LENNOX Air Conditioner/heat Pump(outside Unit) Manual L0806497

User Manual: LENNOX LENNOX Air conditioner/heat pump(outside unit) Manual LENNOX Air conditioner/heat pump(outside unit) Owner's Manual, LENNOX Air conditioner/heat pump(outside unit) installation guides

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'1_2006 Lennox Industries Jnc,

Dallas, Texas, USA

INSTALLATION

INSTRUCTIONS

HPXA16 Series Units

HEAT PUMP UNITS _Technical

504,954M LLJJ Publications

08/06 Litho U.S.A.

Supersedes 03/06

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

_, WARNING

CAUTION

AIMPORTANT

_, IMPORTANT

HPXA16 Outdoor Unit .......................... 1

Shipping & Packing List ........................ 2

General Information ........................... 2

Unit Dimensions ............................... 2

Parts Arrangement ............................ 3

Setting the Unit ............................... 3

Electrical ..................................... 4

Refrigerant Piping ............................. 6

Refrigerant Metering Device .................... 8

Flushing Existing Line Set & Indoor Coil .......... 8

Manifold Gauge Set ........................... 10

Service Valves ................................ 10

Leak Testing .................................. 11

Evacuation ................................... 12

Start-Up ...................................... 12

Refrigerant Charging .......................... 12

System Operation ............................. 15

Defrost System ............................... 16

Maintenance .................................. 21

Optional Accessories .......................... 21

Check Points ................................. 22

Homeowner Information:

Maintenance .................................. 23

Thermostat Operation .......................... 24

Lennox HPXA16 outdoor units use HFC-410A refrigerant.

This unit must be installed with a matching indoor coil and

line set as outlined in the Lennox Engineering Handbook.

Elite ® Series HPXA16 outdoor units are designed for use

in check expansion valve (CTXV) systems only and must

not be used with other refrigerant flow control devices,

See Lennox Engineering Handbook list of indoor expan-

sion valve kits (ordered separately).

08/06

IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Page 1 504,954M

IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

Check unit for shipping damage, Consult last carrier imme-

diately if damage is found,

1 -Assembled HPXA16 outdoor unit

2 - Grommets (for liquid and vapor lines)

When servicing or repairing HVAC components, ensure

the fasteners are appropriately tightened, Table 1 shows

torque values for fasteners.

Table 1

Torque Requirements

Part Recommended Torque

Service valve cap 8 ft.- lb. 11NM

Sheet metal screws 16 in.- lb. 2 NM

Machine screws #10 28 in.- lb. 3 NM

Compressor bolts 90 in.- lb. 10 NM

Gauge port seal cap 8 ft.- lb. 11NM

These instructions are intended as a general guide and do

not supersede local codes in any way. Consult authorities

who have jurisdiction before installation,

WARNING

Model A B C

HPXA16-024,-036 30-7/8 (784) 12-3/4 (324) 17-1/4 (438)

HPXA16-048, -060 44-7/8 (1140) 14-1/4 (362 18-3/4 (476)

COMPRESSOR j

INLET AIR

O INLET

AIR

_i 32-1/8 (816) i_

(51)

ELECTRICAL

VAPOR

LINE INLET'-_

4-1/2

(114)

C J_ 2-_/16

LIQUID

LINE INLET 1-3/6

(35)

z_ Coil drain outlets (around

INLET AIR perimeter of base)

Top View

504954M 08/06

Page 2

RUN CAPACITOR

START CAPACITOR

(-024 UNIT ONLY)

CHARGE COMPENSATOR

(-048 UNITS)

TXV/CHECK VALVE

DISCHARGE LINE

COMPRESSOR TERMINAL PLUG

VAPOR LINE

CONTACTOR

VAPOR VALVE AND GAUGE

PORT

LOW PRESSURE SWITCH TWO-STAGE COMPRESSOR

DISCHARGE TEMPERATURE

SENSOR

DRIER

HIGH PRESSURE SWITCH

Figure 1

CAUTION

These units operate under a wide range of weather condi-

tions; therefore, several factors must be considered when

positioning the outdoor unit. The unit must be positioned to

give adequate clearances for sufficient airflow and servic-

ing. Refer to figure 2 for installation clearances.

1. Place a sound-absorbing material, such as Isomode,

under the unit if it will be installed in a location or posi-

tion that will transmit sound or vibration to the living

area or adjacent buildings.

2. Mount unit high enough above ground or roof to allow

adequate drainage of defrost water and prevent ice

build-up.

3. In heavy snow areas, do not locate unit where drifting

will occur. The unit base should be elevated above the

depth of average snows.

NOTE -Elevation of the unit may be accomplished by

constructing a frame using suitable materials. If a sup-

port frame is constructed, it must not block drain holes

in unit base.

Installation Clearances

as noted

,,11- 30" _ _} not_

(762 mm)

l as noted J

NOTE - A service access clearance of 30" (762 mm) must be main-

tained in front of the service access panel. Clearance to one side must

be 36" (914 mm), Clearance to one of the remaining two sides may be

12" (305 mm) and the final side may be 6" (152 ram).

NOTE -A clearance of 24" (610 mm) must be maintained between

two units.

NOTE -48" (1219 mm) clearance required on top

of unit. Maximum soffit overhang is 36" (914 mm).

Figure 2

4. When installed in areas where low ambient tempera-

tures exist, locate unit so winter prevailing winds do

not blow directly into outdoor coil.

5. Locate unit away from overhanging roof lines which

would allow water or ice to drop on, or in front of, coil

or into unit.

Page 3

HPXA16 SERIES

Slab Mounting

When installing unit at grade level, top of slab should be

high enough above the grade so that water from higher

ground will not collect around unit, See figure 3. Slab

should have a slope tolerance away from the building of 2

degrees or 2 inches per 5 feet (51 mm per 1,5 m), This will

prevent ice build-up under unit during a defrost cycle. Re-

fer to roof mounting section for barrier construction if unit

must face prevailing winter winds.

Slab Mounting

discharge air building

structure

2 DEGREES OR

2 IN. PER 5 FOOT

(51 MM PER 1.5 M)

SLOPE

TOLERANCE mounting

AWAY FROM /slab

BUILDING /

STRUCTURE

ground level

Figure 3

Roof Mounting

Install the unit a minimum of 6 inches (152 mm) above the

roof surface to avoid ice build-up around the unit. Locate

the unit above a load bearing wall or area of the roof that

can adequately support the unit. Consult local codes for

rooftop applications.

If unit coil cannot be mounted away from prevailing winter

winds, a wind barrier should be constructed. See figure 4.

Size barrier at least the same height and width as outdoor

unit, Mount barrier 24 inches (610 mm) from the sides of

the unit in the direction of prevailing winds.

Rooftop Wind Barrier Construction

O prevailing winter

winds

I wind barrier I

inlet air T (21'0

O inlet air

Figure 4

In the U,S.A., wiring must conform with current local codes

and the current National Electric Code (NEC). In Canada,

wiring must conform with current local codes and the current

Canadian Electrical Code (CEC).

Page 4

Refer to the furnace or blower coil installation instructions

for additional wiring application diagrams and refer to unit

nameplate for minimum circuit ampacity and maximum

overcurrent protection size.

_WARNING

Install line voltage power supply to unit from a properly

sized disconnect switch,

Ground unit at unit disconnect switch or to an earth

ground,

NOTE -Connect conduit to the unit using a proper

conduit fitting. Units are approved for use only with

copper conductors, Refer to figure 5 for high voltage

field wiring diagram, A complete unit wiring diagram is

located on the back side of the unit's access panel.

OUTDOOR

FAN

Typical Field Wiring Diagram

START CAPACITOR AI08 GROUND

DEFROST CONTROL LUG

C7 r_

POTENTIAL RELAY 6[_ K195

T4 SOLENOID

KSI TRANSFORMER RELA_

ORANGE-COMMON

BLACK-RUN

PURPLE-CAPACITOR

C_8

DUAL

CAPACITOR

GND

COMPRESSOR 230/

CONTACTOR 60/1

ILl

208-

WARNING! - ELECTRIC SHOCK HAZARD. Can cause INJURY or

DEATH. Unit must be grounded in accordance with national and local

codes.

NOTE - For use with copper conductors only. Refer to unit rating

alate for minimum circuit ampacity and maximum over-current

3rotection size

Figure 5

NOTE -For proper voltages, select thermostat wire

gauge per the following chart:

Wire run length AWG # Insulation type

less than 100' (30m) 18 color-coded, temperature

more than 100' (30m) 16 rating 35°C minimum

Install room thermostat (ordered separately) on an in-

side wall approximately in the center dthe conditioned

area and 5 feet (1.5 m) from the floor. It should not be

installed on an outside wall or where it can be effected

by sunlight, drafts or vibrations,

Install low voltage wiring from outdoor to indoor unit

and from thermostat to indoor unit, See figures 6

through 8.

