372778G1

Fibre strap
Fibre strap

6403513PI
6403513P2

6444011P1
6444084P1

ClarapforEC-1 trip device
Clamp forEC-2trip device

Overcurrent trip device

Buffer paddle assembly

Slndicator link
indicator link

Inside barrier
Inside barrier
Muffler
Muffler

6555445?!
386A163P1

Outside barrier, left
Outside barrier, left

62488giPl
631763401
6403366
386A100G1
2761127401

Arc quencher cap

Outside barrier, right
Outside barrier, right

Arc quencher cap

Arc quencher assembly
Arc quencher assembly

6403140P1
9921666G1
99216G6G2
6444907P1

6403138P2
6302324P1

6372758P2
6403139P2
6403130P1
6403138P1

Arc quencher clamp

Reinforcing barrier
Arc quencher damp

Pole unit base
Pole unit base

Side frame, left

64035I1O2
640350'XJt

Side frame, right

Recommended for stock for normal m.iiiUcmincc.

5 For manual breaker witliout auxiliary switch,

For manual breaker with auxiliary switch or lor oleclric breaker.
1 Original breaker had no suffix letter or numeral.

0 When orderms; specify complete nameplate data of device being replaced. The only part furnished for the EC-2 device is
the case (Cat. No. 242C645P1).
^

TYPES AK-1-15 AND AK-1-25 POWER CIRCUIT BREAKERS

Number Required for 3-pole Breaker
For Type AK-1-25

For Type AK-1-15

tlA 1-11-21-3 -4 -5 -6 -7 -6 -9 -10

6372922
6248846F2
6403546P1

Opening spring
Opening spring cap

372A215P1
6403546P1
6372924

Prop, electric breakers
Prop, manual breaker
Prop, return spring, manual

Prop, return Spring, manual

6444012P1
6372914

Prop, pin
Reset spring

6372742G1
6372784G1
412A253
365A331
6372739P1
6444010P1
6444044P1
6248832P3
6447336P1
6372808P6

Prop, manual and electrical
breakers

and electric breakers only

38
39
40
41
42
42
43
44

Indicator assembly, moving
Cam return spring
Cam return spring

Toggle link
Pin
Pin

Main shaft, stationaryor drawout
breakers

Main shaft, stationary ordrawout

Main shaft, stationary breaker

Main shaft, stationary breaker

Main shaft, drawout breaker-

Main shaft, drawout breaker

only
Crank and roller

6317758P1
6372809P3

Trip latch
Trip shaft

(See Note)
(See Note)

Front escutcheon assembly
Front escutcheon assembly
Manual with a trip button

6372788P1
6372788P3

Indicator
Indicator

Front escutcheon
Sliaft and roller

49
50
51
52
53
54
54
55
56
57
58
59
59
60
♦61
62
63
64
65
66
♦67
68
69
70
70
*♦71
♦72

6372807G1
6248845P1
6319448G1
6317570P2

Trip roller
Closing switch
Handle
Handle

275B887P1
624S844P4

6403396
6372788P3

Trip button return spring

Front escutcheon
Shaft and roller

Trip rod and button
Trip rod support

117A538G1
117A539P1
6401282
6319448G4
276B191P1
6319467G1
6319467G3

Trip button return spring
Closing switch
Handle

Solenoid control device. A-C
Solenoid control device. D-C

Main stationary contact

t Original breaker modelhas no suffix letter or numeral.
-♦ Not shown.

• Kecommended for stock for normal maintenance.

NOTE; When replacing complete front escutcheon assembly or escutcheon plate, ordering information must '"clude complet

nameplate reading of breaker involved and must also indicate whether manually or electrically operated to enable factory to ^

select proper superseding new design assembly.

TYPES AK-1-15 AND AK.1.25 POWER CIRCUIT BREAKERS

Number Required for 3 -pole Breaker
Fig. Kef
No

*86
•86
87
•88
•89
90
91

-1 -2 -3 -4 -5 -6 -7 -8 -9 -10

Main moving contact
Seal-in stationary contact
Seal-in moving contact

pin
Seal-in moving contact
pin

6302797
6302791
6403351
6302795
CR-1070C122-A3

1 Original breaker model had no suffix letter or numeral.
+ Not shown.

• Recommended for stock for normal maintemuice.

6403076P1
6404345P1
6444848

-2 -3 -4 -5 -6 -7 -8 -9

For Type AK-1-25

For Type AK-1-15

spring;A-C
spring, D-C
spring, A-C
spring, D-C

(See page 7) Closing solenoid coil

6372797P1
6403836G1

Armature guide
Armature and link assembly
Armature and link assembly
372A354C1
(See page 7) "Y" relay complete
(See page 7) "Y " relay complete

Main contact
Main contact
Beam return
Beam return

(See page 7)
(See page 7)

(See page 7)
6960045G11
9921661P4

"X" relay complete
Coil

Contact kit (complete set)
Prop switch
Maintenance operating handle

TYPES AK-1-15 AND AK-1-25 POWER CIRCUIT BREAKERS

Fig. 6. Solenoid operating mechanism
with obsolete control device

k
PMOio ec-i mj I

Fig. 7. Solenoid operating mechanism
with modern X-Y relay control unit

Fig. 8. Maintenance operating handle
(ref. 91)

TYPES AK-1-15 AND AK.1-25 POWER CIRCUIT BREAKERS

Closing Solenoid Coll (Ret. 82)

Control Device Coll

3-Pole Breakers

(Ref. 71)
48
123

250
115
208
230
460
575

G47
G48
G48
G41

G9
G29
G6
G1
G31

6275014 G27
G28
G8

G23
G30
G9
G25
G16
G15

G44
G39
039
G34

115
208
230
460

and 4-Pole
-A- to -5

Used on-10 only.

AK-1-15, A-2 to -9
AK-1-25. A-2 to -9

§ Colls for "Y"

AK-1-15, -4 to -9
AK-1-25, -4 to -9

Coil only
(Ref. 88)

Relay
Complete
(Ref. 85)

CR-2810-A14AC2
CR-2810-A14AC3

22D135G2
22D135G3

176L162G10
176L162G11

366A716G4
366A716G3

CR-2810-A14AC17
CR-2810-A14AC18

176L162G20
176L162G26
176L162G21

366A716G2
366A716G6
366A716G3

CR-2810-A14AC18

22D135G17
22D135G18
22D135G18

176L162G16
176L162G25

CR-2810-A14AC8
CR-2810-A14AC9

22D135G8
22D135G9

176L162G17
176L162G18

366A71GG1
366A716G2
366A716G2
366A716G3

22D135G2~
22D135G3
22D135G3
22D135G4

176L162G12
176L162G24
176L162G13
176L162G14

366A716G1
366A716G2
360A716G2
366A716G3

Relay Complete
(Ref. 87)
125
250

§ -'Y" Relay for:

CR-2810-A14AC3
CR-2810-A14AC3
CR-2810-A14AC4

295B444P10
295B444P13
295B444F5
295B444P5

295B444P11
295B444P14
295B444P5
295B444P8

295B444P11
295B444F14

•relays on AK-1-15-2. -3 and AK-1-25-2, -3 are no longer available. If necessary to replace

This coiYthe complL -Y" relay as listed for AK-1-15-4 to -9 or AK-1-25-4 to -9 should bo ordered.

TYPES AK-M5 AND AK-T.25 POWER CIRCUIT BREAKERS

(PHOTO 8004006)
(PHOTO 8016254)

Fig. 9. Auxiliary switch

Fig. 10. Primary disconnect

2 stages (ref. 92)

Fig. 11. Secondary disconnect.

Stotionary, left; moving, right
(ref. 97, 98)

t845C276Gl
t845C276G3

S453A100P2
A6D23600G2
A.38tj.MI0G2

'ion
101
102
M03

657811002
6578110G5

(See page 9(
(See page 91

AuMliary swilcli (2 stajros, 4 contacts)
Auxiliary swiicli (5 stages, 10 contacts)
Primary disconiioct (AK-1-15 only)
Primary disconnect (AK-1-25 only)
Spring
Contact

Soconclary disconnect, stationary, for drawout breaker
Secondary disconnect, movable, for drawout breaker
Stiunl trip device
Coil

(Sec page- 9)
(See page 9)

6444315P1
6403126PI

6319456G10 (time)

6275081G15
6275081G9
6273081G18
6275081G57

G275081G26
6275081G29
6275081G29

6275081G12
6275081G10

C319456G1
6275081G24
6275081G26

6275081G12
627508IG12
627508! G3
6275081G8

631D456G8 (time)
6275081G25
627508IG26.

G275081G4
6275081G29

6319456G7 (inst.)

6275081G26
C275081C27
6275081G7

6275081G26
6275081G27
6275081G7
6275081G31
6275081020

TYPES AK-1-15 AND AK-1-25 POWER CIRCUIT BREAKERS

(PHOTO 8018193)

(PHOTO 8018914)

Fig. 14. Material required to convert
mani^ai breaker to electric operation

Fig. 15. Material required to convert

with X-Y control scheme

obsolete control device scheme to

electrically operated breaker from
modern X-Y control scheme (two

mounting brackets not shown)
•Conversion Kits for Electric Operation

Catalog
Nuiiiljer

STATIONAilY I3HEAKERS

tManual operation

New style electric operation (X-Y

tManual operation

New style electric operation (X-Y

TOld stylo electric operation
(usintt ••control device")

New style electric operation (X-Y

HOld stylo electric operation

New style electric operation (X-Y

scheme), with S closing switch

(usiiifi ••control device")

scheme), witliout closing switch
scheme), with S closing switch
scheme), without closing switch

DRAWOUT BREAKERS

tMajiual operation

New style electric operation (X-Y

tManual operation

scheme), with § closing switch
New style electric operation (X-Y
scheme), withoui closing swilch

tlOld stylo electric operation

New style electric operation (X-Y

(usinii ••control device"!

tiOld style electric operation
(usiiic ••control device")

scheme), with S closing swilch
New style electric operation (X-Y
scheme), witliout closing switch

•includes all necessary parts to convert breaker. NOTE: When ordering, be sure to include complete
nameplaic- reading of breaker, and specify voltage and frequency to l>e used.
tAll AK-1-15 and AK-1-25 lireakers through -10.
TAK-1-15. AK-1-15-1. AK-1-25. and AK-1-25-1 only. Later breakers have new style parts.
SCTosing .switch mounts on breaker front escutcheon.

TYPES AK-1-1S AND AK-1.25 POWER CIRCUIT BREAKERS

(Art PBB 3".»^041

Fig. 16. Field discharge (middle) pole
of type AKF-1B field breaker

TYPES AKF-ID TO AKF-lB-5
Ref.
No.

Center Pole
No.

6372777G2
631799 5G3

117
118
Hi)
120

6372777G2
6317995G2

6403109G4
6403324
62488e7P2
393A557P1

0403321
6403135G2

6403109 G4
6372917
6248887P2

393A557P1
6403135G2

Moving contact assembly

Insulating link

Each Outside Pole

Description
Catalog

Each Outside Polo

•ITPES AKF-lD-6 lO AKF-lB-10

Stationary contact

Discharge switch assembly

695C138G1
372A359G2

Slalioiiary contact spring

372A367P2
393A557P1

372A3G7P2
393A557PI

Upper stud cap
Discharge switch spring

TYPES AK-1-15 AND AK-1-25 POWER CIRCUIT BREAKERS

Tlif following tools are recommended for proper maintenance of the AK-1-15 and
AK-1-25 Air Circuit Breakers. NOTE: Obtain from local hardware firm; do not
order on General Electric Co.

SOCKET WRENCHES (1/2 IN. DRIVE)

Sliurt heavy, slotted screw
Standard, slotted screw

10 in. extension bar
6 in. extension bar

Long thin, slotted screw

7/16 in. socket
9/16 in. socket
5/8 in. socket
3/4 in. socket
13/16 in. socket
15/16 in. socket

Phillips. No. 1

Phillips, No. 2 (8 in. shalt)
Phillips, No. 3
PLIERS

Pointed nose, side cutting. 6 in.
Waldes Truarc, No. 2, straight
Waldes Truarc, No. 2, 90 degree
END WRENCHES

1/16 in., for No. 6 screw
5/64 in., for No. 8 screw
3/32 in., for No. 10 screw

1/8 in., for 1/4 in. screw
5/16 in., for 3/8 in. screw

Adjustable, B in

1/4 in.
in - 5/16 in.,
ii open ends
5/16 in - 11/32 in., open ends
3/8 in. 7/16 in., open ends
1/2 in. - 9/16 in., open ends
5 ''8 in

ALLEN HEAD WRENCHES

3/4 in., open ends

B.\ll peen hammer, 8 ounce

"Spintite" wrench, 3/8 in.
Open box wrench, 6 point, 5/8 in.

rSW VOLTAGE SWITGHGEAR DEPARTMENT

GENERAL A ELECTRIC
PHILADELPHIA, PA.

Handbook Koforonco 6963

Power Circuit
Breakers

Types AK-2/2A-15
AK-2/3/2A/3A-25
AKU-2/3/2A/3A-25
'Includes Supplement a£/-B5r53

INTRODUCTION
OPERATION

Electrical Operation
Manual Operation
Electrical with Manual Operation
MAINTENANCE

Inspection
Separation of Front and Back Frames
Lubrication

Trouble Shooting

BASIC BREAKER COMPONENTS
Disconnects
Arc Quencher
Breaker Contact Structure
Contact Adjustments

Contact Replacement
Mechanism
Auxiliary Switch

Electrical Control Components

Closing Solenoid
"X" Contactor

Closing Switch
Shunt Trip Device

PROTECTIVE DEVICES

Overcurrent Trip Device
EC-2 Overcurrent Trip Device
EC-1 Overcurrent Trip Device
Reverse Current Trip Devices
Power Sensor Trip Device
Selective Tripping

Static Time Delay Undervoltage Tripping Device
Instantaneous Undervoltage Device
Undervoltage Lockout Device
Bell Alarm Switch and/or Lockout Attachment
Open Fuse Lockout Device

AKD-5 Interlock

MISCELLANEOUS
Maintenance Tools

POWER CIRCUIT BREAKERS

Types AK-2"15 and AK-2/3-25
IIMTRODUCTION

The instructions contained herein provide in

formation for performine maintenance procedures
and for replacing AK-2/3-15/25 breaker compo

the receiving, handling, storage and installation
of these brewers, refer to GEK-7302 furnished
with all AK breakers.

nents and accessories. For information regarding
OPE RATION
ELECTRICAL OPERATION

The electrically operated breaker closes when
ever the closing solenoid coil is energized. This
causes an upward movement of the solenoid arma

ture, which initiates the mechanical closit^ action.
The closing signal may be given either by a

remote switch or relay, or by a closing button

escutcheon if the breaker is so

equipped. Either action (refer to the elementary
of the wiring diagram) energizes the coil of the
X relay through the bb contacts of cutoff switch

G and the normally closed contacts of the Y relay.
When the X relay or contactor is energized, it
closes its contacts. One of these (Xl-2) seals
in the X coil. The other three sets of contacts,
which are arranged in series, activate the closing
solenoid.

The breaker may be tripped open by any one
of a number of electrical tripping devices which

will be described in detail later in these instruc
tions. An individual breaker may have none or

any combination of these devices. They are the
overcurrent tripping device, shunt tripping device,
undervoltage tripping device, reverse current trip
ping device, and open fuse lockout device. AU

of them effect tripping by displacing the trip latch
of the mechanism.
The trip latch is
attached to a trip shaft which runs through the
breaker from left to right. Whenever tte trip
shaft is rotated in a counterclockwise ^rection

looking from the right, the latch is displaced.
The tripping devices are all equipped withstrikers
or trip arms which act against trip paddles rigidly

fastened to the trip shaft, causing it to rotate
on its bearings in a direction to trip the breaker.
The reverse current device and the shunt

The breaker control scheme has an anti-

tripping device each have a set of auxiliary switch

the breaker for a single operation of the closing
switch no matter how long the switch may be
held closed. This prevents the repeated operations

is open when the breaker contacts are open.)

pump feature which allows only one closure of
that would ensue if one of the automatic trip
devices was activated at the time of closing. The

Y relay, together with the cut-off switch, provides
the anti-pump feature. The mechanical action of
closing operates the cut-off switch, reversing
the position of the contacts from that shown on
the diagram. This energizes the Y relay, if
contact is still maintained at the closing switch,
with the result that the X relay circuit is opened

"a" contacts in their circuits.

(An "a" contact

This prevents their operation unless the breaker
is closed.

The undervoltage device coil is normally
continually energized. When the control voltage is
low or non-existent, as when the breaker has been

pulled out for inspection or maintenance, the

breaker is rendered trip-free by the imdervoltage
device.

If it is desired to close the breaker,

the device armature must be tied down or blocked

closed against the magnet. The open fuse lockout

by Y contacts 5-6, This prevents the X relay
from again becoming energized. Y contact 1-2

device is used on all AKU breakers and breaker
fuse combinations. The purpose of this device

tained at the closing switch.

one of the breaker fuses.

seals in the Y coil as long as contact is main

Electrically operated breakers may also be
closed by means of the maintenance handle which
is furnished with the breaker. This is a separate
tool and is simply a lever which permits an

operator to push upwards on the closing solenoid
armature.

Two small hooks on one end of main

tenance handle are engaged in slots (9A) Figure 5,
located in the lower portion of the front escutcheon
(8A) Figure 5. Rotation of the long end of the
handle downwards forces the shorter end of the

handle upward against the bottom of the solenoid

armature, and closes the breaker.

is to trip the breaker upon the blowing of any
MANUAL OPERATION

The manually operated breaker is closed by
first rotating the handle in a coimterclockwise
direction through 90 degrees, then rotating it
clockwise back to its normal vertical position.
The counterclockwise stroke resets the mechanism,

readying it for the clockwise closing stroke.

The breaker may be tripped manually by

pushing the manual trip button. This actionpushes

These instrvetions do not purport to cover all details or variations in equipment nor to provide for

confingency *o be met in connection with installation, operation or maintenance. Should further information be o®'"'™
or should particular problems arise which are not covered sufficiently for the purchaser's purposes, the matter shou d
be referred to the General Electric Company.

= GEIi-5p299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
, A

a rod against a trip paddle of the trip shaft,
rotating it, and causing the mechanism trip latch

^jfeto^be displaced.

solenoid connecting link and manual cam connecting
link are both connected to the closing spring pin
at the top of the mechanism, thus compressing
the springs when force is provided by either

This allows the mechanism

f ^linkage to collapse through the action of the
mechanism operating springs.

means of breaker closing.

CAUTION: If the breaker is tripped manually
while the operating handle is in the reset position,
the handle should be lowered by the right hand

The breaker is manually closed by rotating
the closing handle 90 degrees counterclockwise.
No reset stroke is necessary as is the case with

while operating the trip button with the left hand.

the standard manual breaker. Electrical closing
may be performed either locally or remotely in

ELECTRICAL WITH MANUAL OPERATION

the same manner as the standard electrical breaker.

This operating mechanism provides both man

ual and electrical closing.

The operating mech

Tripping is accomplished by the manual trip

anism is similar to the mechanism of the standard

button on the escutcheon or by any of the electrical

electrical breaker with the addition of the manual

tripping devices available for use on the standard

handle, cam and mechanism connecting link. The

A-TERMINAL BOARD LOCATED TOP RtCHT,
FRONT VIEW

F-ANTt-PUM? PERMISSIVE RELAY.
C-(oO-bb) - CUT-OFF SWITCH
K-KI- CLOSING CONTACTOR-3 SETS OF CONWCTS IN SERIES (MAIN) 8 I SET

L-»u«.»->AUX_SW-2o"a ifb: CONTACTS

(STOI OR Sb a SB (SPECIAL)

AUTCl-SMUNT TRIP DEVICE.

N-wci-SOLENOIO CLOSING COIL.
P-i«t>-CLOSING SWITCH ON BREAKER
T-TRANSFORMER.

NQT&W^N senRATE POWER SOURCE FOR CLOSmC

COL S USED,OMIT JUMPERS AhA3 S A2*A4 THEN
CONNECT POWER TO Al 8

f2—H-K2 —^ I
-KioVec

l-KIO-t-o 2 =>--Ta-;

C >—X CLOSING

) KT-t-o S^.-TJ

•5?'?--xtrip
SOURCE

X TRIP
-Y SOURCE

^CUSTOMER WIRING
—oFACTORT WIRING

-cFACTORY WIRING FOR ENCLOSED BKR
CUSTOMER WIRING FOR STATIONARY BKR
Ft PI AS

ALTERNATE WRNG FOR USE WITH
FOLLOWING

CONTROL VOLTAGE

S7S/230V A C. 60—
I

57S/230 V A C 90—

Figure 1. (695C160-1) & (695C159-1) Typical Wiring Diagram

front frame and mechanism of the breaker from

the back frame or base, which consists of the
BEFORE

current carrying parts of the breaker and their

NANCE WORK IS DONE, BE SURE THAT THE

supporting structure.

BREAKER IS IN THE OPEN POSITION.

operation is as follows:

ELECTRICAL POWER, BOTH PRIMARY AND
CONTROL SOURCES, SHOULD ALSO BE DIS

The procedure for this

Remove the arc quenchers (see section on

"Arc Quenchers").

Periodic inspection of the circuit breaker
is recommended at least once a year.
More
frequent inspections are recommended, if severe
load conditions, dust, moisture, or other un

Disconnect the two insulated connecting links

favorable conditions exist.

ered pin, (5) Figure 5 in the mechanism.

If the breaker remains open or closed for
a long period of time, it is recommended that
arrangements be made to open and close it several
times in succession, preferably under load.

(6), between the mechanism and the crossbar

(10), by removing the tie bolt (7), and slipping
the ends of the links off the ends of the should
3.

Also remove any wiring bundle
retainers that may be attached to the back

At all times it is important not to permit pencil
lines, paint, oil or other foreign materials to re
main on the insulating surfaces of the breaker
as they may cause low resistance between points
of different potential and result in eventual elec

If the breaker is a drawouttype, with secondary

disconnects. Figure 2, remove the secondary
disconnect supporting bracket from the breaker
frame.

Remove one elastic stop nut from each of
two studs (3), which tie the upper ends of the
mechanism frame to the back frame of the
breaker.

trical breakdown.

Always inspect the breaker after a short
circuit current has been interrupted.

Remove the two elastic stop nuts (9/16" Hex.)
which fasten the wrap around portion of the
front frame to the back frame. One of these

At the time of periodic inspection, the follow
ing checks should be made after the breaker has

is located on each side of the breaker, about

been de-energized.

of the back frame.

Manually operate the breaker several times
checking for obstructions or excessive friction.

Electrically operate the breaker several times
(if breaker has electrical control) to ascertain

2/3 of the distance down from the top edge
On drawout breakers for AKD Equipment, the

bottom plate must be removed by first remov

ing two #8-36 screws located at the front of the
bottom plate and then freeing the plate from the
slots located in the bottom of the back frame.

whether the electrical attachments are func

tioning properly.

The two frames are now disconnected. How

Remove and inspect the arc quencher. Break
age of parts or extensive burning will indicate
need for replacement.

ever, care should be exercised in separating
them to avoid damage to the trip shaft arms
and paddles. While the back frame is held
steacty, lift the front frame and mechanism

Check contact condition and wipe

up and out so that the trip paddles on the
trip shaft clear the trip arms of the overload

Check latch engagement.

Check operation of tripping devices, including
overcurrent trip devices, making sure all
have positive tripping action. (Discernible
movement in tripping direction beyond point
of tripping.)

(For detailed information on breaker features
listed, refer
instructions.)

sections of these

Reassembly of the two breaker halves is
accomplished by following the procedure out
lined in reverse order.
LUBRICATION

In general,- the circuit breaker requires very
little lubrication.
Bearing points and sliding
surfaces should be lubricated very lightly at the

regular inspection periods with a thin film of

SEPARATION OF FRONT AND BACK FRAMES

Figure 3
Many maintenance operations will either re
quire or be greatly facilitated by separating the

extreme temperature, high pressure, light grease,
similar to G.E. Spect. No. D50H15 or RPM No. 5.
Hardened grease and dirt should be removed from
latch and bearing surfaces by the use of a safe
cleaning solvent such as kerosene. Latch surfaces
should be left clean and dry and not be lubricated.

'(3EI-50299 Power Circuit Breakers Types AK-2-I5 and AK-2/3-25
TROUBLESHOOTING

ALL EXCESS LUBRICANT SHOULD BE REMOVED
A CLEAN CLOTH IN ORDER TO AVOID

/^NY ACCUMULATION OF DIRT OR DUST.
At each

maintenance period, all silver to

silver friction points, such as primary disconnects,
should be cleaned and given a fresh coat of G.E.
Spec. No. D50H47 lubricant.

AK-2/3 Breakers

The following table lists several typical symp
toms of breaker malfunction, together with their

causes and remedies.
If, at any time, these
symptoms are observed, their cause should be
determined and the necessary corrective action
should be taken.

Contacts not aligned
Contacts dirty, greasy or coated with dark
fUm

Adjust contacts.
Clean contacts

Contacts badly burned or pitted

Replace contacts

Current carrying surfaces dirty

Clean surfaces of current carrying parts

Corrosive atmosphere

Relocate or provide adequate enclosure

bisuKiclent bus or cable capacity

Increase capacity of bus or cable

Bolts and nuts at terminal connections

Tighten, but do not exceed elastic limit of

bolts or fittings.

Current in excess of breaker rating

Check breaker application or modify circuit
by decreasing load

Excessive ambient temperature

Provide adequate ventilation

Travel of tripping device does not provide

positive release of tripping latch

Re-adjust or replace tripping device and
check mechanism latch adjustment

Worn or damaged trip unit parts

Replace trip unit

Bind in overcurrent trip device

Replace overcurrent trip device

Overcurrent trip device pick up too low

Check application of overcurrent trip device

Overcurrent trip device time setting too short Check application of overcurrent trip device

Failure to trip
AK-2 Breakers

Bind in overcurrent trip device

Replace overcurrent trip device

Failure to Close and Latch

Binding In attachments preventing resetting
of latch

Re-align and adjust attachments

AK-2/3 Breakers

False Tripping
AK-3 Breakers

Latch out of adjustment

Latch return spring too weak or broken

Hardened or gummy lubricant

Clean bearing and latch surfaces

Closing solenoid burned out

Replace solenoid coU

Solenoid control device not functioning
properly

Re-adjust or replace device

Captive Thump screw on Power Sensor
loose fall-safe circuitry reverts
characteristic to minimum setting and
maximum time delay

Tap setting dial on Power Supply incorrectly
set

Tighten thumb screw on desired setting

Set dial to correspond with Power Sensor coil
tap

Refer to Figure 22, page 29 for polarity and

External Ground Sensor Coil Improperly
connected

connections. Check continuity of shield and

conductors connecting the external Ground
Sensor coil.

Failure to Trip
AK-3 Breakers

Loose or disconnected power sensor dis
connect plugs

Tighten or reconnect disconnect plugs

Loose or broken power sensor coil tap

T^hten or reconnect tap connections

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299
BASIC BREAKER COMPONENTS
DISCONNECTS

ducting spring loaded plunger to which a flexible

PRIMARY DISCONNECTS

lead is attached.

The primary disconnects are attached to the
ends of the breaker studs on the rear side of the
breaker base. Each disconnect assembly consists

of two pair of opposed contact fingers. These are
secured to the breaker stud by a bolt which passes

through the assembly and the stud. When engaged
with the stationary stud of the enclosure, the
disconnect fingers exert a set amount of force

against the stationary stud through the action of
the comoression springs.

The movable part of the secondary disconnect
consists of an insulating body which holds a con

Retainers and spacers

hold the' contact fingers in correct alignment for
engagement with the stud. The amount of force
which the fingers exert against the stud is deter

REPLACEMENT OF MOVABLE SECONDARY DIS
CONNECTS

Unfasten disconnect body from breaker back
frame.

Open tabs which hold wires on inner side.

Pull contact tip loose from hollow tube.

Remove contact tip by cutting wire at its

mined by degree to which the springs are com

pressed by the bolt and nutwhichholdthe assembly
together. This pressure is factory set between

Push wire through hollow tube of new dis
connect assembly.

60 andTOpounds. If, for any reason, the disconnects

must be taken apart, the position of the nut on
the bolt should be carefully noted, so that in
reassemblying, the original amount of compression
can be restored by replacing the nut at its former
position on the bolt.
SECONDARY DISCONNECT, FIGURE 2.

As the breaker moves into its

enclosure, the plunger is depressed by sliding
onto the stationary disconnects of the enclosure.

6. Strip Insulation off end of wire to about 1/4
of an inch from end.

Place new contact tip on end of wire and
crimp.

Pull wire through hollow tube until contact

tip fits snugly against end of hollow tube.

The secondary disconnects serve as connec

tions between breaker control circuit elements
and external control circuits. They are used only
on drawout type breakers. A terminal board serves

purpose enclosure moxmted breakers. Thesecond
ary disconnects allow removal of the breaker with

10. Any hollow tubes which are not used should
be pushed into the disconnect body and held

the same purposeon stationary mounted and general

out the necessity of having to detach external con
nections.

Crimp tab on other side of assembly to hold
wire in place.

in that position by placing fibre spacers over
inner ends of tubes and spreading tabs.

^ H
Figure 2. (8017973) Movable Secondary Disconnects

ir. When all wires have been connected, refasten
the body of the assembly to the breaker back
lErame.
ARC QOENCHER

The arc quencher is an integral riveted as
sembly composed of two ceramic side plates, a
series of steel plates, and a muffler. The assembly
is covered by a wrap around of insulating material
which inhibits any sidewise emission of gases. The
steel plates are held in position and supported by
the ceramic sides which are grooved vertically
to provide recesses for the vertical edges of the
steel plates.

their safe and controlled

escape at a cooler temperature.
The muffler at the top of the assembly is a

serpentine sh^ed strip ofperforated,copper plated
steel. It is important that the perforations of the
muffler be kept open, since their closure could
tend to prevent the escape of the gases along the
desired path. At the regular maintenance inspec

tion, it^quld be well to check their condition and
any ^
logged.

approximately at their mid-points. The end ai the
contact opposite to the contact tip end is formed

into the shape of a small hook. A tension spring
engages this hook and provides the necessary
contact pressure at the pivot and also at the point
of contact with the movable contact arm. When the

breaker contacts open, a projection on the contact

tip end of the stationary contact bears against a
stop pin restrictii^ the movement of the stationary
contact. This arrangement results in a continual
high force existing between the mating pivot
surfaces.

The bottom edges of the latter form

an inverted "V" along the path of the arc that
may be drawn between the breaker contacts during
interruption. The steel plates have the effect of
breakup up the arc, and cooling it and the gases
that result from interruption. The entire assembly
provides a "chimney" effect which directs the hot,
ionized gases upwards through the steel plates and
mufflers

surfaces mates with the concave pivot surface on
the rear side of the stationary contacts. Each of
the stationary contacts pivot in a horizontal plane

The movable contact arms pivot in a vertical

plane, each making contact with apair of stationary
contacts, and thus providing four low resistant
parallel paths of current for each breaker pole.
The movable contacts rotate about a burnished,

silver plated, copper pin which, in turn, is held
by a pivot support. Each side of the pivot siqpport

bears against &e lower, outer surface ofthe contact

arm and supplies a second low resistance path
through the pivot. A "U" shaped spring clip made
of silver plated conducting material provides an
additional current path and protects the other con
tact surfaces of the pivot against pitting when in
motion.

It also contributes to the force tending to

increase the contact pressure between the lower
ends of the movable contacts and the pivot support.

the perforations that appear to be

If any very extensive burning or corrosion
is noted in the arc quencher, it should be replaced.
Replacement is also indicated if any breaks or
cracks are noted in the ceramic material.

The movable contact pivot support is mounted

securely to the breaker base. If, as is normally
the case, the pole is equipped with an overcurrent
trip device, one of the terminals of the series coil
of the trip unit is fastened to the lower end of
the pivot support.
The other terminal of the
coil fastens to the lower stud.

CONTACT ADJUSTMENTS

Removal of the arc quencher is simply a matter
of lifting the assembly up and out, after the steel
retainer across the front of the arc quenchers has
been removed. The upper edge of the steel arc
runner, fastened to the back plate of the breaker,
fits into a recess in the back portion of the arc
quencher which locates it in its proper position
upon replacement. Make sure the steel retainer
is replaced and fastened firmly to its mounting
studs after the arc quenchers have been replaced.
BREAKER CONTACT STRUCTURE

copper current carrying parts of the

The only adjustment to be made on the breaker
contacts is that of contact wipe.

described as the distance the movable and station

ary move while they are touching
the process of breaker closing.
contact wipe can be measured by
position of the front surface of

one another in
The amount of
comparing the

contact when the breaker is open to its position
when the breaker is closed, in reference to some
absolutely stationary part of the breaker. The
most convenient stationary part of the breaker to
use as a reference point is the steel arc runner
above and behind the stationary contacts.

breaker are all mounted on a common base of

insulating material made of polyester glass mat.
The copper of each pole consist of an upper stud
and pivot, stationary contacts, two movable contact
arms, a movable contact pivot, and the lower stud.
The upper stud branches into two pivot surfaces
orT its inner end on the forward or front side of
the breaker base.
Each of these convex pivot

The amount of wipe the contacts should have

is nominally 1/8 of an inch.

A plus or minus

tolerance of l/32 of an inch is allowed.

The means of adjusting contact wipe is pro
vided by an eccentric pin which passes through
the center of the movable contact assembly. Each

end of this pin has a free, projecting, hexagon

shaped section which is easily accessible to a
small, open end, 1/4 inch wrench. Two cantilever
springs, which bear on each end against a portion
of the hexagon section of the pin, lock the ad
justing pin in place and provide index stops for
the process of adjustment. The right hand hexagon
shaped end of the pin is numbered from 1 to 6,
which provides a reference for making wipe
adjustments.

GENERAL PREPARATION

Lift off the three arc quenchers.

Remove the U shaped insulation (5) Figure 3
from each pole by lifting it and disengaging
the rivet heads thru the keyholed slots in the

When contacts are to be adjusted, the recom
mended procedure is as follows:
1.

