LENNOX Air Conditioner/heat Pump(outside Unit) Manual L0806540

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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INSTALLATION
INSTRUCTIONS

®
,1,_2008
Lennox
industries
Inc,
Dallas,
Texas,
USA

Dave Lennox Signature ®
Collection XP15 Units
HEAT PUMP
505,328M

_-_Technical
U£[ Publications

UNITS

04/08

Litho U.S.A.

Supersedes 03/08

RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE

X_ WARNING

_, CAUTION

A IMPORTANT

IMPORTANT

XP15 Outdoor Unit ............................
Shipping and Packing List ......................
Unit Dimensions ...............................
General Information ...........................
Recovering Refrigerant from Existing System .....
Positioning New Outdoor Unit ..................
Removing Panel ..............................
Electrical Connections .........................
New or Replacement Line Set ...................
Brazing Line Set Connections ...................
Removing Existing Refrigerant Metering Device . ..
Testing for Leaks ..............................
Removing Service Valve Port Core ..............
Flushing Existing System .......................
Installing New Refrigerant Metering Device .......
Installing Service Valve Port Core ...............
Evacuating the System .........................
Start-Up Procedures ...........................
System Operations ............................
Lennox System Operation Monitor (LSOM) .......
Defrost System ...............................
Maintenance ..................................
Homeowner Information ........................
Start-Up and Performance Checklist .............

1
1
2
2
4
5
6
7
9
11
11
11
12
12
13
14
14
15
19
19
21
26
26
28

The Lennox XP15 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, XP15 series outdoor units are
designed for use in check expansion valve (CTXV)
systems only, and are not designed to be used with other
refrigerant flow control devices. The Lennox Engineering
Handbook lists compatible indoor CTXV kits which are
ordered separately.

1 - Assembled XP15 outdoor unit
1 - Bushing (for low voltage wiring)
2 - Grommets (for liquid and vapor lines)
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.

04/08

IIIHIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

Page 1

505,328M

IIIIIIIIIIIIIIIIIIIIIIHIIIIII

39-1/2

DISCHARGE

(1003)

AIR

35-1/2
(902)

ELECTRICAL

IN_ETS

37 (94O)
[-024 thru -042]
47 (1194)
[-048 and -060]

VAPOR LINE

4-7/16.__
(113)

INLET

LIQUID LINE
/INLET

18!1/2
(470)

7-8 (203)
1 (25)

SIDE VIEW

ACCESS VIEW

UNIT SUPPORT
FEET \
FAN
DEFROST CONTROL

Y
16-7/8

(429)

COMPRESSOR
DOME

VAPOR VALVE AND
26-7/8

(6_3)

8 -3/4

CAPACITOR

SYSTEM
OPERATION
MONITOR
CONTACTOR

GAUGE PORT ..

DISCHARGE

COMPRESSOR
PLUG

LINE

LOW PRESSURE

(2_2)

3-3/4 (95)
_'
4-5/8
(117)

3-1/8
(79) "-_

VAPOR
FILTER

HIGH PRESSURE
SWITCH

BASE WITH ELONGATED LEGS
XP15

WARNING

Parts Arrangement

I
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
who have jurisdiction before installation.
When servicing or repairing HVAC components, ensure
caps and fasteners are appropriately tightened. Table 1
lists torque values for typical service and repair items.
Table 1. Torque Requirements
Part

Page 2
505328M

04/08

Recommended

Torque

Service valve cap
Sheet metal screws

8 ft.- lb.
16 in.- lb.

11 NM
2 NM

Machine screws #10

28 in.- lb.

3 NM

Compressor bolts

90 in.- lb.

10 NM

Gauge port seal cap

8 ft.- lb.

11 NM

USINGMANIFOLD

GAUGE SETS
HFC-410A refrigerant manifold gauge sets must be
capable of handling higher system operating pressures.
The gauge set shall be rated for use with pressures of 0 800 psig on the high side, and a low side of 30 inches of
vacuum (Hg) to 250 psig, which retards when opened to
500 psig. Gauge hoses must be rated for use up to 800 psig
of pressure with a 4000 psig burst rating,
OPERATING SERVICE VALVES

2. Connect gauge to the service port.
3. When testing is completed, replace service port cap and
tighten as follows:
•

With Torque Wrench: Finger tighten and then
tighten per table 1 on page 2.

•

Without Torque Wrench: Finger tighten and with an
appropriately sized wrench to turn an additional
1/6 turn clockwise as illustrated in figure 1.