NOTE -24V, Class II circuit connections are made in

the low voltage junction box.

504954M 08/06

HPXA16 Outdoor Unit and Blower Unit

Thermostat Designations

(Some connections may not apply. Refer to specific thermostat

and indoor unit

Outdoor Unit

,Defrost _

',Board

i Y2 __

:out

L.....

]

Indoor Unit TB1 I

I I

q--I--

J--i--_lIi

-i- i--

- --t J

A2 Thermostat

®1

Figure 6

HPXA16 Outdoor Unit and CB31MV/CB32MV

Thermostat Designations

(Some connections may not apply. Refer to specific thermostat

and indoor unit.) r i

CB31MV/ I Signature_at

Outdoor Unit / CBX32MV TB1 A2 Thermostat

_---

I [Defrost,

I 'Board

i Y2 i

I, OUT '

i_ _ _ _ )

I I

_ L_I_ _..

i i

-v- -•

IIf ®--i

_LI__® I

- +---®- -i

I I

k I

Figure 7

(_) [ 1R4T"

@.L

HIGH Z_ BI

COMPRESSOR

PRESSURE

SW[TCH_ _L_

RT21

$87 LDW LI RTE3 DEFROST RT28

PRESSURE REVERSING AMBIENT CDIL OISCHARGE

SWITCH VALVE SENSOR SENSOR SENSOR

HPXA16 Wiring Diagram A

--,_,--_DENOTES OPTIONAL COMPONENTS

LINE VOLTAGE FIELD INSTALLED

-- -- -- CLASS II VOLTAGE FIELD INSTALLED

z_K5B-I

BLAC_I

_ AIO8

COIL FAN

@ KI

_MB

-(z)OIS K2

LO-PS

__YIOUT 24v

HI-PS

rl I

s©

'©

NOTE-

FOR USE WITH COPPER CONDUCTORS ONLY.REFER

TO UNIT RATING PLATE FOR MINIMUM CIRCUIT

AMPACITY AND MAXIMUM OVER-

CURRENT PROTECTION SIZE

REFER TO COMPRESSOR IN UNIT

FOR ACTUAL TERMINAL ARRANGEMENT,

WARNING-

ELECTRIC SHOCK HAZARD,CAN CAUSE INJURY

OR DEATH,UNIT MUST BE GROUNDED IN

ACCORDANCE WITH NATIONAL AND LOCAL CODES•

REMOVE JUMPER FOR TWO STAGE COOL

RTi4 SENSOR,OUTDOOR TEMP IOPTIONAL)

K31 AND C7 ARE USED ON 024 UNITS ONLY

SII AND KSB ARE OPTIONAL LOW AMBIENT CONTROLS

L3¢,SECOND STAGE, SOLENOID IS LOCATED IN

COMPRESSOR, COIL IS 24VOC, DO NOT CONNECT

24VAC T_OY_IU TER_[N_.

z_Y2 OUT NOTUSEDIN HARMONYIIIZONE CON_ OL APPLICATIONS

CB31MV

CBX32MV

TBI

-_):>-I-

Q-I--

-4_-I- -

SIGNATURE

81MBB

THERMOSTAT

-- 9 IRT,A

®®

, _ F" BLUE WIRE

Y2 OUT _-_ -- 0 WITH CRIMPED

1 °_ m _1 TERM,NAL

/I I 111

DEFROST o

BOARD _'/'_lil

DETAIL _ _'_-_-_

BLUE { _ __

Z_ Shipped as shown above with terminal crimped to blue wire; use terminal or

cut off terminal and splice blue wire with Y2 wire to indoor unit.

Figure 8

Page 5

HPXA16 SERIES

If the HPXA16 unit is being installed with a new indoor coil

and line set, the refrigerant connections should be made

as outlined in this section. If an existing line set and/or in-

door coil is going to be used to complete the HPXA16 sys-

tem, refer to the following section which includes flushing

procedures.

Field refrigerant piping consists of liquid and vapor lines

from the outdoor unit (sweat connections) to the indoor coil

(flare or sweat connections). Use Lennox L15 (sweat, non-

flare) series line sets as shown in table 2 or use field-fabri-

cated refrigerant lines. Valve sizes are also listed in table 2.

Refrigerant Connections - HPXA16 Matched

with New Indoor Coil and Line Set

If an existing indoor coil which was equipped with an RFCl

metering device is being replaced, the liquid line must also

be replaced prior to the installation of the HPXA16 unit.

Table 2

Refrigerant Line Sets

Mod-

-024

-036

-048

-060

Field

Connections

Liquid Vapor

Line Line

3/8in. 7/8 in

(10 mm) (22 mm)

3/8 in, 1-1/8 in.

(10 mm) (29 mm)

Recommended Line Set

Liquid Vapor L15

Line Line Line Sets

3/8 in, 7/8 in L15-65

(10ram) (22ram) 15ft,-50ft,

(4.6 m - 15 m)

3/8 in, 1-1/8 in, Field

(10 ram) (29 ram) Fabricated

1, Placement--Be aware some localities are adopting

sound ordinances based on how noisy the unit is at the

neighbors' home, not at the original installation. Install

the unit as far as possible from the property line, When

possible, do not install the unit directly outside a bed-

room window, Glass has a very high level of sound

transmission, Figure 9 shows how to place the outdoor

unit and line set,

Outside Unit Placement and Installation

Two 90 ° elbows installed in line set

will reduce line set vibration,

NOTE -Units are designed for fine sets of up to fifty feet

(15m),

Installing Refrigerant Line

Pay close attention to line set isolation during installation of

any heat pump or a/c system. When properly isolated from

building structures (walls, ceilings, floors), the refrigerant

lines will not create unnecessary vibration and subsequent

noises. Also, consider the following when placing and

installing a high-efficiency outdoor unit:

Refrigerant Line Sets:

Figure 9

2. Line Set Isolation--The following illustrations dem-

onstrate procedures which ensure proper refrigerant

line set isolation, Figure 10 shows how to make a tran-

sition from horizontal to vertical. Figure 11 shows how

to install line sets on vertical runs. Figure 12 shows

how to install line sets on horizontal runs,

Transition From Vertical To Horizontal

ANCHORED

HEAVY NYLON

WIRE TIE

AUTOMOTIVE

MUFFLER-_PE

HANGER

WALL

STUD

504954M 08/06

Strap Liquid

Line To Va-

por Line

UID LINE

METAL VAPOR LINE - WRAPPED

SLEEVE IN ARMAFLEX

WALL

STUD

Strap Liquid Line

To Vapor Line

Figure 10

Page 6

LIQUID LINE

METAL VAPOR LINE - WRAPPED

SLEEVE IN ARMAFLEX

Refrigerant Line Sets: Installing Vertical Runs (new construction shown)

NOTE -Similar installation practices should be used if line set is to be installed on exterior of outside wall.

OUTSIDE WALL IMPORTANT - Refrigerant

lines must not contact wall. VAPOR LINE LI UID LINE

IMPORTANT!

Refrigerant

lines must

not contact

structure.

VAPOR LINE WRAPPED

1_ CAULK

PVC PIPE FIBERGLASS

INSULATION

-_. WIRE TIE

INSIDE WALL

- STRAP

SLEEVE

"_- WIRE TIE

"_ ----------WOOD BLOCK

_. _ WIRE TIE

STRAP

SLEEVE

Figure 11

Refrigerant Line Sets: Installing Horizontal Runs

To hang line set from joist or rafter,

use either metal strapping material

or anchored heavy nylon wire ties. WIRE TIE

8 feet (Around vapor line only)

STRAPPING MATERIAL

(Around vapor line only) FLOOR JOIST OR

ROOF RAFTER

TAPE OR

8 feet WIRE TIE

METAL FLOOR JOIST OR .

SLEEVE ROOF RAFTER

Strap the vapor line to the joist or

rafter at 8 ft. intervals then strap

the liquid line to the vapor line.

TAPE OR WIRE TIE _rl

Figure 12

Page 7

HPXA16 SERIES

Isolation Grommets

Locate the provided isolation grommets. Use a knife to slit

the webbing on each grommet. Slide larger grommet onto

vapor line and smaller grommet onto liquid line. Insert

grommets into mullion to isolate refrigerant lines from

sheet metal edges,

WARNING I

Brazing Connection Procedure

1, The end of the refrigerant line must be cut square and

its internal shape must remain round. The line must be

free of nicks or dents and must be deburred (I,D, and

O.D,)

2, Before making line set connections, use dry nitrogen

to purge the refrigerant piping. This will help to prevent

oxidation and the introduction of moisture into the sys-

tem.