With the breaker in the open position and usii^
the numbers on the right end of each adjusting

pin as a reference, set each pin in the same
position. ]b many cases, the number 3 is a
good beginning point. The proper view of the
number on the adjusting pin is obtained by

viewing the breaker from the front and the

adjust&g pin from approximately a 15 degree
angle with respect to the mov^le contacts.

Note that the numbers on the pin are not in
numerical sequence as the pin is rotated.

reference to the steel arc runners above and

As an aid to future reassembly of the-movable

contacts, note the position of all stationary

insulation barriers with respect to barriers
moxmted on the cross bar.

REMOVAL OF MOVABLE CONTACTS
(18) Figure 3.

Screw the threaded end of the steel rod

With a pair of long nosed pliers, unhook

Grasp movable contact assembly and remove

By measurement, establish the position of the
front surfaces of the stationary contacts with
behind the contacts.

Remove arc quencher retainer (1), Figure 5
by loosening the two captured nuts with a

lightly into pivot pin (11) on the right pole.

safety pin type spring clip (9) and extract
pin (11) and remove spring clip (9).
it from its seat on the cross bar.

Close the breaker, and establish the amount
of wipe by again measuring as in step two,
and comparing the measurements with those

t^en with the breaker open.
4.

If any set of contacts lead or lag the others,
open the breaker and advance or retard the
adjusting pin to the next higher or lower
number. Moving the adjusting pin to a higher
number will increase the contact wipe and
moving to a lower number will decrease the
contact wipe.

toward the front of the breaker.

round off the flats of the hex section of the pin.
5.

Move the cross bar downward to disengage

it from the contact wipe adjusting pin (15)
on the center pole, then move the cross bar
Remove the split pin retaining the center
pole pivot pin.
Remove the pivot pin and movable contact
assembly.

NOTE: No attempt should be made to move
the adjusting pin when the breaker is closed.

Besides being more difficult, the additional
force required to move the pin will tend to

Repeat procedure 1, 2, and 3 above on the
left pole.

REMOVAL OF STATIONARY CONTACTS

When all the contacts have the recommended

Slip the blade of a heavy screw driver between
the two upper contacts and force the contacts

adjustments are complete.

disengage the contact stop surface from the pin.

toward their pivot point sufficiently far to

wipe of 3/32 to 5/32 of an inch, the contact
CONTACT REPLACEMENT

The contact can then be removed by disengaging
the end of the contact from its spring.

The two lower contacts can be similarily

Figure 3
The normal situation that will

matter of contact replacement will call for re

placement of all the movable and stationary con
tacts at the same time.

This will be the case

where long use of the breaker in service has
resulted

REPLACEMENT OF STATIONARY CONTACTS

or erosion of the

silver alloy contact tips.
A commonly used
"rule of thumb" is that contact replacement is
indicated if less than one-half of the original

Coat the contact pivot area only of each of
the four contacts with a thin coat of D50H47

Use only D50H47 grease.

thickness (1/8 of an inch) of the contact tip
material remains.

Note the difference between the two types of

.,GEI-5(J299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
stationary contacts and be sure to locate them
• in the breaker with the upper and lower contacts
having their stop projecting surfaces as shown

in the section AA, Figure 3. The upper left
and lower right contacts are identical as are
the lower left and upper right contacts.

By placing the hook on the end of the contact
through the loop of the contact spring, the con
tact can be pushed toward the pivot surface
and slipped behind the stop pin. Install all
stationary contacts in all poles.

REPLACEMENT OF MOVABLE CONTACTS

(18) Figure 3.
1.

Coat the pivot area only of the new movable

contacts with a thin coat of D50H47 grease.
2.

Assemble the center pole movable contacts,
align the pivot pin holes with the bullet nosed
rod, and install the pivot pin and split pin.

Move the cross bar assembly into position
and insert the eccentric contact wipe adjust-

SWTOT *1*
FRONT VIEW OF

STATIONARY CONTACTS &

STATIONARY CONTACTS &
SPRINGS

SPRINGS
AK.2.25

Figure 3. (549D409-2)

Breaker Base
Insulation
Insulated Stud

Upper Stud Barrier

Links (Insulated)

Contact Assembly

15. Contact Wipe Adjustment Pin

Spring Clip (Retainer)

Cross Bar
Pivot Pin
Lower Stud

17. Upper Stud & Arc Runner

Contact Pivot Support
Spring

Movable Contact

21. Stationary Contacts

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299
ment pin (15) on the center pole into position.
Be

sure the stationary insulation barriers

are correctly located.

Align the cross bar with the left and right
pole pivot supports and install the left and
right pole movable contacts. Use the bullet
nosed steel pin to aid in aligning the holes
in the cross bar, the contacts and the pivot
supports.

Install the left and right pole pivot pins while
threading them through the sprir^ clips and lock
the spring clips (9). Be sure the pivot pins
are fully inserted.

Adjust the contact wipe to 1/8" i 1/32" by
adjusting the eccentric contact wipe adjusting

pin (15). The breaker must be open to adjust
the wipe. In the event acceptable wipe cannot

be obtained by moving the contact wipe ad

justing pin (15), from the movable contact
forward or backward as necessary to bring
the wipe within the range of the contact wipe
adjusting pin (15). Do not exceed the recom
mended settir^s for wipe;
otherwise the
breaker may not close completely.
When
viewed from the top with the breaker closed,
the movable contact should be centrally located
with respect to the stationary contacts. If
the movable contacts are not centrally located
as shown in section CC, form the movable
contacts until they are nominally centered.

If the moving contacts are not centered with

1/8" separation when closed against the fixed
contacts, they should be bent laterally (after

opening the breaker contacts). To do this
without squeezing the two movable contact
arms together, a 1/8" spacer plate should be
inserted between them;

Figure 4. (8039851) AK-2-25 Back Frame-Loca
tion of Crossbar and Pole Shields

then the pair can be

Stationary Contacts

grasped with pliers and bent in the desired

Movable Contacts

direction for centering.

Upper Stud Asbestos Shield

eccentric numbers 1, 2, or 3. These numbers
are the ones visible when viewing the breaker

Crossbar Plastic End Shield

Crossbar Assembly
Crossbar Asbestos Inner Shield

Lower Stud Asbestos Shield

from the front, not from above. (The higher
numbers should be reserved for tightening

at future maintenance readjustments after
wear.)
Also, if higher numbers are used,
where adequate wipe is obtainable at settings
1, 2, or 3, it is possible that the stationary
contacts will bottom, producing excessive back
force on the breaker closing mechanism so that
the toggle link will not pass center. As a
result.the breaker will not complete its stroke,

and inadequate pressure and wipe will result;
burn-up of contacts from just load current
will follow.

If the required wipe of new contacts cannot be
obtained with eccentric number of 3 or lower,
bending of the contact arms toward the closed

position is required.

This should be done

individually, using an 8" Crescentor 1/2 - 5/8"
tapered open end wrench to grasp the contact
and a 10" Crescent or the 1" - 1-1/8" tapered

open-end wrench to grasp the pivot portion of
the arm. The soft copper arm will bend with
little difficulty.
Both arms should be bent
identically.

Operate breaker several times, and recheck
wipe to make sure bending of movable arms
did not occur in these operations.

Operate the breaker manually several times
to assure proper functioning occurs, then
replace the U shaped insulation (5) Figure 3
and arc quenchers. When replacing the arc
quenchers be sure the quencher is seated
downward completely and that the quencher
clamp covers the knobs protruding through
the arc quencher insulation.

listed is that of proper mechanism latch engage
ment, the amount of engagement between the latch

CONTACT SPRINGS

(19) Figure 3
^

minimum force of 5 lbs and a maximum

force of 9 lbs. should be required to begin move
ment of a single stationary contact from the open
position towards the closed position.

be checked by using a push scale applied at the
point at which the movable contact touches the

stationary contact.
If these pressures are not
obtained or if the spring is damaged, replacement
is required.
In order to replace the contact spring the upper
stud (17) must be removed. The hardware which
fastens the stud to the breaker base consists of

two screws (16), and nut (20). When These are
removed, the stud inay be withdrawn from the
base in a forward direction.

(7) and latch roller (5), Figure 6. This is the only
adjustment that is required on the breaker mech
anism, and proper latch engagement is obtained in
the following manner:

(NOTE - Before making latch adjustments, check
to make sure that the buffer paddle which stops
against the end of the latch adjustment screw is

rigidly fastened to the trip shaft.

the buffer paddle.
If any relative movement
between the two is noted, tighten the fasteners
holding the buffer paddle to the trip shaft.)
Latch Adjustment - Manual Breaker

After the stud has

been removed, it is a simple matter to disconnect
the two ends of the spring (19) and replace it

with a new one.
MECHANISM

The breaker mechanism is a spring actuated,

over-center toggle type of mech^sm. As the

clockwise, setting the closing mechanism in
the reset position. Turn the adjusting screw
.into the locknut imtil the closing mechanism
trips open, the closing handle returning to its

operatii^ handle or the closing solenoid armature,
energy is stored in the operating springs. After
the springs have gone over center, movement of the
output crank of the mechanism is still blocked

normal vertical position. ' NOTE:

for a time by a cam arrangement. As the springs

HANDS CLEAR OF THE CLOSING HANDLE
WHEN MAKING THIS ADJUSTMENT.

are further extended, the blocking cam moves
away from the ou^ut crank, and the springs are
allowed to discharge part of their stored energy,
closing the breaker contacts.
This assures a fast-snapping closing action
regardless of the speed at which the closing handle

Withdraw the adjusting screw from the locknut

1/4 turn at a tjme, attempting to close the
breaker after each 1/4 turn, and observing
whether the contacts move toward closing

breaker mechanism'is tripped by the

before tripping occurs. If the contacts move
before tripping occurs, you have established
the position of the" adjusting screw where the

displacement of the trip latch (7), Figure 6.
Looking at the breaker from the right hand side

some cases, it may be necessary to turn the

latch and latch roller begin to engage.

to establish the position where the contacts

begin to move before tripping occurs. When
this position is established, note the position
of the slot in the head of the adjusting screw.

When the latch moves off the trip latch roller (7),
the remaining force in the operating spring causes

adjusting screw less than 1/4 turn in order

as in Figurp 5, the tripping movement of the latch
is counter-clockwise.
Operation of any of the
automatic trip devices or the trip push button
causes the latch to move in the tripping direction.
A

Locate the latch adjustment screw on the
lower, outer side of the right-hand mechanism
side frame. This screw is threaded through
a nylon insert locknut which, in turn, is welded
to a projecting bracket on the side frame.

2. Rotate the clos^ handle 90 degrees counter

closing force is applied, either by movement of the

shidt (8), Figure 5, steady and attempt to move

opening of the brewer contacts.

Withdraw the adjusting screw three and one- •
half turns from the position noted in step 3.

the mechanism toggle to collapse, resulting in the

This sets the proper amount of latch engage

Since all the mechanism adjustments are
carefully set by e:q)erienced factory personnel
after assembly at the factory, it should normally
not be necessary to make any adjustments in the
field. At the time of installation, and also in the
course of a maintenance inspection, if the breaker

Latch Adjustment - Electrical Breaker
1.

latch adjustment screw on the

outer side of the right mechanism

side frame. This screw is threaded through
a nylon insert locknut which, in turn, is
welded to a projecting bracket on the side

fonctions properly through several repeated opera
tions, it is'best to assume that adjustments are

With the breaker in the open position turn the

If the breaker mechanism does not function

adjusting screw' into the locknut one complete

properly, it is best to first perform the available

turn at a time, closing the breaker after each

remedi^ measures listed in the "Troubleshooting"
chart of these instructions.

One of the remedies

complete turn of the adjusting screw, until

the breaker will not close. Use the maintenance

• closing handle whenever closing or attempting
to close the breaker during this entire opera
tion.

Withdraw the adjusting screw from thelocknut

1/4 turn at a time, attempting to close the

breaker after each 1/4 turn, and observing
whether the contacts move toward closii^

before tripping occurs. If the contacts move
toward closing before tripping occurs, youhave
established the position of the adjusting screw

where the latch and latch roller begin to engage.
In some cases, it may be necessary to turn

the adjusting screw less than 1/4 turn to
establish the position where the contacts move
before tripping occurs. When this position is
established, note the position of the slot in
the head of the adjusting screw.

Withdraw the adjusting screw three and onehalf turns from the position noted in step 3.
This sets the proper amount of latch engage
ment.

Figure 5. (8024457) Cut Away Model of Electrically Operated AK-2 Breaker
Arc Quencher Retainer

8A. Front Escutcheon

Cut off Switch Actuator

9A. Location of Slots for

Connecting Link

Trip Latch Roller

Trip Shaft
Closing Solenoid
Maintenance Handle

10. Closing Solenoid Armature
11. Cover Retainer of Overload Device

12. Lower Stud
13. Socket Head Screws

14. Upper Stud
15. Stationary Contacts
and Springs
16. Arc Runner

GEi-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
Should

the mechanism continue to function

improperly after the proper latch engagement

manually operated breakers, see procedure
described below.)

has been set and the corrective measures listed

' in the "Trouble Shooting" chart carried out, it is
generally recommended that no attempt be made
to repair the mechanism interior but that a re

placement mechanism assembly be obtained from
the factory.

Remove arc quenchers (See "Arc Quencher").
Disconnect the two insulated connecting links
between the mechanism and the contacts as in

step 2 of the procedure for "Separation of
Front and Back Frames".

If the breaker is electrically operated, remove
the front escutcheon by taking four screws
from flange. If the breaker is a drawout type,
two small

round head screws must also be

removed from the bottom edge of the escutch
eon.

{For removal of front escutcheon from

Remove the two elastic stop nuts, whichfasten
the upper extensions of mechanism frame to

studs connecting with rear frame.
Remove four screws which fasten the bottom
of the mechanism frame to the horizontal
cross member of the front frame.

Figure 6. (8024516) Cut Away Model of Manually Operated AK-2 Breaker
Arc Quencher Muffler

Handle Return Spring

Ceramic Side Plates
Steel Plates
Fixed Centers in Mechanism

Overload Device

16. Contact Wipe Adjust

Latch Roller
Escutcheon

Series Coil of Overload Device

Movable Contact Pivot
ment Pin

Trip Arm of Overload Device
Trip Paddle

Movable Contact Pivot Support

19. Steel Back Plate

Movable Contact

18. Moulded Compoimd Bar

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-502g9
M the breaker is manually operated, and has
no auxiliary switch, it is now free to be lifted
* clear of the breaker. If it has an auxiliary

AUXILIARY SWITCH

switch, this may be disconnected from the

mechanism as described under "Auxiliary

Replacement, elsewhere in these

H the breaker is electrically operated, it will
be necessary to disconnect the mechanism from
the solenoid armature.

In order to do this,

raise the mechanism as far as the travel of the

armature will permit and remove the screw
which binds together the two extensions of the
armature. After this is removed, the armature
extensions must be spread apart to release
them from the link connecting with the mech
anism.

This can be done by threading a

#10-32 screw at least 1-3/4 inches long into
the top hole of the armature extension. This
hole is just above the one from which the
binding screw has been removed. As the end
of the screw butts against the far extension,
the two extensions will be spread open, re

ting shaft is linkedto the outputcrank of the breaker
mechanism.

Through a cam arrangement, the

An "a" pair of contacts is always in

operating shaft of the switch controls the open and
closed positions of the individual contact pairs.
Each stage of the switch, whichis usually two-stage
or five-stage, contains one "a" and one "b" set
the same position as the main breaker contacts.
That is, open when the breaker contacts are open,
and closed when the breaker contacts are closed.

Just the oposite is true of the "b" contacts. The

terminals of the switch are covered by a sheet of

insulating material held in place by two screws
fastened along its left edge. Whenthis is removed,
the terminals are esqjosed. The upper pairs of
terminals are those which connect to "a" switches.
The lower terminals connect to "b" switches.
REPLACEMENT

leasing the mechanism link.

Remove auxiliary switch cover.

The replacement mechanism may be installed
by reversing the order of procedure for dis

Disconnect leads to switch terminals.

Remove two screws which fasten switch to

assembly. After reassembly, check the opera
tion of the breaker and, if necessary, adjust
the latch engagement.

REMOVAL OF FRONT ESCUTCHEON
OF MANUAL BREAKERS

The auxiliary switch is mounted on the left
side of the operating mechanism frame. Its opera

side of mechanism frame,

Remove switch by moving towards left.

Before mounting replacement switch, turn the
crank end

of the switch operating shaft in

position to engage the hole in the link con
necting with with the breaker mechanism.

Remove set screw fastening the plastic handle
to steel operating shaft and remove the oper

Be sure the bearing washer is in place between
the mechanism link and the switch operatii^

Open and remove annealed (soft) retainer and
two flat washers from shaft.

Remove four screws from flange of escutcheon
If the breaker is a drawout type, two small

ELECTRICAL CONTROL COMPONENTS

• rovind head screws must also be removed from

the bottom edge of the escutcheon.

Push steel operating shaft through escutcheon

Complete mounting by followii^ disassembly

steps in reverse order.

These consist of the following:

Closing solenoid

Remove handle reset sprii^ (8) Figure 6, and

"X" contactor (relay)

escutcheon is free of breaker.

"Y" permissive relay

Handle and escutcheon assembly can be as
sembled most easily by exactly reversing the

escutcheon it may be necessary to use pliers

Shunt-trip device

procedure for disassembly.

In replacing the

to pull the operating shaft fully into the
escutcheon in order to have space enough to
replace the flat washers and the soft retainer.
The latter may be closed on its groove in
the shaft by ordinary gas pliers. After re
placement,
check operation of breaker.

The last two of these components may or

may not be present in the control arrangement.

CLOSING SOLENOID

need not be removed from the old bracket. This

" The closing solenoid consists of a magnet,

^armature and coil.

This assembly is located

directly beneath ttie breaker mechanism to which
it is connected by a link which ties the upper end
of the

can be taken off the breaker simply by removing
the two screws whichfasten it to the bres^er frame.
If the breaker is a drawout type, the siq)porting
bracket of the "Y" relay may be temporarily
displaced to provide access to the screws.

armature to the spring carrier of the

mechanism. (See Figure 5.)

When voltage is applied to the coil, the

magnetic force generated pulls the armature up
into the coil and magnet assembly.
This, in
turn, rotates the spring carrier about its pivot,
extending the mechanism spring and causing its
line of action to move "over center", resulting
in a closing operation.

Since tiie e:q)endable parts ofthe"X" contactor
are the contacts and the coil, ease of replacement
of these parts has been designed into the relay.
Methods of procedure are as follows:
Contacts

Remove relay cover.

Remove terminal binding screw of stationary
contact to be replaced.

The only replacement operation that might
conceivably be required on this assembly is that
of the solenoid coil.
To replace this, proceed

lift out the stationary contact.

Remove escutcheon by unfastening four flat
head screws in flange.

Remove closing switch. (See "Closing switch".)

Cut off or disconnect the

Lightly pinch with pliers (pointed end) the
split section of the contact which enters the
hole in the compound body of the device and

With the fingers, pull forward on the spring
guide of the movable contact, compressing

&e contact spring as far as possible.
5.

With the spring thus held, grip the end of the
contact strip with pointed pliers, turn it through
90 degrees on its long axis, and withdraw it.

Replace new contacts by reversing the pro

Remove four screws which fasten lower section

of magnet to upper section.

Allow lower section of magnet and coil to
slide downward until clear of armature.

Reassemble with new coil by reversing order

Remove relay cover.

Turn the two retaining spring clips on the ends
of the device through 90 degrees about their

of procedure.
"X" CONTACTOR

The "X" contactor is a heavy-duty relay which
performs the function of closing the circuit of the
breaker solenoid during electrical operations.

Pull out the two halves of the body of the device

which carry the stationary contacts. When
these are clear of the frame, the armature
and movable contact assemblywill move aside,
exposing the coil.

Three of the four sets of contact of the device are

arranged in series to minimize the duty required of

any one contact. As explained imder "Operation",
the fourth contact is used to "seal-in" the "X" coil.

The "X" contactor is located on the right
beneath the horizontal front frame member.
is

mounted on three

of its retaining spring clips.

which fasten it to a

mounting bracket which is suspended from the
frame.
Rubber bushings on the mounting studs
provide anti-vibration and anti-shock protection
for the relay.
The relay contacts and their
terminals are covered by a molded piece of
insulation which fits over spring clips that bold
the cover in place.

Removal of the complete device is accomp5lished by removing the cover, disconnecting the
leads from the terminals, and removing the nuts
from the three mounting studs. If the replacement
unit includes the moimting bracket, the relay

Place new coil on pole piece inside of the

spring clips and fasten terminals to leads.
6.

Just start the replacement of one of the
compound blocks which hold the stationary
contacts into its groove in the franie.
Position the armature and movable contact

assembly to allow the entrance of the second
stationaz7 contact block.

Remove the terminal screws of the coil and

When these parts are all properly aligned,
with the stationary contacts under the movable
contacts, push them into their guiding grooves
in the frame until they bottom.

Kotate the retaining spring clips to the locked
• position, making sure that each clip is in its
proper recess, and replace the device cover.

After the old relay has been removed, the
wire leads to the relay should be stripped of
insulation to about 1/4 of an inch from the ends.

A good mechanical connection should be made
before soldering.

As described under "Operation", the "Y" relay
is a permissive relay which limits to one the number
of breaker closures possible on one closing signal.
On drawout breakers, the "Y" relay mounting
bracket is fastened to the right hand side member
of the breaker frame by two mounting screws. On
terminal board breakers, it is fastened to the rear
side of the terminal board support. The relay

After all connections are completed, the relay

may should again be moimted to the breaker by

means of its supporting, brackets and hardware.

After replacement has been completed, the

relay may be checked electrically in the following

itself is fastened to an intermediate bracket which

is detachable from the main support. The junctures
between the relay and the intermediate bracket
and between the two brackets are rubber cushioned

Apply closing voltage to terminal board or
secondary disconnects.

Push button of closing switch and hold closed.

Continuing to hold push button in closed posi
tion, manually trip the breaker open.

against vibration and shock.
REPLACEMENT

If replacement of the "Y" relay becomes
necessary, it may be detached from its supporting
brackets by removgl of the fastening hardware.
The leads to the relay should be cut off as closely
as possible to the soldered connections so that
enough wire will remain for connection to the
new relay. Sufficient original wire is allowed
for this purpose.

If the breaker stays open, and makes no

attempt to close, the "Y" relay is fimctioning
properly,

While releasing the close button, observe
the "Y" relay. It should open as the closing
switch is released.

Figure 7. (695C162) Cut-Off Switch
1.
2.

4! Movable Contact Assembly

Actuator
Pivot Pin

Contact (AA)
Support

. 'GEI-S0299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
<

Mount the replacement switch by reversing
the order of procedure.

As emlained under "Operation", the function
of the cut-off switch is to de-energize the "X"
contactor coil and energize the "Y" relay coil
as the breaker mechanism moves from the opened
to the closed position.

flange of the closing solenoid coil. A hole in the

The switch is operated by the movement of
a mechanism link against the switch actuator
(6). This causes the actuator and movable contact
assembly (4) to rotate counterclockwise about

(4). When the button is pressed, movable contact
(5) deflects and impinges upon stationary contact
(2). This energizes the "X" relay coil which
seals itself in, and, in turn, energizes the closing

pin (7), opening the "bb" contacts (8) and closing
the "aa" contacts at (9).
Overtravel of the
actuator (6) beyond the point of making contact
at (9) is absorbed by spring (5) which couples
the movable contact (4) to the actuator. Spring

The closing switch is mounted on the iqiper

escutcheon (3) permits access to the switch button

Remove escutcheon (3).

(3) resets the switch after the breaker contacts
open and the breaker mechanism resets.

Disconnect leads from switch terminals.

The point at which the cutoff switch operates

Deflect the left end of hinge (7) to the left
so that the movable contact (5) may be dis

during the breaker closing cycle is after the spring

engaged from the switch assembly.

charged mechanism has been driven over-center.
This assures that the cutoff switch cannot operate

too early in the breaker closii^ cycle, thus the
X and Y relays are de-energized and energized,
respectively, at the proper time and the circuits
anti-pump feature is maintained. When the closing
mechanism is driven over-center, the force of

the previously charged closit^ springs is released,

^^^closing the breaker.
REPLACEMENT

Removal of the two screws (10) from speed-

nuts (9) completes the disassembly of the
switch.

Reassembly with new parts is a matter of
reversing the described procedure. In re
assembling, be sure the tab on the left end of
hinge (7) is bent to the right far enough to
avoid any possibility that movable contact (5)
might become free of the assembly.

The cut-off switch is located above the breaker

mechanism. It is fitted between the upper portions
of the steel side plates that make up the mechanism
frame. A raised horizontal ridge on each side of
the molded body of the switch fits into a cor
responding groove in each of the steel side plates.
A

roimd head screw on

each side fastens

switch and side plate together. Replacement of
the switch is accomplished by the following pro
cedure:

Remove the cover on the top of the switch
by taking out the two screws which hold it
in place.
After taking careful note of the connection
arrangements, disconnect the leads from the
switch terminals.

Remove the two screws, one on each side,
which

fasten the switch to the

Note that the one on the right

hand side also holds a wiring cleat and spacer

SHUNT TRIP DEVICE

The shunt trip device is mounted underneath
the horizontal cross frame member, just to the
left of the front escutcheon.

of a magnet, coil and armature. The armature
has an extended arm or striker (11) which bears
against the trip paddle (12) on the trip shaft
when the coil (8) is energized. This displaces
the trip latch in the breaker mechanism, opening
the breaker contacts.

The trip device is generally activated by a
remote switch or relay which closes the shxmt
trip coil circuit.

In order to avoid unnecessary heating of the
coil of the device, an auxiliary switch "a" contact
is wired in series with the coil.

the energization of the coil if the breaker is open.

which serves to hold the wires clear of the

link connecting the mechanism and the breaker
position indicator.
Remove the front escutcheonfrom the breaker.

Slide the cut-off switch out from between the

steel side plates by pulling straight forward.

The entire shunt trip device may be dismoimted by disconnecting the coil leads and re
moving nuts (1). However, the only part of the
device that might conceivably need replacement

during the life of the breaker is the coil (8). This

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299

Figure 8. (805B905)

Closing Switch (Top View)

Movable Contact

Stationary Contact

Front Escutcheon
Push Button

Closing Solenoid

Speed Nut
Screw

-LI —i-O 6 0 •if
-M2—*-0 7 ©•
O 8 0

Figure 9.
1.
2.

( 695C161) Shunt Trip Device

11.
12.
13.
14.

Trip Paddle
Mechanism Frame

Trip Shaft Clamp

. may be replaced without removing the device from

^^e breaker by proceeding as follows:
..

Disconnect leads of coil (8).

Remove two screws (6) which fasten magnet
(7) and coil to the frame (2).

Connect coil leads.

The only adjustment required on the shunt

trip device is that which ensures positively that

Having removed the magnet from the device,
straighten the end of clamp (9).

the breaker will trip when the device is activated.
In order to be sure of this, armature arm (11)
must travel from 1/32 to 1/16 of an inch beyond
the point at which the breaker trips. A good

Remove the coil from the magnet.

between the magnet and armature at (10). and with

Install new coil, again forming end of clamp
(9) as shown.

Reassemble to frame.

method of checking this is to hold a l/32nd shim

the breaker closed, push upwards at (5), closing

the armature against the magnet. If the breaker
trips, there is sufficient overtravel. If adjustment
is necessary, trip paddle (12) may be formed
towards or away from armature arm (11).

An AK-2/3 breaker may be equipped with
the following protective devices:

used when the short-time delay feature is required,

or when the trip device is used to operate a special
over-current ^arm switch.

Overcurrent trip (Magnetic) AK-2

Power Sensor Trip (Static) AK-3

overcurrent trip devices either of the dual m^netic
type (instantaneous and time delay tripping) or

Reverse Current Trip AK-2

instantaneous alone.

Most circuit breakers are equipped with series
Breakers are designed to

carry up to 100% of the continuous current rating
4.

Under Voltage Trip & Lockout Device

Bell Alarm and/or Lockout device

Open Fuse lockout device.

AKD-5 Interlock AK-2A/AK-3A
OVERCURRENT TRIP DEVICE

of their trip devices. Any attempt to carry higher
currents for a prolonged period will cause over
heating and possible damage.
EC-2 OVERCURRENT TRIP DEVICE

The Type EC-2 overcurrent tripping device
is available in three forms:

Dual overcurrent trip, with long-time delay
and high-set instantaneous tripping.

and a pivoted armature.

Low-set instantaneous tripping.

When current flow through the series coil
generates a magnetic field strong enough, the
armature overcomes the restraining force of a
calibration spring attached to it, and closes against
&e magnet.
This trips the breaker by means

High-set instantaneous tripping.

The dual trip has adjustable long-time and
instantaneous pick-up settings and adjustable time
settings. Both forms of instantaneous trips have

adjustable pick-up settings.

The typical overcurrent trip device consists

of a magnetic structure, a series current coil,

extension on the armature which strikes

against a trip paddle on the trip shaft.
DUAL OVERCURRENT TRIP,
Depending on the type of individual device,
the movement of the armature may be delayed
for a time by a timing device.
If a relatively

long time-delay (seconds or minutes) is desired,
the velocity of armature movement is governed

by a piston moving through an oil dashpot. If
only a short-time delay (cycles or milli-seconds)
is required, movement is controlled by an escape-

^-»»^ent gear and pallets arrangement.

An AK-2-15/25 breaker may be equipped with
either the EC-2 or EC-1 overcurrent trip device.
The majority of applications will require the use
of the EC-2 device. The EC-1 device is normally
20

DELAY AND HIGH-SET INSTANTANEOUS TRIP
PING.

By means of the adjustment knob (5), Figure 10,

which can be manipulated by hand, ^e current
pick-up point can be varied from 80 to 160 percent
of the series coil rating.
The indicator and a
calibration plate (4), Figure 10, on the front of
the case provide a means of indicating the pick-up
point setting in terms of percentage of coil rating.
The calibration plate is indexed at percentage
settings of 80, 100, 120, 140 and 160.

\ V,*^ • -»T-^

Figure 11. (8024843) EC-2 Overcurrent Trip With
Cover Removed.

Instantaneous Calibration Spring

Movable Nut (Index Pointer)
Time-Delay Calibration Spring
Instantaneous Pickup Adjustment Screw

Time-Delay Adjustment Screw
Oil Dashpot

Connecting Link

Instantaneous Pickup Calibration Marks

counter-clockwise motion decreases it. The dash-

Figure 10. (8024842) EC-2 Overcurrent Trip
1.

Trip Adjustment Screw

Opening lor Time Adjustment

Pickup Indicator & Calib. Plate
Pickup Adjustment Knob

pot arm (7), Figure 11 is indexed at four points,
maximum - 2/3 - 1/3 - minimum from the left,
as viewed in Figure 11. When the index mark on
the connecting link (8), Figure 11, lines up with a
mark on the dashpot arm, the approximate tripping
time as shown by the characteristic curve is in
dicated . The 1A and IB characteristic devices are

shipped with this setting at the 2/3 mark and the
IC characteristic at the 1/3 mark. The standard
characteristic curves are plotted at the same
settings.

The long-time delay tripping feature can be
supplied with any one of three time-current char
acteristics which correspond to the NEMA stand
ards maximum, intermediate and minimum long
time delay operating bands. These are identified

as lA, IB and IC characteristics, respectively.
Approximate tripping time for each of these, in

the same order are 30, 15 and 5 seconds at 600%
of the pick-up value of current. (See time-current

characteristic curves 286B201A, B, and C).
The tripping time may be varied within the
limits shown on the characteristic curvesby turning

the time adjustment screw (5), Figure 11. Turning
in a clockwise directionincreases the tripping time;

values are inversely proportional to

the effective length of the dashpot arm. There
fore, the linkage setting that gives the shortest
time v^ue is the one at which dimension "A"
F^re 11, is greatest.
The time adjustment
screw (5), Figure 11, may be turned by inserting
a Phillips head screwdriver through the hole in
the front of the case, but if it is desired to relate
the linkage setting to the index marks on the
linkage it will be necessary to remove the case.
This may be done by removing the two mounting
screws, one on each side of the case, which
may be taken off without disturbing the trip unit
itself.

GEI-&0299 Power Circuit Breakers Types AK-2-I5 and AK-2/3-25

Escape Wheel
Driving Segment

S.TJD. Armature

UfT SIDE VIEW SHOWING
SHORT TIME DELAY MECHANISM

LONG T(ME OEtAY MECHANISM

S.T.D. Calibration Spring
Trip Arm
Trip Paddle
Trip Paddle Adjusting Screw

L.T.D. Armature

L.TJ). Calibration Spring
Instantaneous Trip Spring
(High Set)
Spring Holder
Calibration Clamp Nut

Cylinder (Dashpot)

Calibration Plate

Clamping Bracket

FRONT VIEW SHOWING
MOUNTCNG BRACKET

Figure 12. (695C189) EC-1 Type Overcurrent Trip Device

NOTE:
Forcing the adjusting screw to either
extreme position may cause binding of the device
and should be avoided.

INSTANTANEOUS LOW-SET TRIPPING

The low-set instantaneous pick-up point may
be varied by the adjustment knob (5), Figure 10.
The calibration in this case usually ranges from

80% to 250% of the series coil rating, the calibra
tion plate being indexed at values of 80?c, 100%,
200% and 250% of the rating.
INSTANTANEOUS HIGH-SET TRIPPING

by stampings on the arm as follows:
4X
6X
9X

At the factory, the pick-up point has been set
at the nameplate value of the instantaneous trip
current. (Usually expressed in times the ampere

rating of the trip coil.)

The variation in pick-up

setting is accomplished by va^ing the tensile

force on the instantaneous spring. Turning the
adjustment screw changes the position of the

movable nut (2), Figure 11, on the screw. The
spring is anchored to this movable nut so that

The high set instantaneous pick-up value may

have one of the following three ranges: 4 to 9
times coil rating;
6 to 12 times coil rating or
9 to 15 times coil rating. The pick-up setting
may be varied by turning the instantaneous trip

adjusting screw (4), Figure II.
Three standard calibration marks will appear
jn the operating arm at (9), Figure 11, and the
value of these calibration marks will be indicated

when the position of the nut is changed, there is
a corresponding change in the spring load. As
the spring is tightened, the pick-up point is in
creased.
The top edge of the movable nut (2),
Figure 11 serves as an index pointer and should
be lined up with the center of the desired calibration
mark, punched slots on operating arm, to obtain
the proper instantaneous trip setting.