To Open and Close Angle-Type Service Valve:

IMPORTANT

A valve stem cap protects the valve
contamination and assures a leak-free seal.

stem

from

1, Remove stem cap with a wrench,
2. Use a service wrench with a hex-head extension
(3/16" for liquid-line valve sizes and 5/16" for
vapor-line valve sizes) to back the stem out
counterclockwise as far as it will go.
3. Replace the stem cap and tighten as follows:

The liquid and vapor lines service valves with gauge ports
as illustrated in figures 2 and 3 are used for removing
refrigerant, flushing, leak testing, evacuating, checking
charge and charging,
Each valve is equipped with a service port which has a
factory-installed valve stem.

•

With Torque Wrench: Tighten finger tight and then
tighten per table 1 on page 2.

•

Without Torque Wrench: Finger tighten and with an
appropriately sized wrench to turn an additional
1/12 turn clockwise as illustrated in figure 1,

NOTE -A label with specific torque requirements may be
affixed to the stem cap, If the label is present, use the
specified torque listed,
SERVICE

PORT

CAP

1/12 TURN

1/6 TURN

SERVICE

PORT

VALVE IS FRONT-SEATED
(CLOSED)

jSERV,CEPORT

CLOSED TO BOTH
INDOOR AND
OUTDOOR UNITS]
VALVE STEM

FRON%SEATEI_
TO INDOOR
UNIT CORE

This illustrates how to use a wrench to tighten caps an additional
1/6 or 1/12 turn clockwise.

Figure 1. Cap Tightening

,, HHERE
_

TO OUTDOOR
UNIT

IMPORTANT

PORT

_:_

Valve

VALVE IS(oPENED)BACK=SEATED

SERVICE

PORT

_
(VALVE STEM

OUTDOOR UNITS]
VALVE STEM

Service

CAP _

CORE
SERVICE
PORT
OPEN
TO BOTH
INDOOR AND

Angle-Type

Distances
SERVICE

Operating

SHOWN
OPEN)INSERT
HEX
WRENCH HERE

TO INDOOR
UNIT

To Access Angle-Type Service Port:
A service port cap protects the service port core from
contamination and serves as the primary leak seal.

BACKED-SEATE_

TO OUT
UNIT

1. Remove service port cap using an appropriately sized
wrench.

Figure 2. Angle -Type Service Valve

Page 3
XP15 SERIES

Operating

Bali-Type

Service

Valve

To Access Bali-Type Service Port:
A service port cap protects the service port core from
contamination and serves as the primary leak seal,
1, Remove service port cap using an appropriately sized
wrench,
2. Connect gauge to the service port.
3, When testing is completed, replace service port cap and
tighten as follows:
•
•

Remove existing HCFC-22 refrigerant using one of the
following methods:
METHOD 1:
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 or refrigerant to flush the system:

With Torque Wrench: Finger tighten and then
tighten per table table 1 on page 2.

1, Disconnect all power to the existing outdoor unit,
2, Connect to the existing unit a gauge set, clean
recovery cylinder and a recovery machine. Use the
instructions provided with the recover machine on how
to setup the connections,

Without Torque Wrench: Finger tighten and use an
appropriately sized wrench to turn an additional
1/6 turn clockwise as illustrated in figure 1,

To Open and Close Bali-Type Service Valve:
A valve stem cap protects the valve stem
contamination and assures a leak-free seal,

3, Remove all HCFC-22 refrigerant from the existing
system, Check gauges after shutdown to confirm that
the entire system is completely void of refrigerant,

from

1, Remove stem cap with a wrench,

4, Disconnect the liquid and vapor lines from the existing
outdoor unit,

2, Use an adjustable wrench to open, To open valve,
rotate stem counterclockwise 90 °, To close rotate
stem clockwise 90 ° .
3, Replace the stem cap and tighten as follows:
•
With Torque Wrench: Finger tighten and then
tighten per table 1 on page 2.
•

5, Remove the existing outdoor unit,
NOTE - Use recovery machine instructions
setup requirements.

Without Torque Wrench: Finger tighten and use an
appropriately sized wrench to turn an additional
1/12 turn clockwise as illustrated in figure 1.

Recovery Machine

NOTE - A label with specific torque requirements may be
affixed to the stem cap. If the label is present, use the
specified valve listed.
To
Open to line set when valve
is closed, to both line set
and unit when valve is open.

INDOOR

for specific

Manifold Gauges

UNIT

Ball (Shown Closed)
Clean Recovery Cylinder

Outdoor/_Unit

Valve Stem

Figure 4. Typical Refrigerant Recovery (Method 1)
Service Port

METHOD 2:

Service Port
Core

Service Port
Cap
STEM

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 -

CAP

1, Start the existing HCFC-22 system in the cooling
mode and close the liquid line valve,

To outdoor unit

2, Pump all of the existing HCFC-22 refrigerant back into
the outdoor unit,

Use Adjustable Wrench To open: rotate Stem Counter-Clockwise 90 °.To close: rotate Stem clockwise 90 °.

Figure 3. Bali-Type Service Valve

NOTE - It may be necessary to bypass the low pressure
switches to ensure complete refrigerant evacuation.