3, Use silver alloy brazing rods (5 or 6 percent minimum

silver alloy for copper4o-copper brazing or 45 percent

silver alloy for copper-to-brass or coppeFto-steel

brazing). Wrap a wet cloth around the valve body and

the copper tube stub. Remove light maroon washers

from service valves and shield light maroon stickers in

order to protect them during brazing, Braze the line set

to the service valve,

4, Quench the joint with water or a wet cloth to prevent

heat damage to the valve core and opening port,

NOTE -The tube end must stay bottomed in the fitting

during final assembly to ensure proper seating, seal-

ing and rigidity.

HPXA16 units may be used in check expansion valve

(CTXV) systems only, See indoor coil installation instruc-

tions and the Lennox engineering handbook for approved

HFC-410A TXV match-ups and application information,

NOTE -HFC-410A systems will not operate properly with

an HCFC-22 valve.

Check Expansion Valve Systems

Check expansion valves equipped with either Chatleff or

flare-type fittings are available from Lennox. Refer to the

Engineering Handbook forapplicable expansion valves for

use with specific match-ups.

If you install a check expansion valve with an indoor coil

that includes a fixed orifice, remove the orifice before the

check expansion valve is installed. See figure 13 for instal-

lation of the check expansion valve.

II Metering Device Installation

_oO-RING EXPANSION VALVE &

_-_% / /O-RING (See NOTE)

/° STRA,NER

DISTRIBUTOR __ LITQuU;DLINE

NOTE - Ifnecessary,remove HCFC-22 flowcontroldevice(fixed

orifice/checkexpansionvalve)from existinglinesetbeforeinstalling

HFC-410A approved expansionvalveand o-ring.

Figure 13

A, IMPORTANT

NOTE -If the indoor unit line and set are new, skip this sec-

tion and go on to the Manifold Gauge Set section.

_WARNING

A IMPORTANT

504954M 0_06

Page 8

IMPORTANT

CAUTION

Required Equipment

You will need the following equipment in order to flush the

existing line set and indoor coil: two clean HCFC-22 recov-

ery bottles, an oilless recovery machine with a pump down

feature, and two sets of gauges (one for use with HCFC-22

and one for use with the HFC-410A).

Flushing Procedure

1. Remove existing HCFC-22 refrigerant using the ap-

propriate procedure below.

If the existing outdoor unit is not equipped with

shut-off valves, or if the unit is not operational

AND you plan to use the existing HCFC-22 refrig-

erant to flush the system -

• Disconnect all power to the existing outdoor unit.

• Connect to the existing unit, a clean recovery cyl-

inder and the recovery machine according to the

instructions provided with the recovery machine.

• Remove all HCFC-22 refrigerant from the existing

system. Check gauges after shutdown to confirm

that the entire system is completely void of refrig-

erant.

• Disconnect the liquid and vapor lines from the ex-

isting outdoor unit.

If the existing outdoor unit is equipped with

manual shut-off valves AND you plan to use NEW

HCFC-22 refrigerant to flush the system -

• Start the existing HCFC-22 system in the cooling

mode and close the liquid line valve.

• Pump all of the existing HCFC-22 refrigerant back

into the outdoor unit. (It may be necessary to by-

pass the low pressure switches to ensure com-

plete refrigerant evacuation.)

• When the low side system pressures reach 0 psig,

close the vapor line valve.

• Disconnect all power to the existing outdoor unit.

Check gauges after shutdown to confirm that the

valves are not allowing refrigerant to flow back into

the low side of the system.

• Disconnect the liquid and vapor lines from the ex-

isting outdoor unit.

2. Remove the existing outdoor unit. Set the new

HFC-410A unit and follow the brazing connection pro-

cedure (see page 8) to make line set connections.

DO NOT install metering device at this time.

3. Make low voltage and line voltage connections to the

new outdoor unit. DO NOT turn on power to the unit

or open the outdoor unit service valves at this

time.

IMPORTANT

4. Remove the existing refrigerant flow control orifice or

thermal expansion/check valve before continuing with

flushing procedures. The existing devices are not ap-

proved for use with HFC-410A refrigerant and may

prevent proper flushing, Use a field-provided fitting to

reconnect the lines.

Flushing Connections

RECOVERY CYLINDER

Inverted HCFC-22 Cylin-

der

(Contains clean

HCFC-22 to be used for

flushing)

EXISTING VAPOR LINE

VAPOR LINE

SERVICE VALVE

EXISTING LIQUID LINE LIQUID LINE

SERVICE VALVE

Tank ReturnInlet

Discharge

RECOVERY MACHINE

Figure 14

Low High

Pressure Pressure

NOTE - The inverted HCFC-22 cyl-

inder must contain at least the

same amount of refrigerant as was

recovered from the existing sys-

tem.

Page 9

HPXA16 SERIES

5, Remove the pressure tap valve cores from the

HPXA16 unit's service valves. Connect an HCFC-22

cylinder with clean refrigerant to the vapor service

valve, Connect the HCFC-22 gauge set to the liquid

line valve and connect a recovery machine with an

empty recovery tank to the gauge set.

6, Set the recovery machine for liquid recovery and start

the recovery machine, Open the gauge set valves to

allow the recovery machine to pull a vacuum on the ex-

isting system line set and indoor coil.

7, Invert the cylinder of clean HCFC-22 and open its

valve to allow liquid refrigerant to flow into the system

through the vapor line valve. Allow the refrigerant to

pass from the cylinder and through the line set and the

indoor coil before it enters the recovery machine,

8, After all of the liquid refrigerant has been recovered,

switch the recovery machine to vapor recovery so that

all of the HCFC-22 vapor is recovered,

NOTE -A single system flush should remove all of the

mineral oil from the existing refrigerant lines and in-

door coil. A second flushing may be done (using clean

refrigerant) if insufficient amounts of mineral oil were

removed during the first flush, Each time the system

is flushed, you must allow the recovery machine

to pull avacuum on the system at the end of the

procedure.

9, Close the valve on the inverted HCFC-22 drum and

the gauge set valves. Pump the remaining refrigerant

out of the recovery machine and turn the machine off.

10, Use dry nitrogen to break the vacuum on the refriger-

ant lines and indoor coil before removing the recovery

machine, gauges and HCFC-22 refrigerant drum. Re-

install pressure tap valve cores into HPXA16 service

valves.

11. Install the provided check expansion valve (approved

for use with HFC-410A refrigerant) in the liquid line at

the indoor coil,

Manifold gauge sets used with systems charged with

HFC-410A refrigerant must be capable of handling the

higher system operating pressures. The gauges should be

rated for use with pressures of 0 - 800 on the high side and

a low side of 30" vacuum to 250 psi with dampened speed

to 500 psi. Gauge hoses must be rated for use at up to 800

psi of pressure with a 4000 psi burst rating,

The liquid line and vapor line service valves (figures 15 and

16) and gauge ports are used for leak testing, evacuating,

charging, and checking charge. See table for torque requi-

rements.

Front-Seated Liquid Line Service Valve

(Valve Shown Closed) SERVICE

Insert hex wrench here

STEM

CAP

indoor coil

To outdoor coil

(Valve Shown Open)

insert hex wrench here SERVICE

PORT

STEM

CAP

Service port Is open to

line set when valve is

closed (front seated) To outdoor coil

Figure 15

indoor coil

Bali-Type Vapor Valve (Valve Closed)

STEM

CAP TO

OUTDOOR

USE ADJUSTABLE WRENCH _.. STEM _(STEM COIL

TO OPEN: ROTATE STEM ._L_I:,_ _._---,_ \

COUNTER-CLOCKWISE 90 °. __

TO CLOSE: ROTATE STEM

CLOCKWIS_ BALL (SHOWN

CLOSEO

TO _; SCHRADER VALVE

,NDOOR

COIL SERVICE

PORT CAP

Figure 16

Each valve is equipped with a service port which has a fac-

tory-installed Schrader valve. A service port cap protects

the Schrader valve from contamination and serves as the

primary leak seal.