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299
EC-1 OVERCURRENT TRIP DEVICE

The EC-1 device can be provided with the
following tripping combination

Long time delay, short time delay and in
stantaneous -tripping.

breaker mechanism or the overcurrent trip devices
have been replaced.

Positive tripping is achieved when adjustment
screw (2), Figure 10, is in such a position that
it will always carry the trip paddle on the trip
shaft beyond the point of tripping the mechanism,
when the armature closes against the magnet.

Long time and short time delay tripping only.

In order to make the adjustment, first unscrew

trip screw (2), Figure 10, until it wiU not trip the

Long time delay and instantaneous tripping.

Short time delay and instantaneous tripping.

breaker even though the armature is pushed against
the magnet. . Then, holding the armature in the
closed position, advance the screwuntil it just trips

Short time delay tripping only.

the breaker. After this point has been reached,
advance the screw two additional full turns. This

Instantaneous tripping only.

Adjustable (Low set)

will give an overtravel of 1/16 of an inch and will

make sure that activation of the device will always
trip the breaker.

Non-adjustable (High set)
SHORT TIME DELAY TRIPPING, Figure 12.

Adjustment screw (2), Figure 10, can best be

manipulated by an extended 1/4 inch hex socket
wrench.

In order to gain access to the adjustment
screw on the center pole overload device, it will
be necessary to remove the nameplate from the

The armature (7) is retained by calibrating
spring (8).
After the magnetic force, produced
by an overcurrent condition, overcomes this re
straining force, the armature movement is further
retarded by an escapement mechanism which

front escutcheon of the breaker. This will reveal

produces an inverse time delay characteristic.

engage the adjustment screw.

The mechanism is shown in the left side view of

Figure -12.
The pickup for this device can be field set

a hole, centrally located in the escutcheon, by
means of which the extended socket wrench can

REPLACEMENT, EC-1 and EC-2

Replacement of either the EC-1 or EC-2
overcurrent trip device is accomplished by the

between limits having a ratio of 2-1/2 to 1 in
the range of 200 to 1000% of the coil rating.

following procedure:

LONG TIME DELAY TRIPPING, Figure 12

Separate the breaker's front and back frames
as

The armature (12), is retained by the calibra
tion spring (13). After the magnetic force, produced
bs an overcurrent condition, overcomes this re
straining force, the armature movement is further
retarded by the flow of silicone oil in a dashpot,
which produces an inverse time delay character
istic. The mechanism is shown in the right side
view of Figure 12.

Remove the steel clamps which fasten the cover

Pickup settings on the cover of each device are
calibrated for the specific device. When re
placing covers, replace on associated device.

Remove the 3/8 inch hexagon headed bolts
which fasten the coil of the overload device
to the breaker copper.

Adjustable instantaneous tripping takes place
after the magnetic force produced by an overcurrent condition, overcomes the restraining

force of the adjustable calibration spring (13).
b.

in the section- under "Main

of the device to the back of the breaker. NOTE:

INSTANTANEOUS TRIPPING, Figure 12.
"iC

Remove the round head screw which fastens

the frame of the overload to the breaker base.

Nonadjustable instantaneous tripping takes
place after the magnetic force produced by an

After reassembling breaker with new overload
device, adjust for "positive trip" as described
under "Adjustments" of this section.

overcurrent condition overcomes the restrain

REVERSE CURRENT TRIP DEVICE

ing force of a nonadjustable spring (14).

Figure 13.
ADJUSTMENTS, EC-1 AND EC-2
In addition to the pick-up settings and timedelay adjustments already described, overcurrent
trip devices must be adjusted for positive trippii^.
This adjustment is made at the factory on new
breakers, but must be made in the field when the

The reverse current trip device sometimes
used with d-c breakers will trip the breaker open
if

the direction of current flow is reversed.

This device is similar in appearance and is
mounted in the same way as the overcurrent trip.

armature to rest against stop screw (9) attached
to a bearing plate on the right side of the device.
If the current through the series coil (1) is
reversed, armature (6) tends to move in a clockwise
direction against the restraint of calibration spring
(3). When tiie current reversal exceeds the calibra
tion setting, the armature will move in a clockwise
direction. This causes trip rod {2B) to move up
wards against trip paddle (14), tripping the breaker

P0«.A«ITY RCrEKCffCe

roR rcsT-cAusci
BRCANCft TO TRIC

The only adjustment to be made on the reverse
current device is to make sure that the trip rod

has a minimum overtravel of 1/32 of an inch beyond
the point of tripping the breaker. The only occasion
this adjustment should have to be made is when an

old device is being replaced by a new one.

The new device will be factory adjusted so that

the top end of the trip rod (2B)will extend 1/2 inch

CONTACtS
tw»ACK FRAME
AETIC SENSORS

POWER SENSOR
UNIT

After the PST-1 Test Kit has been used to
determine the adequacy of performance of the Power

Sensor Unit, it may be advisable or required to
test the magnetic coils by the use of a hi-current
Low voltage type test set. In this event, only one
test per phase need be made. This test should
be made at some convenient multiple of pick-up

setting such as 300% for comparison with published
time-current curves.
COMMON NECATIVE

In the event the breaker is equipped with

ground sensor, the ground sensor will cause tripping
on single phase testing unless the signal is shorted
at the terminal board (Figure 22). Jumper points
1 and 5 during overcurrent test.
JWI«t

The above considerations should indicate which

of the four major components is faulty and in

need of replacement.
REPLACEMENT OF POWER SENSOR
COMPONENTS

POWER SENSOR UNIT (Figure 16).
I
I

ICWtSCUSSEKTI *

connecting the unit

Slide unit forward.

Remove control plug by alternately loosening

the two retaining screws.

Figure 20. (0133C9017) Power Sensor Cabling

Replace in reverse order.

MAGNETIC TRIP DEVICE (Figure 17).

Remove trip solenoid wires from the terminal
board on power supply.

Remove four screws holding power supply to
breaker frame.

Pull power supply forward until restricted by
wiring.

Lift out trip device.

Replace in reverse order.

POWER SUPPLY (Figure 15).
o

Remove magnetic trip wires from the terminal
board on POWER SUPPLY

Figure 21. (8039962) Power Sensor Test Kit

four screws holding power supply

to breaker frame.

cjroumd a t
transformer. MEv'TRAL

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(BREAKER, CASLINT, , UfEOUUO SEnSoR
DiSCou'mECT and CAT^RnAL ORoumO

CHECe Ho continuity A ORC TOR fSuiELCl

Typical agQyuDPfiJLT ConnecTionc

YJfiYfr 'Z3AScc/^A/ac.7-

0 ^ CHECK CONTlNUtTY A TO C
0

SROUNO SEMSOR ZVtff^'VWT-

PART OF PS-1 POWES SENSOR. TRIP

CHECK CONTlMyiTY R TO SHIELD OF

NEUTIVAL CSROUNO SENSOR COiL.

•Z^gr/p/c
Sw/^iZyVM/rc

ftHirc /%iAA/*-y Z3AK-l-SO

weSETTABLE DELAY TIME -IS DURATION OF FAULT CURRENT WHICH MAY PERSIST ATA

dt 0OIVEM VALUE AND THEN DROP TO 80%OF THE LOKO TIME DELAY PICKUP SETTINO.
WITHOUT THE BREAKER TRIPPIN8.

PICKUP TOLERANCC ARE PLUS OR MINUS 10% FOR LOHO TIME 8 INSTANTANEOUS

©FOR MORE detail INFORMATION ORDER DW6.286B20IA,B,C FROM LOCAL APPARATUS

I "11 I
CURRENT IN TIMES COIL RATING

Figure 23. (286B209) Time-Current Characteristic - EC Devices

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299

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Figure 24. (109HL687) Time Curve

Remove four screws holding escutcheon to
mechanism frame

Figure 25. (109HL689) Time Curve

and remove escutcheon.

Disconnect control plug to power sensor coils
and power sensor imit.

Remove cable clamps holding cabling inplace.

Separate the breaker front and back frame
as

in the section under "Main

Remove three 3/8 hexagon headed bolt con
necting coils to breaker copper.

Replace in reverse order.

SENSOR COILS (Figure 14).

Remove primary disconnects per instructions
under disconnects.

Remove power supply unit with attached cabl
ing.

Unsolder three leads at groimd disconnect
and pull wire through hole in back frame.
On stationary breakers with fourth wire ground
disconnect, unsolder leads at external ground
coil and pull wire through hole in back frame.

With the back frame in the vertical position,
and supported, grasp the outside coils and
lift coil assembly from back frame. When

carrying or moving sensor coil assembly,
always support the outside coils.

Remove two screws holding sensor coil dis
connect plug bracket to back frame.

Remove bolt holding resistor bracket to back
frame.

Remove 2 screws holding capacitor bracket
to back frame.

SELECTIVE TRIPPING

Selective overcurrent tripping is the applica
tion of circuit breakers in series so that oidy the
circuit breaker nearest the fault opens. Anyone
or combination of two or more of the preceding
over-current devices may be used in a selective

system. The breaker having the shorter time
setting and lower pickup will trip before the

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breaker having the longer setting and higher pick
up, provided the fault is on the part of the line
protected by the breaker having the lower setting.

on the breaker is always connected through either
its secondary disconnects or terminal board, to
terminals #4 and #5 of the time delay box.

For the exact characteristics and setting of
each breaker in a selective system, reference

approximately 80% of bus voltage and drop out

should be made to a

coordination chart for the

between 30% and

particular system.

(Figures 23, 24, and 25)

STATIC TIME DELAY
UNDERVOLTAGE TRIPPING DEVICE

The Static Time Delay Undervoltage Tripping
Device consists of an undervoltage device mounted
on the breaker, a static time delay box mounted

separately from the breaker and a control power
transformer which is also mounted separately from
the breaker when the reference voltage is other
than DC., 208V AC or 230V AC. Refer to wiring

diagram 0102C3698 (Figure 26).
The voltage 208V AC or 230V AC, to be
monitored is

connected to terminals #1 and #2

of the time delay box.

The imdervoltage device

The undervoltage device is set to pickup at

The undervoltage device coil circuit is con
tinuously rated and will remain picked up as long
as the voltage remains above the predetermined
drop out voltage. The time delay is field adjust
able between 1 and 5 seconds, it is factory set at
the minimum setting, and once the time delay is
established, it is consistent.
No more than one imdervoltage device should
be connected to a static time delay box.

The Static Time Delay Undervoltage can a).so
be furnished in conjunction with the termotector
control package, as shown on wiring diagram
0102C3699 (Figure 27). Overheating of the motor

windings causes the termotector, imbedded in the
motor windings, to open and allow the "Z" relay
of the control box to instantaneously trip the

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breaker through a normally closed "Z" contact
in series with the undervoltage device mounted

approximate voltages are as follows:

on the breaker.

WARNING - Do not use bell set to check con

208 Volt A.C.177L316G-12-110 volts D.C.
230 Volt A.C. 177L316G-12-120 volts D.C.

tinuity of bridge circuit in static time delay box,

only a volt-ohm meter or vacuum tube volt meter
should be used.

125 Volt D.C. 177L316G-14 50 volts D.C.

In the event the device fails to pick-up, the

250 Volt D.C. 177L316G-15-100voltsD.C.

following checks are recommended to determine
whether the magnetic device on the breaker or

The resistance of the under-voltage coils are

the static time delay unit is the faulty component.

Check input voltages across terminals 1 & 2
on static box. These voltages should be as

6275080 G-59 - 1830 Ohms.

Device 177L316G-12-208or230voltsA.C.

Device 177L316 G-14-125 volts D.C.

Device 177L316 G-15-250 volts D.C.

Check output voltages on terminals 4 & 5
with the under volt^e device connected. The

The entire device may be dismounted by
Reconnecting the coil leads and removing screw
(1) and nuts 16. Normally, only the coil (12)

will ever need replacement. This may be removed
from the device by taking out screws (11) which
wUl free both the magnet (10) andthe coil. Straight33

•, GEI-^0299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25

1. Moimting Screw
2. Frame
3. Armature

4. Spring
5. Shading Ring
6. Adjusting Screw

Bushing
Clamp
Magnet

8.
9.
10.
11.
12.
13.
14.
15.
16.
17.

Adjusting Screw
Locking Wire
Moimting Nut
Mechanism Frame

18. Trip Paddle Clamps
19. Trip Paddle
20. Adjusting Screw

Figure 28. (0152C9206) Undervoltage Tripping Device

ening of the bend in clamp (9) will separate the
coil from the magnet. The coil leads, of course,
must be disconnected.
INSTANTANEOUS UNDERVOLTAGE
TRIPPING DEVICE

mounted in the same location and manner as the

static time-delay device and its construction is
similar.

replacement of t is

device are the same as those described above for

the static time-delay undervoltage device.
UNDERVOLTAGE LOCKOUT DEVICE

The undervoltage lockout device holds an

^^^f^re 29. (0101C7842) Undervoltage Lockout Device

the undervolt^e device armature in the closed

Left Side Frame

air gap position to prevent tripping the breaker
in the event the undervoltage device coil is de-

Trip Paddle
Undervoltage Armature

energized. This feature when used in conjunction
with normally-closed auxiliary contacts of an

open breaker trip-free when the coil of the device
is deenergized. When the breaker is in the closed
position, linkage operated by the breaker mech
anism cam positions itself to mechanically hold

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299

^ idternate breaker presents a convenient method

of mechanically interlocking two or more breakers

to assure that no two brewers may be closed at

Lever (2) is connected to the breaker mech
anism so that when the breaker opens lever (2)
rotates counterclockwise about pin (14).
The
motion is transmitted through links (1) and (13)
to paddle (12) which operates bell alarm switch

BELL ALARM SWITCH AND/OR
LOCKOUT ATTACHMENTS

If the device has the lockout feature, the

movement of link (13) also causes lockout link
(8) to slide in a direction that results in its

The bell alarm device is mounted on top of
the horizontal cross frame member just to the

striking trip paddle (5) which, by displacement of
the breaker mechanism trip latch, makes it im

left of the mechanism frame when the breaker

possible to reset the breaker mechanism until

is viewed from the front. This device operates
a switch with two sets of contacts, one normally
open, the other normally closed. The switch may
be used to open or close an external circuit,
giving a bell or light indication of a protective

the bell alarm mechanism is reset.

Link (6) serves as a latch in the bell alarm
mechanism.
If it is displaced, link (10) is free

trip device operation.

to rotate about its lower pin. This deprives the
linkage of its normally fixed center of rotation

If the breaker is tripped open by any means
other than the manual trip button or the shimt
trip device, the bell alarm mechaiiisnj is activated.

about pin (15) and defeats both the bell alarm and
the lockout operation. Operation of either the
manual trip button or the shimt trip device will
displace latch (6) and have this effect. Thus if

the breaker is tripped by either of these means,

alarm is shut off and the bell alarm and

the bell alarm and/or lockout will not operate.

lockout mechanism is reset by operation of the
manual trip button or shunt trip device. If the
device is a bell alarm only, the bell alarm mech
anism is also reset simply by closing the breaker.

Also, operation of either of these devices will
reset the switch and inactivate the lockout.

TYPICAL CONNECTION
DIAGRAM

Figure 30. (695C158) Bell Alarm and Lockout Device
1.
2.
3.
4.
5.
6.

Trip Shaft
Trip Paddle

7.
8.
9.
10.
11.
12.

Trip Arm
Lockout Link
Frame
Link
Switch
Paddle

13.
14.
15.
16.

OPEN FUSE LOCKOUT DEVICE

The Open Fuse Lockout Device consists of
-two or three separately operated devices (one per
phase). Each wired in parallel to corresponding
breaker fuses.

This device is furnished on all

The purpose of this device is

Check that each armature holds the breaker

trip free when the armature position is limited
in reset by the lower latch surface on the

With the breaker in the closed position, the

top collor must clear the trip shaft paddle

by more than 1/32 inch.

to trip the breaker upon the blowing of any one of
the breaker fuses and render the breaker trip
free until the blown fuse is replaced and the
associated coil assembly reset.

OPERATION, Figure 31.

When any one of the breaker fuses blow, the

coil (6) in that phase is energized and the armature
(5) closes. With the armature closed, leaver (2)
slips imder the armature and latches it in the

closed position.

Remove coil leads from fuses and work wire
harness back to the device. Remove device
from breaker.

Replace new unit in reverse order and check
procedure under ADJUSTMENTS.

The latched closed armature

holds the breaker in the trip free position until

AKD-5 INTERLOCK

it is released by pushing the associated reset

The coil is deenergized as soon as

the breaker opens.

The rackout mechanism is interlocked so that

the
ADJUSTMENTS

circuit breaker must be open before the

Set top cylindrical collor (not shown) to engage
the trip shaft paddle in the tripped position.

breaker is closed, the interlock link (1) operated
by the breaker cross bar blocks the interlock

linkage on the rackout mechanism.

Figure 31. (8041865) Open Fuse Lockout Device

Figure 32. (8039852) AKD-5 Interlock

Rackout Mechanism Interlock

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299

Ml S C E L L AIM E OUS

Changes in breaker requirements may oc
casionally bring about the necessity of adding or
changing breaker components or accessories in

the field. The AK-2 breaker has been designed
so that such additions or conversions are simple
and easy to make, requiring only a minimum of
time or skill on the part of the operator.
Special instructional drawings are available
which will further simplfy the addition of such

MAINTENANCE TOOLS

The following tools are recommended for
proper maintenance of AK-2-15 and AK-2/3-25
breakers. {NOTE: Obtain from local hardware

firm; do not order on General Electric Company.)
Screw Drivers

shipped without them.

Long thin, slotted screw
Standard, slotted screw
Phillips, No. 2, (8" shaft)

These drawii^s will accompany the necessary
material when it is shipped from the factory. They
will also be available upon request. The drawings
and the accessory additions which they cover are

accessories to breakers which were originally

When an accessory is added to a breaker, it
is recommended that the section of instructions

contained herein covering that particular accessory
be reviewed, in addition to referring to the following
instructional drawing. Any adjustments described

Waldes Truarc, No. 2 straight
Long Nose, side cutting, 6"
End Wrenches

Adjustable, 8"
1/4" open end

in these instructions should be carefully made after
the device has been assembled on the breaker.

Allen Head Wrenches

Conversion of breakers from manual to elec
trical operation is also covered on an instructional

5/16" for 3/8" screw
1/8" for 1/4" screw

tion of the front and back frames of the'breaker as
described under "Maintenance" in these instruc

Socket Wrenches (3/8" drive)

drawing. This operation consists simply of separa

tions and the reassembly of the existing back frame
with the new front frame.
Addition of

Shunt Trip Device

Auxiliary Switch

Undervoltage Device

Bell Alarm & Lockout Device

Drawout Mechanism

Conversion to Elec. Oper.

Ratchet Handle
12" extension bar

3/8" socket
9/16" socket

7/16" socket (long)
Miscellaneous Tools

1/4" Spintite (long shank)
7/16" Spintite

8 '32 screw (at least 2" long)

When ordering renewal parts, address the
nearest Sales Office of the General Electric

Company, specifying the quantity required. Com

plete nameplate data of the breaker involved should

be given as well as an accurate description of the

parts required. If the parts needed are illustrated

in this book, refer to the figure number and part

number involved.

Renewal Parts which are furnished may not

be identical to the original parts since from time
to time design changes may be made. The parts
supplied, however, will be interchangeable with
the original parts.
Renewal Parts Bulletin
Bulletin
GEF-4149F

AK-2-15/25
AK-3-25

Gei-sozg9D
INCLUDES SUPPLEMENT
GEI-93a63A

POWER CIRCUIT BREAKERS
TYPES

AK-2/3/2A/3A-25

AKU-2/3/2A/3A-25

Electrical Operation

Manual Operation

Electrical with Manual Operation

Separation of Front and Back Frames
Trouble Shooting

BASIC BREAKER COMPONENTS

Contact Adjustments

Breaker Contact Structure
Contact Replacement

Auxiliary Switch
Electrical Control Components

Closing Solenoid
"X" Contactor

Closing Switch
Shunt Trip Device

PROTECTIVE DEVICES
Overcurrent Trip Device

EC-2 Overcurrent Trip Device

EC-1 Overcurrent Trip Device

Reverse Current Trip Devices

Power Sensor Trip Device
Selective Tripping

Undervoltage Lockout Device

Static Time Delay Undervoltage Tripping Device
Instantaneous Undervoltage Device
Bell Alarm Switch and/or Lockout Attachment

Open Fuse Lockout Device
AKD-5 Interlock

MISCELLANEOUS
Maintenance Tools

POWER CIRCUIT BREAKERS

Types AK-2-15 and AK-2/3-25
IIMTROOUCTIOIM

The instructions contained herein provide in

formation for performing maintenance procedures

and for replacing AK-2/3-15/25 breaker conn)0-

the receiving, handling, storage and installation
of these breakers, refer to GEK-7302 furnished
with all AK breakers.

nents and accessories. For information regarding
OPERATIOIM
ELECTRICAL OPERATION
Figure 1

The electrically operated breaker closes when
ever the closing solenoid coil is energized. This
causes an upward movement of the solenoid arma

ture, which Initiates the mechanical closing action.
The closing signal may be given either by a
remote switch or relay, or by a closing button
in the front escutcheon if the breaker is so

equipped. Either action (refer to the elementa^

of the wiring diagram) energizes the coil of the
X relay through the bb contacts of cutoff switch

G and the normally closed contacts of the Y relay.
When the X relay or contactor is energized, it
closes its contacts. One of these (Xl-2) seals
in the X coil. The other three sets of contacts,
which are arranged in series, activate the closing
solenoid.

An individual breaker may have none or

any combination of these devices. They are the

overcurrent tripping device, shunt tripping device,
undervoltage tripping device, reverse currenttrip
ping device, and open fuse

of them effect tripping by displacing the trip latch
of the mechanism. The trip latch is rigi^y
attached to a trip shaft which runs through the
breaker from left to right. Whenever the trip
shaft is rotated in a counterclockwise direction

looking from the right, the latch is displaced.

The tripping devices are all equipped withstrikers

or trip arms which act against trip paddles rigidly

fastened to the trip shaft, causing it to r

on its bearings in a direction to trip the bre

The reverse current device and the shunt

The breaker control scheme has an anti-

tripping device each have a set of auxiliary switch

the breaker for a single operation of the closing
switch no matter how long the switch may be
held closed. This prevents the repeated operations
that would ensue if one of the automatic trip
devices was activated at the time of closing. The

is open when the breaker contacts are open.)
This prevents their operation unless the breaker

pump feature which allows only one closure of

"a" contacts in their circuits.

(An "a" contact

The undervoltage device coil is normally
continually energized. When the control voltage is

Y relay, together with the cut-off switch, provides
the anti-pump feature. The mechanical action of
closing operates the cut-off switch, reversing
the position of the contacts from that shown on
the diagram. This energizes the Y relay, if

pulled out for inspection or maintenance, the

by Y contacts 5-6. This prevents the X relay
from again becoming energized. Y contact 1-2

device is used on all AKU breakers and breaker
fuse combinations. The purpose of this device

tained at the closing switch.

one of the breaker fuses.

contact is still maintained at the closing switch,
with the result that the X relay circuit is opened
seals in the Y coil as long as contact is main

The breaker may be tripped open by any one
of a number of electrical tripping devices which
will be described in detail later in these instruc

Electrically operated breakers may also be

closed by means of the maintenance handle which
is furnished with the breaker. This is a separate
tool and is simply a lever which permits an

operator to push upwards on the closing solenoid
armature.

Two small hooks on one end of main

tenance handle are engaged in slots (9A) Figure 5,
located in the lower portion of the front escutcheon

Rotation of the long end of the

handle downwards forces the shorter end of the

handle upwards against the bottom of the solenoid
armature, and closes the breaker.

low or non-existent, as when the breaker has been

breaker is rendered trip-free by the undervoltage

device. If it is desired to close the breaker,
the device armature must be tied down or blocked

closed against the magnet. The open fuse lockout

is to trip the breaker upon the blowing of any
MANUAL OPERATION

The manually operated breaker is closed by
first rotating the handle in a counterclockwise
direction through 90 degrees, then rotating it

clockwise back to its normal vertical position.
The counterclockwise stroke resets the mechanism,

readying it for the clockwise closing stroke.

The breaker may be tripped manually by

pushing the manual trip button. This action pushes

rfiM. iminjciion* do no/ purport to cover all details or variations in equipment nor to provide for every possible
or should particular problems arise which are not covered sufficiently for the purchaser s purposes, the motter shoutd

eonlingeney to be met in connection with installation, operation or maintenance. Should further inforrnation be desir^
be referred to the Genera/ Electric Company.

GEI-50299 Power Circuit Breakers Tjrpes AK-2-15 and AK-2/3-25
solenoid connecting link and manual cam connecting

a rod against a trip paddle of the trip shaft,
rotating it, and causing the mechanism trip latch
to be displaced.
This allows the mechanism
linkage to collapse through the action of the

link are both connected to the closing spring pin

at the top of the mechanism, thus compressing
the springs when force is provided by either
means of breaker closing.

mechanism operating springs.

If the breaker is tripped manually

The breaker is manually closed by rotating

while the operating handle is in the reset position,

the closing handle 90 degrees counterclockwise.

the handle should be lowered by the right hand

No reset stroke is necessary as is the case with
the standard manual breaker. Electrical closing

while operating the trip button with the left hand.

may be performed either locally or remotely in

ELECTRICAL WITH MANUAL OPERATION

the same manner as the standard electrical breaker.

This operating mechanism provides both man
ual and electrical closing. The operating mech
anism is similar to the mechanism of the standard

Tripping is accomplished by the manual trip
button on the escutcheon or by any of the electrical

electrical breaker with the addition of the manual

tripping devices available for use on the standard

handle, cam and mechanism connecting link. The

A-TERMMAL BOARO LOCATCO TOP RICHT.
FRONT VIEW
STRP

F-ANTI-PUIC? PERMISSIVE RELAY.
G*(ao-bb) - CUT-OFF SWITCH
K-(il*CLOStNG eONTACTOR*3 SETS OP CON
TACTS (N SERIES (MAINI a I SET
FOR 8EAL-(N

i-(mi.9v>-aux sw-eVa EK contacts
6T0I OR sId' a sV (SPECIAL)
M-tTU-SHUNT TRIP DEVICE

N-tcet-SOL£NOlO CLOSING COIL.

P-t*»i-CLOSmG SWITCH ON BREAKER
3f

note,when SERWATE power source 2?" CLCSy®

COC S USED. OMfT XMPERS AI*A3 B

CONNECT POWER TO Al S A2

-K2-'-® I *•-T* - :CL0SE
A6MI

-Kl —oS»;
-LI—

-Ni-r-04 » -Tl
-Kl —o J

I?"?--X TRIP
--r SOURCE

LI • •06^*
-Mi- . ^ 7 0-*

. X CLOSING
Y- SOURCE

'CUSTOMER WIRING
'.FACTORY WIRING

'FACTORY WIRING /OR ENCLOSED BKR

CUSTOMER WIRING FOR STATIONARY BKR

alternate WBNG POR use Wl-TO

FOLLOWING CONTROL VOLTAGE HATING
SYS/iJOV A C 60—

575/aO V A C SO—

CONNECTION DIAGRAM

Figure 1. (695C160-1) &(695C159-1) Typical Wiring Diagram

MAINTENANCE
INSPECTION

BEFORE INSPECTION OR ANY MAINTE
NANCE WORK IS DONE, BE SURE THAT THE
BREAKER IS IN THE OPEN POSITION.

ELECTRICAL POWER, BOTH PRIMARY AND
CONTROL SOURCES, SHOULD ALSO BE DIS

front frame and mechanism of the breaker from
the back frame or base, which consists of the
current carrying parts of the breaker and their

supporting structure.

operation is as follows:
1.

Periodic inspection of the circuit breaker

frequent inspections are recommended, if severe

arrangements be made to open and close it several
preferably under load.

At all times it is important not to permit pencil
lines, paint, oil or other foreign materials to re

Remove one elastic stop nut from each of
two studs (3), which tie the upper ends of the
•mechanism frame to the back frame of the

main on the insulating surfaces of the breaker

trical breakdown.
5.

Remove the two elastic stop nuts (9/16" Hex.)
which fasten the wrap around portion of the
front frame to the back frame. One of these

circuit current has been interrupted.
f.

If the breaker is a drawout type, with secondary

disconnects. Figure 2, remove the secondary
disconnect supporting bracket from the breaker
back frame. Also remove any wiring bundle
retainers that may be attached to the back
frame.

as they may cause low resistance between points
of different potential and resxilt in eventual elec
Always inspect the breaker after a short

(6), between the mechanism and the crossbar
(10), by removing the Ue bolt (7), and sUpping
ered pin, (5) Figure 5 in the mechanism.

a long period of time, it is recommended that
times in succession,

Disconnect the two insulated connecting links
the ends of the links off the ends of the should

load conditions, dust, moisture, or other un
favorable conditions exist.

If the breaker remains open or closed for

Remove the arc quenchers (see section on
"Arc Quenchers").

is recommended at least once a year.

The procedure for this

is located on each side of the breaker, about

At the time of periodic inspection, the follow

ing checks should be made after the breaker has

2/3 of the distance down from the top edge

been de-energized.

of the back frame.

Manually operate the breaker several times
checking for obstructions or excessive friction.

On drawout breakers for AKD Equipment, the
bottom plate must be removed by first remov

Electrically operate the breaker several times
(if breaker has electrical control) to ascertain

slots located in the bottom of the back frame.

ing two #8-36 screws located at the front of the
bottom plate and then freeing the plate from the

whether the electrical attachments are func-

tionit^ properly.
3.

Remove and inspect the arc quencher. Break
age of parts or extensive, burning will indicate
need for replacement.

Check contact condition and wipe

Check latch engagement.

Check operation of tripping devices, including
overcurrent trip devices, making sure all
have positive tripping action. (Discernible

The two frames are now disconnected. How

ever, care should be exercised in separating
them to avoid damage to the trip shaft arms

While the back frame is held

stea(ty, lift the front frame and mechanism

up and out so that the trip paddles on the
trip shaft clear the trip arms of the overload
trip devices.

movement in tripping direction beyond point

of tripping.)
(For detailed information on breaker features

listed, refer to

appropriate sections of these

instructions.)
SEPARATION OF FRONT AND BACK FRAMES

Figure 3
Many maintenance operations will either re

quire or be greatly facilitated by separating the

Reassembly of the two breaker halves is
accomplished by following the procedure out
lined in reverse order.
LUBRICATION

In general, the circuit breaker requires very
little lubrication.
Bearing points and sliding
surfaces should be lubricated very lightly at the

regular inspection periods with a thin film of
extreme temperature, high pressure, light grease,
similar to G.E. Spect. No. D50H15 or RPM No. 5.
Hardened grease and dirt should be removed from
latch and bearmg surfaces by the use of a safe
cleaning solvent such as kerosene. Latch surfaces
should be left clean and dry and not be lubricated.

GEI-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25

ALL EXCESS LUBRICANT SHOULD BE REMOVED
WITH A CLEAN CLOTH IN ORDER TO AVOID
ANY ACCUMULATION OF DIRT OR DUST.
At each maintenance period, all silver to

silver friction points, such as primary disconnects,
should be cleaned and given a fresh coat of G.E.
Spec. No. D50H47 lubricant.

AK-2/3 Breakers

The following table lists several typical symp
toms of breaker malfunction, together with their
causes and remedies.
If, at any time, these

symptoms are observed, their cause should be
determined and the necessary corrective action
should be taken.

TROUBLESHOOTING

Contacts not aligned

Adjust contacts.

Contacts dirty, greasy or coated with dark

Contacts badly burned or pitted

Rqilace contacts

Current carrying surfaces dirty

Clean surfaces of current carrying parts

Corrosive atmosphere

Relocate or provide adequate enclosure

Insufficient bus or cable capacity

Increase capacity of bus or cable

Bolts and nuts at terminal connections
not tight

Tighten, but do not exceed elastic limit (rf

Current In excess of breaker rating

Check breaker application or modify circuit
by decreasing load

Excessive ambient temperature

Provide adequate ventilation

Travel of tripping device does not provide
positive release of tripping latch

Re-adJust or replace tripping device and

Worn or damaged trip unit parts

Replace trip unit

Bind in overcurrent trip device

Replace overcurrent trip device

Overcurrent trip device pick up too low

Cheek application of overcurrent trip device

Overcurrent trip device time setting too Short Check application of overcurrent trip device

Failure to trip
AK-2 Breakers

Failure to Close and Latch

AK-2/3 Breaxers

False Tripping
AK-3 Breakers

Failure to Trip

check mechanism latch adjustment

Bind in overcurrent trip device

Replace overcurrent trip device

Binding In attachments preventing resetting

Re-allgn and adjust attachments

Latch out of adjustment

Latch return spring too weak or broken

Hardened or gummy lubricant

Clean bearing and latch surfaces

Closing solenoid burned out

Replace solenoid coil

Solenoid control device not functtonlng
properly

Re-adJust or replace device

Captive Tlnimp screw on Power Sensor
loose fail-safe circuitry reverts

Tighten thumb screw on desired setting

ciiaracteristlc to minimum setting and
maiTd"""" time delay

Tap setting dial on Power Supply incorrectly

Set dial to correspond with Power Sensor coil

External Ground Sensor CoU Imprt^erly

Refer to Figure 22, page 29 for poUrity and
connections. Check continuity of shield and
conductors connecting the external Ground

bolts or fittings.

lioose or disconnected power sensor dis
connect plugs

Loose or broken power sensor coU tap
connections

Tighten or reconnect disconnect plugs
Tighten or reconnect tap connections

Power Circolt Breakers Types AK-2-15 and AK-2/3-25 GEIBASIC BREAKER
nrsroNNECTS

PRIMARY DISCONNECTS

The primary disconnects s^e attached to the
ends of tne breaker studs on the rear side of
breaker base. Each disconnect assembly consists
of two pair of opposed contact fingers. These are
secured to thebyeaker stud by a bolt which passes

The movable part of the secondary disconnect
ducting spring loaded plunger to which a flemble
lead^ attached. As the breaker moves mto its
enclosure, the plunger is depressed
onto the stationary disconnects of the enclosure.
REPLACEMENT OF MOVABLE SECONDARY DIS
consists of an insulating body

through the assembly and the stad. When engaged

1. Unfasten disconnect body from breaker back

against the stationary stud through the action of
the compression springs.
^

2. Open tabs which hold wires on inner side.

engagement with the stud. The amoi^ of force
which the fingers exert against the stud is determUied by S^ree to which the springs are com
pressed by the bolt and nutwhich holdthe assrably
together. This pressure is factory set between
80 andTOpounds. If,for any reason, t^®
must be taken apart, t^®
^

4. Remove contact tip by. cutting wire at its

with the stationary stud of the enclosure, the
disconnect fingers exert a set amoimt of force
hold the contact fingers in correct

the bolt should be care^Uy noted, so that m
reassemblying, t^ original
can be restored by replacing the nut at its former

position on the bolt.