Page 4
505328M

04/08

3. Whenthe lowsidesystempressuresreach0 psig,
closethevaporlinevalve,
4. Disconnectall powerto the existingoutdoorunit.
Checkgaugesafter shutdownto confirmthat the
valvesarenotallowingrefrigerant
toflowbackintothe
lowsideofthesystem,
5. Disconnect
theliquidandvaporlinesfromtheexisting
outdoorunit.
6. Removetheexistingoutdoorunit,

Install unit away
from windows

CAUTION
Two 90 ° elbows installed in line set
will reduce line set vibration.

See Unit Dimensions on page 2 for sizing mounting slab,
platforms or supports, Refer to figure 5 for mandatory
installation clearance requirements.

Figure 6. Outside Unit Placement
PLACING UNIT ON SLAB
When installing a unit at grade level, the top of the slab
should be high enough above the grade so that water from
higher ground would not collect around the unit as
illustrated in figure 7. Slab may be level or have a slope
tolerance away from the building of not more than two
degrees, or 2 inches per 5 feet (51 mm per 1524 mm).
Install unit level or, if on a slope, maintain slope tolerance of 2
degrees (or 2 inches per 5 feet [50 mm per 1.5 m]) away from
building structure.

Building
Structure

J
NOTES:
7/
Service clearance of 30 in, (762 mm) must be maintained on one of
the sides adjacent to the control box,

Mounting
Slab

Clearance to one of the other three sides must be 36 in, (914 mm)
Clearance to one of the remaining two sides may be 12 in. (305
mm) and the final side may be 6 in, (152 mm)

-T--

48 in, (1219 ram) clearance required on top of unit,

Figure 7. Ground Level Slab Mounting

A clearance of 24 in, (610 mm) must be maintained between two
units

Figure 5. Installation Clearances
POSITIONING CONSIDERATIONS
Some localities are adopting sound ordinances based on
the unit's sound level registered from the adjacent
property, not from the installation property, Install the unit
as far as possible from the property line. When possible,
do not install the unit directly outside a window, Glass has a
very high level of sound transmission.
For proper
placement of unit in relation to a window see the provided
illustration in figure 6.

INSTALLING UNIT ON ROOF
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 as illustrated in
figure 8. 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.

Page 5
XP15 SERIES

PREVAILING
WINTER
WINDS _.
I
WIND BARRIER
INLET AIR

With unit
Iouvered
brackets
practices;

positioned at installation site, remove two side
panels to expose the unit base pan. Install the
as illustrated in figure 10 using conventional
replace the panels after installation is complete.

2_'_6" 10 ram)

IMPORTANT
INLETAIR

INLET AIR

Figure 8. Rooftop Application and Wind Barrier
NOTE - If necessary for stability, anchor unit to slab as
described in Stabilizing Unit on Uneven Surfaces.

Slab Side Mounting

#101/2" LONG
SELF-DRILLING
SHEET
METAL SCREWS

ELEVATING THE UNIT
These units are outfitted with elongated-shaped
illustrated in figure 9.

feet as
STABILIZING BRACKET
(18 GAUGE METAL - 2"
RW/DTDH
i HEIGHT
BASE

AS _,_1 f, _

#10 1-1/4" LONG HEX
HD SCREW AND
FLATWASHER

PLASTIC

ANCHOR

- USE IF CONCRETE

(HOLE DRILL 1/4"); NOT IF PLASTIC
(HOLE DRILL 1/8").

SLAB

Mounting
STABILIZING
BRACKET (18
GAUGE METAL - 2"
LEG DETAIL

2"(50.8MM)
SCH 40
FEMALE
THREADED
ADAPTER

WIDTH; HEIGHT
AS REQ'D); BEND
TO FORM RIGHT
ANGLE

Deck Top

MINIMUM 1
PER SIDE

FOR EXTRA
STABILITY

ONE BRACKET PER SIDE (MIN.); FOR EXTRA STABILITY,
TWO BRACKETS PER SIDE, 2" FROM EACH CORNER.

Figure 9. Elevated Slab Mounting using Feet
Extenders (Larger Base Units)

Figure 10. Installing Stabilizer
If additional elevation is necessary, raise the unit by
extending the height of the unit support feet. This may be
done with 2" SCH 40 female threaded adapter. The
specified coupling will fit snuggly into the recess portion of
the feet. Use additional 2" SCH 40 male threaded adapters
which can be threaded into the female threaded adapters
to make additional adjustments to the level of the unit.
NOTE - Keep the height of extenders short enough to
ensure a sturdy installation, If it is necessary to extend
further, consider a different type of field-fabricated
framework that is sturdy enough for greater heights.
STABILIZING

UNIT ON UNEVEN SURFACES

To help stabilize an outdoor unit, some installations may
require strapping the unit to the pad using brackets and
anchors commonly available in the marketplace.
Page 6
505328M

04/08

CAUTION

Brackets

MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE
AS POSSIBLE) WHILE INSTALLING PANEL.