504954M 08/06

Page 10

IMPORTANT

To Access Schrader Port:

1. Remove service port cap with an adjustable wrench,

2. Connect gauge to the service port.

3, When testing is completed, replace service port cap. Re-

place the stem cap. Tighten finger tight; then torque per

table 1 (Page 2),

To Open Front-Seated Service Valves:

1. Remove stem cap with an adjustable wrench,

2. Use a service wrench with a hex-head extension

(3/16" for liquid-line valve sizes; 5/16" for vapor-line

valve sizes) to back the stem out counterclockwise as

far as it will go,

3. Replace the stem cap, Tighten finger tight; then torque

per table 1 (Page 2),

To Close Front-Seated Service Valves:

1. Remove the stem cap with an adjustable wrench,

2. Use a service wrench with a hex-head extension

(3/16" for liquid-line valve sizes; 5/16" for vapor-line

valve sizes) to turn the stem clockwise to seat the

valve. Tighten it firmly,

3, Replace the stem cap, Tighten finger tight; then torque

per table 1 (Page 2),

Bali-Type Service Valve (Vapor Line)

Ball-type service valves function the same way as the oth-

er valves; the difference is in the construction, These

valves are not rebuildable, If a valve has failed, you must

replace it. A ball valve is illustrated in figure 16,

The ball valve is equipped with a service port with a factory-

installed Schrader valve. A service port cap protects the

Schrader valve from contamination and assures a leak-

free seal,

After the line set has been connected to the indoor and out-

door units, the line set connections and indoor unit must be

checked for leaks,

Xk WARNING

, WARNING

,&WARNING

Using an Electronic Leak Detector

1. Connect a cylinder of HFC-410A to the center port of

the manifold gauge set.

2, With both manifold valves closed, open the valve on

the HFC-410A cylinder (vapor only),

3, Open the high pressure side of the manifold to allow

the HFC-410A into the line set and indoor unit, Weigh

in a trace amount of HFC-410A, [A trace amount is a

maximum of 2 ounces (57 g) or 3 pounds (31 kPa)

pressure,] Close the valve on the HFC-410A cylinder

and the valve on the high pressure side of the manifold

gauge set, Disconnect the HFC-410A cylinder.

4, Connect a cylinder of dry nitrogen with a pressure reg-

ulating valve to the center port of the manifold gauge

set.

5, Connect the manifold gauge set high pressure hose to

the vapor valve service port. (Normally, the high pres-

sure hose is connected to the liquid line port; however,

connecting it to the vapor port better protects the man-

ifold gauge set from high pressure damage.)

6, Adjust the dry nitrogen pressure to 150 psig (1034

kPa). Open the valve on the high side of the manifold

gauge set which will pressurize line set and indoor unit.

7, After a few minutes, open a refrigerant port to ensure

the refrigerant you added is adequate to be detected.

(Amounts of refrigerant will vary with line lengths.)

Check all joints for leaks. Purge dry nitrogen and

HFC-410A mixture. Correct any leaks and recheck,

,& IMPORTANT

Page 11

HPXA16 SERIES

Evacuating the system of noncondensables is critical for

proper operation of the unit. Noncondensables are defined

as any gas that will not condense under temperatures and

pressures present during operation of an air conditioning

system. Noncondensables and water vapor combine with

refrigerant to produce substances that corrode copper pip-

ing and compressor parts,

A, IMPORTANT

1, Connect manifold gauge set to the service valve ports

as follows:

• low pressure gauge to vapor line service valve

• high pressure gauge to liquid line service valve

2. Connect micron gauge.

3. Connect the vacuum pump (with vacuum gauge) to

the center port of the manifold gauge set,

4, Open both manifold valves; start the vacuum pump.

5, Evacuate the line set and indoor unit to an absolute

pressure of 23,000 microns (29,01 inches of mercu-

ry). During the early stages of evacuation, it is desir-

able to close the manifold gauge valve at least once to

determine if there is a rapid rise in absolute pressure,

A rapid rise in pressure indicates a relatively large

leak, If this occurs, repeat the leak testing procedure,

NOTE -The term absolute pressure means the total

actual pressure within a given volume or system,

above the absolute zero of pressure, Absolute pres-

sure in a vacuum is equal to atmospheric pressure mi-

nus vacuum pressure,

6, When the absolute pressure reaches 23,000 microns

(29.01 inches of mercury), close the manifold gauge

valves, turn off the vacuum pump and disconnect the

manifold gauge center port hose from vacuum pump.

Attach the manifold center port hose to a dry nitrogen

cylinder with pressure regulator set to 150 psig (1034

kPa) and purge the hose. Open the manifold gauge

valves to break the vacuum in the line set and indoor

unit, Close the manifold gauge valves,

WARNING I

7, Shut off the dry nitrogen cylinder and remove the man-

ifold gauge hose from the cylinder, Open the manifold

gauge valves to release the dry nitrogen from the line

set and indoor unit.

Reconnect the manifold gauge to the vacuum pump,

turn the pump on, and continue to evacuate the line set

and indoor unit until the absolute pressure does not

rise above 500 microns (29.9 inches of mercury) within

a 20-minute period after shutting off the vacuum pump

and closing the manifold gauge valves.

When the absolute pressure requirement above has

been met, disconnect the manifold hose from the vac-

uum pump and connect it to an upright cylinder of

HFC-410A refrigerant. Open the manifold gauge

valves to break the vacuum from 1 to 2 psig positive

pressure in the line set and indoor unit, Close manifold

gauge valves and shut off the HFC-410A cylinder and

remove the manifold gauge set,

A, IMPORTANT

1, Rotate fan to check for frozen bearings or binding,

2, Inspect all factory- and field-installed wiring for loose

connections.

3, After evacuation is complete, open the liquid line and

vapor line service valves (counterclockwise) to re-

lease refrigerant charge (contained in outdoor unit)

into the system,

4, Replace stem caps and secure finger tight, then tight-

en an additional (1/6) one-sixth of a turn,

5, Check voltage supply at the disconnect switch. The

voltage must be within the range listed on the unit

nameplate. If not, do not start the equipment until the

power company has been consulted and the voltage

condition has been corrected.

6, Set the thermostat for a cooling demand. Turn on pow-

er to indoor blower unit and close the outdoor unit dis-

connect to start the unit,

7, Recheck voltage while the unit is running. Power must

be within range shown on the nameplate.

This system is charged with HFC-410A refrigerant which

operates at much higher pressures than HCFC-22. The

field-provided check expansion valve for the indoor unit

must be approved for use with HFC-410A. This unit is NOT

approved for use with coils which include metering orifices

or capillary tubes.

Factory Charge

The unit is factory-charged with the amount of HFC-410A

refrigerant indicated on the unit rating plate, This charge is

based on a matching indoor coil and outdoor coil with a 15

foot (4,6 m) line set. For varying lengths of line set, refer to

table 3 for refrigerant charge adjustment,

504954M 0_06

Page 12

HPXA16 Cooling Cycle (Showing Gauge Manifold Connections)

DISTRIBUTOR OUTDOOR UNIT NOTE _ARROWS INDICATE

DIRECTION OF REFRIGERANT FLOW

REVERSING VALVE

PRESSUREEXPANSION/PRESSURE

CHECK VALVE

BIFLOW

FILTER /

DRIER OUTDOOR

COIL

LOW HUGH

INDOOR I INI

..---1

VA R VAPORPORT

I A I X VAPORSERVICE

N svc

POR VALVE Vl

S COMPRESSOR

i ,

EXPANSION/CHECK VALVE -- -4_111

NOTE- Use gauge ports on vapor line valve and liquid valve for evacuating refrigerant lines and indoor coil. Use vapor INDOOR

gauge port to measure vapor pressure during charging. COIL

Table 3

Refrigerant Charge per Line Set Lengths

Liquid Line Ounces per 5 feet (grams per 1.52 meter)

Set Diameter adjust from 15 ft. (4.57m) line set*

3/8 in. (9.5ram) 3 ounces per 5 feet (85 grams per 1.52 meter)

*Add the amount shown if line length is greater than 15' (4.57m), sub-

tract the amount shown if less than 15'.

IMPORTANT

Checking Charge

The outdoor unit should be charged during warm weather.

However, applications arise in which charging must occur

in the colder months. The method of charging is deter-

mined by the outdoor ambient temperature.

Measure the liquid line temperature and the outdoor ambi-

ent temperature as outlined below:

1. Connect the manifold gauge set to the service valves:

• low pressure gauge to vapor valve service port

• high pressure gauge to liquid valve service port

Close manifold gauge set valves. Connect the center

manifold hose to an upright cylinder of HFC-410A. See

figure 17.

2. Set the room thermostat to call for heat. This will

create the necessary load for properly charging the

system in the cooling cycle.

3. Record outdoor ambient temperature using a digital

thermometer.

4. When the heating demand has been satisfied, switch

the thermostat to cooling mode with a set point of 68 '_F

Figure 17

(20_C). When pressures have stabilized, use a digital

thermometer to record the liquid line temperature.

5. The outdoor temperature will determine which charg-

ing method to use. Proceed with whichever of the fol-

lowing charging procedure deemed appropriate for the

situation.

Charge Using the Weigh-in Method -

Outdoor Temperature < 65°F (18°C)

If the system is void of refrigerant, or if the outdoor ambient

temperature is cool, first, locate and repair any leaks and

then weigh in the refrigerant charge into the unit.

1. Recover the refrigerant from the unit.

2. Conduct leak check; evacuate as previously outlined.

3. Weigh in the unit nameplate charge. If weighing facili-

ties are not available or if charging the unit during

warm weather, use one of the following procedures.