3. Pull contact tip loose from hoUow tube.
base.

5. Push wire through hollow tube of new dis
connect assembly.

6. Strip Insulation off end of wire to about 1/4
of an inch from end.

7. Place new contact tip on end of wire and
crimp.

SECONDARY DISCONNECT, FIGURE 2.
The secondary disconnects serve as connec

tions between breaker control circuit elemente
and external control circuits. They are used only

SS drawout type breakers. Aterming toard serves
the same purposeon stationary naounted^dgener^
puroSe enclosure mounted breakers. The secondiWscSiiects
allow removal ofJheb^akervntto^ the necessity of having to detach external con

PuU wire through holldw tube

tip fits snugly against end of hollow tube.
9. Crimp tab on other side of assembly to hold
wire in place.

10. Any hoUow tubes which are not used should
be pushed into the disconnect body and held

in that position by placing ff^*"®
over
inner ends of tubes and spreading tabs.

Figure 2. (8017973) Movable Secondary Disconnects

11. When all wires have been connected, refasten

the body of the assembly to the breaker back

The arc quencher is an integral riveted as
sembly composed of two ceramic side plates, a
series of steel plates, anda muffler. The assembly

is covered by a wrap around of insulating material

which inhibits any sidewise emission of gases. The

steel plates are held in position and supportedby

the ceramic sides which are grooved vertically

to provide recesses for the vertical edges of the
steel plates. The bottom edges of the latter form
an inverted "V" along the path of the arc that

may be drawn between the breaker contacts during
interruption. The steel plates have the effect of

breaking up the arc, and cooling it aud the gases
that result from interruption. The entire assembly

provides a "chimney" effect which directs the hot,

ionized gases upwards through the steel plates and
mufflers and allows their safe and controlled
escape at a cooler temperature.
The muffler at the top of the assembly is a

serpentine shaped strip ofperforated,copper plated

steel. It is important that the perforations of the
muffler be kept open, since their closure comd

tend to prevent the escape of the gases along the
desired path. At the regular maintenance inspec

tion, it would be well to check their condition and
open any of the perforations that appear to be
clogged.

If any very extensive burning or corrosion
is noted in the arc quencher, it should be replaced.

Replacement is also indicated if any breaks or
cracks are noted in the ceramic material.
REPLACEMENT

surfaces mates with the concave pivot surface on
the rear side of the stationary contacts. Each of

the stationary contacts pivot in a horizontal pl^e
approximately at their mid-points. The end of the
contact opposite to the contact tip end is formed
into the shape of a small hook. A tension spring

engages this hook and provides the necessary

contact pressure at the pivot and also at t^ point

of contact with the movable contact arm. When the
breaker contacts open, a projection on the contact
tip end of the stationary contact bears against a
stop pin restricting the movement of thestationary
contact. This arrangement results in a continue

high force existing between the mating pivot
suifaces.

)
The movable contact arms pivot in a vertical

plane, each making contact with apairof statioiwry
contacts, and thus providing four low resist^t
parallel paths of current for each breaker pole.
The movable contacts rotate about a burnished,

silver plated, copper pin which, in turn, is heW
by a pivot support. Each side of the pivot support
bears against the lower,outer surface ofthe contact
arm and supplies a second low resistance path
through the pivot. A "U" shaped spring clip made
of silver plated conducting material provides an
additional current path and protects the other con
tact surfaces of the pivot against pitting when m
motion. It also contributes to the force tending to
increase the contact pressure between the lower
ends of the movable contacts and the pivot support.

The movable contact pivot support is mounted

securely to the breaker base. K, as is normally
the case, the pole is equipped with an overcurrent
trip device, one of the terminals of the series coil
of the trip unit is fastened to the lower end of
the pivot support. The other terminal of the
coil fastens to the lower stud.
CONTACT ADJUSTMENTS

Removal of the arc quencher is simply a matter

of lifting the assembly up and out, after the steel
retainer across the front of the arc quenchers has
been removed. The upper edge of the steel arc

runner, fastened to the back plate of the breaker,

The only adjustment to be made on the breaker

contacts is that of contact wipe. This may be
described as the distance the movable and station

fits into a recess in the back portion of the arc

ary move while they are touching one another in
the process of breaker closing. The amount of
contact wipe can be measured by comparing the
position of the front surface of the statiOMry

studs after the arc quenchers have been replaced.

when the breaker is closed, in reference to some

BREAKER CONTACT STRUCTURE

most convenient stationary part of the breaker to
use as a reference point is the steel arc runner
above and behind the stationary contacts.

quencher which locates it in its proper position
upon replacement. Make sure the steel retainer
is replaced and fastened firmly to its mounting

The copper current carrying parts of the

breaker are all moimted on a common base of

contact when the breaker is open to its position

absolutely stationary part of the breaker. The

insulating material made of polyester glass mat.

The amoimt of wipe the contacts should have
is nominally 1/8 of an inch. A plus or minus
tolerance of l/32 of an inch is allowed.

The upper stud branches into twopivot surfaces

vided by an eccentric pin which passes through
the center of the movable contact assembly. Each

The copper of each pole consist of an upper stud
and pivot, stationary contacts, two movable contact
arms, a movable contact pivot, and the lower stud.
on its inner end on the forward or front side of
the breaker base. Each of these convex pivot

The means of adjusting contact wipe is pro

end of this pin has a free, projecting, hexagon

shaped section which is easily accessible to a

GENERAL PREPARATION

rings, which bear on each end against a portion
of the hexagon section of the pin, lock the ad
justing pin in place and provide index stops for
the process of adjustment. The right handhexagon
shaped end of the pin is numbered from 1 to 6,
which provides a reference for making wipe

/'^^all, open end, 1/4 inchwrench. Two cantilever

Lift off the three arc quenchers.

Remove the U shaped insulation (5) Figure 3
from each pole by lifting it and disengaging
the rivet heads thru the keyholed slots in the

When contacts are to be adjtisted, the recom

mended procedure is as follows:

With the breaker in the open position and us^
the numbers on the right end of each adjusting

pin as a reference, set each pin in the same
position. In many cases, the number 3 is a
good beginning point. The proper view of the

number on the adjusting pin is obtained by

viewing the breaker from the front and the
adjusting pin from approximately a 15 degree
angle with respect to the movable contacts.

mounted on the cross bar.

REMOVAL OF MOVABLE CONTACTS
(18) Figures.

Screw the threaded end of the steel rod

With a pair of long nosed pliers, unhook
safety pin type spring clip (9) and extract

By measurement, establish the position of the
front surfaces of the stationary contacts with
reference to the steel arc runners above and

Close the breaker, and establish the amoimt
of wipe by again measuring as in step two,
and comparing the measurements with those

Moving the adjusting pin to a higher

number will increase the contact wipe and

round off the flats of the hex section of the pin.

Slip the blade of a heavy screw driver between
the two upper contacts and force the contacts
toward their pivot point sufficiently far to
disengage the contact stop surface from the pin.

The contact can then be removed by disengaging

wipe of 3/32 to 5/32 of an inch, the contact
adjustments are complete.

the end of the contact from its spring.

Figure 3
The normal situation that will exist in the

where long use of the breaker in service has
resulted

|i,/f«^ver alloy contact tips.

or erosion of the

A commonly used

REPLACEMENT OF STATIONARY CONTACTS
(21) Figure 3.

rule of thumb" is that contact replacement is
uidicated if less than one-half of the original

thickness (1/8 of an inch) of the contact tip
material remains.

The two lower contacts can be similarity
removed.

matter of contact replacement will call for re
placement of all the movable and stationary con
tacts at &e same time. This will be the case

Remove the pivot pin and movable contact

REMOVAL OF STATIONARY CONTACTS

When all the contacts have the recommended

CONTACT REPLACEMENT

Remove the split pin retaining the center
pole pivot pin.
assembly.

No attempt should be made to move

the adjusting pin when the breaker is closed.
Besides being more difficult, the additional
force required to move the pin will tend to

Move the cross bar downward to disengage
it from the contact wipe adjusting pin (15)
on the center pole, then move the cross bar
toward the front of the breaker.

moving to a lower number will decrease the
contact wipe.

Repeat procedure 1, 2, and 3 above on the
left pole.

lasting pin to the next higher or lower

Grasp movable contact assembly and remove
it from its seat on the cross bar.

If any set of contacts lead or lag the others,
open the breaker and advance or retard the
number.

lightly into pivot pin (11) on the right pole.
pin (11) and remove spring clip (9).

behind the contacts.

taken wi& the breaker open.
4.

As an aid to future reassembly of the movable
contacts, note the position of all stationary
insulation barriers with respect to barriers

Note that the numbers on the pin are not in

numerical sequence as the pin is rotated.

Remove arc quencher retainer (1), Figure 5
by loosening the two captured nuts with a

Coat the contact pivot area only of each of
the four contacts with a thin coat of D50H47

Use only D50H47 grease.

Note the difference between the two types of

GEI-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
stationary contacts and be sure to locate them
in the breaker with the upper and lower contacts
having their stop projecting surfaces as shown
in the section AA, Figure 3. The upper left
and lower right contacts are identical as are
the lower left and upper right contacts.

REPLACEMENT OF MOVABLE CONTACTS
(18) Figure 3.

Coat the pivot area only of the new movable

Assemble the center pole movable contacts,

Move the cross bar assembly into position
and insert the eccentric contact wipe adjust-

By placing the hook on the end of the contact
through the loop of the contact spring, the con
tact can be pushed toward the pivot surface

and slipped behind the stop pin. Install all
stationary contacts in all poles.

contacts with a thin coat of D50H47 grease.

align the pivot pin holes with the bullet nosed
rod, and install the pivot pin and split pin.

a=£fl]
SECTION B-B

STATIONARY CONTACTS St

STATIONARY CONTACTS St

SPRINGS
AK-2-1S

Figure 3. (549D409-2) Contact Assembly

Upper Stud Barrier

Links (Insulated)

Spring Clip (Retainer)

Cross Bar
Pivot Pin

Contact Pivot Support

15. Contact Wipe Adjustment Pin
16. SCX*6W
17. Upper Stud & Arc Runner
18. Movable Contact
19. Spring
20. Nut
21. Stationary Contacts

Power Circuit breakers Types AK-2-15 and AK-2/3-25 GEI-50299
ment pin (15) on the center pole into position.
Be sure the stationary insulation barriers
are correctly located.

Align the cross bar with the left and right,
pole pivot supports and install the left and
right pole movable contacts. Use the bullet
nosed steel pin to aid in aligning the holes
in the cross bar, the contacts and the pivot
supports.

Install the left and right pole pivot pins while

threading them through the spring clips and lock
the spring clips (9). Be sure the pivot pins
are fully inserted.
6.

Adjust the contact wipe to 1/8" —1/32" by
adjusting the eccentric contact wipe adjusting
pin (15). The breaker must be open to adjust
the wipe. In the event acceptable wipe cannot
be obtained by moving the contact wipe ad
justing pin (15), from the movable contact
forward or backward as necessary to bring

the wipe within the range of the contact wipe
adjusting pin (15). Do not exceed the recom
mended settings for wipe;
otherwise the
breaker may not close completely. When
viewed from the top with the breaker closed,
the movable contact should be centrally located

with respect to the stationary contacts.

the movable contacts are not centrally located

as shown in section CC, form the movable
contacts until they are nominally centered.
If the moving contacts are not centered with
1/8" separation when closed against the fixed

contacts, they should be bent laterally (after
opening the breaker contacts). To do this

Figure 4. (8039851) AK-2-25 Back Frame - Loca

without squeezing the two movable contact

tion of Crossbar and Pole Shields

arms together, a 1/8" spacer plate should be
inserted between them; then the pair can be
grasped with pliers and bent in the desired

Movable Contacts

direction for centering.

Upper Stud Asbestos Shield

Crossbar Plastic End Shield

eccentric numbers 1, 2, or 3. These numbers

Crossbar Asbestos Inner Shield

are the ones visible when viewing the breaker

Lower Stud Asbestos Shield

contacts should be

adjustable using

Stationary Contacts

Crossbar Assembly

from the front, not from above. (The higher
numbers should be reserved for tightening

at future maintenance readjustments after
wear.) Also, if higher numbers are used,

open-end wrench to grasp the pivot portion of

where adequate wipe is obtainable at settings
1, 2, or 3, it is possible that the stationary

the arm. The soft copper arm will bend with
little difficulty. Both arms should be bent

contacts will bottom, producing excessive back
force on the breaker closing mechanism so that
the toggle link will not pass center. As a

Operate breaker several times, and recheck
wipe to make sure bending of movable arms

result, the breaker will not complete its stroke,

and inadequate pressure and wipe will result;
• burn-up of contacts from just load current
will follow.

If the required wipe of new contacts cannot be
obtained with eccentric number of 3 or lower,

did not occur in these operations.

Operate the breaker manually several times

to assure proper functionii^ occurs, then

replace the U shaped insulation (5) Figure 3

bending of the contact arms toward the closed
position is required. This should be done

and arc quenchers. When replacing the arc
quenchers be sure the quencher is seated

tapered open end wrench to grasp the contact
and a 10" Crescent or the 1" - 1-1/8" tapered

clamp covers the knobs protruding through
the arc quencher insulation.

individually, using an 8" Crescent or 1/2 - 5/8"

downward completely and that the quencher

CONTACT SPRINGS

(19) Figure 3
A minimum force of 5 lbs and a maximum
force of 9 lbs. should be required to begin move

ment of a single stationary contact from the open

position towards the closed position. This may
be checked by using a push scale applied at the
point at which the movable contact touches the
stationary contact. If these pressures are not
obtained or if the spring is daniiaged, replacement
is required.

In order to replace the contact spring the upper

stud (17) must be removed. The hardware which
fastens the stud to the breaker base consists of
two screws (16), and nut (20). When These are

removed, the stud may be withdrawn from the

base in a forward direction.

After the stud has

been removed, it is a simple matter to disconnect

listed is that of proper mechanism latch engage
ment, the amount of engagement between toe latch
(7) and latch roUer (5), Figure 6. This is the only
adjustment that is required on the breaker mech
anism, and proper latch engagement is obtained in
toe following manner:

(NOTE - Before making latch adjustments, check
to make sure that the buffer paddle which stops

against toe end of toe latch adjustment screw is
rigidly fastened to the trip shaft. Hold toe trip
shaft (8), Figure 5, steady and attempt to move
toe buffer paddle.

holriipg toe buffer paddle to the trip shaft.)

Latch Adjustment - Manual Breaker

Locate toe latch adjustment screw on toe

lower, outer side of toe right-hand mechanism

with a new one.

This screw is threaded through

a nylon insert locknut which, in turn, is welded
to a projecting bracket on toe side frame.

The breaker mechanism is a spring actuated,

over-center toggle type of mechanism. As tte
closing force is applied, either by movement ofthe
operating handle or the closing solenoid armature,
energy is stored in the operating springs. Alter
the springs have gone over center, movement ofthe

The breaker mechanism is tripped by toe

latch and latch roller begin to engage.

to establish toe position where toe contacts

begin to move before tripping occurs. When
this position is established, note toe position

automatic trip devices or toe trip push button
causes toe latch to move in toe tripping direction.

of toe slot in toe head of toe adjusting screw.

When toe latch moves off the trip latch roller (7),

opening of toe brewer contacts.

If toe breaker mechanism does not function

properly, it is best to first perform toe available
remedial measures listed in toe "Trouble Shoottog
chart of these instructions. One of the remedies

Withdraw toe adjusting screw three and onehalf turns from toe position noted in step 3.
This sets toe proper amount of latch engage

some cases, it may be necessary to turn toe
adjusting screw less than 1/4 turn in order

Operation of any ra toe

tions, it is best to assume that adjustments are

Withdraw toe adjusting screw from toe locknut

before tripping occurs, you have established
toe position of the adjusting screw where toe

displacement of the trip latch (7), Figure 6.
Looking at the breaker from toe right hand side
as in Figure 5, toe tripping movement of the latch

not be necessary to make any adjustments m toe
field. At toe time of installation, and also in toe
course of a maintenance inspection, if the breaker
functions properly through several repeated opera

1/4 turn at a time, attempting to close toe

carefully set by experienced factory personnel
after assembly at toe factory, it should normaHy

breaker after each 1/4 turn, and observing
whether toe contacts move toward closing
before tripping occurs. If toe contacts move

regardless of the speed at which the closing handle

Since all toe mechanism adjustments are

the closing mechanism in

normal vertical position.

closing the breaker contacts.
This assures a fast-snapping closing action

toe remaining force in the operating spring causes
toe mechanism toggle to collapse, resultmg m toe

clockwise, setting

HANDS CLEAR OF THE CLOSING HANDLE
WHEN MAKING THIS ADJUSTMENT.

are further extended, the blocking cam moves

allowed to discharge part of their stored energy,

Rotate the closing handle 90 degrees counter

trips open, the closing handle returning to its

for a time by a cam arrangement. As the springs

away from the output crank, and the springs are

toe reset position. Turn toe adjusting screw
into toe locknut until toe closing mechanism

output crai^ of the mechanism is still blocked

If any relative movement

between toe two is noted, tighten toe fasteners

the two ends of the spring (19) and replace it

is counter-clockwise.

Latch Adjustment - Electrical Breaker

Locate toe latch adjustment screw on toe

lower, outer side of toe right mechanism
side frame.

This screw is threaded through

a nylon insert locknut which, in turn, is

welded to a projecting bracket on the side

2. With toe breaker in toe open position turn toe

adjusting screw into toe locknut one complete

turn at a time, closing toe breaker after each

comnlete turn of toe adjusting screw, until

the breaker will not close. Use the maintenance

closing handle whenever closing or attempting

to close the breaker during this entire opera

Withdraw the adjusting screw from thelocknut

1/4 turn at a time, attempting to close the

breaker after each 1/4 turn, and observing
whether the contacts move toward closing

before tripping occurs. If the contacts move
toward closing before tripping occurs, you have
established the position of the adjusting screw

where the latch and latch roller begin to engage.

In some cases, it may be necessary to turn

the adjusting screw less than 1/4 turn to

establish the position where the contacts move
before tripping occurs. When this position is
established, note the position of the slot in
the head of the adjusting screw.

Withdraw the adjusting screw three and onehalf turns from the position noted in step 3.
This sets the proper amount of latch engage
ment.

Figure 5. (8024457) Cut Away Model of Electrically Operated AK-2 Breaker

Arc Quencher Retainer
Cutoff Switch
Cutoff Switch Actuator

8. Trip Shaft
8A, Front Escutcheon
9. Closing Solenoid

9A. Location of Slots for

13. Socket Head Screws

15. Stationary Contacts
and Springs

Maintenance Handle

Closing Solenoid Armature

Connecting Link

Trip Latch Roller

ii. Cover Retainer of Overload Device

GEI-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25

manually operated breakers, see procedure

Should the mechanism continue to function

described below.)

improperly after the proper latch engagement
has been set and the corrective measures listed
in the "Trouble Shooting" chart carried out, it is

to repair the mechanism interior but that a re

generally recommended that no attempt be made

Disconnect the two insulated connecting links
between the mechanism and the contacts as in

placement mechanism assembly be obtained from

step 2 of the procedure for "Separation of

Front and Back Frames".

Remove arc quenchers (See "Arc Quencher").

If the breaker Is electrically operated, remove
the front escutcheon by taking four screws

Remove the two elastic stop nuts, whichfasten

the upper extensions of mechanism frame to
studs connecting with rear frame.

from flange. If the breaker is a drawout type,
two small roimd head screws must also be
removed from the bottom edge of the escutch
eon. (Eor removal of front escutcheon from

Remove four screws which fasten the bottom
of the mechanism frame to the horizontal
cross member of the front frame.

Figure 6. (8024516) Cut Away Model of Manually Operated AK-2 Breaker
Arc Quencher Muffler

Handle Return Spring

Ceramic Side Plates
Steel Plates
Fixed Centers in Mechanism

Overload Device

Series Coil of Overload Device

Trip Arm of Overload Device

Latch Roller
Escutcheon

Trip Paddle
Movable Contact Pivot Support

15. Movable Contact Pivot
16. Contact Wipe Adjust
ment Pin

17. Movable Contact
18. Moulded Compound Bar
19. Steel Back Plate

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299
K the breaker is manuaUy operated, and has
no auxQiary switch, it is now free to be lifted

clear of the breaker. If it has an auxilia^

switch, this may be disconnected from the

mechanism as described under "Auxil^ry
Switch - Replacement, elsewhere in these
7.

The auxiliary switch is mounted on the left
side of the operating mechanism frame. Its operatine shaft is linkedtotheoutput crankof the breaker
^hanism. Through a cam arrangement, the

operating shaft of the switch controls the open and

If the breaker is electrically operated, it will
be necessary todisconnectthe mechamsmfrom

or five-stage, contains one a and one b set
of contacts. An "a" pair of contacts is always in

closed positions of the individual contwt P^js.

the solenoid armature. In order to do mw,
raise the mechanism as far as the travel of the
armature will permit and remove the ^rew
which binds together the two extensions of the
armature. After this is removed, the armature
extensions must be spread apart to release
them from the link connecting with the mech
anism. This can be done ^ threading a
#10-32 screw at least 1-3/4 inches long into

the top hole of the armature extension. TWs
hole is just above the one from which the

hifiriinp screw has been removed. As the end
of the screw butts against the far extension,

ATrXTLIARY SWITCH

Each stage of the switch, which is usually bvo^

the same position as the main breaker contacts.
That is, openwhen the breaker contacts are open,

and closed when the breaker comets are closed.

Just the oposite is true of the T) contacts. The

terminals of the switch are covered by a sheet of
insulating material held in place by two screv/s

fastened along its left edge. When thisis rernoved,
the terminals are exposed. The upper pairs of
terminals are those which connect to a swtches.
The lower terminals connect to "b" switches.
REPLACEMENT

the two extensions will be spread open, re
leasing the mechanism link.

Remove auxiliary switch cover.

The replacement mechanism may be installed
by reversing the order of procedure for dis
assembly. After reassembly, checkthe opera

Disconnect leads to switch termin.

tion of the breaker and, if necessary, adjust
the latch engagement.

/^.EMOVAL OF FRONT ESCUTCHEON

crank end of the switch operating shaft in
position to engage the hole in the link con
necting with with the breaker mechamsm.

Remove set screw fastening the plastic handle
to steel operating shaft and remove the oper

Be sure the bearing washer is in place between
the mechanism lirdc and the switch operating

Open and remove annealed (soft) retainer and
two flat washers from shaft.

6. Complete mounting by following disassembly
steps in reverse order.

Remove four screws from flange of escutcheon

ELECTRICAL CONTROL COMPONENTS

If the breaker is a drawout type, two small

round head screws must also be removed from
the bottom edge of the escutcheon.

Remove switch by moving towards left.

5. Before mounting replacement switch, turn the

JF MANUAL BREAKERS
1.

Remove two screws which fasten
side of mechanism frame.

Push steel operating shaft through escutcheon

These consist of the following:

Closing solenoid

Remove handle reset spring (8) Figure 6, and

"X" contactor (relay)

"Y" permissive relay

sembled most easily by exactly reversmg the

escutcheon it may be necessary to use pliers

Shimt-trip device

escutcheon is free of breaker.

Handle and escutcheon assembly can be as

procedure for disassembly. In replacing the
to pull the operating shaft fully into the
escutcheon in order to have space enough to

replace the flat washers and the soft retainer.

The latter may be closed on its groove in
the shaft by ordinary gas pliers. After re

check operation of breaker.

The last two of these components may or

may not be present in the control arrangement.

CLOSING SOLENOID

need not be removed from the old bracket. This

The closing solenoid consists of a magnet,

can be taken off the breaker simply by removing
the two screws which fasten it to the breaker frame.

armature and coil. This assembly is located
directly beneath the breaker mechanism to which
it is connected by a link which ties the upper end
of the armature to the spring carrier of the
mechanism. (See Figure 5.)

If the breaker is a drawout type, the supporting
bracket of the 'T" relay may be temporarily

When voltage is applied to the coil, the

of these parts has been designed into the relay.

magnetic force generated pulls the armature up
into the coil and magnet assembly. This, in
turn, rotates the spring carrier about its pivot,
extending the mechanism spring and causing its
line of action to move "over center", resulting
in a closing operation.

displaced to provide access to the screws.
Since the expendable parts of the "X" contactor
are the contacts and the coil, ease of replacement
Methods of procedure are as follows:
Contacts

Remove escutcheon by unfastening four flat
head screws in flange.

Remove closing switch. (See "Closing switch".)

Cut off or disconnect the coil leads.

With the fingers, pull forward on the spring
guide of the movable contact, compressing
the contact spring as far as possible.

With the spring thus held, grip the end of the
contact strip with pointed pliers, turn it through
90 degrees on its long axis, and withdraw it.

Replace new contacts by reversing the pro
cedure.

Allow lower section of magnet and coil to
slide downward until clear of armature.

Reassemble with new coil by reversing order

Remove relay cover.

Turn the two retaining spring clips on the ends
of the device through 90 degrees about their

of procedure.
"X" CONTACTOR

The "X" contactor is a heavy-duty relay which
performs the function of closing the circuit of the
breaker solenoid during electrical operations.

arranged in series to minimize the duty required of
any one contact. As explained under "Operation",

exposing the coil.

the fourth contact is used to "seal-in" the "X" coil.

The "X" contactor is located on the right
beneath the horizontal front frame member.

mounting bracket which is stispended from the
frame.
Rubber bushings on the mounting studs
provide anti-vibration and anti-shock protection
for the relay.
The relay contacts and their
terminals are covered by a molded piece of

Just start the replacement of one of the
compound blocks which hold the stationary
contacts into its groove in the frame.

Position the armature and movable contact

assembly to allow the entrance of the second
stationary contact block.

Removal of the complete device is accomp
lished by removing the cover, disconnecting the
leads from the terminals, and removing the nuts
from the three mounting studs. If the replacement
unit includes the mounting bracket, the relay

Place new coil on pole piece inside of the
spring cUps and fasten terminals to leads.

insulation which fits over spring clips &at hold

the cover in place.

Remove the terminal screws of the coil and

pull it free of its retaining spring clips.

is mounted on three studs which fasten it to a

Pull out the two halves of the body of the device
which carry the stationary contacts. When
these are clear of the frame, the armature
and movable contact assembly will move aside,

Three of the four sets of contact of the device are

Lightly pinch with pliers (pointed end) the
hole in the compound body of the device and
lift out the stationary contact.

Remove four screws which fasten lower section

of magnet to upper section.

Remove terminal binding screw of stationary

split section of the contact which enters the

Remove relay cover.
contact to be replaced.

The only replacement operation that might
conceivably be required on tMs assembly is that
of the solenoid coil. To replace this, proceed
1.

When these parts are all properly aligned,
with the stationary contacts under the movable
contacts, push them into their guiding grooves
in the frame until they bottom.

Rotate the retaining spring clips to the locked
position, making sure that each clip is in its
proper recess, and replace the device cover.

After the old relay has been removed, the
wire leads to the relay should be stripped of
insulation to about 1/4 of an inch from the ends.

A good mechanical connection should be made
before soldering.

As described under "Operation", the "Y" relay

is a permissive relay which limits to onethe number

After all connections are completed, the relay-

may should again be mounted to the breaker by
means of its supporting brackets and hardware.

of breaker closures possible on one closing signal.
On drawout breakers, the "Y" relay mounting
bracket is fastened to the right hand side member
of the breaker frame by two mounting screws. On
terminal board breakers, it is fastened to the rear

side of the terminal board support. The relay
itself is fastened to an intermediate bracket which

After replacement has been completed, the

relay may be checked electrically in the following
manner:

Apply closing voltage to terminal board or
secondary disconnects.

is detachable from the main support. The junctures

between the relay and the intermediate bracket
and between the two brackets are rubber cushioned
against vibration and shock.

Push button of closing switch and hold closed.

Continuing to hold push button in closed posi
tion, manually trip the breaker open.

If the breaker stays open, and makes no

If replacement of the "Y" relay becomes
necessary, it may be detached from its supporting

brackets by removal of the fastening hardware.
The leads to the relay should be cut off as closely

as possible to the soldered connections so that
enough wire will remain for connection to the
new relay.

attempt to close, the "Y" relay is functioning
properly.

Sufficient original wire is allowed

for this purpose.

While releasing the close button, observe
the "Y" relay. It should open as the closing
switch is released.

Figure 7. {695C162) Cut-Off Switch

Movable Contact Assembly

Spring
Actuator

Contact (BB)
17

GEI-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
6. Mount the replacement switch by reversing

the order of procedure.

As eitplained under "Operation", the imction

of the cut-off switch is to de-energize the 'X
contactor' coil and energize the "Y" relay coil
as the breaker mechanism moves from the opened
to the closed position.

The switch is operated by the movement of
a mechanism link against the switch actuator

(6), This causes the actuator and movable contact
assembly (4) to rotate counterclockwise about
pin (7), opening the "bb" contacts (8) and closing

the "aa" contacts at (9).

Overtravel of the

actuator (6) beyond the point of making contact
at (9) is absorbed by spring (5) which couples
the movable contact (4) to the actuator.

(3) resets the switch after the breaker contacts
open and the breaker mechanism resets.

The point at which the cutoff switch operates
during the breaker closing cycle is after the spring
charged mechanism has been driven over-center.

This assures that the cutoff switch cannot operate

too early in the breaker closing cycle, thus the
X and Y relays are de-energized and ene^zed,
respectively, at the proper time and the circuits
anti-pump feature is maintained. When the closing
mechanism is driven over-center, the force of

the previously charged closing springs is released,
closing the breaker.
REPLACEMENT

The cut-off switch is located above the breaker
mechanism. It is fitted between the upper portions
of the steel side plates that make up the mechanism
frame, A raised horizontal ridge on each side of
the molded body of the switch fits into a cor

responding groove in each of the steel side plates.

A round head screw on each side fastens the

switch and side plate together. Replacement of

the switch is accomplished by the following pro
cedure:

escutcheon (3) permits access to the switch button
(4). When the button is pressed, movable contact
(5) deflects and impinges upon stationary conact

This energizes the "X' relay coil which

seals itself in, and, in turn, energizes the closing
solenoid.

Remove escutcheon (3).

2. Disconnect leads from switch terminals.
3. Deflect the left end of hinge (7) to toe left
so that toe movable contoct (5) may be dis
engaged from the switch assembly.
4.

Removal of the two screws (10) from speednuts (9) completes toe disassembly of toe
switch.

5. Reassembly with new parts is a matter of

reversing toe described procedure. In r^
assembling, be sure toe tob on toe left end a
hinge (7) is bent to toe right far enough to
a^d any possibility that movable contoct (5)
might become free of toe assembly.
SHUNT TRIP DEVICE

The shunt trip device is mounted underneath
toe horizontal cross frame member, just to toe
left of toe front escutcheon. It is composed
of a magnet, coil and armature. The armature
has an extended arm or striker (11) which bears

Remove the cover on the top of the switch
by ♦airing out the two screws which hold it

when toe coil (8) is energized. This displaces

After taking careful note of the connection
arrangements, disconnect the leads from the

remote switch or relay which closes toe shunt

switch terminals.

The closing switch is mounted on the upper

flange of the closing solenoid coil^. Ahole tome

against toe trip paddle (12) on toe trip shaft

Remove the two screws, one on each side,
which fasten the switch to the mechanism

Note that the one on the right

hand side also holds a wiring cleat and spacer
which serves to hold the wires clear of the

toe trip latch in toe breaker mechanism, opening
toe breaker contacts.

The trip device is generally activated by a

trip coil circuit.

In order to avoid unnecessary heating of toe

coil of the device, an auxiliary switch "a" contact
is wired in series with toe coil. This prevents
toe energization of toe coil if the breaker is open.

link connecting the mechanism and the breaker

Remove the front escutcheonfrom the breaker.

mounted by disconnecting toe coil leads and re

Slide the cut-off switch out from between the

position indicator.

steel side plates by pulling straight forward.

The entire shunt trip device may be dis

moving nuts (1).

However, toe only part of the

device that might conceivably need replace^nt
during toe life of the breaker is toe coil (8). This

Pcfwer Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299

Figure 8. (805B905) Closing Switch (Top View)
1.

Stationary Contact

Front Escutcheon
Push Button

Movable Contact

Closing Solenoid

Speed Nut
Screw

-O 7 »
O 00
090

Figure 9. ( 695C161) Shunt Trip Device
1.
2.

6.
7.
8.
9.
10.

Mechanism Frame

Trip Shaft Clamp

may be replaced without removing the device from
the breaker by proceeding as follows:

Connect coil leads.

Disconnect leads of coil (6).

Remove two screws (6) which fasten magnet
(7) and coil to the frame (2).

The only adjustment required on the shunt

trip device is that which ensures positively that

straighten the end of clamp (9).

the breaker will trip when the device is activated.
In order to be sure of this, armature arm (11)
must travel from 1/32 to 1/16 of an inch beyond
the point at which the breaker trips. A good

Remove the coil from the magnet.

between the magnet and armature at (10). and with

Install new coU, again forming end of clamp
(9) as shown.

Reassemble to frame.

Having removed the magnet from the device,

method of checking this is to hold a l/32nd shim

the breaker closed, push upwards at (5), closing
the armature against the magnet. If the breaker
trips, there is siifficient overtravel. If adjustment
is necessary, trip paddle (12) may be formed
towards or away from armature arm (11),

An AK-2/3 breaker may be equipped with
the following protective devices:

used when the short-time delay feature is required,
or when the trip device is used to operate a special
over-current adarm switch.

Overcurrent trip (Magnetic) AK-2

Power Sensor Trip (Static) AK-3

Reverse Current Trip AK-2

instantaneous alone.

Under Voltage Trip & Lockout Device

carry up to 100% of the continuous current rating
of their trip devices. Any attempt to carry higher
currents for a prolonged period will cause over

Bell Alarm and/or Lockout device

Open Fuse lockout device.

AKD-5 Interlock AK-2A/AK-3A

Most circuit breakers are equipped with series
overcurrent trip devices either of the dual magnetic

type (instantaneous and time delay tripping) or

OVERCURRENT TRIP DEVICE

Breakers are designed to

heating and possible ^mage.

EC-2 OVERCURRENT TRIP DEVICE

The Type EC-2 overcurrent tripping device
is available in three forms:

Dual overcurrent trip, with long-time delay
and high-set instantaneous tripping.

and a pivoted armature.

Low-set instantaneous tripping.

When current flow through the series coil
generates a magnetic field strong enough, the

High-set instantaneous tripping.

armature overcomes the restraining force of a

The dual trip has adjustable long-time and
instantaneous pick-up settings and adjustable time
settings. Both forms of instantaneous trips have

The typical overcurrent trip device consists
of a magnetic structure, a series current coil,

calibration spring attached to it, and closes against
the magnet.

This trips the breaker by means

of an extension on the armature which strikes

adjustable pick-up settings.

against a trip paddle on the trip shaft.
DUAL OVERCURRENT TRIP, WITH LONG-TIME
Depending on the type of individual device,
the movement of the armature may be delayed
for a time by a timing device. If a relatively
long time-delay (seconds or minutes) is desired,
the velocity of armature movement is governed
by a piston moving through an oil dashpot. If

only a short-time delay (cycles or milli-seconds)
is required, movement is controlled by an escape
ment gear and pallets arrangement.

An AK-2-15/25 breaker may be equipped with
either the EC-2 or EC-1 overcurrent trip device.

The majority of applications will require the use
of the EC-2 device. The EC-1 device is normally
20

DELAY AND HIGH-SET INSTANTANEOUS TRIP
PING.

By means of the adjustment knob (5), Figure 10,
which can be manipulated by hand, the current

pick-up point can be varied from 80 to 160 percent
of the series coil rating.
The indicator and a
calibration plate (4), Figure 10, on the front of
the case provide a means of indicating the pick-up

point setting in terms of percentage of coil rating.
The calibration plate is indexed at percentage
settings of 80, 100, 120, 140 and 160.

.•I ."i ., •..••'

•' •'••

#y"-- •
•?-;•

»^;i.
rr'-'* -"
V
"..

Figure 11. (8024843) EC-2 Overcurrent Trip With
Cover Removed.

Instantaneous Calibration Spring
Movable Nut (Index Pointer)
Time-Delay Calibration Spring
Instantaneous Pickup Adjustment Screw
Time-Delay Adjustment Screw

Oil Dashpot
Dashpot Arm

Connecting Link

Instantaneous Pickup Calibration Marks

counter-clockwise motion decreases it. The dashFigure 10. (8024842) EC-2 Overcurrent Trip
1.

Trip Adjustment Screw
Opening for Time Adjustment
Pickup Indicator Si Calib. Plate
Pickup Adjustment Knob

pot arm (7), Figure 11 is indexed at four points,

maximum - 2/3 - 1/3 - minimum from the left,
as viewed in Figure 11. When the index mark on
the connecting link (8), Figure 11, lines up with a
mark on the dashpot arm, the approximate tripping
time as shown by the characteristic curve is in
dicated . The lA and IB characteristic devices are

shipped with this setting at the 2/3 mark and the
IC characteristic at the 1/3 mark. The standard
characteristic curves are plotted at the same
settings.

The long-time delay tripping feature can be
supplied with any one of three time-current char
acteristics which correspond to the NEMA stand

ards maximum, intermediate and minimum long
time delay operating bands. These are identified
as lA, IB and 10 characteristics, respectively.
Approximate tripping time for each of these, in
the same order are 30, 15 and 5 seconds at 600%
of the pick-up value of current, (See time-current
characteristic curves 286B201A, B, and C).

The tripping time may be varied within the
limits shown onthe characteristic curves by turning

the time adjustment screw (5), Figure 11. Turning
in a clockwise direction increases the tripping time;

Time values are inversely proportional to

the effective length of the dashpot arm.

fore, the linkage setting that gives the shortest
time value is the one at which dimension

Figure 11, is greatest.

The time adjustment

screw (5), Figure 11, may be turned by inserting
a Phillips head screwdriver through the hole in
the front of the case, but if it is desired to relate
the linkage setting to the index marks on the
linkage it will be necessary to remove the case.
This may be done by removing the two mounting
screws, one on each side of the case, which
may be taken off without disturbing the trip unit
itself.

GEI-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25

Escape Wheel
Driving Segment

S.TJD. Armature

S.T.D. Calibration Spring

Trip Arm
Trip Paddle

Trip Paddle Adjusting Screw
L.T.D. Armature

L.TJD. Calibration Spring

Instantaneous Trip Spring
(High Set)
Spring Holder
Calibration Clamp Nut
Plunger
Cylinder (Dashpot)

Calibration Plate

Clamping Bracket

UNO TiUe Oe^AV MCCHiMSM

$HOAT TM€ OCLAV ttEOUMSW

12.
KIGMT SlO€ View SHOWING

urT 5(oe vtew sHowtKc

FMNT View SNOWING

0
Figure 12. (695C189) EC-1 Type Overcurrent Trip Device

NOTE: Forcing the adjusting screw to either
extreme position may cause binding of the device
and should be avoided.

INSTANTANEOUS LOW-SET TRIPPING

The low-set instantaneous pick-up point may
be varied by the adjustment knob (5), Figure 10.
calibration in this case usually ranges from
80% to 250% of the series coil rating, the calibra
tion plate being indexed at values of 80%, 100%,

200% and 250% of the rating.

INSTANTANEOUS HIGH-SET TRIPPING

The high set instantaneous pick-up value may
have one of the following three ranges: 4 to-9
times coil rating; 6 to 12 times coil rating or
9 to 15 times coil rating. The pick-up setting
may be varied by turning the instantaneous trip
adjusting screw (4), Figure 11.

Three standard calibration marks will appear
on the operating arm at (9), Figure 11, and the
value of these calibration marks will be indicated

by stampings on the arm as follows:
4X
6X
9X

At the factory, the pick-up point has been set

at the nameplate value of the instantaneous trip
current. (Usually expressed in times the ampere
rating of the trip coil.) The variation in pick-up
setting is accomplished by va^ing the tensile

force on the instantaneous spring. Turning the
adjustment screw changes the position of the
movable nut (2), Figure 11, on the screw. The

spring is anchored to this movable nut so that

when the position of the nut is changed, there is

a corresponding change in the spring load. As
the spring is tightened, the pick-up point is in
creased. The top edge of the movable nut (2),
Figure 11 serves as an index pointer and should
be lined up with the center of the desired calibration

mark, punched slots on operating arm, to obtain
the proper instantaneous trip setting.

Power Circuit Breakers Types AK-2-I5 and AK-2/3-25 GEI-50299
EC-l OVERCURRENT TRIP DEVICE

The EC-l device can be provided with the
following tripping combination

Long time delay, short time delay and in
stantaneous -tripping.

breaker mechanism or the overcurrent trip devices
have been replaced.

Positive tripping is achieved when adjustment
screw (2), Figure 10, is in such a position that
it will always carry the trip paddle on the trip
shaft beyond the point of tripping the mechanism,
when the armature closes against the magnet.

Long time and short time delay tripping only.

Long time delay and instantaneous tripping.

Short time delay and instantaneous tripping.

Short time delay tripping only.

Instantaneous tripping only.

Adjustable (Low set)
or

Non-adjustable (High set)
SHORT TIME DELAY TRIPPING, Figure 12.
The armature (7) is retained by calibrating

After the magnetic force, produced

by an overcurrent condition, overcomes this re
straining force, the armature movement is further
retarded by an escapement mechanism which
produces an inverse time delay characteristic.
The mechanism is shown in the left side view of
Figure -12.

In order to make the adjustment, first unscrew

trip screw (2), Figure 10, untU it will not trip the

breaker even though the armature is pushed against

the magnet. . Then, holding the armature in the
closed position^ advance the screw untilit justtrips

the breaker. After this point has been reached,
advance the screw two additional full turns. This

will give an overtravel of 1/16 of an inch and will
make sure that activation of the device will always

trip the breaker.

Adjustment screw (2), Figure 10, can best be
manipulated by an extended 1/4 inch hex socket
wrench.

In order to gain access to the adjustment
screw on the center pole overload device, it will
be necessary to remove the nameplate from the
front escutcheon of the breaker. This will reveal

a hole, centrally located in the escutcheon, by
means of which the extehded socket wrench can
engage the adjustment screw.

REPLACEMENT, EC-l and EC-2

The pickup for this device can be field set
between limits having a ratio of 2-1/2 to 1 in
the range of 200 to 1000% of the coil rating.

following procedure;

LONG TIME DELAY TRIPPING, Figure 12

Replacement of either the EC-l or EC-2

overcurrent trip device is accomplished by the

bs an overcurrent condition, overcomes this re

straining force, the armature movement is further
retarded by the How of silicone oil in a daslq)ot,
which produces an inverse time delay character
istic. The mechanism is shown in the right side
view of Figure 12.

Adjustable instantaneous tripping takes place
after the magnetic force produced by an overcurrent condition, overcomes the restraining
force of the adjustable calibration spring (13).

Nonadjustable instantaneous tripping takes
place after the magnetic force produced by an
overcurrent condition overcomes the restrain

ing force of a nonadjustable spring (14).
ADJUSTMENTS, EC-l AND EC-2

In addition to the pick-up settings and timedelay adjustments already described, overcurrent
trip devices must be adjusted for positive tripping.
This adjustment is made at the factory on new

breakers, but must be made in the field when the

Remove the steel clamps which fasten the cover
of the device to the back of the breaker. NOTE:

Pickup settings on the cover of each device are
calibrated for the specific device. When re
placing covers, replace on associated device.

Remove the 3/8 inch hexagon headed bolts
which fasten the coil of the overload device
to the breaker copper.

INSTANTANEOUS TRIPPING, Figure 12.

described in the section under "Main

The armature (12), is retained by the calibra

tion spring (13). Afterthe magnetic force, produced

Separate the breaker's front and back frames

Remove the round head screw which fastens
the frame of the overload to the breaker base.

After reassembling breaker with new overload

device, adjust for "positive trip" as described

under "Adjustments" of this section.
REVERSE CURRENT TRIP DEVICE

Figure 13.
The reverse current trip device sometimes
used with d-c breakers will trip the breaker open
if the direction of current flow is reversed.

This device is similar in appearance and is
mounted in the same way as the overcurrent trip.

armature to rest against stop screw (9) attached
to a bearing plate on the right side of the device.
If the current through the series coil (1) is
reversed, armature (6) tendsto move ina clockwise
direction against the restraint of calibration spring
(3). When the current reversal exceecte the calibra
tion setting, the armature will move in a clockwise
direction.

i.< A9 •QU MMC"

This causes trip rod (2B) to move up

wards against trip paddle (14), tripping the breaker
open.

ADJUSTMENTS
KARCJl ^

The only adjustment to be made onthe reverse
current device is to make sure that the trip rod
has a minimum overtravel of 1/32 of an inch beyond

fljr'ta ii——-"-^—L'.,.,-(
[• 7 s. y •« I '
' * »

the point of tripping thebreaker. Theonly occasion
this adjustment should have to be made is when an
old device is being replaced by a new one.

The new device will be factory adjusted so that

the top end of the trip rod (2B)wiU extend 1/2 inch
above the top of the device case, and no additional
adjustments of the trip rod should be required. To

ADOttfl
U*ir«cn

tb
WpmiL COL mmrnt

obtain the proper 1/32 of an inch overtravel, close

the breaker and proceed as follows:

rrmuL eONKCTte^ OUQ^m

Figure 13. (286B209) Reverse Current Tripping

Loosen the locking nut (2A).

Manually lift the trip rod and vary the position
of the adjusting nut (2), thus establishing the
position of the adjusting nut where the breaker
is just tripped. (NOTE - Be sure that all parts
of the person are kept clear of movingbreaker

1.
2.
2A.
2B.
3.
4.
5.
6.
7.

Adjusting Nut
Locking Nut
Trip Rod

8. Counterweight
9. Stop Screw
10.. Mounting Screw

11.
12.
Potential Coil
Calibration Nut 13.
14.
Armature

Screw (Lower Stud)
Trip Crank
Screw (Lower Stud)
Trip Paddle

parts when tripping the breaker.
With this position of the adjusting nut estab

lished, advance the adjusting nut upward one
and one half turns.

4. Tighten the locking nut and the minimum 1/32
of an inch overtravel of the trip rod should be

The device consists of a series coil (1), with an
iron core mounted between two pole pieces (7) and

a potential coil connected across a constant source
of voltage and mounted around a rotary type arma
ture (6). Calibration spring (3) determines the
armature pick-up value when a reversal of current
occurs.

As long as the flow of current through the
breaker is in the normal direction, the magnetic
flux of the series coil and the magnetic flux of the

potential coil produce a torque which tends to
rotate the armature counterclockwise. The calibra

tion spring (3) also tends to rotate the armature
in the same direction.

This torque causes the

Replacement of the ED-1 Reverse Current
Device is accomplished by means of the same

procedure as that followed in the case of the EC

Overcurrent Trip Devices. There is, however,
one additional step to the taken. This consists

of disconnecting the leads of the potential coil.
These are connected to a small two point terminal
board mounted between two of the phases on the
breaker base. After the new device has been

installed, adjust for overtravel of the trip rod as
described above.

POWER SENSOR TRIP

GENEBAL DESCRIPTION

All AK-3 Type Air Circuit Breakers contain
Power Sensor Overcurrent Trip Devices. The
Power Sensor Trip functions with solid state

components with the exception of the Magnetic
Trip Device which is used to trip the breaker on
signal from the Power Sensor Unit. The Power
Sensor Overcurrent Trip Device consists of four
major components.

The magnetic coils around the breaker con
ductors (Figure 14).

The Power Supply which provides both the

tripping energy and the comparison basis for
overcurrent detection (Figure 15).

neutr^ conductor with its secondary combined
with the secondaries of the three phase sensors
which are mounted on the breaker. On Draw-out

must enter the breaker by a control disconnect
(Figure 19) which is mounted lowandonthe centerline on the back of the breaker. Refer to Figure
20 for Power Sensor Cabling diagram.

The Power Sensor Unit with the varit^ pick
up settings and time delay selection taps
(Figure 16).

four wire systems) must add to zero '^bss
ground current is flowing. Therefore, if me
electrical system is a four wire wye system w^
the neutral grounded at the transformer, thefourtt
sensing coil (Figure 18) must be included on the
breakers, the output of the external neutral sensor

The Ground Sensing Device works on the principle
that the instantaneous value of current flowing in
the three conductors (or; in four conductors on

When mal-functioning of the Power Sensor Trip

The Magnetic Trip Device which physically
trips the breaker (Figure 17).
In addition to the phase overcurrent protection,

a ground fault sensing feature may be provided.

is indicated the trouble should be traced to one

or more of these four components involved, and

that component should be replaced as a unit. The
following steps should be taken to detect a mal
functioning unit.

Figure 14. (8041866) Magnetic Coils
25

3EI-50299 Power Circuit Breakers Types AK-2-15 and AK-2/3-25
the breaker to trip as a proper response to

NOTE: No adjustment to the taps controlling

3ick-up or timing should be made wi& the breaker

:arrylng current.

these abnormal circuit conditions.

2. The possibility of the breaker being trip

free by mechanical interferences along the
trip shaft or inadvertent sh^t trip

In the event the Power Sensor Device must
be made non-operative to allow the breaker

tio?s should be positively

investigating the Power SeMor. Successful

to continue carrying current

current protection, it is recommended toat
the leads to the tripping solenoid be removed

onerations in the test position should be ob
tained before proceeding with tiie Power Sensor

to completely eUminate
breaker tripping. Do not

power on the main contacts while the msconnect plug to the magnetic coils is dis

trouble shooting.

Sensor Unit for correct

A PST-1 Power Sensor Test Kit must be

t,a5Sl=. (Figure 21).

nick-up setting and one point on each time
riplav characteristic. Then check for the

Check for the existence of overcurrent or

SSct wSSou ot eecl. phase rf the ^wer

* ground fault conditions that may be causing

Supply Vnit. This
the instruction manual (GEK-^Oi) lor me
PST-1 Test Kit, and GEK-7309 Power Sensor

EfsT^cJons."^'If the test 'res^

test do not deviate mo^e th^ l^c from toe
published curves, proceed to step 4. If toe

deviation is more than 10% contact toe factory
?or?osstole
replacement of the Power Sensor
Unit.

If toe breaker is equipped with groimd fault

proleca™. determitfe whether the false tnpis the result of

overcurrent trip or a ground trip sign^- This
may be determined by temporarily elinnnating

toe ground trip signal by shorting out toe
ground signal points 1 and 5 at the ground
signal terminal board
of toe breaker. Terminals 1 and 5 ®s.n be
identified by the 0.15UF capacitor connected

Fig. 15. (8039850) Power Supply
4. Female Disconnect Plug

2. Mounting Bracket
5. Terminal Mock
3. Male Disconnect Plug 6. Mounting Bracket

i-ei AY t»|it t VI ^

Figure 16.(8041864) Power Sensor Unit

Figure 17. (8041863) Magnetic Trip Device
1.

Mounting Bracket

Captive Thumb Screw

Spring
Trip Arm

Adjusting Screw

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299
between them. See drawing 138B2454 (Figure
22) with the breaker restored to service with

the ground fault detector deactivated, establish
whether there is false tripping due to overcurrent.

FALSE TRIPPING CAUSED BY FAULTY GROUND
FAULT DETECTION

If the breaker is equippedforfourwire service

(fourth C.T. remotely mounted, Figwe 18) it is
important that the shielding be effective by having
continuity from the disconnect plug at the Power
\

Sensor Unit to the external C.T. and further, that
this shield be isolated from the signal conductors.

It is also important that continuity exists through

the ground signal circuit. Check these conditions
as follows; referring to Figure 22.
1.

Remove connection plug at Power Sensor Unit
and check continuity between A and C (Signal).
Letters are located on end of plug.

Check to be sure no continuity exists between

Temporarily connect jumper from shield to

R and A, or between R and C.

either terminal at remote C.T. and check to
assure the shield is continuous from Power

Sensor Plug to remote C.T. by checking for
continuity between R and A. If continuity
does not now exist, shield is not continuous
and point of discontinuity must be found. Check
the control disconnect as the possible point

of discontinuity.

Remove jumper at remote

C.T. after shield continuity is established.

Note the polarity marks on the ground sensors.
Be sure the external groxmd C.T. senses the
neutral current associated with the particular
breaker load current and that polarity marks
are in accordance with 138B2454 (Figure 22).
If the breaker bottom studs connect to the

source, the external C.T. must also have its

polarity mark toward the source.

Figure 18. (8041867) Ground Sensor Coil
(Remotely Located)

External Ground Sensor Coil

White Polarity Dot

Figure 19. (8918380A) Control Disconnect Plug
1.

Female Disconnect Plug

Mounting Bracket

AK-3-e5
POWER SENSOR TRIP CABUNG
BACK PRAMC
MACNETIC SENSORS

POWER SUPPLY
UNIT

\0J33C90/r
POWER SENSOR
UNIT

setting such as 300% for comparison with published
COMMON WEGATtVE

In the event the breaker is equipped with

1
.TO se*
IMOOC

ground sensor, the groimd sensor will cause tripping
on single phase testing unless the signal is shorted
at the terminal board (Figure 22). Jumper points
1 and 5 during overcurrent test.

The above considerations should indicate which

..il&r
ul p®.
ROWER

After the PST-1 Test Kit has been used to

determine the adequacy of performance of the Power
Sensor Unit, it may be advisable or required to
test the magnetic coils by the use of a hi-current
Low voltage type test set. In this event, only one
test per phase need be made. This test should
be made at some convenient multiple of pick-up
time-current curves.

TESTING MAGNETIC COILS

of the four major components is faxilty and in
need of replacement.
REPLACEMENT OF POWER SENSOR
COMPONENTS

POWER SENSOR UNIT (Figure 16).

Loosen screw connecting the unit to the
front frame.

2.
$urr«i*soiit

Slide unit forward.

Remove control plug by alternately loosening
the two retaining screws.

Figure 20. (0133C9017) Power Sensor Cabling

Replace in reverse order.

MAGNETIC TRIP DEVICE (Figure 17).

Remove trip solenoid wires from the terminal
board on power supply.

Remove four screws holding power supply to
breaker frame.

Pull power supply forward until restricted by
wiring.

Ixjlts holding trip device to

Lift out trip device.

Replace in reverse order.

POWER SUPPLY (Figure 15).
1.

Remove magnetic trip wires from the terminal
board on POWER SUPPLY

2.
Figure 21. (8039962) Power Sensor Test Kit

Remove foiir screws holding power supply
to breaker frame.

SOURCE
«;ro».;wo a t

T1?Ar4SF0I?V.eR »EJTe«L
"tw

1"
POWER S6»JS0R JMiT
^UWO fttMWR SiCiUAk
CAR

POWER SUPPt'T I

jOLOlEIWMI
fe«T. eo»(W)!

(pM*rCA srAnaAfiKrSKE^K-Sfiy

lUn'/AC /ASTACi-fiTTM

^e^^AoJk
T>ASCeAfA/£t:.-r
CHECK CONTINUITY A TO C
^
CHECK HO OOwrinUlT^ AORC TO R iSw^—Cl

CHECK COMTIMOITY K To

load 4 vJlRE SYSTEKA
TrfiCAu ftgOO?JO CO'JLT ConnECTiOnC

(eREAtCEK, CAEUm?, I

OISCOUMECT AMO CltTriRNHl.

PARTOP Pfr-? TOWB-' SENSoR TRl®

HEUTRAL dROOMO SENSOR COiU.
-A
T^tETAfi. Z?iC

• ="
^MfSC'Zi

^Ao SE//g>OR
Cote.

•»Hirs AiAAirv S«r

Figure 22. (138B2454) Ground Fault Wiring Diagram
29

1-50299 Power Circuit Breakers Types AK-2-I5 and AK-2/3-25
-LOMS time OELAT rick or

WITH CALISHATEO MAJIKS

80-100^20-140-160

orer cert or coil ratirs. set at IOO /•
WRER

LONS TIHE AOJOSTIieHT^
lA-15 TP 38 SEC.

IB—7.5 TO 18 SEC.
IC—33 TO 8.2 sec

30 40 9060 60 100

IZX IHSTARTAREOUS
'

SETTIM9
illustrated

6TO 12 ti«s' ?s7uLrtHEo""Les''5

(Doreraroe available rer device, rarbe of oi«
OTHERWISE SRECIRIEO-SETTIROS ARE AT 12 TIMES RATIR8.

©CURVES ARE RLOTTEO AT 25*C AMBIERT

(SItoTAL CLLARIR6 TIME - IS OURATIOR OR FAULT CORRERT IRCLU0IR6 ARCIHB TIME.

without the breaker thirriro.

CURRENT IN TIMES COIL RATING

Figure 23. (286B209) Time-Current Characteristic - EC Devices
30

Power Circuit Breakers Types AK-2-15 and AK-2/3-25 GEI-50299

iiiiMiiiiiiSKumse^tiiinwiiiiiniiiip

a
CWtCtirt tH iMAtinii 09

Figure 25. (109HL689) Time Curve

Figure 24. (109HL687) Time Curve

Remove four screws holding escutcheon to
mechanism

Unsolder three leads at groimd disconnect
and pull wire through hole in back frame.
On stetionary breakers with fourth wire ground
disconnect, unsolder leads at external ground
coil and pull wirejthrough hole in back frame.

Remove primary disconnects per instructions

and remove escutcheon.

Disconnect control plug to power sensor coils
and power sensor unit.

Remove cable clamps holding cabling inplace.

Remove power supply unit with attached cabl

under disconnects.

Separate the breaker front and back frame
as described
tenance".

Remove three 3/8 hexagon headed bolt con
necting coils to breaker copper.

Replace in reverse order.

SENSOR COILS (Figure 14).
1.

in the section under

With the back frame in the vertical position,

and supported, grasp the outside coils and
lift coU assembly from back frame. When
carrying or moving sensor coil assembly,
always support the outside coils.
SELECTIVE TRIPPING

Remove two screws holding sensor coil dis
connect plug bracket to back frame.

Remove bolt holding resistor bracket to back
frame.

Remove 2 screws holding capacitor bracket
to back frame.

Selective overcurrent tripping is the applica
tion of circuit breakers in series so that only the
circuit breaker nearest the fault opens. Anyone
or combination of two or more of the preceding

over-current devices may be used in a selective
system.
The breaker having the shorter time
setting and lower pickup will trip before the

23ov. ao'^'sec
itz£

PujH-lsaTT*w
R£-*r C0^4*^ACT2
Pop IWST. Xt'lbrntMii
T.: S : C0N»J6i*5 ®

Jr< ' -TC^Cft.
inst is mot

Ju^a£P uv Te T6i

C,.C*.Cj.Ct,Ci • JOu^ tio7. 600 WVOC
Ci-5J<»*f

D. Da s, Di.Bt t«i54o -400 -<*.«>ae'c
(?. -15 A zw 4 s%

Rf iSaoA 5w lift

Rs- 75 J>. 5w 4 i%

Ra Rj.«i,Rl -'OA /jW
Rb • 2750 A. 20W 4 5 7.
Rh- 0-25.000iL IS W
R5 • 5ao A. 3W 4 54%

breaker having the longer setting and higher pick
up, provided the fault is on the part of the line
protected by the breaker having the lower setting.

on the breaker is always connected through either
its secondary disconnects or terminal board, to
terminals #4 and #5 of the time delay box.

For the exact characteristics and setting of
each breaker in a selective system, reference

approximately 80% of bus voltage and drop out

should be made to a coordination chart for the

particular system.

(Figures 23, 24, and 25}

STATIC TIME DELAY

UNDERVOLTAGE TRIPPING DEVICE

The Static Time Delay Undervoltage Tripping
Device consists of an undervoltage device mounted
on the breaker, a static time delay box mounted

separately from the breaker and a control power
transformer which is also motmted separately from
the breaker when the reference voltage is other
than DC., 208V AC or 230V AC. Refer to wiring
diagram 0102C3698 (Figure 26).

The undervoltage device is set to pickup at

between 30% and 60%.
The undervoltage device coil circuit is con
tinuously rated and will remain picked up as long
as the voltage remains above the predetermined
drop out voltage. The time delay is field adjust
able between 1 and 5 seconds, it is factory set at
the minimum setting, and once the time delay is
established, it is consistent.
No more than one undervoltage device should
be connected to a static time delay box.

monitored is connected to terminals #1 and #2

The Static Time Delay Undervoltage can aJ^o
be furnished in conjunction with the termotector
control package, as shown on wiring diagram
0102C3699 (Figure 27). Overheating of the motor
windings causes the termotector, imbedded in the
motor windings, to open and allow the "Z" relay

of the time delay box.

The voltage 208V AC or 230V AC, to be

The undervoltage device

control box to instantaneously trip the

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2JdV 60'o5 SST with ground fault on 3-wire
load.

GE!-€6153 SST Conversion Kits

FRONT VIEW OF BACK FRAME

HARNESS CONNECTOR
TO PROGRAMMER

HOLE "X"THRU
BACK FRAME

econdary disconnect
lock for 4th—wire
eutral sensor-mounts

HARNESS "X'
FLUX SHIFT
TRIP DEVICE

n rear of back frame.

FIG. 12 Harness connections for ail drawout breakers
equipped with 4-wlre ground fault. For elementary
diagram see Fig. 14.

INSTALLATION STEPS
1. Connect the A, B, and C phase sensor leads
respectively to TB1, TB2 & TBS. Identify per
Table 5.

2. Mount the neutral sensor disconnect block 120
to the rear of the back frame per Fig. 13. Use
existing mounting holes.
3.

Insert the two prepared leads of harness 128

into the harness connector: Black to socket N,
white to socket L

Feed the opposite end of harness 128 thru hole
"X" in the back frame and connect leads to
block 120 as shown in Fig. 13.

GEI-86153 SST Conversion Kits

FRONT VIEW OF BACK FRAME

(WHITE)
REAR OF BACK FRAME
TAP

4.75 APPROX. REF
ENLARGE THIS HOLE
TO .312 DIA.

REAR VIEW OF BACK FRAME

Fig. 13 — Mounting detail for secondary disconnect block 120
for 4th-wire neutral sensor (drawout breakers only).
13

aACK^A^r-rj-^BREAKER

(48V. dc)
ANODE]

NEUTRAL
SENSOR
DISCONNECrr

equipment—mounted
NEUTRAL SENSOR

HARNESS
CONNECTOR

na • „
PROGRAMMER

- SCT With ground lauH on 4.wiro

FLUX SHIFT
TRIP DEVICE

PROGRAMMER
UNIT

(48V. dc)
(TO SCR
ANODE)

AL
SENSOR
TERMINAL
BOARD

BUCK
LOAD
HARNESS

EQUIPMENT—MOUNTED f
neutral SENSOR

(AMP 201298-1) CONNECTOR
" (AMP 201297-1)

Rg. IS —Cabling piagram —SST with ground fault on 4-wire
load — stationary breaker.

GEl-aei 53 SST Conversion Kits

FRONT VIEW OF BACK FRAME

HARNESS CONNECTOR
TO PROGRAMMER

HARNESS"X"
FLUX SHIFT
TRIP DEVICE

\r0 4TH-WIRE
NEUTRAL

Fig. 16 Harness connections for stiaiionary breakers
equipped with 4>wire groundfault. Forelementary
diagram see Fig. 15.
INSTALLATION STEPS
1. Connect the A, B and C phase sensor leads re

spectively to TB1, TB2 &TB3. Identify per Table

2. Mount neutral sensor terminal board TBS (part
of harness 110) to the back frame.

3. Insert the prepared leads on the opposite end
of harness 110 into the harness connector:
Black to socket N, white to socket L

AFTER BREAKER IS REASSEMBLED,

ADJUST THE FLUX SHIFT TRIP ROD
AS FOLLOWS: WITH BREAKER OPEN
AND THE TRIP SHAFT RESET, TURN
ADJUSTER UNTIL GAP IS .093 TO .125.

THEN LOCK WITH JAM NUT.

WHEN REASSEMBLING THE FRONT
AND BACK FRAMES, ENGAGE BUSH

ING 49 (IN RH OPER. LINK) WITH

OPERATING LEVER OF THE FLUX
SHIFT TRIP DEVICE AS SHOWN. SEE
FIGS. 4 & 5.

RIGHT
OPER
LINK

RIGHT SIDE OF
MECHANISM FRAME
VIEWED FROM REAR
OF FRONT FRAME

SECTION C-C
SECTION B-B
OF FIG. 1

ON POWER SENSOR BKRS. EQUIPPED
WITH SHUNT TRIP, MOUNT FLUX SHIFT
TRIP DEVICE ON TOP OF THE SHUNT

TRIP BRACKET. IF NO SHUNT TRIP,
USE SPACER 46 PROVIDED.

ON EC EQUIPPED BKRS. IT WILL BE
NECESSARY TO DRILL & TAP THIS
#10-32 HOLE IN THE FRONT FRAME.
USE THE FLUX SHIFT TRIP DEVICE
BRACKET AS TEMPLET.

~~ ing
R'Qht
side view of mechanism frame showing mount
of flux shift trip device 40,

GEi-86153 SST Conversion Kits

Rg. 18 — Rear view of front frame showing location of trip
paddle for flux shift trip device.

Gcl-o6153 SST Conversion Kirs

g. 19 — Right side view of operating mechanism showing
mounting of flux shift trip device.

GEI-861S3 SST Conversion Kits

SECURE WIRE HARNESS "X" WITH
TIES P54 AFTER ASSEMBLY OF
FRONT FRAME TO BACK FRAME.

PROGRAMMER SHIELD
AND BRACKET

HOLE IN
SHIELD
WIRE
HARNESS

Rg. 20 — Connection of Harness "X" from flux shift trip device
to terminal board TB4 on back frame.
INSTALL NEW BRACKET 71

USE EXISTING BRACKET

ON ALL AK-2/2A MODELS;
USE MOUNTING HARDWARE

FOR ALL AK-3/3A MODELS.

72. 73, 74 PER FIG. 1.

ENGAGE TRAPPED SCREW ON
PROGRAMMER ENCLOSURE
WITH STUD ON P71
FRONT
FRAME

SHOULDERED PIN ENGAGES
KEYSLOT IN P70

ATTACH PROGRAMMER UNIT AFTER
JOINING FRONT AND BACK FRAMES

CAUTION: HARNESS CONNECTOR
MUST BE SECURELY ATTACHED TO
PROGRAMMER UNIT BEFORE ENER
GIZING BREAKER — OTHERWISE
THERE WILL BE A SHOCK HAZARD
AND POSSIBLE DAMAGE TO SENSOR
COILS AND HARNESS.

Fig. 21 — Right side view of breaker showing mounting of
programmer unit.
19

AK-25 breaker wllh SST conversion completed.
(AKD-5 type drawout shown)

GEI-86153 SST Conversion Kits

IV. EQUIPMENT MODIFICATIONS
3TE:

The following modifications are required ONLY
in conjunction with breakers being equipped with
4-wire Ground Fault trip elements.

1. Mount the neutral sensor (01) in the outgoing
neutral lead, normally In the equipment's bus
or cable compartment. See Fig. 23 for the sen
sor's bar drilling plan. Check to insure that the
neutral and phase sensors match, i.e., have the
same ampere range.

neutral sensor stationary disconnect block 121
inside the breaker compartment at the lower
rear as shown in Figs. 24 or 25, whichever

applies. For the AKD-5 type equipments of Fig.
24, be careful to select the correct mounting
bracket (Part 126 or 127).
3. Connect the neutral sensor to disconnect block

121 per wiring instructions of Rg. 26. For sta
tionary breakers, the neutral sensor is conn ected to TBS.