Charge Using the Subcooling Method -

Outdoor Temperature < 65°F (18°C)

When the outdoor ambient temperature is below 65°F

(18°C), use the subcooling method to charge the unit. It

may be necessary to restrict the air flow through the out-

door coil to achieve pressures in the 325-375 psig

(2240-2585 kPa) range. These higher pressures are nec-

essary for checking the charge. Block equal sections of air

intake panels and move obstructions sideways until the liq-

uid pressure is in the 325-375 psig (2240-2585 kPa) range.

See figure 18.

locking Outdoor Coil

*Outdoor coil should be blocked one

side at a time with cardboard or plastic

sheet until proper testing pressures

are reached.

cardboard or plastic sheet

*FouFsided unit shown.

Figure 18

Page 13

HPXA16 SERIES

1. With the manifold gauge hose still on the liquid service

port and the unit operating stably, use a digital ther-

mometer to record the liquid line temperature.

2. At the same time, record the liquid line pressure reading,

3. Use a temperature/pressure chart for HFC-410A to

determine the saturation temperature for the liquid line

pressure reading, See table 4.

Table 4

HFC-410A Temperature (°F) - Pressure (Psig)

°F Psig °F Psig °F Psig °F Psig

32 100.8 63 178.5 94 290.8 125 445.9

33 102.9 64 181.6 95 295.1 126 451.8

34 105.0 65 184.3 96 299.4 127 457.6

35 107.1 66 187.7 97 303.8 128 463.5

36 109.2 67 190.9 98 308.2 129 469.5

37 111.4 68 194.1 99 312.7 130 475.6

38 113.6 69 197.3 100 317.2 131 481.6

39 115.8 70 200.6 101 321.8 132 487.8

40 118.0 71 203.9 102 326.4 133 494.0

41 120.3 72 207.2 103 331.0 134 500.2

42 122.6 73 210.6 104 335.7 135 506.5

43 125.0 74 214.0 105 340.5 136 512.9

44 127.3 75 217.4 106 345.3 137 519.3

45 129.7 76 220.9 107 350.1 138 525.8

46 132.2 77 224.4 108 355.0 139 532.4

47 134.6 78 228.0 109 360.0 140 539.0

48 137.1 79 231.6 110 365.0 141 545.6

49 139.6 80 235.3 111 370.0 142 552.3

50 142.2 81 239.0 112 375.1 143 559.1

51 144.8 82 242.7 113 380.2 144 565.9

52 147.4 83 246.5 114 385.4 145 572.8

53 150.1 84 250.3 115 390.7 146 579.8

54 152.8 85 254.1 116 396.0 147 586.8

55 155.5 86 258.0 117 401.3 148 593.8

56 158.2 87 262.0 118 406.7 149 601.0

57 161.0 88 266.0 119 412.2 150 608.1

58 163.9 89 270.0 120 417.7 151 615.4

59 166.7 90 274.1 121 423.2 152 622.7

60 169.6 91 278.2 122 428.8 153 630.1

61 172.6 92 282.3 123 434.5 154 637.5

62 175.4 93 286.5 124 440.2 155 645.0

4. Subtract the liquid line temperature from the saturation

temperature (according to the chart) to determine sub-

cooling. (Saturation temperature - Liquid line tem-

perature = Subcooling)

5. Compare the subcooling value with those in table 5, If

subcooling is greater than shown, recover some refrig-

erant, If subcooling is less than shown, add some re-

frigerant. Be aware of the HFC-410A refrigerant cylin-

dec It will be light maroon-colored. Refrigerant should

be added through the vapor line valve in the liquid

state.

NOTE -Some HFC-410A cylinders are equipped with a dip

tube that allows you to draw liquid refrigerant from the bot-

tom of the cylinder without turning the cylinder upside-

down. The cylinder will be marked if it is equipped with a dip

tube.

Table 5

Subcooling Values for Charging

Second Stage (High Capacity)

Model Number Subcooling Values Conversion Temp. -

Liquid Line Temp. °F (°C)

HPXA16-024 11.0+ 1(6 + .5)

HPXA16-036 8.5 + 1 (4.7 + .5)

HPXA16-048 7.5 + 1 (4.1 + .5)

HPXA16-060 7.0 + 1 (3.9 + .5)

Charge Using the Approach Method -

Outdoor Temperature _>65°F (18°C)

The following procedure is intended as a general guide and

is for use on expansion valve systems only. For best re-

sults, indoor temperature should be 70°F (21°C) to 80°F

(26°C). Monitor system pressures while charging.

1. Record outdoor ambient temperature using a digital

thermometer,

2. Attach high pressure gauge set and operate unit for

several minutes to allow system pressures to stabilize.

3. Compare stabilized pressures with those provided in

tables 6 and 7, "Normal Operating Pressures."

XkIMPORTANT

504954M 08/06

Page 14

Table 6

HPXA16 Normal Operating Pressures

COOLING (Liquid +10 & Vapor +5 psig)*

-024 -036 -048 -060

°F (°C)** uqlvopuqlvapu lvo u lvo

First Stage (Low Capacity)

65 (18.3) 217 143 227 142 222 140 225 140

75 (23.9) 250 145 262 145 258 143 259 142

85 (29.4) 291 147 305 146 298 145 293 146

95 (35.0) 336 149 352 148 343 147 356 147

105 (40.6) 386 151 403 152 402 147 408 147

115 (49.0) 440 153 458 155 452 152 455 151

Second Stage (High Capacity)

65 (18.3) 222 143 244 136 232 134 249 126

75 (23.9) 256 145 282 139 266 136 289 134

85 (29.4) 302 145 325 142 309 139 330 140

95 (35.0) 349 147 377 144 359 142 378 143

105 (40.6) 403 149 428 146 410 144 433 146

115 (49.0) 464 152 488 148 468 147 492 149

*These are most-popular-match-up pressures. Indoor match

up, indoor air quality, and indoor load cause pressures to vary

**Temperature of the air entering the outside coil.

Table 7

HPXA16 Normal Operating Pressures

HEATING (Liquid +10 & Vapor +5 psig)

-024 -036 -048 -060

°F (°C)**

First Stage (Low Capacity)

40 (4.4) 321 99 296 95 315 97 319 93

50 (10) 340 120 310 112 330 114 335 111

Second Stage (High Capacity)

20 (-7.0) 273 68 277 60 294 60 300 57

30 (-1.0) 296 80 296 74 303 75 312 70

40 (4.4) 321 95 321 88 314 90 323 83

50 (10) 341 115 341 104 325 106 339 97

*These are most-popular-match-up pressures. Indoor match

up, indoor air quality, and indoor load cause pressures to vary

**Temperature of the air entering the outside coil.

4. Use the same digital thermometer used to check

outdoor ambient temperature to check liquid line

temperature. Verify the unit charge using the approach

method.

5. The difference between the ambient and liquid

temperatures should match values given in table 8. If

the values don't agree with the those in table 8, add

refrigerant to lower the approach temperature or

recover refrigerant from the system to increase the

approach temperature.

Table 8

Approach Values for Charging

Second Stage (High Capacity) Ap-

Model Number proach Temperature Liquid Line Temp. -

Outdoor Ambient °F (°C)

HPXA16-024 4.0 + 1 (2.2 + .5)

HPXA16-036 7.0 + 1 (3.9 + .5)

HPXA16-048 8.0 + 1 (4.4 + .5)

HPXA16-060 10.0 + 1 (5.6 + .5)

The outdoor unit and indoor blower cycle on demand from

the room thermostat. When the thermostat blower switch

is in the ON position, the indoor blower operates continu-

ously.

Thermostat Operation

Some indoor thermostats incorporate isolating contacts

and an emergency heat function (which includes an amber

indicating light). The thermostat is not included with the

unit and must be purchased separately.

Emergency Heat (Amber Light)

An emergency heat function is designed into some room

thermostats. This feature is applicable when isolation dthe

outdoor unit is required, or when auxiliary electric heat is

staged by outdoor thermostats. When the room thermostat is

placed in the emergency heat position, the outdoor unit con-

trol circuit is isolated from power and field-provided relays by-

pass the outdoor thermostats. An amber indicating light si-

multaneously comes on to remind the homeowner that he is

operating in the emergency heat mode.

Emergency heat is usually used during an outdoor unit

shutdown, but it should also be used following a power out-

age if power has been off for over an hour and the outdoor

temperature is below 50°F (10°C). System should be left in

the emergency heat mode at least six hours to allow the

crankcase heater sufficient time to prevent compressor

slugging.

Filter Drier

The unit is equipped with a large-capacity biflow filter drier

which keeps the system clean and dry. If replacement is

necessary, order another of like design and capacity. The

replacement filter drier must be suitable for use with

HFC-410A refrigerant.