2. On drawout type breakers, mount the 4th-wlre

Fig. 23 — Outline of SST Neutral Sensors:
Cat. 139C4475G1
70-225 amp
Cat. 139C4475G2 200-600 amp
(from outline dwg. 139C4476)

^ OF BREAKER
3.25 !

TOP VIEW OF
COMPARTMENT
BOTTOM

CORRECT
BRACKET
FROM KIT

REAR OF
BBEAKER

COMPARTMENT
BOTTOM

o'4ft.wlre
compartmente and AKD-S

rear VIEW OF BOX
Fig.2S -

LEFT SIDE VIEW
Uj

Neutral CT markings of LINE and LOAD must be
respected when making bus or cable connections.

^JNECTTO TERMINAL BOARD TB'S ON

Polarity of connecting wires from Secondary of

SIATIONARY BREAKERS, OR TO

Neutral CT to Terminal Block or CT Disconnect

NEUTRAL SENSOR STATIONARY

Block must also be respected: Tap to Tap, Com.

DISCONNECT BLOCK FOR DRAWOUT

NOTE: BOND ON LINE SIDE ONLY
UNE

#14 MIN. WIRE, WIRES
MUST BE RUN TOGETHER
AND TIED TO PREVENT LOOPS
TAP

COM
100 FT. MAX.

#5 BINDING
HEADSCREW

#6 PAN HEAD SCREW
TERMINAL STRAPS

4TH-WIRE NEUTRAL
SENSOR STATIONARY
DISCONNECT BLOCK 121

SPRING LOADED
BUTT CONTACTS

(DRAWOUT BKRS.)

FRONT VIEW LOOKING INTO BREAKER COMPARTMENT

Fig. 26 — Connecting the 4th-wire neutral sensor.
23

GEI-86153 SST Conversion Kits

V. FUNCTIONAL TESTING

Before the breaker is reinstalled to service:

1. Megger breaker primary circuit using a 1000V

B — Using a single-phase, high current-low volt

age test set, test each trip element (L, S, I,

Perform either of the following tests:

G) to assure proper protective device opera
tion. Compare results with applicable timecurrent characteristic curves reproduced on

A — Using ECS/SST test set Catalog #TAK-TS1,

test per instructions GEK-64454 to assure

proper operation of the breaker and its trip

When testing units equipped with a ground
fault trip element, the latter must be deactiv
ated by using Ground Fault Defeat Cable

Catalog #TGFD as shown in Fig. 27 below,
if this defeat cable is not available, the
breaker can be tested by connecting two
poles in series.

m
BREAKER
HARNESS

GROUND FAULT DEFEAT CABLE

' O-HC
Any SST
Programmer
Unit with

Ground Fault
Element

NEUTRAL
SENSOR
DISCONNECT
MALE
END

Fig. 27 — Cabling diagram with Ground Fault Defeat Cable
Inserted between breaker harness and SST Pro

grammer Unit — for use during single-phase, high
current — low voltage testing.

TABLE 6 — TRIP CHARACTERISTICS — SST CONVERSION KITS
r^ppHcabia time^rrent Curves: GES-€0338, 6034A, 603SB
SST Programmer Ad)ustment Range (Set Points)
Breaker
Frame

Pickup
/ Multiple \

Sensor Taps
(X)
(Amperes)

300, 400, 600, 800

Pickup
/MulUplel

70.100,150,225
Maximum 1.75,2, Maximum
22
2.25,25,
0.35

200,300,400,600
AK-SO

600, 800,1200,1600

800,1200,1600,2000

.2, .25. .3.
.4, .5, .6 (X)

Intermed.
0.165

.6, .7, .8,
.9, 1, 1.1

(X)
Minimum
0.065

Minimum 3. 4,5,6,
4

1200,1600, 2000, 3000 .3, .35, .37 (X)

1600, 2000,3000, 4000 .25, .27, .3 (X)

0 X a Sensor ampere tap "• trip rating
Pickup tolerance •

(DUma delay at lower limit of band@6L
0 Time delay at lower limit ofband

MtitTiniS OF LONG-TIME FICXUF (U
2

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MifMmwnn fofvl

Pfcfcup Po4o4*ewAa g*••$«
lignoll 0OE<«O<« OM *9 EMM* tGTy'9*>OM

Applioitlon OoloimiiiM
find «l Cuffv*
AK A«fl.SO

4 COO
is:oc
6i}00

44 !• M 7||4Mf

MULTIPLES OF LCNG-nME PICKUP (L)

GENERAL'^ ELECTRIC

AK/AKR LOW-VOITAGE POWER ORCUIT BREAKERS

Z s CtirrwM Umtm Tap* (Ainpwio^

I 44*liiy, Shoit-tiw d«ley
ond InMantanaout TTnnKurrmit CurvM
Ct>r4h*p

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NM 9«tA« lAMOE

GSNBui eiscraic co.. cikuit pROTECiive cevicss dot., puinvius. conn, ombj

GEI-86153 SST Conversion Kits
MuiTinja OF ojiwatT sensor tap (X)

Gfognd favlf
Pfckyp Foinft
AIC-1S/3S

i!/, L" r • iri I 1
lnt«ffvt«dtotp /

Intarmadleta j /f

MULTIPLES OF CURRENT SENSOR TAP (X)
* C««af*e www ••• ta«iH O* «*t !•*<

G£MERAL<@ ELECTRIC

LOW-VOLTAGE POWER CIRCUIT BREAKERS

SST SOLID-STATE OVERCURRENT TRIP OEVIGE

CwEHwi Sawiar Tap*lAatpami
A«

Ground Trip Timt-current Curve*

*0 ' « *53 rJ5 OP:00. 300 400 ©00

300 400 ©00 900 SP ©00 900. -300 '©00

so 335 330 OP 300 aOO ©00 300
m»mw «» Mr dO N*ni

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Graunp lawit Pkawpi
A<>S 3$
ANft-30
AK AR0-SO

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4* U
4* 9* I 0* C 1 3s
35* 3* 4> Ss as 4 7m

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Mksimum lAPap^aaioia 4 MtaimvPN

OENERAl ElECniC CO.. CICUIT PROTECTIVE DEVICES DEPT.. PUINViuf. CONN. OMOl

GENERAL ELECTRIC COMPANY

CIRCUIT PROTECTIVE DEVICES DEPARTMENT

PLAINVILLE, CONNECTICUT 06062

GENERALS ELECTRIC

' j : r • 1 ,•

GEI-50299A
SUPERSEDES

CIRCUIT BREAKERS

AK.2.15
AK-2.25

GENERAL^ELECTRIC
PHILADELPHIA. PA.

OPERATION
ELECTRICAL OPERATION

MANUAL OPERATION

ELECTRICAL AND MANUAL OPERATION

INSPECTION
SEPARATION OF FRONT AND BACK FRAMES
LUBRICATION
TROUBLESHOOTING

BASIC BREAKER COMPONENTS

ARC QUENCHER
BREAKER CONTACT STRUCTURE

CONTACT ADJUSTMENTS
CONTACT REPLACEMENT
MECHANISM
AUXILIARY SWITCH

ELECTRICAL CONTROL COMPONENTS

CLOSING SOLENOID

"X" CONTACTOR
"Y" RELAY
CUTOFF SWITCH
CLOSING SWITCH
SHUNT TRIP DEVICE

PROTECTIVE DEVICES

OVERCURRENT TRIP DEVICE

EC-2 OVERCURRENT TRIP DEVICE

EC-1 OVERCURRENT TRIP DEVICE
TIME-CURRENT CURVE

REVERSE CURRENT TRIP DEVICE

UNDERVOLTAGE TRIP DEVICE

BELL ALARM - LOCKOUT DEVICE

MAINTENANCE TOOLS
RENEWAL PARTS

TYPES AK-2-15
Ki-^'

INTRODUCTION
herein

AK-2-15/25 breaker componenta and ac
cessories.

For information reading the

receiving, handling, storage and fastallation

of these breakers, refer to GBa-2031A,
furnished wltii all AK breakers.

OPERATION
ELECTRICAL OPERATION
FIG. 1
The electrically operated breaker
closes whenever the closing solenoid coil

is ener^ed. This causes an upwardmove

ment ca the solenoid armature, which in
itiates the mechanical closing action. The
closing signal may be given either by a
remote switch or relay, or by a closing

-ic.->-.N.CL0SINS

MWWe
KI"-o9e..J

button in the front escutcheon if the breaker

is so etpiipped. Either action (refer to the

elementary of the wiringdiagram) energizes

•—O—*90UW«

the coUof the X relay through the bb con' tacts of cutoff switch O and the normally

closed contacts of the Y relay. When the
X relay or contactor isenerkized,itcloses

its contacts. One of these C|Cl-2; seals in
the

coil. The other three sets of con

»•"-«eo8Tuiie«

tacts, whichare arranged in series, activate
the closing solenoid.

The breaker control scheme has an

anti-pump feature which aiiows only one
closure of the breaker for a single opera

tion of the closing switch no matter how
long the switch may be held closed. This
prevents the repeated (derations that would
ensue if one of the automatic trip devices

»—-"swroev Immns

MJOSMTE wms FOR USE MIN

Fciimnm control voume rrtM
-HI

COfWECTIOtl DIAeRAM

was activated at the time (d closing. The

Y relay, together with the cut off switch,
provides the anti-pump feature. Themeclmo»

nical action of closing operates the cutofif

switch reverstng the position of the con

tacts from diat shown on the diagram. This

energizes the Y relay, if contact is stiii

maintained at the closing switch, with the

result that the X relaycircuit is opened Ijy
Y conUcts 5-6. Thisprevents the X relay

from again becoming energized. Y contact
1-3 seals in the Y coilas' long as contact is
maintained at the closing switch.

Biectrically operated breakers may

also be closed by means of the maintenance
handle which is lumlshed with the breaker,

^is is a separate tool and is simply a
lever which permits an operator to push
upumrds on the closing solenotd armature.
Two small hooks on one end of maintenance
(»A) Fig. 6,

loca^ in tte lower portion of the front
®o»a«onforces
ofthelong
9^ ei ^the handle downmrds
the
SfSiL
^handle
against
the bottom of
the solenoidupwards
armature,
and
closes the breaker.

—«•«, ana

Typical Wiring Oi

MAINTENANCE
INSPECTION
BEFORE INSPECTION OR ANY MAIN

TENANCE WORK IS OWE. BE SURE THAT
THE BRBAKERISIN THE OPEN POSITION.

ALL ELECTRICAL POWER, BOTH PRI
MARY AND CONTROLSOURCES, SHOULD
ALSO BE DISCONNECTED.

Periodic Inspection of the circuit
.breaker Is recommended at least once a
year. More frequent Inspections are recom

mended, If severe load conditions, dust,

6. Check operatlonoftrlpplngdevlces.
Including overcurrent trip dmces, making
sure all have positive trippingaction. (Dis
cernible movement In tripping direction
beyond point of tripping.)
(For detailed Information on breaker

features listed, refer to appropriate sec
tions of these InstructionsJ

SEPARATION OF FRONT
AND BACK FRAMES

moisture, or other unfavorable conditions
exist

If the breaker remains open or closed

.for a long period oftime, it Is recommended
that arrangements be made to open and
close It several, times In succession, pre
ferably under load.

At all times It Is Important not to
permit pencil lines, paint oil or other
foreign materials to remain on the In-

nng surfaces of the breaker as they
nay cause low resistance between points
of different potential and result In eventual
electrical breakdown.

Always Inspect the breaker after a

short circuit current has been Interrupted.
... ..At the time of periodic Inspection, the
.following checks should be made after the
breaker has been de-energlzed.
^1. Manually operate the breaker sev

FIG. 3
maintenance (iterations

separating the front frame and mechwlsm

of the breaker from the backframe or tose,
which consists of the current carrying
parts of the breaker and their supporting

6. The two frames are now dlscimnected. However, care should be exercised

In separating them to avoiddamage to the
trip shaft arms and paddles. Emlle the
back frame is held steady, lift the front
frame and mechanism up a^ out so thattrip arms cS the overload tr^- d^css.
Reassembly of the two breaker halves

Is accomplished by following the procedureoutlined In reverse order.

1. Remove the arc quenchers (see
'

section on "Arc Quenchers^),

2. Disconnect the two Insulated con

necting links (6), between the mechanism

and the crossbar (10), fay removing the tie
Iwlt (7), and slipping the ends oflhe links
cO the ends of theshoulderedpln, (5) Fig. 5,

In the mechanism.
r . >/ » ,
3. If the breaker Is a drawout type,
with secondary disconnects. Fig. 2, remove

the secondarydlsconnectsuppor^g bracket
from the breaker ba(d( frame. Also remove

any wiring bundle retainers that may he

4. Remove nut from
each of two studs (3), which tie the upper

ends of the mechanism frame to the back
attachments are functioning properly.
frame of the breaker.
...
Remove and inspectthe arc quench5. Remove the two elastic stop nuts
Sl«
^ partsreplacement.'
or extensiveburnliw (9/16"
will Indicate needfor
Hex.) which fasten the wrap around

portion of the front frame to the back frame.
One of these Is locatedon each side of the
breaker, about 2/3 of the distance down

from the top edge of the back frame.

structure. The procedure for this operation

attached to the back frame.

6. Checklatch engagement.

from the slots located In the bottom at me '

either recpilre or be greatly facilitated by

excessive friction.

4. Check contact condition and

#8-36 screws located at the front of the -

bottom plate and then freeing the plate.. --

the trip paddles on the trip s^t clew, the

eral times, checkang for obstructions or

2. Electrically operate the breaker
several times (If breaker has electrical
cmtrol) to ascertain whether the electrical'

On drawout breakers, the bottom plate -.. '
must be removed by first removing two %;

In general, the circuitbreaker retpilres

vere little lubrlcmtlon. Bearing points and

".S, "8»lar inspection periods

with a thin film of extreme temperature,
high pressure, light grease, similar to

G. E. Stcc. No. D50H1S or RPM No. S.
Hardened grease and dtrt should be re*

moved from latcdi and bearing surfaces by

the use (d' a' safe
such as
"•
* cleaning
* • solvent
lOlV
kerosene. Latch surfaces should be left'
clean and dre and not be lubricated. ALL
EXCESS LUBRICANT SHOULD BE RE
MOVED WITH A CLEAN CLOTH INORDER
TO AVOID ANY ACCUMULATION OF DIRT
OR DUST.

At each maintenance period, all silver

to silver friction points, such as primary'
disconnects, should be cleaned-anil given a'

fresh coat of G. E. Spec. No. O50H471ubrlcant.

TROUBLE SHOOTING

The following table lists several typlchl

symptoms of breaker malfunction, together
with their causes and -^'•MwesM.we
remedies. .sop
If. at
any
aw Ait/
time, "•
these symptoms are (taserved. thetr
cause should be determined and the necbh- '
.

sary corrective action sho^ im. taken.

. %'•>;* -.1-

Power Circuit Breakers Types AK-2-1S and AK-2-25 OBI-50209

TROUBLE
Overheating

Contacts not aligned.
Contacts dirty, greasy or coated with dark film.
Contacts liadly burned or pitted.
Current carrying surfaces dirty.
Corrosive atmosphere.
Insufficient bus or cable cqtaciw.
Bolts and nuts at terminal connections not tight.
Currat In excess of breaker rating.

Check breaker appllcatla or modify circuit by decreasing'

Excessive ambient temperature.

Provide adequate ventilation.

Travel cf tripping device does not provide

Re-adJust or replace tripping device and check mechanism ^
latch adjustment.

Adjust contacts.
Clean contacts.

Replace contacts.

Clean surfaces of current carrying parts.

Relocate or provide adequate enclosure.
Increase capacity of bus or cable.

Tighten, but do not exceed elastie limit of bolts or fltttags.":. s
load.

Failure to Trip

positive release of tripping latch.

Worn or damaged trtp unit parts.

Replace trip unit.

Bind In overcurrent trip device.

Replace overcurrent trip device.

Overcurrent trip device pick up too low.

Check application id overcurrat trip device.
Check application of overcurrat trip device.

Overcurrat trip device time setting too short
Bind ill overcurrrent trip device.
Failure to Close

Binding in attachments prevatlng resetting of

Latch out of adjustmat
Latch return spring too weak or broken.
Hardaed or gummy lubricant

Replace overcurrat trip device.

Re-allgn md adjust attachmats.

Clean bearing and latch snrtaca.
Replace solaold colL

Re-adJust or replace: device.

BREAKER COMPONENTS

SECONDARY DISCONNECT, FIG. 2

4. Remove contact tto by cutting wife'

The secondary disconnects serve as
PRIMARY DISCONNECTS

connections between breaker control circuit
elements and external control circuits.

The primary disconnects are attached

to the ends eS the lireak^r stsds ontte rear

side of the breaker tase. Each disconnect

assembly consists of two pair of cnposed

contact fingers. These are secureifto the
breaker stud by a bolt whlchpasses through
the assembly and the stud. When engaged
with the Btatlona^. stud of the enclosure,
the disconnect fln^re exert a set amount
of force against the stationary, stud through
the actlm of. the compression brings.

Retainers and qiacers hold the contact

flnms Incorrectallgnmehtforeni^gement

The amount of force edilcb

the fln^s exert against the stud is determbied by degree to which the sp^gs are
compressed by the bolt and nut whlui hold

the assembly together,
for any reason,
the dlsconnecte must be taken apart, the

position of the. nut on the bolt should be

wefnlly noted,, so that In reassemblylng,

the. orl^nal amount of coupressltm can be
Testoed

'^'posittdn a thai

Solenoid control device not functioning properly.

mrt at Its former

Adjust latch.
Replace spring.

Closing solaold burned out.

with file stud.

They are used only on drawout ^npe break

5. Push wire through hoUow tubei^^^^^

new disconnect assembly.

..5.? :'' -' " ^

A terminal board serves the same

purpose on stationary mounted and general
purpose enclosure mounted breakers. The

secondary disconnects allow removal of the

6. Strto insnlatloa oR ad ol.wlreito,-,-;^i
of wlfe
about 1/4 of an inch from end.

breaker without the necessity of having to
detach external connections.

The movable part of the secondary dis

connect consists of an insulating bodywhich
holds a conducting spring loaded plunger to
which a flexible lead is atteched.

breaker moves into Its enclosure, the

plwer Is depressed by sltdbig ato the
stationary disconnects of the enclosure.

REPLACEMENT OP: BTOVABLE SECOND
ARY DISCONNECTS

1. Unfasten, disconnect body! from
breaker back frame.
1

3. Pull contact tip loose from hollow
tube.

\ .. 8. Puli wife through'fapile well to check their condition and open
any of the perforations that appear to te

If any very extensive burning or cor

rosion Is note^ in the arc quencher, it

should be replaced. Replacement is ^so
indicated

noted In the ceramic material.
REPLACEMENT

Removal of the arc quencher Is sim

ply a matter of lifting &e assembly up
and out, after the steel retainer across

the front of the arc quenchers has been
removed.
The upper edge of the steel

arc runner fastened to the back plate of
the breaker fits into a recess in the back

portion of the arc quencher and locates

it in its proper position upon replace
ment.

M^e sure the steel retainer is

replaced and fastened firmly to its mount

ing studs after the arc quencher has been
replaced.

Fig. 2 Kovable SecMi4ary Disconnecta
contact tip end is formed into the shape
of a small hook. A tension spring engages
this hook and provides the necessary con
tact pressure at the pivot and also at the

CONTACT ADJUSTMENTS
The only adjustment to be made on

point of contact with the movable contact

arm. When the breaker contacts open, a
projection on the contact tip end of the
stationary contact bears against a stop

distance the movable and stationary con
tacts move while they are touching one

pin restricting the movement of the station
ary contact. This arrangement results in
a continual high force existing between
the mating pivot surfaces and eliminates
the necessity offast-weartngflexlbleshunts
around the pivot point.

The movable contact arms pivot in
a vertical plane, each making contact with
a pair of stationary contacts, and thus
providing four low resistant parallel paths
of current for each breaker pole. The

movable contacts rotate about a burnish^,
silver plated, copper pin whtcl^ in turn,
is held tiy a/ pivot support.

Is that of contact

described as the

another in the process of breaker closing.
The amount of contact wipe can be meastired by comparing the position of the
front surface of the stationary contact
when the breaker is open to its position
when the breaker is closed, in reference
to some absolutely stationary part of the
breaker. The moat convenient stationary
part of the breaker to use as a reference
point Is the steel arc runner above and

behind the stationary contacts.
The amount of wipe the
th contacts should

have is nominally 1/8
of
inch. A
A plus
m
of an inch.
or minus tolerance of 1/32 of an Inch is
allowable.

of the pivot support bears against the

The copper current carrying parts of
the breaker are all mounted on a com
mon base of insulating material made of

polyester glass mat

lower, outer surface of the contact arm

and supplies a second tow resistance path

through the pivot.

A "U" shaped spring

clip made of silver plated conducting ma
terial provides an additional current path
and protects the other contact surfaces of

the pivot against pitting when in motion.

pole consist of an upper stud and pivot,

It also contributes to Che force tending
to increase the contact pressure be^een

arms, a movable contact pivot, and the

the lower ends of the movable contacts and
the ptvot support.

stationary contacts, two movable contact
lower stud.

The upper stud branches Into two

i'lvol surfaces on iU Inner end on the
orward or front side of the breaker base.

The movable contact pivot support is
mounted securely to

the breaker teee.

Each
these convex pivot surfaces mates
ij of. the
concave
pivot surface
swe
stationary
contocts.on the
Eachrear
of

If, as la normally the case, the pole is

^e apprt^mately at their mid-points,

end of the pivot support.

the stationary contacts pivot in ahorlzontal
ine end oi the contact opposite to the

equipped with an overcurrent trip device,
one of the terminals of the series coll

The means of adjusting contact wipe
la provided by an eccentric pin which

passes through the center of the morale
contact assembly.

Each end of this pin

has a free, projecting, hexagon shaped
section which is easily accessible to a

small, open end, 1/4 inch wrench.

cantilever springs, which bear on each
end against a portion of the hexagon sec

tion of the pin, lock the adjusting pin in
place and provide index stops lor the
process of adjustment.
The right hand
hexagon shaped end of the pin Is numbered
from 1 to 6, which provides a reference
for making wipe adjustments.

When contacts are to be adjueted, the

of the trip unit Is fastened to the lower

recommended procedure is as follows:

1. With the breaker in the open posi
tion and using the numt>8re on the right

coil fastens to the lower

Power Circuit Breakers Types AK-2-15 and AK-2r25 GBI-SQ299

end of each adjusting pin as a reference,

set each pin in the same position.

many cases, the number 3 is a go^ begin

ning point. The proper view of the number

on the adjusting pin is obtained by viewing
the breaker from the front and the ad-

Justing pin from approximately a 15 degree
angle with respect to the movable con

tacts. Note that the numbers on the pin
are not in numerical sequence as the pin
is rotated.

2. By measurement, establish

position of the front surfaces of the station
ary contacts with reference to the steel
arc runners above and behind the con
tacts.

3. Close thq breaker, and establish

the amount of wipe

as in step two, and comparing the meas
urements with those taken with the breaker
open.

4. If any set of contacts lead or lag
the others, open the breaker and advance
or retard tiie adjusting pin to the next
higher or lower n u m b e r t h e adJusting pin to a higher nUmber will in
crease the contact wipe and. moving to a
lower number will decrease ^e contact
wipe.

No attempt should be made

to move the adjusting pin when the break

Besides being more dif

ficult. the additional force required to

move the pin will-tend to round off the

flats of the hex section of the pin.
5. When all the contacts have the

recommended wipe of 3/32 to 5/32 of an

Inch, the contact adjustments are com
plete.

CONTACT REPLACEMENT
FIG. 3
The normal situation that will exist

in the matter of contact replacement will
call for replacement of all the movable
and stationary contacts at the same time.

This will be the case where long use of

the breaker in service has resulted in
extensive wear or erosion of the silver

allOT contact tips. . A commonly used
"rule of thumb" is that contact- replace
ment Is indicated if less than one-half :of

the original thickness; (1/8 of an - inch)
of the contact tip material renmlns.

FRONT VIEW OF
STATIONARY CONIACTS a

SrATiONARY CONTACTS B
When the movable breaker contacts

SPRINGS
AK-2-25

are toi be replaced, remove the front

SPRINGS
AK-2-15

frame from the back frame as described

"Separation of Front and

Frames" of these instructions.. The sta

tionary contacts can be replaced with the
breaker intact.
The procethures for re
placing both stationary and movable con
tacts is described as follows:

STATTONART CONTACTS (21)

1. Breaker Baae
3. Ineoletion

Without s^aratlng the breaker front

and back frames, force the contacts away

3.' Ineul'ated Stud
4. Diver Stud Barrier.

from the contact assembly center shmpln

screwdriver until die contacts stop. sur
face is free of the center stop pin. The

and toward their own pivot point with a

6. Llnka (Iniulated)
B. Sprlne

9. Spring Clip (Retainer)
10. Croia Bar
11. Pivot Pin
12. Lower Stud

13. .Contact Pivot Support
14. Spring

15. Contact Wipe Adjuataent
Pin

contact can thqn be renloved with the fin

disen^gihg'thd'Coniact .from its

Contact Asaenbly

17. Upper Stud A Are Aaner
18. lioveble Oontaet

' 19. Spring
20. Nut

21. Stetionary'Contacte

GEI-S0299 Power Circuit Breakers Types AK-2-15 and AK-2-25
7. If spring clip retainer (9) has not
already been removed, il may nowbepulled
off and the center pole pivot pin (11) drifted
out, freeing the contact assembly.
REASSEMBLY

Reassembly is accomplished by re
versing the procedure of disassembly. Im

portant factors to remember tn performing
the reassembly are as follows:
1.

stationary contacts must be

arranged in the pole units as shown in
sections A-A and B-B of Fig. 3. Note
the position of the back projection of each

If the contacts are not arranged

as shown, the back of the contacts will

bear against the stud supports, causing
possible damage to the contacts or fail

ure of the breaker to latch in, when the
breaker Is closed.

2. In replacing the stationary con

tacts, first place the hook on the end of
the

spring (19), then push sidewise until the
back projection on the opposite end of
the contact can be slipped behind the

stop pin in the center d the contact as
sembly.

3. The adjustment of contact wipe
will be facilitated by following the pro
cedure

"Contact Adjust

ments" of these instructions.

4. When reassembling the crosst>ar
assembly, the crossbar shields should be
located with respect to the asbestos pole
shields as shown in Fig. 4. If the cross

bar shields are not located as shown,
breakage may occur when the breaker ts

operated.
CONTACT SPRINGS (19)
A minimum force of S lbs and a maxi

mum force of 9 lbs. should be required to
1. Stationary Contacts

begin movement of a single stationary con
tact from the open position towards the
closed position. This may be checked by

S' Crossbar Assembly

2. Uovable Contacts

6. Crossbar Asbestos Inner Shield

3. Upper Scud Asbestos Shield

7. Lower Stud Asbestos SHieid

using a push scale applied at the point at
which

4. Crossbar Plastic End Shield

AK-2-2S Back Frsae - location of Crossbar and Pole Shields

Remove each stationary contact

stationary contact. If these pressures are
not obtained or if the spring Is damaged,
replacement is required.

4. The pivot pin (11) of the outer

In order to replace the contact spring

poles Is tapped on Its outer end.

thread size Is 48-32. A *8-32 screw may
be used to engage the threads and drift
out the pin. If no screw is available, the

The hardware which fastens

MOVABLE CONTACTS (18)

moved, the stud may be withdrawn from

1. Separate the front frame from the

back frame of the breaker.
dealing with subject).

the upper stud (17) must be removed.

tn this manner.

may be pushed out from its inner

(16), and nut (20).
the base in a

5. After the pivot pins have been

the breaker base consists of two screws

When these are re

the stud has been removed, it is a simple
matter

to disconnect the two ends of the

removed from the outer poles, the outer

spring (19) and replace It with a new one.

small amount of force will be required
to do this as springs (8) and (14) wUI offer

side of the insulation clears the head of

the rivet which holds it in place.

some resisting force.

2. Remove insulation (5) by lifting

and pinching sides together so that the

enlarged portion of the slotted hole In each

3. Release the pivot pin spring clip

retainer (9).
On the outer poles this
retainer is similar to a safety pin and ts
released by menlng Its ends as with a

The center pole is equipped

^wllh a clothes pin type retainer which

can simply be pulled off the pivot pin (II).

movable contact assemblies may be pulled
free of the crossbar assembly (IC^. A

6. The crosst»r assembly (10) may
lie removed from the center pole

contact assembly.

AK-2 breaker mechanism is a

spring actuated, over-center toggle type
Again, the retaining

As the closing force ts

applied, either by movement of the oper
ating handle or the closing solenotd arma

forces of springs (8) and (14) must be
overcome.
The pivot pin (11) of the

center pole Is shorter than its counter

center, movement of the output crank of the

energy is stored In the operating

springs, ^ter the springs tiave gone over

part In the outer poles and does not en

mechanism is still blocked for a time by

gage the bracket on the crossliar assembly.

a cam arrangement.

As the springs are

Power Circuit Breakers Types AK-2-15 and AK-2-2S

further extended, the blocking cam moves

awaf from the cutout crank, and the springs
are allowed to discharge part of their

stored energy, closing the breakercontacts.
This assures a fast-snapping closing
action regardless of the speed at which the
closing handle Is operated.

The breaker mechanism is tripped by
the displacement of the trip latch (7), Fig.
6. Looking at the breaker from the right
hand side as In Fig. S, the tripping move
ment of (he latch is

counterclockwise.

Operation of any of the automatic trip

devices or the trip push button causes
the latch to move In the tripping direction.

When the latch moves off the trip latch
roller (7), the remaining force In the
operating spring causes the mechanism
toggle to course, resulting In the opening
of the breaker contacts.
ADJUSTMENT

Since all the mechanism adjustments are

carefully set by experienced factory per
sonnel after assembly at the factory, it

should normally not be necessary to make
any adjustments In the field. At the time
of Instellallon, and also in the course of a
maintenance inspection. If the breaker func

tions properly through several repeat^
operations, it is beat to assume that ad
justments are satisfactory.
If

the breaker mechanism does not

function properly, It is best to first per
form

listed in the "Trouble Shooting" chart of
these Instructions.

One of the remedies

listed is that d proper mechanism latch
engagement,

between the latch (7) and latch roller (5),

Fig. 6, This Is the only adjustment that
Is required on the breaker mechanism,
and proper latch engagement Is obtained
In the following manner:

(NOTE - Before making latch adjustments,
check to make sure that the l>uuer paddle
which stops against the end of the latch

adjustment screw ts rigidly fastened to
the trip shaft. Hold the trip shaft (B),
Fig. S, steady and attempt to move the

If any relative movement

between the two Is noted, tighten the fast
eners holding the buffer paddle to the
trip Shalt.)

lv:vable Contact Pivot

Contact Vipe Adjustment Pin

Movable Contact

8. Handle Return Spring

Moulded Corvpoisid Base

9. Overload Device

Steel Back Plate

10. Series Coll of Overload Device

tive measures listed In the "Trouble Shoot

ing" chart carried out. It is generally
recommended that no attempt be made to

Cut AHsy Model of Manually Operated AK-2 Breaker

repair the mechanism interior but that a
replacement mechanism assembly be ob
tained from the factory.
REPLACEMENT

2. Remove arc quenchers (see "Arc
Quencher").
3. Disconnect the two Insulated con

I. It the breaker is electrtcally oper
ated, remove the front escutcheon by taking

four screws from flange. If the broker is
be

edge of the escutcheon. (For removal of
front escutcheon from manually operated
breakers, see procedure described below.)

necting links between the mechantsm and
the contacts as In step 2 of the procedure

for "Separation of FrontandBackPrames".

6. If the breaker is manually oper

ated, and has no auxiliary switch, it is
now free to be lifted clear of the breaker.

a drawout type, twosmall round head screws
must also

5. Remove four screws which fasten
the bottom of the mechanism frame to the
horizontal cross member of
the front

Remove the two elastic stop nuts,

which fasten the upper extensions of mech
anism frame to studs connecting with rear
frame.

If it has an auxiliary switch, this may be

disconnected from the mech^ism as des

cribed under "Auxiliary Switch - Replace
ment, elsewhere in these instructions.

Power Circuit Breakers Types AK-2-15 and AK-2-25 GBI-S0299
7. U the breaker is electrically oper

ated, It will be necessary to disconnect the
mechanism from the solenoid armature.
In order to do this, raise the mechanism
as far as the travel of the. armature will
permit and remove the screw which binds

sheet of Insulating material held
by two screws fastened along
edge.
When this is removed,
minals are exposed. The upper
to "b" switches.

release them from the link connecting with

the ter
pairs of

This can be done Iw

5. Allow lower section of magnet and
coll to slide downward until clear of arm

1. Remove auxiliary switch cover.

ture extension.

This hole Is Just above

2. Disconnect leads to switch termin

As the end of the screw

Inches long Into the top hole of the arma

butts against the Car extension, the two

extensions will be spread open, releasing
the mechanism link.

6. The replacement mechanism may

be Installed by reversing the order of
procedure for disassembly. After reas
sembly, check the operation of the breaker

and, If necessary, adjust the latch en

3. Remove two screws which fasten
switch to side of mechanism frame.

4. Remove switch by moving towards
left.

5. Before mounting replacement
switch, turn the crank end of the switch
operatmg shaft In position to engage the
mechanism.

The "X" contactor is a heavy-duty

relay whlchperforms the function ofclosing
the circuit of the breaker solenoidduring
electrical operations.

Three of the four

sets of con&ct of the device are arranged
In series to minimize the duty required of

any one contact.

As. explained imder

"C^eratlon", the fourth contact Is used to
"seal-In" the "X" coll.

the switch operating shaft.