Page 15

HPXA16 SERIES

Defrost System Description

The demand defrost controller measures differential tem-

peratures to detect when the system is performing poorly

because of ice build-up on the outdoor coil. The controller

"self-calibrates" when the defrost system starts and after

each system defrost cycle. The defrost control board com-

ponents are shown in figure 19.

Defrost Control Board

Note -Component Locations Vary by Board Manufacturer.

TEST PINS

DEFROST _ t_i

TERMINATION

PIN SETTINGS

SENSOR -- _

PLUG IN

(COIL & AM_

BENT

SENSORS)

DELAY --

PINS

REVERSING

VALVE

PRESSURE /

SWITCH CIR-

CUIT CONNEC- _,

TIONS

AMBIENT

THERMOSTAT

PINS

LEDS

24V TERMINAL

STRIP

CONNECTIONS

Figure 19

The control monitors ambient temperature, outdoor coil

temperature, and total run time to determine when a de-

frost cycle is required. The coil temperature probe is de-

signed with a spring clip to allow mounting to the outside

coil tubing. The location of the coil sensor is important for

proper defrost operation.

NOTE -The demand defrost board accurately measures

the performance of the system as frost accumulates on the

outdoor coil. This typically will translate into longer running

time between defrost cycles as more frost accumulates on

the outdoor coil before the board initiates defrost cycles.

Defrost Board Diagnostic LEDs

The state (Off, On, Flashing) of two LEDs on the defrost

board (DS1 [Red] and DS2 [Green]) indicate diagnostics

conditions that are described in table 10 (on page 20).

Defrost Board Pressure Switch Connections

The unit's automatic reset pressure switches (LO PS - $87

and HI PS - $4) are factory-wired into the defrost board on

the LO-PS and HI-PS terminals, respectively.

Low Pressure Switch (LO-PS)--When the low pressure

switch trips, the defrost board will cycle off the compressor,

and the strike counter in the board will count one strike.

The low pressure switch is ignored under the following

conditions:

• during the defrost cycle and 90 seconds after the ter-

mination of defrost

• when the average ambient sensor temperature is be-

low 15° F (-9°C)

• for 90 seconds following the start up of the compressor

• during "test" mode

High Pressure Switch (HI-PS)--When the high pressure

switch trips, the defrost board will cycle off the compressor,

and the strike counter in the board will count one strike.

Defrost Board Pressure Switch Settings

High Pressure (auto reset) - trip at 590 psig; reset at 418

psig.

Low Pressure (auto reset) - trip at 25 psig; reset at 55

psig.

Pressure Switch 5-Strike Lockout

The internal control logic of the board counts the pressure

switch trips only while the Y1 (Input) line is active. If a pres-

sure switch opens and closes four times during a Y1 (In-

put), the control logic will reset the pressure switch trip

counter to zero at the end of the Y1 (Input). If the pressure

switch opens for a fifth time during the current Y1 (Input),

the control will enter a lockout condition.

The 5-strike pressure switch lockout condition can be reset

by cycling OFF the 24-volt power to the control board or by

shorting the TEST pins between 1 to 2 seconds. All timer

functions (run times) will also be reset.

If a pressure switch opens while the Y1 Out line is en-

gaged, a 5-minute short cycle will occur after the switch

closes.

Defrost System Sensors

Sensors connect to the defrost board through a field-re-

placeable harness assembly that plugs into the board (see

figure 21). Through the sensors, the board detects outdoor

ambient, coil, and discharge temperature fault conditions.

As the detected temperature changes, the resistance

across the sensor changes. Figure 20 shows how the re-

sistance varies as the temperature changes for both type

of sensors. Sensor resistance values can be checked by

ohming across pins shown shown in table 9.

504954M 08/06

Page 16

NOTE -When checking the ohms across a sensor, be

aware that a sensor showing a resistance value that is not

within the range shown in table 9, may be performing as

designed. However, if a shorted or open circuit is detected,

then the sensor may be faulty and the sensor harness will

need to be replaced.

NOTE -Under certain ambient conditions, the internal

cabinet temperature of the HPXA16-036 cabinet will

affect the temperature that is sensed by the coil sen-

sor. This can set up acondition where the defrost

board may not initiate adefrost cycle. To overcome

this issue, the coil sensor should be moved to the al-

Table 9

Sensor Temperature /Resistance Range

Pins/VV

Temperature Resistance values ire

Sensor Range °F (°C) range (ohms) Color

Outdoor -35 (-37) to 120 (48) 280,000 to 3750 3 & 4

(Black)

Coil -35 (-37) to 120 (48) 280,000 to 3750 5 & 6

(Brown)

Discharge (if 24 (-4) to 350 (176) 41,000 to 103 1 & 2

applicable) (Yellow)

Note: Sensor resistance decreases as sensed temperature increases

(see figure 20).

ternate location on the other side of the cabinet to the

coil hairpin shown in figure 21.

Ambient and Coil Sensor

3OO

_7450 280

260

240

11775

_m 15425 _ 220

mmllmlml!19975 _ 200

e Sensor

m250

mm325

_425

_600

825

26200 _ 180

m34375 _ 160

m46275 _ 140 2500

I62700 3000

85300 120 3750

I m ¢650 5825

IlOO

10000 30000 50000 70000 90000 lOOO 2000 3000 4000 5000 6000

RESISTANCE (OHMS) RESISTANCE (OHMS)

Figure 20

B1175

WOO

,025

HPXA16-036 ALTERNATE

COIL SENSOR LOCATION

DISCHARGE

LINE SENSOR

ALTERNATE

COIL

SENSOR

LOCATION.

Sensor Locations

AMBIENT SENSOR -

(inside PVC tube) Extend

tip of plastic sensor just

outside of plastic sleeve.

COIL SENSOR DETAIL - Sensor

clips on the return bend as shown,

located on bends as follows:

HPXA16-024:

6th bend from top on outside

column.

HPXA16-036*, -048, -060:

5th bend from bottom on

outside column.

NOTE - DIAGRAMS ARE TYPICAL OF @24

AND @36 COIL; -048 & @60 COILS HAVE

MORE COIL SURFACE AREA AND

GREATER NUMBER OF BENDS.

* - @36 MODEL HAS ALTERNATE

LOCATION ON OPPOSITE SIDE AS SHOWN

TO THE LEFT

Figure 21

Page 17

HPXA16 SERIES

Defrost System Sensors

Ambient Sensor--The ambient sensor considers out-

door temperatures below -35°F (-37°C) or above 120°F

(48°C) as a fault. If the ambient sensor is detected as being

open, shorted or out of the temperature range of the sen-

sor, the board will not perform demand defrost operation.

The board will revert to time/temperature defrost operation

and will display the appropriate fault code. Heating and

cooling operation will be allowed in this fault condition.

Coil Sensor--The coil temperature sensor considers out-

door temperatures below -35°F (-37°C) or above 120°F

(48°C) as a fault. If the coil temperature sensor is detected

as being open, shorted or out of the temperature range of

the sensor, the board will not perform demand or time/tem-

perature defrost operation and will display the appropriate

fault code. Heating and cooling operation will be allowed in

this fault condition.

Discharge Line Sensor--If the discharge line tempera-

ture exceeds a temperature of 300°F (148°C) during com-

pressor operation, the board will de-energize the compres-

sor contactor output (and the defrost output, if active). The

compressor will remain off until the discharge temperature

has dropped below 225°F (107°C) and the 5-minute anti-

short cycle delay has been satisfied. This sensor has two

fault and lockout codes:

1. If the board recognizes five high discharge line tem-

perature faults during a single (Y1) compressor de-

mand, it reverts to a lockout mode and displays the ap-

propriate code. This code detects shorted sensor or

high discharge temperatures. (Code on board is "Dis-

charge Line Temperature Fault and Lockout").

2. If the board recognizes five temperature sensor range

faults during a single (Y1) compressor demand, it re-

verts to a lockout mode and displays the appropriate

code. The board detects open sensor or out-of-tem-

perature sensor range. This fault is detected by allow-

ing the unit to run for 90 seconds before checking sen-

sor resistance. If the sensor resistance is not within

range after 90 seconds, the board will count one fault.

After 5 faults, the board will lockout. (Code on board

is "Discharge Sensor Fault and Lockout").

The discharge line sensor, which covers a range of 150°F

(65°C) to 350°F (176°C), is designed to mount on a V:" re-

frigerant discharge line.

NOTE -Within a single room thermostat demand, if

5-strikes occur, the board will lockout the unit. Defrost

board 24 volt power "R" must be cycled "OFF" or the

"TEST" pins on board must be shorted between 1 to 2sec-

onds to reset the board.