OF MANUAL BREAKERS

1. Remove set screw fastening the
plastic handle to steel qieratlng shaft and
remove the operating handle.

6. Complete m'otmtlng byfollowingdis
assembly steps In reverse order.

The "X" contactor Is located on the
right beneath the horizontal front frame
member.
It Is mounted on three stads

which fasten It to a mounting bracket which

2. Open and remove annealed (soft)
retainer and two flat washers from shaft

3. Remove four screws from flange

Be sure tte bearing washer

Is In place between the mechanism link and

REMOVAL OF FRONT ESCUTCHEON

6. Reassemble with new coll by re
versing order of procedure.

hole In the link connecting with the breaker

3. Cut off or disconnect the coil leads.
4. Remove four screws which fasten
lower section of magnet to upper section.

threading a #10-32 screw at least 1 3/4

the one from which the binding screw has

2. Remove closing switch. (See"Clos
ing switch".)

terminals are those which connect to "a"
switches.
The lower terminals connect

together the two extensions of the arm

ature. After this is removed, the arm
ature extensions must be spread apart to

In place
Us left

U- the breaker Is a draw-

out ^type, two small round head screws
must also be removed from the bottom
edge'of the escutcheon. ^

4. Push steel operating shaft tbrou^
escutcheon bushing.

5. Remove handle reset spring (8)

Fig. 6, and escutcheon Is free of breaker.

Is suspended from the frame.

These consist of the foUowlng:

terminals are covered by a moulded piece

of Insulation .which fits over spring clips
that hold the cover In place.

1. Closing solenoid
2. "X" contactor (relay)
3. "Y" permissive relay

4. Cut-off switch

Removal of the complete device Is

accomplished by removing the cover, dis
connecting the leads from the terminals,

5. Closing switch
6. Shunt-trip device

The last two of these components may
or may not be present In the control ar

6. Handle and escutcheon assembly
can be assembled most easily by exactly
reversing the procedure for disassembly.
In replacing the excutcheon It may be
necessary to use pliers to pull the oper

ating shaft fully Into the escutcheon In

order to have space enough to replace

the flat washers and the soft retainer.

The latter may be closed on Its groove

In tte shaft by ordinary gas pliers. After
replacement, check operation of breaker.

and removing the nuts from the three
mounting studs.
If the replacement unit

Includes the mounting bracket, the relay
heed not be removed from the old bracket.
This can be taken off the breaker simply

by removing the two screws which fasten
It to the breaker frame. If the breaker

The closing solenoid consists of a

magnet, armature and coll.

bushings on the mounting studs provide
antl-vibratlon and anti-shock. protection
for the. relay. The relay contacts and their

Is a drawout type, the supporting bracket;
of the "Y" relay may be temporarily dis
placed to provide access to the screws.

bly Is located directly beneath the breaker

mechanism to which It Is connected by a

link which ties the upper end of the arm
ature to the spring carrier of the mech
anism. (See Fig. 50

Since the expendable parts of the "X"

contactor are the contacts and the coU,

ease of replacement of these parts hfks.

been designed Into the relay.

procedure are as follows:

AUXILIARY SWITCH
The auxiliary switch Is mounted on

the left side of the operating mechanism
frame. Its operating shaft Is linked to the
ou4)ut crank of the breaker mechanism.

Through a cam arrangement, the operating
shaft of the switch controls the open and
closed positions of the Individual contact

pairs. Each stage of the switch, which
Is usually two-stage or five-stage, con
tains one "a" and one "b" set of contacts.

An "a" pair of contacts Is always In the
same position as the main breaker con
tacts.
That Is, open when the breaker
contacts are open, and closed when the

When voltage Is applied to the coll,
the magnetic force generated pulls the
armature up Into the coll and magnet
assembly.
This, In turn, rotates the

terminals of the switch are covered by a

1.; Remove relay cover.

spring carrier about Its pivot, extending
the mechanism spring and causing Its line
of action to move "over center", resulting
In a closing operation.

end) the split section of the contact which

The only replacement operation that
might conceivably be required on this as
sembly Is that of the solenoid coll.
replace this, proceed as follows:

2. Remove terminal binding screw of
stationary contact to be replaced.

3. Lightly pinch with pliers (pointed

breaker contacts are closed. Just the op
posite Is true of the "b" contacts.

1. Remove escutcheon by unfastening
four flat head screws In flange.

enters the hole In the compound body of
the device and lift out the statlmiary con
tact.

4. With the fingers, puU forward on
the spring guide of the movable contact,
compressing the contact spring as far as.
possible.

GEI-S0299 Power Circuit Breakers Types AK-2-15 and AK-2-25
5. With the spring thus held, grip the
end of the contact strip with pointed pliers,
turn it through 90 degrees on its long axis,
and withdraw it.

6. Replace new contacts by reversing
the procedure.
CoU

1. Remove relay cover.

2. Turn tite two retaining spring clips
on the ends of the device through 90 degrees
about their pivots.

3. Pull out the two halves of the body
of the device which carry the stationary contects. When these are clear of tte frame,
the armature and movable contactassembly
will move asldei eiqitosing the coil.
4. Remove the terminal screws of the

coll and pull it free of its retaining spring
clips.

5. Place new coil on pole piece inside
of the spring clips and fasten terminals to

0. Just start the replacement of oneof
the conmound blochs which hold tte station

ary contacts into its groove in the frame.

1. Sere*
2. Vaaher

7. Position the armature and movable

3. Spring
4. Movable Contact
Aatcnbiy

contact assembly to allow the entrance of
the second stationary contact block.

5. ^ring
6. Actuator

7. Pivot Pin
8. Contact (BB)

9. Contact (M)
10. Support

8. When these parts are all properly
aligned, with the stationary contacts under
the movable contacts, push them into their
~ grooves In the frame until they

from the ends. A good mechanical connec
tion should be made before soldering.

contacts at (9). Overtravel of the actuator
the movable contact (4) to the actuator.
Spring (3) resets the switch after the breaker

the locked position, making sure that each
clip is in its proper recess, and replace the

After all connections are completed,
the relay should aratn be mounted to the
breaker by means of its supporting brackets
and hardware.

After replacement has been completed,
the relay may be checked electrically in
the following manner.

9. Rotate the retaining spring clips to

As described under "Operation", the
"Y" relay is apermtsslve relay whichlimits

1. Apply closlnj
board or secondary

to terminal
connects.

to one the number of breaker closures

possible on one closing signal.

2. Push button of closing switch and
hold closed.

On drawout breakers,, the "IT' relay

mounting bracket is fastened to the ri^t
hand side member of the breaker frame by

3. Continuing to hold push button in
closed position, manually trip the breaker

two mounting screws.' On terminal bohrd
breakers, it is fastened to the rear side of

the terminal board mqiport. The relay itself

is fastened to an intermediatebracketw^h

is detachable from the main siqport. ^e
Junctures between the relay and the inter
mediate

brackets are rubber cushioned against
vibration and shock.

4. U the breaker stays open, and makes
no attempt to close, the "Y" relay is
functioning properly.

5. While releasing the close button.
Observe the. "Y" relay. It should open as
the olosing switch is released.

^ beyond
the point of making contact at
is absorbed Iqr spring (5) which couples

contacts open and the breaker mechanism

The point at which the cutoff switch
operates during the breaker closing cycle
is after the spring chared mechanism has
been driven over-center.
This assures
that the cutoff switch cannot operate too

early in the breaker closing cycle, thus the

relays are de-energized and

enerrized, respectively, at the proper time
and the circutts'antl-pump feature is main
tained. When the closing mechanism is
driven over-center, the force of the pre

viously cfaargedclostng springs is released,

closing the breaker.
REPLACEMENT

The cut-oR switch is located above the
breaker mechanism. It is fitted between

the upper portions of the steel side plates
that make up the mechanism frame.

If replacementof the "Y" relay becomes
necessary, it may be detached from its

supporting brackets by removal of the fast

ening hardware. The leads' to the relay
should be cut off as closely as possible to

the soldered connections so that enough

wire will remain for connection to the new

Sufficient original wire will be

allowed for this purpose.

After the old relay has been removed,
wire leads to the relay should be
stripped of insulation to about l/4y
the time it takes to displace the piston a
short distance through the oil. The minimum time delay thus afforded is 3 seconds.
The dqpth of the oil in the dashpot should be

1/4 to 3/8 of an Inch. The oil level may be

case, and no additional adjustments of the
trip rod should be required. To obtain the

proper 1/32 of an lnch overtraVel, close
the breaker and proceed as follows:

The new device will be factory adjusted

extend 1/2 inch above the top of the device

checked Iw unscrewing cylinder (12) from
its cap. If additional oil is needed, G. E.
>
silicone oil SF96-40, or its equivalent should ^

old device is being replaced by a new one.

so that the top end of the trip rod (2B) will

Adjustment screw (24) is used to pro
vide an overtravel of from 1/32 to 1/16 of
an inch twyond the point of tripping. If the
armature is manually held down with the

de-energized breaker in the closed posi
tion, and then allowed to gradually move to
17

CEI-S0299 Power Circuit Breakers Types AK-2-15 and AK-2-25
the point of tripping the breaker, the amount
of further

armature movement may be

noted visually.
If tbls Is approximately
within the range stated, the positive trip

adjustment Is satisfactory.

The time delay of the device may be
varied somewhat by changing the relotlve
positions 01 the connecting rod 110) and

clevis (7). This Is accomplished by first
loosening the locking nut (8), then raising

3. Adjustina Nut
3A. Locking Nut
3B. Trip Rod
3. Spring
4. Potential Coil
5. Calibration Nut
6. Amature

RM TtSTBKAKCR TO TKt^

8. Counterweight
9. Stop Screw
10. Mounting Screw
11.
>{•

Screw (Lower
Stud)

13. Screw (Lower
Stud)
14. Trip Paddie

when any time delay of 3 to 10

seconds exists from loss
voltage, the
device Is considered satisfactorily adjusted.
The value of Increasing voltage at
whtch the open armature will pick-up and
close, allowing closure of the breaker. Is
determined by a sliding stop which sets
the open gap of the armature. This Is a
factory adjustment, and should not be set
In the field. The pick-up point of voltage

Is 80% of normal voltage.
Calibration spring (4) establishes the
drop out value of voltage, which results
In breaker trlppli^ This setting Is made

at the factora.

Dr^out voltaige Is set

at lietween 3<% and 60% of normal voltage.
REPLACEMENT

The entire device may be dismounted

by disconnecting the coll leads and re

moving screw (1) and nuts (20). Normally,

foiDnw. COL «nKM

only the coll (16) will ever need replace

TTPICLL CONWCnOH CMUH

or lowering the plunger (11), fay turning the
connecting rod which Is threaded Into the

ment.
This may be removed from the
device by taking out screws (15) which will
free both the mamet (14) and the coll.

ReverM Current Tripping Device

Straightening of the bend In clamp (13)
will separate the.coll from the magnet.
The coil leads, of course, must be dis
connected.

on top of the horizontal cross frame mem
ber just to the left of the mechanism
frame when the breaker is viewed from

the front. Tbls device operates a switch
with two sets of contacts, one normally
Open, the other normally closed. The
switch may be used to open or close an
external circuit, giving a bell or light
Indication of a protective trip device oper
ation.

• Ob
• ••
• To

•••
• I09

UmmOOAGC TRFPtNO O^VICC

If the breaker Is tripped open by
means other than the manual trip

button or the shunt trip devic^ the bell
alarm mechnism is activated. The alarm
is shut off and the bell alarm and lockout

mechanism is reset by operation of the

manual trip button or shunt trip device.
If the device is a bell alarm only, the
1. Mounting Screw

3. Device Frasie

10. Coimecting Rod

11. Plunger (Piston)

4. Spring
5. Shading King-

13. cylinder (Oashpot)
13. Clanp
14. Magnet

6. Pin
7. Uevis

18. Adjusting Screw

bell alarm mechanism is also reset sim

ply by closing the breaker.

19. Locking Vire
30. Mounting Mit

31. Mechanism Frame
33. Trip Paddle Clamps
33. Trip Paddle
34. Adjusting Screw

Lever (2) is connected to the.breaker
mechanism so that when the breaker opens
lever (2) rotates counterclockwise about

Undarvoltags Tripping Davica

pin (14). The motion is transmitted through

liidcs (1) and (|3) to paddle (12) which

PowerCircuit Breakers Types AK-2-1S andAK-2-2S GEI-S0299
operates bell alarm switch (11). If the
device has^ the lockout feature, the move
ment of link (13) also causes lockout link

(8) to slide in a direction that results

in its striking trip paddle (5) which, by
displacement of the breaker mechanism

trip latch, makes it impossible to reset

the breaker mechanism until the bell alarm
mechanism is reset.

Link (6) serves as a latch in the bell

alarm mechanism. If it is dispiaced, link
(10) is free to rotate about its lower pin.
This deprives the linkage of its normally
fixed center of rotation about pin (IS) and
defeats both the l>ell alarm and the lockout
operation. Operation of either the manual

trip button or the shunt trip device will
dlsplacd latch (6) and have this effect.

Thus if the breiiker is tripped by either
of these means, the bell alarm and/or

lockout will not operate. Also, operation

TYPICAL CONNECTION

of either of these devices will reset the
switch and inactivate the lockout

1. Link
2. Lever
3. Pin

7. Trip Arm
8. Lockout I.ink
9. Frame
10. Link

4. Trip Shaft
5. Trip Paddle

11.
13.
13.
14.

Switch
Paddle
Link
Pin

16. Springs
17. Spring

Bell Alarm and Lockout Device

MISCELLANEOUS
Changes in breaker requirements may
occasionally bring about the necessity of
adding or changing breaker components
or accessories in the field.

breaker has been designed so that such

additions or conversions are simple and
easy to make, requiring only a minimum of

tio^e or skill on the part of the operator.

Conversion of breakers from manual

to electrical operation is also covered
on an instructional drawing. This oper
ation consists simply of separation of the
front and back frames of the breaker as
described imder "Maintenance" in these

instructions and the reassembly of the
existing back frame with the new front

Phillips, No. 2, (8" shaft)
PLIERS

END WRENCHES
'• -"'I

Adjustable, 8"
698C900

Auxiliary Switch

ALLEN HEAD WRENCHES

These drawings will accompany the
necessary material when it is shipped

Undervoltage Device

5/18" for 3/8" screw

Irom the factory. They will also be avail
able upon request. The drawings and the

Bell Alarm & Lockout Device

Drawout Mechanism

Conversion to Elec. Oper.

accessory additions which they cover are
listed below.

When an accessory is added to a
breaker, it is recommended that the sec
tion of Instructions contained herein cover

ing that particular accessory be reviewed,
In addition to referring to the following

instructional drawing.

Any adjustments

described in these instructions should be

carefully made after the device has been
assembled on the breaker.

MAINTENANCE TOOLS

1/8" for 1/4" screw'

SOCKET WRENCHES (3/8" DRIVE)
Ratchet handle
12" extension bar

3/8" socket
9/16" socket

7/16" socket (long)

The following tools are recommended
for proper maintenance of AK-2-1S and 25

MISCELLANEOUS TOOLS

1/4" Spintlte (long shank)
7/16" Spintlte
8/32 screw (at least 2" long)

(NOTE - Obtain from local

hardware firm; do not order on General
Electric Company.)

RENEWAL PARTS
When ordering renewal parts, address

^8 nearest Sales Office • Wlk«n Yotf Kavt CIsctftcRt ffobltmt •, • N««d Furthtf Information .
MAINE

SAin OfFICC CODE KEY

SEIoclrte UtUMy Eqvtpmont Softs

.77 Ctnlrol Si.

DItfribiitor) Satos

Marino ond Ooftnio Eqotpmoni Solot
Compontnt SoIh Oporoilon

111 Pork Avt.
,.1095 Jofftrion Blvd.

Birmlnghora 5 •
SMobOtU....

..3151 Htghlond Avt.
. .704 Covommtnt St.

31 St. iemti Avt.
120 Mopie St.

* t 3 9 Botton IB...
* t
Springfield 5.
*

3550 N.Cafttral Avt.
...151 $.Tucton Blvd.

North lIlHt Rock.

..1900 E. Weihlngtofi
P. O. Bor 1033

CALIFORNIA
Frotno 21

,. .321 Poltorion BIdg.
....212 N. Vfgntt St.

let Angolti54..
} S lot Angoltt 5...,

...3325 Wilihiro Blvd.
. . . .409 Thlrtoonth St.
2407 " r St.

Ooktond 12
Socremonto IB.

SenBonMrdlne.337N.RfvorsldtAvtMRiolto,Cal.

t i SenProftdicoB

235 Montgemory St.

*
Sonioto
COLORADO

.....2155 So. Plm St.

• t 3 I DonvorB

201 Unlvorrity Blvd.

Hertford 5
NtwHovtnB.

7B4 Atylvcn Avt.
.129 Church St.

DilTRia OP COLUMBIA

777~14th St., N.W.

60B^15th St., N.W.

RORIDA
Jockiomin. 6.
MlsmT32

1901 HHISt.
25 S.E. Stcond Avt.
5353 aw. 3Bth St.

tPMSoeola....
t
Tsnipa 1 ....
2

•Htndtrson Blvd. at loll Avt.
l30BN.*«A*'$t.

.1840 Puehtr.. Rd.,N.W.
6B2 ClMriy SI.
40 Ea» Boy St.

• t 1 S Chkogo SO
• t
PoaHo2
•

640 S. Conol St.
200S N.E. Pony Avo.

4223 Eott Slot# St.

407 E.Adont St.

Evonivlll. 3
Fort Woyoo 4

270P Wothlnolon Avo.
.1435 Breodwoy

3750 N. Morldlon St.

410 N. Michigan St.

653 S. Soginow St.
Grand Roptdi I .... .2821 Moditon Ave., S.E.
Jockion
210 W. Fronklin St.
ICoiomosoo. ..
927 S. Burdiek St.
Laming 8..... .814 Micliigon Notional Towtr
Soginaw
. .Stcond NalTonol Bonk BIdg.

..........700 Anfoinettt St.

Norby BIdg.. Room 4

200 E. Pint St.

Baton Reugo 4
loko ChorUi.

3170 Florida Blvd.
422 Sovonlh St.

• t 2 { NowOrlooRi 12.:

837 Orovlor SI.

..207 io*Pron BIdg.
.203 W. Copltol St.

.204 Bach BIdg.

701 N. Sovonlh St.

732 Norlh IBth St.
1001 Stoto St.
841 Ook St. i

S Phlladetphto 2
.3 Ponn Contor Ploco -'i '
Pitttburgh 22... .tho Otivor BIdg., Mollen So. ' *

9 Pittsburgti 28

.733 Wothlngton Ro. >

1310 lady Si.
.108 W. Wothlngton St.

TB4NESSEE
MISSOURI

iopUn
Koniot City 5.

St. louli 1,.,.

832 Coorglo Avo.

Knonvlll. 14...

.1301 Hennoh Avoi, NiW.

Momphli 4....
Nothvlllo 3....

.1420 Union Avo,
......1717 W. End Avo.

* t t S Choltonoogo 2.
Klngiport

320Vk W. Fourth St.
, 1 0 6 W. Fourfttnth St.
818 Ollvo St.

.. .303 N. Broodwoy
.103 14. Wyoming St.

AbBono
AniNBrillo
Bteumonl......

loi V.gaf i
MaMli.0

TYPE AK POWER CIRCUIT BREAKERS

Fig. 2A. Spring (back
of pivot)

tPHOTO 9026295)

Fig. 3. Moving and stationory contacts
and cross bar assembly

Fig.2. Type AK-2-25 power circuit breaker

back frame (operating mechonism removed)

(PHOTO 8024266)

Fig. 4. Cutaway view of type AK.2-25
electrically operated power circuit breaker

Fig. 5. Type AK-2-25 electrically operated
power circuit breaker (escutcheon removed
and dismanlled)

TYPE AK POWER CIRCUIT BREAKERS

tlB
2
2
3
»4
♦5
*6
♦6
*1
♦7A
8

8A
9
10
*11
12
12
13
14
15
16
17
17
18

tl9
120
*21
21A
21B

122
23
*24
25
26
27
28
28
29
29
30
30
30A
31
*32
33
33
34
35

Quantity Required
for 3-pole Breaker
Frame
size
225 Amp** 600 Amp**
1
3
3
3
-

2
2
2
6
3
6
1
2
1
1
1
3
6
3

2
2
2
12
3
6
1
2
1
1
1
3
6
3

227D190P1
269C260G1
269C260G2

269C283G1
269C283G2

Back plate
Insulation for upper stud, rear
Insulation for upper stud, front
Upper stud assembly
Upper stud assembly

269C257G1
269C257G2
269C257G14
269C257G15
412A2S0
269C2eOP5
269C277P9
269C277P10

Stationary contact assembly
Stationary contact assembly
Moving contact

Cross bar assembly

269C258G3
269C280P8
269C258G1
269C258G2
263C526P1
269C280P7
269C280P6

Spring (outside poles)
Spring clip (center pole)
Barrier

Barrier, complete (includes Ref. Nos. 8 and 8A)
Pivot

Spring (back of pivot)
Lower stud assembly (not used on AK-3 or AK-3A)
Lower stud assembly

Insulation (under lower stud)
Support (outside)

Support (intermediate)

121C7514G2
269C273G2
269C280P4

Arc quencher clamp AK-3 or 3A only

177L215P219
393A993P9
412A286
412A208

Insulation for Ref. No. 18

269C277P11
269C280P1
269C280P2
0412A0290

622C521G1
See table B
See note below
386A163P1
6S5544SP1

269C281P5
269C281P6
845C276G2
845C276G4
412A222
269C281P3
453A100P2
4S3A129P1
4S3A129P2
457A681P4

Arc quencher clamp (sand gray) AK-2 or 2A
Stud, arc quencher clamp

Stop nut for Ref. No. 18
Stationary contact spring
Movable contact spring
Spring clip

Moving contact pivot pin (center pole)
Moving contact pivot pin (outside poles)
Spring
fiMagnet and armature assembly
(Closing coil
Overcurrent trip device

Clamp for EC-2 trip device
Clamp for EC-1 trip device
Retaining ring
Retaining ring
Primary disconnect assembly
Primary disconnect assembly
Spring
Retainer

Contact finger
Retainer

Screw, hex. hd, 1/4 in. -20 by 3 1/2 in.

* Recommended for stock for normal maintenance,

** See breaker nameplate for frame size.

6 Electrically operated breakers
Note for overcurrent trip devices
(1) No parts furnished for field installation on EC-1 trip devices.

(2) Only part furnished for field installation on EC-2 or EC-2A trip devices is plastic cover, Cat. No. 242C64SP1.
(3) When replacement trip devices are ordered, it is imperative that order includes complete nameplate reading

of the breaker or brewers involved and, if a contemplated ampere rating change is involved, the order should
also include information as to ampere rating, time-current characteristic, and instantaneous trip setting
desired.

Note for operating mechanisms:

(1) Individual parts cannot be furnished for operating mechanisms.
(2) When replacement is necessary give complete nameplate reading when ordering.

TYPE AK POWER CIRCUIT BREAKERS

Quantity Required
for 3'-pole Breaker
Frame

225 Amp^^ 600 Amp^^
36
37
38
38

4 maximum 4 maximum

Movable secondary disconnects (drawout breaker)

Cutoff switch (electrically operated breaker)
Auxiliary switch, 2 stages

432A671G2
432A671G5
269C268P1
269C268P12

622C502G1
622C529G1
101C7891G1
10107891G2

Auxiliary switch, 5 stages
Manual trip button
Trip label
Spring for manual trip button
Shunt trip device with coil
Closing switch

Shaft assembly (Manual Breaker only) order Ref. 43 and 43A together
Link assembly

Escutcheon, manual breaker (black)
Escutcheon, electrically operated breaker (black)
Escutcheon, electrically operated breaker (with handie) (black)

259C607G1
259C607P10
259C607G2
259C607G3
259C607P11
259C607G4

Escutcheon, electrically operated breaker (blue) with pistol grip handle

276B191P1
669D807P1

Escutcheon, manual breaker (blue)

Escutcheon, electrically operated breaker (blue)
Handle (black)

Handle (gray)
"X" relay (see Table A, page 6)
"Y" relay (see Table A, page 6)

148A2238
295B445P221
295B445P222

Return spring, rear of escutcheon
Stationary contacts, "X" relay

Springs, moving contacts, "X' relay \
Stationary contacts, "X' relay

tA»52A
tA*52B
tA52C

116B7197P221
116B7197P223
116B7197P222

Moving contacts, "X" relay

' On early AK-2-15, AK-2-25 and

AKF-2-25 with no suffix number

Molded moving arm, "X" relay (with moving contacts)

Armature return spring, "X' relay

derating coil, "X' relay (see Table A, page 6)

622C501P1
6220501P2

Cover, "X" relay / On early AK-2-15, AK-2-2S and AKF-2-25

Jumper, "X' relay (

with no suffix number

Coil for shunt trip device (see Table B, page 7)
2690282G2

.2690282G5
57
57
♦58
59

tinstantaneous undervoltage device, a-c (with coil)
tinstantaneous undervoltage device, d-c (with coil)
Time-delay undervoltage device, a-c
Time-delay undervoltage device, d-c

Coil for undervoltage device (see Table B, page 7)
Static time delay, a-c or d-c (replaces complete time delay and volt
device coil only)

6172594
2690299G2
6293908G275
6293908G274
846C865G1
6314936P1
6314936P2
6314936P3
295B475P2

62
62
63
64
64
64
65
66
67
67

275B995P1
6950131P1
394A106P1
457A673G1
2690276G2

Spring, for undervoltage device
tBell alarm device

Terminal board, 6 terminals
.^Terminal board, 10 terminals

Link and bushing for auxiliary switch
Cover for auxiliary switch, 1 stage
Cover for auxiliary switch, 2 stages
Cover for auxiliary switch, 5 stages
Base for wall mounted, general purpose breaker
Angle for wall mounted, general purpose breaker
Terminal for wall mounted, general purpose breaker
Terminal for wall mounted, general purpose breaker
Cable clamp for wall mounted, general purpose breaker
Cable clamp for wall mounted, general purpose breaker
Maintenance handle

♦ Recommended for stock for normal maintenance.
♦♦

See breaker nameplate for frame size,

t If at any time a breaker is to have added to it either shunttrip, undervoltage device, or bell alarm device, the order for
the device must include the following information:

(1) Complete nameplate reading of breaker involved.
(2) Desired voltage rating of device, whether a-c or d-c, and if a-c, the frequency.
(3) In the case of undervoltage devices, specify whether instantaneous or time delay.
A On -1, specify Cat. No. of "X* relay when ordering these parts.
A Order by circuit breaker Serial No.
4

Fig. 6. "X" contactor
(ref. 47)

Fig. 7. "Y" relay

Fig. S. Shunt trip

device (ref. 41)

Time delay undervoitage
device (ref. 57)

Fig. 10. Cutoff twitch

Fig. 11. Bell alarm

device (ref. 61)

Fig. 13. Terminal
board (ref. 62)

Fig. 13. Auxiliary

twitch (ref. 38)

Static time delay

TYPE AK POWER CIRCUIT BREAKERS

(PHOTO 8026400)

Fig. 14. Manual (left) and electrical (right)
front frame ocsemblies for

Type AK-2-15 and -25
power circuit breakers
NOTES FOR FIG.

(1) Should it become necessary to replace the complete front frame of the breaker, it is necessary that the order
include complete namepiate reading of existing breaker.

(2) U an existing manual breaker is to be converted to electrical operation, the order must include, in addition to
complete namepiate reading, a description of desired change and complete voltage and frequency rating of both
closing and tripping circuits.
TABLE A

Catalog Number
"X" Relay

Complete, Ref. 47
Volts

Coil, only
(Ref. 53)

Complete, Ref. 47

for A and Early -1

for Late -1, and all -2

295B445P1
295B445P2
29SB445P3
295B445P4
295B445P7

116B7197P2
116B7197P3
n6B7197P4
I16B7197P7
116B7197P10
116B7197P13

116B7197P2a2
116B7197P203
116B7197P204

295B445P6
295B445P9

295B445P206
295B445P209
295B445P212
295B445P214
295B445P216
295B445P205
295B445P208
295B445P211

295B445P15
295B445P5
295B445P8

A Original breaker had no suffix numeral or letter.
Only complete relay furnished.

295B445P207
295B445P210
295B445P213

116B7197P207
116B7197P210
116B7197P213
116B7197P216

295B444P3
295B444P4
295B444P7
295B444P10
295B444P13

295B444P5
295B444P8
295B444P11
295B444P17
295B444P14
295B444P5

116B7197P8
116B7197P11

295B444P11
295B444P14

n6B7197P5
116B7197P9
116B7197P12
11607197 P17
11687197 PIS

116B7197P206
116B7197P209
116B7197P212

TYPE AK POWER CIRCUIT BREAKERS

ly only to Types AKF-2-2S and AKF-2A-25. All other parts are Identical to those used on
Type AK-2-25.
Ref.
No.

073-412A404P136
108C9694P7
269C257G1

Qty. Per
Cataloe No.

073-108C9697P9
108C9698G1

Lower pivot
Stationary
contact

108C9695P9
148A2279P1

Adiustable
bushing
Bearing

269C283G4
108C0697P11

contact spring
Upper stud
Contact spac
er right side

108C0696P14
269C258G13

Moving con
tact pivot pin
Spacer

377A871P12
108C969SP10

108C9696G1
108C9695G3

Crossbar
Cam assem

Idy, right
110
111

108C9695P6
108C9604P8

108C9695P3
304A133P9

Lower stud
insulation
Connector

* Recommended for stock for normal maintenance.
10

Arc quencher
Insulation

203B288G1
10SC9697G3
108C9698G2

Moving con
tact

Supersedes GEF-4150G

TYPES AK-2/3/2A/3A-50,
AKU-2/3/2A/3A-50,
AKT-2/3/2A/3A-50

ORDERING INSTRUCTIONS

1. Always specify complete nameplate data of the breaker.

2. Specify the quantity, catalog number (if listed), reference number (if
listed), description, and this bulletin number.
3. Standard hardware such as screws, bolts, nuts, washers, etc,, is not listed
in this bulletin. Such items should be purchased locally.

4. For prices, refer to the nearest office of the Genera! Electric Company.

(PHOTO 6029418)

Manual breaker. Type AK-2-50

TYPE AK POWER CIRCUIT BREAKERS

Fig. 1. Pol* unit

TYPE AK POWER CIRCUIT BREAKERS
No. Required per Pole 1

AK-2A-50
Man. Elcc

Man.lElec. Man. Elec
}
J

1
2
2
3
3
*4
•4

371A208P1
9921S87P1
449A994P3
117A512P1
452A542P1
29SB40eCl
295B408C1

295B408G3
295B408G3

Stop. AK-50AC
Stop. AK50 DC. AKU-50, AKT-50
Block. AK-50AC

Block, AK50 DC. AKU-50. AKT-50
Stationary arcing contact, AK-50 AC
Stationary arcing contact, AK-50 DC,
AKU-50. AKT-50
Stationary arcing contact. AK-50 AC

Stationary arcing contact, AK-50 DC.
AKU-50, AKT-50

Spring for stationary arcing contacts,
(outer) AK-50 AC
Spring for stationary arcing contacts,
(outer) AK50 DC, AKU-50, AKT-50
Spring for stationary arcing contacts.
(inner) AK-50 AC
Spring for stationary arcing contacts,
(inner) AK-50 DC, AKU-50. AKT-50

Spring guide for stationary arcing
contact springs. AK-50 AC
Spring guide for stationary arcing con
tact springs. AK-50 DC, AKU-50,
AKT-50

Pivot pin for stationary arcing contacts,

Pivot pin for stationary arcing contacts.

Leaf spring for stationary arcing

Leaf spring for stationary arcing con

Insulation for stationary arcing contacts,

Insulation for stationary arcing contacts,

AK-50 DC, AKU-50. AKT-50

contacts, AK-50 AC
tacts. AK-50 DC, AKU-50, AKT-50
AK-50 AC

AK-50 DC, AKU-50. AKT-50
Moving arcing contact. AK-50 AC
Moving arcing contact. AK-50 DC,
AKU-50. AKT-50
Stationary main contact

•14!
•15
16
17
18

293B220G7
293B220G4
4S2A528P1
6404784P4
6447153P3

Pin for movable arcing contact link,

394A133P9
275B975P1
275B975P1

6447741P1
6203981PI

293B221G1
4S9A385G1

Stationary intermediate contact
(includes barrier)
Moving main contacts
Moving intermediate contact
Pin for movable main contact
Link for movable main contact

Pin for movable arcing contact link,
AK-50 AC

AK-50 DC, AKU-50, AKT-50
19

24
24
25
26
27
28
29
30
31
32
33
33
34

10
1
1
1
1
1
1
1
1
1
1

394A133P10
4S7A624C1
457A624G2
452A569G2
4S2A529P1
6414314P2
452A564C1
6203981P9
293B287P3
6203981P13
453A116P1
453A116P2
453A116P3
6509893PI
412A0287P1
293B240G1
293B240G2

Link for movable arcing contact, AK-50 AC
Link for movable arcing contact,
AK-50 DC, AKU-50, AKT-50
Insulating tube
Pin for side link
Retainer

Side link, right
Side link, left
Terminal

Leaf spring for movable main contacts
Pole unit base
Lower stud

Pivot pin for movable main contacts
Spacer for terminal
Pivot pin for movable arcing contact
Stop for stationary main contacts
Spacer for stationary main contact stop

^acer for stationary main contact stop
^ring for stationary main contacts
Spring for stationary main contacts
Upper stud, AK-50 AC
Upper stud, AK-5D DC, AKU-50,
AKT-50

6447734P2
238D674C1
238D674G2

Leaf spring for stationary main contacts
Pivot pin for stationary main contacts
Arc quencher, AK-50 AC
Arc quencher, AK-50 DC, AKU-50,
AKT-SO

t To determine quantity required per breaker multiply by number of poles (2, 3 or 4).
t Original breaker had no suffix letter or numeral.
• Recommended for stock for normal maintenance.

TYPE AK POWER CIRCUIT BREAKERS

Arc quencher (R«f. No. M )

AK-2>S0 electrical

TYPE AK POWER CIRCUIT BREAKERS

No. Required per Pole t
Fig.

51
52
52
53
53
54
54
54
55
56

56
56
57
57
58
58

AK-2A-50
AK-3-50
AK-3A-50
Man. Elec. Man. Elec. Man. EUc.