Second-Stage Operation--If the board receives a call for

second-stage compressor operation "Y2" in heating or

cooling mode and the first-stage compressor output is ac-

tive, the second-stage compressor solenoid output will be

energized.

NOTE - Figure 8 on page 5 shows the correct Y2 field wir-

ing.

If first-stage compressor output is active in heating mode

and the outdoor ambient temperature is below the selected

compressor lock-in temperature, the second-stage com-

pressor solenoid output will be energized without the "Y2"

input. If the jumper is not connected to one of the tempera-

ture selection pins on P3 (40, 45, 50, 55°F), the default

lock-in temperature of 40°F (4.5°C) will be used.

The board de-energizes the second-stage compressor so-

lenoid output immediately when the "Y2" signal is removed

or the outdoor ambient temperature is 5°F above the se-

lected compressor lock-in temperature, or the first-stage

compressor output is de-energized for any reason.

Defrost Temperature Termination Shunt (Jumper)

Pins--The defrost board selections are: 50, 70, 90, and

100°F (10, 21, 32 and 38°C). The shunt termination pin is

factory set at 50°F (10°C). If the temperature shunt is not

installed, the default termination temperature is 90°F

(32°C).

Delay Mode

The defrost board has a field-selectable function to reduce

occasional sounds that may occur while the unit is cycling

in and out of the defrost mode. When a jumper is installed

on the DELAY pins, the compressor will be cycled off for 30

seconds going in and out of the defrost mode. Units are

shipped with jumper installed on DELAY pins.

NOTE - The 30 second off cycle is NOT functional when

jumpering the TEST pins.

Operational Description

The defrost control board has three basic operational

modes: normal, defrost, and calibration.

• Normal Mode--The demand defrost board monitors

the O line, to determine the system operating mode

(heat/cool), outdoor ambient temperature, coil tem-

perature (outdoor coil) and compressor run time to de-

termine when a defrost cycle is required.

• Calibration Mode--The board is considered uncali-

brated when power is applied to the board, after cool

mode operation, or if the coil temperature exceeds the

termination temperature when it is in heat mode.

Calibration of the board occurs after a defrost cycle to

ensure that there is no ice on the coil. During calibra-

tion, the temperature of both the coil and the ambient

sensor are measured to establish the temperature dif-

ferential which is required to allow a defrost cycle.

•Defrost Mode--The following paragraphs provide a

detailed description of the defrost system operation.

Detailed Defrost System Operation

The demand defrost control board initiates a defrost cycle

based on either frost detection or time.

Frost Detection--If the compressor runs longer than 34

minutes and the actual difference between the clear coil

and frosted coil temperatures exceeds the maximum dif-

ference allowed by the control, a defrost cycle will be initi-

ated.

IMPQR TANT -The demand defrost control board will allow

a greater accumulation of frost and will initiate fewer de-

frost cycles than a time/temperature defrost system.

504954M 0_06

Page 18

Time--If6 hoursof heatingmodecompressorruntime

haselapsedsincethelastdefrostcyclewhilethecoiltem-

peratureremainsbelow35°F(2°C),thedemanddefrost

controlwillinitiateadefrostcycle.

Actuation--Whenthereversingvalveis de-energized,

theY1circuitisenergized,andthecoiltemperatureisbe-

low35°F(2°C),theboardlogsthecompressorruntime,If

theboardisnotcalibrated,a defrostcyclewillbeinitiated

after34minutesof heatingmodecompressorruntime.

Thecontrolwillattempttoself-calibrateafterthis(andall

other)defrostcycle(s),

Calibrationsuccessdependsonstablesystemtempera-

turesduringthe20-minutecalibrationperiod,Iftheboard

failstocalibrate,anotherdefrostcyclewillbeinitiatedafter

90minutesof heatingmodecompressorruntime,Once

thedefrostboardiscalibrated,itinitiatesademanddefrost

cyclewhenthe differencebetweenthe clearcoil and

frostedcoiltemperaturesexceedsthe maximumdiffer-

enceallowedbythecontrolORafter6 hoursof heating

modecompressorruntimehasbeenloggedsincethelast

defrostcycle.

Termination--Thedefrostcycleendswhenthecoiltem-

peratureexceedstheterminationtemperatureorafter14

minutesofdefrostoperation.Ifthedefrostisterminatedby

the14-minutetimer,anotherdefrostcyclewillbeinitiated

after34minutesofruntime.

Test Mode--[NOTE - Coil sensor temperature must be

below 35°F before the defrost board will initiate a

"test" defrost.] When Y1 is energized and 24V power is

being applied to the board, a test cycle can be initiated by

placing the termination temperature jumper across the

"Test" pins for 2 to 5 seconds. If the jumper remains across

the "Test" pins longer than 5 seconds, the control will ig-

nore the test pins and revert to normal operation, The

jumper will initiate one cycle per test,

Enter the "TEST" mode by placing a shunt (jumper) across

the "TEST" pins on the board after power-up. (The "TEST"

pins are ignored and the test function is locked out if the

shunt is applied on the "TEST" pins before power-up),

Board timings are reduced, the low-pressure switch is ig-

nored and the board will clear any active lockout condition,

Each test pin shorting will result in one test event. For

each "TEST" the shunt (jumper) must be removed for at

least 1 second and reapplied, Refer to flow chart (figure

22) for "TEST" operation,

Note: The Y1 input must be active (ON) and the "0" room

thermostat terminal into board must be inactive.

Defrost Board Diagnostics

See table 10 to determine defrost board operational condi-

tions and to diagnose cause and solution to problems.

Short test pins for longer

than I second but less

than 2,0 seconds

Clear any short cycle lockout

and/or 5-strike fault lockout

function, if applicable. No

other functions will be

executed and unit will

continue in the mode it was

operating.

Test Mode

I Y1 Active ("0" line inactive) ]

Short test pins for more than 2.0 seconds

I If inCOOLING Mode

No further test mode

operation will be

executed until the test

short is removed and

reapplied.

Clear any short cycle lockout or 5-strike fault

lockout function, if applicable.

I I If in HEATING Mode I [ If in DEFROST Mode

Test pin short REMAINS in place for more than 5 seconds

The unit will return to Heat mode uncalibrated with defrost

timer set for 34 minutes. No further test mode operation will

be executed until the test short is removed and re applied.

The controller will check for

ambient and coil faults (open or

shorted). If a fault exists the unit

will remain in Heat Mode and no

further test mode operation will

be executed until the test short

is removed and re applied. If

no fault exists and ambient

temperature is below 35°F, the

unit will go into Defrost mode.

Figure 22

The unit will terminate

defrost and enter Heat

Mode uncalibrated with

defrost timer set for 34

minute test. No further

test mode operation will

be executed until the test

short is removed and

reapplied.

Test pins short REMOVED before a

maximum of 5 seconds

The unit will remain in Defrost mode

until termination on time or temperature

Page 19

HPXA16 SERIES

Table 10

Defrost Control Board Diagnostic LEDs

DS2 DS1

Green Red Condition/Code Possible Cause(s) Solution

OFF OFF Power problem No power (24V) to board termi- 1 Check control transformer power (24V).

nals R & C or board failure. 2 If power is available to board and LED(s) do

not light, replace board.

Simultaneous Normal operation Unit operating normally or in None required.

SLOW Flash standby mode.

Alternating 5-minute anti-short cycle Initial power up, safety trip, end of None required (Jumper TEST pins to override)

SLOW Flash delay room thermostat demand.

Simultaneous Ambient Sensor Problem Sensor being detected open or shorted or out of temperature range. Board will re-

FAST Flash vert to time/temperature defrost operation. (System will still heat or cool).

Alternating Coil Sensor Problem Sensor being detected open or shorted or out of temperature range. Board will not

FAST Flash perform demand or time/temperature defrost operation. (System will still heat or

cool).

ON ON Circuit Board Failure codeIndicatesdoesthatnotboardclear, hasreplaceinternalboard,component failure. Cycle 24 volt power to board. If

FAULT & LOCKOUT CODES (Each fault adds 1 strike to that code's counter; 5 strikes per code = LOCKOUT)

Low Pressure FaultOFF SLOW

Flash

OFF ON

SLOW

Flash

Low Pressure LOCKOUT

OFF High Pressure Fault

ON OFF

SLOW ON

Flash

FAST ON

Flash

OFF Fast

Flash

Fast OFF

Flash

High Pressure LOCKOUT

Discharge Line Tempera-

ture Fault

Discharge Line Tempera-

ture LOCKOUT

Discharge Sensor Fault

Discharge Sensor

LOCKOUT

1 Restricted air flow over indoor or

outdoor coil.

2 Improper refrigerant charge in

system.

3 Improper metering device

installed or incorrect operation

of metering device.

4 Incorrect or improper sensor

location or connection to sys-

tem.