372A275G4
9921630P1
9921630P3
9921630P2
267B101P2
6509914P1

6414763P1
372A275G1
372A275G3
372A275G2

Lifting bracket, right (pearl gray)
Lifting bracket, right (sand gray)
Lifting bracket, left (pearl gray)
Lifting bracket, left (sand gray)
Arc quencher tie bar (pearl gray)
Arc quencher tie bar (sand gray)
Arc quencher tie bar
Cross bar

Opening spring, AC (not used on
AKU or AKT)

Opening spring, AC (AKU or AKT)

evening spring, DC

6548046P3
669D0807P2
698C997P1
275B997P2

Handle (black)
Handle (gray)
Front escutcheon (black)
Front escutcheon (w/o closing switch.

black)
Front escutcheon (with closing switch
black)

58
58
59
60
61
62
63
64
65
66
67
68

1
1
1
1
1
2
2
2
1
2
4

1
1
1
1
2
2
2
1
2
4

1
1
2
2
2
1
2
4

698C997P5
805B975P2
411A904G5
412A139
6203939P3

1
1
1
1
2
2
2
1
2
4

1
1
1
1
2
2
2
1
2
4

Front escutcheon (blue)
Front escutcheon (blue)
Tr^ button and rod assembly
Trip button spring
Hand, trip paddle
Clamp

Trip shaft (outside)

174V536P1
127A6493P2
276B250P2
394A133P1

Coupling
Dowel pin
Trip shaft (center)

Trip shaft bearing (side sheets and

394A133P16
174V531P1
394A133P10

Retainer
Pin
Retainer

mechanism frame)
69
74

t Original breaker had no suffix letter or numeral.

FIG. NO. 5, REF. NO. 152 - GEAR BOXES

177L316 and 177L362 gear boxes are no longer manufactured for AK-50, 75, 100 breakers. A modification ofthe AKR design
electrical closing assembly is available to replace these units. The replacement unit will include a new closing motor. Select
replacement for 175L316G1 or G2 gear box from Column 1. Replacements for 177L362G2 should be selected from Columns 1

to 4, for G3 select from Columns 5 to 8.

REPLACEMENT KIT CAT. NO. 343L761 (Select Group Number Below)
LI

Conventional Close Type

AK-1-50, 75,100
Volts Hertz

AK-2-50,75,100 AK-3A-50
AK-3-50, 75,100 Includes AKU

AKT-2A-50
AKT-3A-50

AK-2A-75,100 AK-2-50, 75,100
AK-3A-75,100 AK-3-50,75,100
Includes AKU

Quick Close Tvne
6
AK-2A-50
AKT-2A-50 AK-2A-75,100
AK-3A-S0 AKT-3A-50 AK-3A-75,100
Includes AKU

Includes AKU
48
125
250
120
208

240
120
208
240

DC
DC
DC
60
60
60
SO

G37
G38
G39
G40
G44
G43
G41
G46
G45

G49
G50
G51
G52
G56
G55
G53
G58
G57

G61
G62
G63
G64
G68
G67
G65
G70
G69

G44
G43
G41
G46

G49
G50
G51
GS2
G56
G55
G53
G58
G57

G61
G62
G63
G64

G68
G67
G65
G70
G69

G37
G38
G39
G40
G44
G43
G41
G46
G45

TYPE AK POWER CIRCUIT BREAKERS

98 99 100 101 102 93 94

AK-2>50 mechanism assembly

AK-2-50 manual front frame

No. Repuired per Ereaker

|AK-2A-50 I AK-3-50 I AK-3A-50

Man. Elec. Man. Eiec. Man. Elec.

> -1 -2 i -1 -2

+
412A140P1
419A3G6P1
6414743P1
6555414P2
412A413P3
412A405P414
6447744P1
457A610G1
64449i6Pl

6414764P1
6403348PI
698C993GI
377A871P2
394A133P9
457A622Gi
6447099P1
6447091P1
6447331P1
148A2213P1
148A2214P1
6447353P1
6203914G1
457A627G1
383A671G2
6403366PI

e48C0487Pl
88gB0410Gl
412A412P2

£ Original breaker had no suffix letter or numeral.

Spring
Prop
Cam

Coupling
Clevis
Pin
Pin

Reset latch
L.atch bolt
Latch

Spring
Prop
Prop shaft bearing
Retainer

Link assembly
Pin
Pin

Spring guide (upper)
Spring reset (inner)
Spring reset (outer)
Spring guide (lower)
Spring support assembly
Buffer assembly
Counter weight
Trip shaft return spring
Latch
Reset latch

Prop stop
Trip paddle

TYPE AK POWER CIRCUIT BREAKERS

AK*2-50 manual closing mechanism

AK-2-50 electrical front frame
assembly

No. Required per Breaker
Fig. Re£.
No.

11-11-2 tkl-2 ~t

i~l t I I
6447761P1
148A1946P10
6447010P1

Trip shaft stop
Spacer

Upper spring guide assembly pin
Spacer

148A1946P1
394A133P4

Pawl spring support (upper)
Pawl spring support (lower)

698C996G4
698C996P13
6447032P2

6447032P1
698C993P4
698C993P3
698C993P5
393A993F24
889B0408G1
273B569G9

698C992G5
69eC992G4
393A554P1

I Buffer stop nut

Spring guide assembly (closing)
Spring guide assembly (closing)

Support (includes bearing less outer race)
Criik (includes outer race of liearing)

Support assembly

127A8306P1
394A133P28
698C985G1

t Original breaker had no suffix letter or numeral.

Buffer pin
Buffer support

Pawl spring rollers

Lower spring guide assembly pin
Lower spring guide assembly pin

Support
Bearing
Ratchet assembly

1Spring
Retainer

Pawl with spring (rear)
Pawl with spring (front)

846C817G1
698C991G5

Spring arm
Prop

412A280P1
698C991F10

Indicator (when ordering Indicator
Include label ref. No. 151)

TYPE AK POWER CIRCUIT BREAKERS

I0«c l4|C«'0t

Section of gear box

Motor cut-off switch

indicator assembly

10
10
10
10
10
10
10
10
10
11
11
11

No. Required per Breaker
AK-2A-50
Ak-3-50

AK-3A-50
Man. Elec Man. Elec.

698C995P14
412A267P1
698C995G1
412A0292P1
698C995G2
259C608P3
6447398P1
393A992P2
6509871P1
372A383P1
393A991P1
6447101P1

149
150
151
153
154
155
156
157
158

Spring
Indicator lever assembly
Spring
Indicator crank assembly

Open-close label
Plug
"O" ring for plug
Spring for ratchet pin
Ratchet pin

Lubricant for gear box (4 oz.)
Gasket motor

Gasket, gear box end plate
Motor, 115 volts, 25, 50, 60 cycles

Motor, 208-230 volts, 25, 50, 60
cycles and 250 volt DC

Cut-off
Cut-off
Cut-off
Cut-off

and 125 volt DC

12
12
12
12
12
12
12

162
163
164
165
166

t Original breaker had no suffix letter or numeral.

192A9792P1
192A71S3P7
371A235P1
371A233G1
371A234G1
394A133P9

switch
switch
switch
switch

"G"
insulation
"F"
cover

Cut-off switch mounting bracket
Cut-off switch lever bracket
Cut-off switch retainer

TYPE AK POWER CIRCUIT BREAKER

Time delay undervoltage device

(Ref. No. 170)
No

Required per Pole t

|AK-2A-50 I AK-3-50 I
Man.lElec. Man.iElec. Man.I Elec.

1—
192A8404P41
See Table "B"
See Table "B"

Cut-off switch spacer

Closing relay (X) - standard
Closing relay (X) - quick close

Anti-pump relay (W) - quick close

Closing solenoid - quick close
Shunt trip device support
Shunt trip device (with coil)
Shunt trip coil
Undervoltage device support
Time delay undervoltage device, AC
Time delay undervoltage device, DC
Static time delay, AC or DC (replaces
complete oil displacement time

13
13
*
14
14
15

170
171
172
173
173
174

177
177
178
179
179

192A9791P3
192A9791P6
192A9791P2

4I1A952GI
887B306G2
887B386G1
6447157P1
457A643P8
127A6463G2

6076402P203
887B387G1
6203934P1
265B268G1
265B268G2

delay undervoltage device)
Undervoltage device coll
Instantaneous undervoltage device,
AC (with coU)
Instantaneous undervoltage device,

DC (with coU)
Auxiliary switch 3
Auxiliary switch 6
Auxiliary switch 2
Auxiliary switch 5

Auxiliary switch crank bracket
Auxiliary switch link assembly

Auxiliaiy switch link assembly
Tube

Groove pin
Auxiliary switch operating rod
Auxiliary switch coupling
Pin

Adjusting plate
Open and close indicator Ibik

(^en and close indicator
Charged and discharged indicator

t Original breaker had no suflut Utter or numeral.

6 When ordering time delay undervoltage devices, the following information must be Included:
(1) Complete nameplate reading of breaker involved.

(2) Desired voltage rating of device, whether a-c or d-c, and if a-c, the frequency.

# Order by circuit breaker Serial No.

stage
stage
stage
stage

TYPE AK POWER CIRCUIT BREAKERS

•r-' m
Fig. 15.

Static time delay,

Fig. 1SA. Oil-diiplocement type
lime-delay undervoilage
tripping device.

AK-2A-50 monual

Time Delay Uiidervoltagc DeviceT

Instantaneous Undervoltacc Device

Complete with Coil ,
Volts

(less mounting)
Reference 170

1 Coil Only
1 Reference 171

Complete with Coil
(less mounting)

(Fig. 13)
24
48
125

208
208
240
240
380
480

139C4378G1
139C4378G3
139C4378G4
139C4378G5
139C4378G6
139C4378G7
139C4378C8
139C4378C10
139C4378CU

Complete with Coil |

lless mounting)

Instantaneous or

Type Time Delay

6275081G55
6275081G28
6275081G29

568B309G1
568B309G2
S68B309G3

6275081G18
6275081019

568D309G7
S68B309GB

6275081G26
627508IG4

S68B309G10
56BB309G1I
S68B309G13
568B309C14

139C4378C18
139C4378G19
139C4378C21
139C4378G22

I Reference 175

6275081C15
6275081G9

6275081G7
6275031G12
6275081G31
6275081G31
6275081G3
6275081G20
6275081G8

139C4378G13
139C4378G14
139C4378G17

Old Design Dashpot

6275081G56
G275081G26
8275081026
6275081G26
6275081G26
62 75081G27
6275081G27
6275081C4
6275081G7
62750B1G29

568B309G17
568D309G18

S68B309G19
568O309G2I
568D309G22

NOTE: Ttie static time undcr.-oltage device (Fig. 14, Ret. 173) when used In combination with the static liming device
(Fig. 15, Rcf, 174) and a slight modification of breaker wiring will replace the older design oil-displacement type
time delay undervoltage device shown in Fig. 15A.
TABLE B

CLOSING BELAYS AND COILS FOR CONVENTIONAL CLOSE AND QUICK CLOSE BREAKERS

Quick close breakers are identified by the letter "S" following the breaker type (i.e.. AK-2A-50S-3).
For Quick Close Breaker

For Conventional

Closing Relay "X"

Relay. Complete ]

12HGAUH52
12HGAnH51

12HGA1IH74
12HGA11H75
12HGAUU75
12HGA11H70
12HGAUH71
12HGA11H71

192A9770P5
192A9770P7

116O7197P206
U6B7197P209

192A9771P3
192A9771P4
i92A9771P5

192A9771P6
192A9771P4

n6B7]g7P20S
n6B7197P2n

192A9771P5>
192A9771P6

• Recommended for stock for normal maintenance.

6 Only complete relay furnished.

'Closing Solenoid,

Complete 6
CR9500B202H3A
CR9500B202H4A
CR9S0OBIO2A6A

CR9500B102A7A
CR9500B102A7A
CR9S00B102A2A
CR9500BI02A3A
CRgSOOBt02A3A

TYPE AK POWER CIRCUIT BREAKERS

(PHOTO B0299IO)

AK-2A-50 manual

Drawout racking mechonism
(Ref. No. 195}

AK-3AMan. E]ec.

394A133P1
6176109 P7

Pawl spring
Link spring

Upper side sheet (left hand side)
Upper side sheet (right hand side)

846C0839G1
192A6976P53
148A1986P1

Interlock link assembly
Mounting stud

e46C0839Pl
6076401P12
177L292P53
646C0839P10
14eA1946P5
177L292PS8
148A1946P6

t Original breaker had no suffix letter or numeral.
X Order as required. Quantity of 3 maximum for AK-50 Breakers.
* Not shown.

Drawout rackii^ mechanism assembly

Terminal board supixirt
Terminal board support

Terminal board (4 point)

Terminal board (6 point)

111111
2 2 2 2 2 2

Spacer for indicator
Spring for indicator

Pin for indicator
Retainer for indicator

6293908G168
6423721P4
9921543P1
238D689G1

Jam nut
Pin
Riret

Latch spring, in back of Ref. 205
Spacer (left)
Screw (left)
Spacer (right)
Screw (right)

6203939PS
192A9567P1

801B138G4
26SB237P1

Secondary disconnect support

386A110G2
362A494P1
6176109P72

Trip paddle
Anti rebound hook and slider

Secondary disconnect device (7 pt.)
Insulation

TYPE AK POWER CIRCUIT BREAKERS
No. Required per Breaker

|AK-2A-50 I AK-3-50 1AK-3A-50

Man. Elec. Man. Elec. Man, Elec.

Movable primary disconnect (not used

Movable primary disconnect (for AKT
only)

*221
*
222
2
223
5
224
4
224
4
225

111
111
333333
---222
111-..
111---

Maintenance handle

Overcurrent trip device

Window (open and close)

Window (charge indicator) (when order

Label (charge indicator)

ing window include label Ref, No, 226)

Bib for front esc. (manual) (blue)

Bib for front esc, (elec. breaker w/o

closing switch) (blue)
Bib for front esc, (elec. breaker with

closing switch) (blue)
* Not .^lown.

1 Original breaker had no suffix letter or numeral.
6 (1) No parts furmshed for field Installation on EC-1 trip devices.
(2) Only part furnished for field installation on EC-2 or EC-2A trip devices is plastic cover. Cat, No. 242C645P1,
(3) When replacemeii trip devices are ordered, it is imperative that order includes complete nameplate reading of the
breaker or breakers Involved and, if a contemplated ampere rating change is involved, the order should also include
information as to ampere rating, time-current characteristic, and instantaneous trip setting desired.
NOTE:

Illustrations and catalog numbers listed on the following pages apply only to Type AK-3-50 and AK-3A-50 breakers.

Primary disconnect assembly

»o CT«i cONirHuowl

3P For AKT-3/3A.50

0133C1555 Gil
0133C1555 G16

TYPE AK POWER CIRCUIT BREAKERS
TABLE D

POWER SENSOR LOGIC UNIT.
TYPE PS-IA

Trip Elements
L
L
L
L
L

Magnet trip device with mounting bracket

Magnet Trip Device with Mountine
•

Bracket - Cat. No. 184L369G1
•

184L410G79
184L410G41

®(L0)
®(HI)
g
CO
^(LO)
®(HI)

®(LO)
®(HI)
®(LO)
^(HI)

®(L0) I
®(HI) ' I
®(L0)
^(HI)
-

®(LO)
®(HI)
®(LO)

184L410G44
184L410G45
184L410G43
I84L410G46
184L4I0G47
184L410G48
I84L410G49
164L410G50

L = Long time-delay element

S(LO) = Short time-delay element (2 to 5Xrange)

®(HI) = Short time-delay element (4 to lOX range)^^^
I = Instantaneous trip element

G ° Ground fault protective element

Ground tensor coilwith neutral mounting

Fourth Wire Grid Sensor Coils - Cat. No. 0152C9219G1

Power tentor kit

Power Sensor Test Kit - Cat. No. 0102D2526G10

>PPW£R aRCUlT
^
iiii-'••• t;»",*> > " t 7.

St '•»r'-v."-Ti'-?v "f-'.- '••••••

•;-:"'-! ?!:••••

i•VAK-2i-25 .•-.lAK^A^aiAC:: /l ^StS^il^S

AKM-2S /AICMA-25.::-^;#-v®^

•••• '1'\r .• '•W'fi-'" i•'^>•i>V':"•^i

•5«£:*?'?•»!

y'siS-t
h-.j;r.x •.yi,'-,-'--;'',*
•

•> •./.'Vm.V , * '

, ':"} w\- '.ii!?'-JCS?*'. •»'••

IPHOTO eo84oai)t'
'•»'-:^';nr,
f,
U ".*-.'- -•

Fig^ 1. Type AK>2>25 mdnually operotMl
pewer circuit breaker
ORDERING lNSTRUCTI(»e

•;;|:;^v;pvV;;l^';Alwayis'' epecify tlie 'comp

catalog number (U lls^d)i ifefereinee mubber^^

Wben Ibcal fablUtles fbrXbreiaker relmllbration are not available, the breakar ahbkt(l(|^^^^^

Jor^ikied to the nearest G-E Service Slitv,'pr to tiiie General EIect^e<(^pany,t 6801
--Ajreane; 'FhUad^tia4gj,'"pa. '
•. ^

hardware, suchas screws, bolts; nuts, washers, etc., ie notUsted iA^ bbiiPtil^:^^
items ahould be j^chased locally.

the nearest otfice of the General Electric Company.

•
--' ~ r '.'J^''-''•
J V f c f * ' iCl^^ASS'
ts'/?

• .= ^-rr^rc:(rV:^^J'rvlr;^^

3
te-^^®!^>'<\v-'.''.
•aHSH-Vfiffl
if^4vffe?Hi-fj^Va2^®?:-®?!

msmm
iisiwilite

.••.•ii ;l. «tlJf !•'f

i Kff*-'. r.»if-I

H '§&! •#:^'

•A-'-''. •.*' •.'>•» r

;•:!% 2^'iVfM: A^2^;|ri^e^:i

V»P««***'8 mecfianltrn ramo^} i

*. ivf.. ^ n• liMiiiiilliii^^M
f'f

if'
laiw K1 -'hs',

|Siii|p^£^:Wgv4-—^
iRir. 4i,'^iid\^ay y^

of type AK*2-25

0 AK-2-25 electrically eperotect
breaker (etcutcli

anri dismanHed)

J-.'y^ '••-':•'•••/'; •' • '.* •;;'£>•"•

^laiitity Re^O^

t^T S-pote Weaker
«»kv«Mwj "

v^rJwr.T;:;.?: i/'>.;U''''..-,-|>rf" ^ 1 r *y*'

-Catalog
Number

r:Ti5'-m--1iaB;IF,T»353aH

J¥i' nf
'-8 ,'

•W. ••>[ i'V

- 3Y': 3
• 3iY 3
-Y8;- 6
•Y-^X :Y6
- i'Y :.«.

;3 :k ,-•3
>'S; Y3
6
••3,

269C28bCl
269C260G2
269C283G1

} ft •; -n«'»

2'
••2ySy
Y'.6; 18';

0412A0290
622082XG1
. See table B

24y 84;.
•; •:^.> Y.-Y;

:?5Affi.vA?..Vv.'?--'J-• •-. 30 ,

•.Y -YY::'.- 'VYiY:YYYYr.jKYk3'^iY^-: N

Priroa^ disccomept assembly

Spring ;[Y ,
:ivYY.Reta4iAr[H vY-

(;;y Obntectfipger

YYS:YSE.)SY;YlSisSSKlYY§fi^!^^B

V - Y'i[ Ri8tainer''v.'Y'> Y

453A129P2
, 6176109P2S
457A681P4 '

'Primary dlseonnect assemb^

[.:)Ok£iiigcbiil'[ ," y . '
iOyerctirrmrt trip diWpb;.
YClamp for BO-2 t^pd^ce
Retaining ring

, 'Spi^ , . liMa^qt and armatu» asisemb^

. Retaining ring

• 269C281P6
845027602
845027604
412A222

YOlamp forBC-l tripdevide

;:. See notielwlbw
- 386A163P1

: 269C277pn. ;;
j 269C280P1
269O280P2

1
Yl'
.;3'
3
6
6
3
3

12 12 12
31=''' t?l' 12; 12

[Arc quencher clamp.:.,

;;Stiid, ate quendieriBlampf
477L215P21ftV lnsuiatibn4or. Ref.' No
>.:393A993P9 . -vStop nut fii^.Ret Ni)^[
: •,412A386 < ! ;

Support (intermediate)'
' ArcjqueniBher ; i :;

.'vArc quient^erclamp

' Sup^rt (outside)

-.f,'
•,-2' •:2y

: Instdatibn.^der lotver,;sbid)^^^?^^^

. OrosB bar assenablyi

j liOwer stud assembjiy. ;•'

269O2S802;'
, 2630526P1
) 269C280P7
269028OP6

',;.-iBarrier'^^..,--.,

'.2' •;2-. •-2:-y 2

Stationai7 contact assenab]^

.U(^r studassembly

; 295B460P1
269C257G1

!il'
•. • m •;.••

. Upper stud assembly

, .;>fosulatibn4or upper etuis,.
,
Insulation for upper stud,')

vl' YP: ::.l
4
1
,?3i •;3Y ,Y3: •Y3Y: 3
'4' '2.:.i '^Yl y-'yy ;.3

;• Retainer.i.
Spacer

Y. Siacer -VY; ;

lY ^Y aerewiEteit.,hd, •1/44b;;:23^S^^iin

Y-'iRecommended lor etiKmlor'inormal.maintenanceYY.
Y'-> • • V;.-y-:,Y' y-.'.,;-.:
-^^i^'YY:Yg[;Y':'-;l'Y.iVi?;Y;;.Y/
;-,[Y. v
; , . ., Y[%;Y;VY.Y;Y!\fiYYYY-YYiiiY
• Y.,

YY'Yi.'YY:-.'Y. YY;Y:vY;

Y.-YYyY; -YYyYyY;' -VvY.V

]H'' /',
Mte'eed fceeeeel eeVtf«^ '^^ee Mm1«3
am am VN^ 4i -am:
a *--» —
«_ __Y L
1•
-a a
'(2) [Only;)^rt funii^

.[(3)'.;'iMien rnpteeementlHp. dey^

on EJC-2 orE0-2A trip devicbs is pWtlc eoyer,;Y0at.YRo. [2w0^^1'^

orderied, itislmpe.rative that order Included[i»mplete naajieplate'Ai*wfie^ii?«

>Y;of the brewer opbreaheite involved, and,^ a contemplated ampere Jteting iiian^'iB ingQirpd, ';i|bn

Y alsoiinclnte infbnnation

• \ ,-desired.••:
deslx
• .Y^;
MttoYfof. cperat^ mediiu^

;Y'Y^;.ii(l). YUdiridtBaip^^

_ •;'<••;
be

;iYi" \:,ifcv;i|^;Y:Y''; Y'

ampera rati^; tiitie-curictn charaieteristt aiul limtaittmteoas'^ip aetm^
, .'..v

Y'-/Y'.-- • Y./ ;

--V;;Y';-YYYY' jiiV

:i:' 1
1
;i!- -1' i •I-'
i /i'- ;l;' I '•
••I.'

':Y:'•!••

>i-. yjy ri''
'-v- fl'- 1

't- •ili
•t; •I;,
,i--- ic

322C529G1
101C7891G1 ;

Closing switdi
Shalt assembly
Link assembly

101C7891G2
259C6OTG1

al breaker,(bila'^'•' - '-i'i'.- ?, \ A'''''

276Bli91Pl
mmnpi

Escu^eoni electric^y

Indicator
"'y,''';' ''
Handie (bl^)
'
' Handle .'(saiid gray);

"X': rel^ (see Table Al
" Y".relay (see Table A,

29SB445P221
vl^i'

118B7l97P223i^
622C501P1 ;
622C501P2.

Coil for shunt trip devicie. (see! Table B;
269C282G2.

{Instantaneous unde^oitage de«4ce

{Instimtaheous uiulervoltage device

Time-delaiyunderyoltage:device,;! ...

TimC-delay undervoltage:derd<^, d-c

:Spi^, for Tindervoltage (teidW
{Belialarih device

. Terminal board, 8 polee

static :timedelay, a-c or d-c.(replaces oraiiptete time
TOltdevioe'coIl.pnly)

Unkend bushl^ for auxWaiy svritdi

Cover for auxiliary switcl^ 1 stage

Cover for auxiliary swltdi, 3 stages

COTer for auxUiaiy swlt^, 5 stages.

Bue for wall mounted, general purpose breaker

Ai^Elefbrv^ll mounted, gdne^^inirpbsebret^
;;.Termi^;fpr'ydOd:moimti^,;(|^erai^pur^
^era* puriKme oreoaer.:' >•,

Ij general purpose

Cable clamp for
MalitteUriiiCe'band

'Pl;^;pii^jialbreamr.h^'np!^^
'•y-.;;V^N6tsiu^n!y'^'^

Terminal board, lO poles

Shunt^trip Aevicowith coU' :; -, :'y.':

Spring for manual trip butbm • • >.• .fV .

Manual trip button
Trip label

Auxiliary ^tch, 5 stages '

Auxiliary swit^, 2 stages

Movable secondary^ disconnectss>(drawout
(^avbut liv^keri
lireCker) V
Vv,;, 'v-;

1
1
/i-•'•4 • •1
•>'• -4'! 1
1- .'l';
1

Wmk^:'4irt^ ii'.'
'44i

073- 386AltOG2
6220S05Q1
432A671G2
432A671G5
269C268P1
269C269P12

ij; generalpurpose'breatoifi.!/;!iicC^j?rfj^^

"'•yr'V^\x'r:''^\

'«as®iis|.( •'•
.•iiSiiiSJ
--/•c-

r-^'"V.•-'•

t'^r»^f^ftfttv*._.-.-Tv''.i' \(-\ ;•,"• >• >•. •• .1 *;i-'-*. V' • ^

•v', ;••• -f ; -' *,- :'. '

AflJfeki/.S/.kHdTOk Tartil

belra ipipplylMiiy 'TypeS'AKF-a-'M a>idl'AkF-2A-2S. AU' othtr parts arsviaonUcai to tiioae used ony'''
-. ;

Qly. P«r
cstttttPote
,f

•.('. . .'>%••• . •'. •

mrl0^
lii®
%Y'..;*

'QtS-lO^OOTPO
108C00080V

(m>«12A404P13«

t.tifiV '. 'yr.'yv'
; Retaining ',

•leilcaosbd'-!^^

;V;er'.'
.: crossbar

Cunfoliotr-.
Cam assem-''

lOOC^PO
208iC»004P8

''-i08d98i»7P«''f' ^Contartsprtt.;«^^M
•:or loft Bide
^^ira80Pi',B|. • Moving'

,tact pivot pin

869CaS8GU: >; I'bower SIM

Unraystttd
Insolatioo k

Opper studV' .
Confattspao.r:er rlgtt

vlilt^iiig eon* <

.108CM88G8: k
lao

i^iseeeianaiidedior stodcten^

teperM^f* GBP*41.49

TYPES AKr2.15 AND AK>2-25

POWER CIRCUIT BREAKERS
> • .

dilitMi&iBWiidl

: H
»... I ' -

"•! «-ni WMr-m-a.

di|5•y,% i' i •ji'14
I
i'l?
^2-25 manually oporaled
power circuit breaker
ORDERING INSTRUCTIONS

1. Always specify the complete nameplate data of the breaker.

2. Specify the quantity, catalog number (If listed), reference number (If listed), description, and this
tnilletin number.

3. CAUTION: When local facilities for breaker recalibration are not available, the breaker should be
fprwaxTled. to the nearest G-E Service Shop, or to the General Electric Company, 6901 Elmwood
Avenue, Philadelphia 42, Pa.
'
«

4. Standard hardware, such as screws, bolts, nuts, washers, etc., is not listed In this bulletin. Such
items should be purchased locally.

5. For prices, refer to the nearest office of .the. General Electric Company.
-^sf
(W--

Wiiin•nIcrMg.nMWirfiiMwif.'elva qMntlly, cslalat numbar. datcripllan e( aoch Ham raealraS, OMl-caM^la nMaplM ra^lag.

'
•
• 't."
la (iiaiia*'«'iha»i aaac*.;

.1 if
. -.-.-la—

•••..
•I..-

. • v-5a>'';.>v^

6-^ ;7Yi. , ,7"K:^
7-!

(PHOTO 6026401)

IPKOTO a0262«S)

Fig. 3. Moving and stationary contacts

Fig.2. Type AK-2-25 power circuit breaker

and cross bar assembly

back frame (operating mechonitm removed)

. "'7- «• f 'rtll
24—

(mhOTO 6024496)

Fig. 4. Cutaway view of type AK-2-25
elect!to 'V !

•2-25 POWlIR CIRCUIT BREAKERS

Quaiitijsl Pltired
for 3-||cie Breaker
AK-2-15

386A110G2
622C505G1

G5
269C268G1
412A133

See Ref. 55,56
622C52gGl
269C272G1
259C607G1
PIO
G2

259C607G3
PlI
G4

Movable secondary disconnects (drawoutbreaker)

Auxiliary swiich, 2 stages
Auxiliary .switch, 5 stages^
Manual trip button
Spring for m:uiual trip button
Shunt trip device
Closing switch.

KKCutcheoii, manual breaker (black) '

Escutcheon, electrically operated breaker (black.
Escutcheon, electrically operated breaker
(with handle) (blank) .

Escutcheon, manual breaker (blue)

Escutcheon, electrically operated breaker (blue)
Escutcheon, electrically operated breaker
(with handle) (blue)

259C608G1
276B191P1
669D807P1

See table A
See table A
412A158

57
♦58
59
♦t60
61
62
62
63
64
64
64
65
66
67
67
68
68
69

Opening spring, rear of escutcheon
Stationary contacts, "X" contactor
Moving contacts, "X" contactor
Springs, moving contacts, "X" contactor
Openiting coil, 'X" contactor

See table A
622C501P1
P2

Handle (black)
Handle (sand gray)

1
1
1
1
1
1
1
1
1
1
1
1

622C502G1
See table B
269C282G2
G5
G6
G7
See table B
269C282G1
6172594
269C299G2

Cutoff swlt;^)) (clecirically operated breaker)

Cover, 'X" contactor
Jumper, "X" contactor
fShunt trip device
Coil for sliuni trip device

tlnstantam ous undervoltage device, a-c
f Instantaneous undervoltage device, d-c
JTime delay undervoltage device, a-c
JTinie detiy undervoltage device, d-c '

Coil for undervoltage device

Time delay dashpot for undervoltage device
Spring, for undervoltage device

tBell ^arm device

6293908G275
G274
269C268G1
6314936P1
P2
P3

295B475P2
394A144P1
275B995P1
695C131P1
394A106P1
457A673G1
269C276G2

Terminal board, 6 poles
Terminal bo:ird, 10 poles

I.ink and husning for auxiliary switch

Cover for auxiliary switch, 1 stage
Cover for auxiliary switch, 2 stages
Cover for auxiliary switch, 5 stages
Base for wall mounted, general purpose breaker

Angle for wall mounted, general purpose breaker
Terminal for wall mpunted, general purpose breaker
Terminal for wall mounted, general purpose breaker

Cable clamp for wall mounted, general purpose breaker
Cable clamp for wall mounted, general'purpose breaker
Maintenance handle

Recommended for stock {or normal maintonance.
Not shown.

If at any time a breaker is to have added to it either shunt trip, undervoltage device, or bell

alarm devico, the order for the device must include the following information:
(1) Complete nameplate reading of breaker Involved.

(2) Desired voltage rating of device, whether a-c or d-c, and if a-c, the frequency.
(3) b the case of undervoltage devices, specify whether instantaneous or time delay.

59
Fig. 6. "X" eonlaclor

Fig. 7. "Y" relay

Fig. 8. Shunt trip

device (ref. 41)

Fig. 9. Undervoltage device
(ref. 57)

(PHOTO 8026402)

Fig. 10. CulofF switch

Fig. 11. Bell alarm

device fref. 61)

Fig. 12. Terminal
board (ref.;62)-

Fig. 13. Auxiliary
switch (ref. 38)

TYPES AK-S-IS AND AK-2-25 POWER CIRCUIT BREAKERS

£.v j-' •- . i

P206
P209
P212
P214
P216

P2()5
P208
P2U
P215

Pb
Pi;t
PiV
pi:>

§ Only complete relay furnished

TYPES AK-2-15 AND AK*2-25 POWER CiRCUIT; BREAKERS

mi-i
(PHOTO 8020580)

Fig. 16. Maintenance handle for
electrically operated breakers not

Fi9 15. Accessories for wall

mounling (ref. 65, 66,67, 68)

equipped with manual handles (ref. 69)

Catalog Number
Rating
Volts

36GA773G17
366A77.3G13
.366A773G15

6275081G55
6275061G28

G275081G29
6275081G30

6275081G18 '
6275081G19

6275081G26
6275081G29
6275081G29
6275081G7
G275081G5

366A77-3G2
366A773G3
3G6A773G5
366A773G6
366A773G8 "
366A773G10

G275081G56
G275081G26
6275081G26
6275081G27
6275081G4
627S081G29

6275081G4
6275081G12
6275081G12
6275081G31

6275081G26
G27S081G26
6275081G27
6275081G7

6275081G7
6275081G31
6275081G20

115
208
230
460
575

366A773G1
366A773G3
60

366A773G4
366A773G7
366A773G9

366A773G6
366A773G14
366A773G11
366A773G12

6275081G10
6275081G10
6275081G17
6275081G21

6275081G3
6275081G8

' ' :V,-'I, •

" diw.
bl.
following tools are recommeiided
for. proper maintenarice of

diircuh'-Breakers*';,:;'",.
', t'' of the AK>2-15 and AK>2-25 Power dircuil
-Breakers^

;:turorlriclicatcd.
NOTE:- Obtain direct from mainiXacturor
iriclicatcd. ^
Catalog

For slotted head'
For slotted head

For Phillips head. No. 2 super

Truarc (straight)

END WllKNCHES
Adjustable

SOCKET WRENCHES (3/8" DRIVE)
Ratchet handle

Extension bar, 12 inch
3/8 inch socket

7/16 inch socket (long)

9/16 inch socket

1/4 bich, open end

^^.Soap Oi,...vv,
Snap On
^''4
Snap On

'"'•^•'4h-'-4

ALLEN HEAD WRENCHES

5/16 inch
MISCELLANEOUS

1/4 inch splntite wrench (long shank)
7/16 inch spintite wrench
'Maintenance operating handle

:
Stevens-Walden

G. E. Co., Phila
V' ' -

* For electrically operated breakers not equipped with manual handles.

LOW VDLTAGE SWITCHGEAD DEPARTMENT

GENERAL^ELi
PHILADELPHIA, PA.

Source Exif Data:
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