1 Remove any blockages or restrictions from

coils and/or fans. Check indoor and outdoor

fan motor for proper current draws.

2 Check system charge using approach & sub-

cooling temperatures.

3 Check system operating pressures and

compare to unit charging charts.

4 Make sure all pressure switches and sensors

have secure connections to system to prevent

refrigerant leaks or errors in pressure and

temperature measurements.

This code detects shorted sensor or high discharge temperatures. If the discharge

line temperature exceeds a temperature of 300°F (148°C) during compressor op-

eration, the board will de-energize the compressor contactor output (and the defrost

output if active). The compressor will remain off until the discharge temperature has

dropped below 225°F (107°C).

The board detects open sensor or out of temperature sensor range. This fault is

detected by allowing the unit to run for 90 seconds before checking sensor resist-

ance. If the sensor resistance is not within range after 90 seconds, the board will

count one fault. After 5 faults, the board will lockout.

504954M 0_06

Page 20

,WARNING

Before the start of each heating and cooling season, the

following service checks should be performed by a quali-

fied service technician. First, turn off electrical power to the

unit prior to performing unit maintenance,

• Inspect and clean the outdoor and indoor coils, The

outdoor coil may be flushed with a water hose,

NOTE -It may be necessary to flush the outdoor coil

more frequently if it is exposed to substances which

are corrosive or which block airflow across the coil

(e.g., pet urine, cottonwood seeds, etc.)

• Visually inspect the refrigerant lines and coils for leaks,

• Check wiring for loose connections,

• Check voltage at the indoor and outdoor units (with

units operating),

• Check the amperage draw at the outdoor fan motor,

compressor, and indoor blower motor. Values should

be compared with those given on unit nameplate,

• Check, clean (or replace) indoor unit filters,

• Check the refrigerant charge and gauge the system

pressures,

• Check the condensate drain line for free and unob-

structed flow; clean, if necessary.

• Adjust blower speed for cooling. Measure the pressure

drop over the coil to determine the correct blower CFM

Refer to the unit information service manual for pressure

drop tables and procedure.

• Check drive belt for wear and proper tension.

NOTE -If owner reports insufficient cooling, the unit

should be gauged and refrigerant charge checked. Re-

fer to section on refrigerant charging in this instruction.

Refer to the Engineering Handbook for optional accesso-

ries that may apply to this unit. The following may or may

not apply:

• Loss of charge kit

• High pressure switch kit

• Compressor monitor

• Compressor crankcase heater

• Hail guards

• Mounting bases

• Timed-off control

• Stand-off Kit

• Sound cover

• Low ambient kit

• Monitor kit

• Dave Lennox SignatureStat Room Thermostat

Page 21

HPXA16 SERIES

Job Name

Job Location

Installer

Unit Model No,

Nameplate Voltage

Rated Load Ampacity

Maximum Fuse or Circuit Breaker

Electrical Connections Tight?

Serial No.

Job no.

City

Compressor Amperage: 1st Stage

Indoor Filter clean?

Indoor Blower RPM

COOLING (2ND STAGE)

Liquid Line Pressure:

HEATING (2ND STAGE)

Liquid Line Pressure: Vapor Pressure:

Vapor Pressure; 1st Stage: 2nd Stage:

Refrigerant Lines: - Leak Checked? _ Properly Insulated?

Service Valves: --- Fully Opened? _ Caps Tight?

SEQUENCE OF OPERATION

Heating Correct? _ Cooling Correct?

S.P. Drop Over Indoor (Dry)

Vapor Pressure:

Date

State

Service Technician

2nd Stage:

Supply Voltage (Unit Off)

Outdoor Coil Entering Air Temp.

Refrigerant Charge Checked?

Outdoor Fan Checked?

Voltage With Compressor Operating

THERMOSTAT

Calibrated? Properly Set? _ Level?

504954M 08/06

Page 22

:c'2006 Lennox industries Inc,

Dallas, Texas, USA HPXA16

In order to ensure peak performance, your system must be

properly maintained. Clogged filters and blocked airflow

prevent your unit from operating at its most efficient level.

1. Ask your Lennox dealer to show you where your indoor

unit's filter is located. It will be either at the indoor unit

(installed internal or external to the cabinet) or behind

a return air grille in the wall or ceiling. Check the filter

monthly and clean or replace it as needed.

2. Disposable filters should be replaced with a filter of the

same type and size.

NOTE -If you are unsure about the filter you need for

your system, call your Lennox dealer for assistance.

AIMPORTANT

3. Many indoor units are equipped with reusable foam fil-

ters. These filters can be cleaned with a mild soap and

water solution. Rinse the filter thoroughly and let it dry

completely before it is returned to the unit or grille.

NOTE -The filter and all access panels must be M

place any time the unit is in operation.

4. Some systems are equipped with an electronic air

cleaner, designed to remove the majority of airborne

particles from the air passing through the cleaner. If

your system is so equipped, ask your dealer for main-

tenance instructions.

5. Inspect and clean indoor coil. The indoor evaporator

coil is equipped with a drain pan to collect condensate

formed as your system removes humidity from the in-

side air. Have your dealer show you the location of the

drain line and how to check for obstructions. (This

would also apply to an auxiliary drain, if installed.)

AIMPORTANT

Heat Pump Operation

Your new Lennox heat pump has several characteristics

that you should be aware of:

• Heat pumps satisfy heating demand by delivering

large amounts of warm air into the living space. This

is quite different from gas- or oil4ired furnaces or an

electric furnace which deliver lower volumes of consid-

erably hotter air to heat the space.

• Do not be alarmed if you notice frost on the outdoor coil

in the winter months. Frost develops on the outdoor

coil during the heating cycle when temperatures are

below 45°F (7°C). An electronic control activates a de-

frost cycle lasting 5 to 15 minutes at preset intervals

to clear the outdoor coil of the frost.

• During the defrost cycle, you may notice steam rising

from the outdoor unit. This is a normal occurrence. The

thermostat may engage auxiliary heat during the de-

frost cycle to satisfy a heating demand; however, the

unit will return to normal operation at the conclusion of

the defrost cycle.

In case of extended power outage...

The heat pump is equipped with a compressor crankcase

heater which protects the compressor from refrigerant

"slugging" during cold weather operation.

If power to your unit has been interrupted for several hours

or more, set the room thermostat selector to the "Emer-

gency Heat" setting to obtain temporary heat without the

risk of serious damage to the heat pump.

In Emergency Heat mode, all heating demand is satisfied

by auxiliary heat; heat pump operation is locked out. After a

six-hour compressor crankcase "warm-up" period, the

thermostat can be switched to the "Heat" setting and nor-

mal heat pump operation may resume.

Page 23

HPXA16 SERIES

Though your thermostat may vary somewhat from the de-

scription below, its operation will be similar,

Temperature Setting Levers

Most heat pump thermostats have two temperature selec-

tor levers: one for heating and one for cooling, Set the lev-

ers or dials to the desired temperature setpoints for both

heating and cooling. Avoid frequent temperature adjust-

ment; turning the unit off and back on before pressures

equalize puts stress on the unit compressor,

Fan Switch

In AUTO or INT (intermittent) mode, the blower operates

only when the thermostat calls for heating or cooling. This

mode is generally preferred when humidity control is a

priority. The ON or CONT mode provides continuous in-

door blower operation, regardless of whether the com-

pressor or auxiliary heat are operating. This mode is re-

quired when constant air circulation or filtering is desired,

System Switch

Set the system switch for heating, cooling or auto opera-

tion, The auto mode allows the heat pump to automatically

switch from heating mode to cooling mode to maintain pre-

determined comfort settings. Many heat pump thermo-

stats are also equipped with an emergency heat mode

which locks out heat pump operation and provides tempo-

rary heat supplied by the auxiliary heat,

Indicating Light

Most heat pump thermostats have an amber light which in-

dicates when the heat pump is operating in the emergency

heat mode,

Temperature Indicator

The temperature indicator displays the actual room tem-

perature,

Programmable Thermostats

Your Lennox system may be controlled by a program-

mable thermostat. These thermostats provide the added

feature of programmable time-of-day setpoints for both

heating and cooling. Refer to the user's information manu-

al provided with your particular thermostat for operation

details,

Preservice Check

If your system fails to operate, check the following before

calling for service:

• Check to see that all electrical disconnect switches are

ON.

• Make sure the room thermostat temperature selector

is properly set.

• Make sure the room thermostat system switch is prop-

erly set.

• Replace any blown fuses, or reset circuit breakers,

• Make sure unit access panels are in place,

• Make sure air filter is clean,

• Locate unit model number and have it handy before

calling,

504954M 0_06

Page 24

LENNOX Air Conditioner/heat Pump(outside Unit) Manual L0806497

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