TO PARALLEL
HOLD DOOR

ANGLE MAY BE TOO
EXTREME

FIRMLY ALONG

THE HINGED SIDE TO MAINTAIN
FULLY-ENGAGED
TABS

PREFERRED
ANGLE
FOR INSTALLATION

REMOVE
4SCREWS
TOREMOVE
PANEL
FOR
ACCESSING
COMPRESSOR
AND
CONTROLS.
_

WITH THE UNIT

INSTALL
BY
POSITIONING
PANEL
WITH
HOLES
ALIGNED;
INSTALL
SCREWS
AND
TIGHTEN.
Detail D

Figure 11. Access Panel

IMPORTANT! DO NOT ALLOW
PANELS TO HANG ON UNIT BY
TOP TAB. TAB IS FOR ALIGNMENT

K-_

ANDNOT
DESIGNED
TOSUPPORT

)

WE,G
HT
OP
FAN
EL
PANEL
SHOWN
SLIGHTLY
ROTATED
TO ALLOW
TOP TAB TO
EXIT (OR ENTER)

TOP SLOT FOR

__
_

PANEL.
REMOVING

(OR INSTALLING)
SCREW

HOLES
......
_

_iii
i_///l

_
t_

Detail A
Detail B

-_-_\_

Figure 13. Removing/Installing Louvered Panels
(Detail D)
ACCESS PANEL
Removal and reinstallation of the access panel is
illustrated in figure 11,
LOUVERED PANELS
Remove the Iouvered panels as follows:
1, Remove two screws, allowing the panel to swing open
slightly.
2, Hold the panel firmly throughout this procedure.
Rotate bottom corner of panel away from hinged
corner post until lower three tabs clear the slots as
illustrated in figure 12, detail B.
3, Move panel down until lip of upper tab clears the top
slot in corner post as illustrated in figure 12, detail A,
Position and Install Panel--Position the panel almost
parallel with the unit as illustrated in figure 13, detail D with
the screw side as close to the unit as possible. Then, in a
continuous motion:
•

•
•

ROTATE IN THIS DIRECTION;
THEN DOWN TO REMOVE PANEL

Figure 12. Removing/Installing Louvered Panels
(Detail A, B and C)

A'kWARNING

Slightly rotate and guide the lip of top tab inward as
illustrated in figure 12, details A and C; then upward
into the top slot of the hinge corner post.
Rotate panel to vertical to fully engage all tabs,
Holding the panel's hinged side firmly in place, close
the right-hand side of the panel, aligning the screw
holes.

When panel is correctly positioned and aligned, insert the
screws and tighten.

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),
ELECTRICAL AND CONTROL CONNECTIONS
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.
NOTE - Connect conduit to the unit using a proper conduit
fitting. Units are approved for use only with copper
conductors. A complete unit wiring diagram is located on
the back side of the unit's access panel.
NOTE - For proper voltages, select thermostat wire gauge
per the following chart:
Page 7
XP15 SERIES

Table 2. Wire Run Length
Wire Run Length

AWG #

Insulation Type

less than 100' (30m)

color-coded, temperature

more than 100' (30m)

rating 35°C minimum

wall or where sunlight, drafts or vibrations affect it.
2. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit as illustrated in
figure 14.
3. Install line voltage power supply to unit from a properly
sized disconnect switch as illustrated in figure 15.
4. Ground unit from ground lug as illustrated in figure 15
to unit disconnect switch, or to an earth ground.

1. Install room thermostat (ordered separately) on an
inside wall approximately in the center of the area and
5 feet (1.5 m) from the floor. Do not install on an outside

_._

CB31MV
CBX32MV

TBI

BLACK

A2 SIGNATURE
81M2B
TWISTEO
PAIR

CONTACTOR
RTI$

(W5_

AMBIENT
SENSOR

(W8

OMPRESSOR
54O
AI32

R721

DEFROST

COIL

"-(v _

SENSOR

S4HIGH
PRESSURE

SWITCH

$87

G
©
@

HRI

LOW

PRESSURE
SWITCH

NOTE
FOR USE WITH
COPPER
CONDUCTORS
ONLY.
REFER
TO UNIT
RATING
PLATE
FOR
MINIMUM
CIRCUIT
AMPACITY
AND
MAXIMUM
OVER CURRENT
PROTECTION
SIZE

REFER ACTUAL
TO COMPRESSOR
FOR
TERMINAL

WARNING
ELECTRIC
SHOCK
HAZARD,CAN
CAUSE
INJURY
OR DEATH.UNIT
MUST
BE GROUNDED
IN
ACCOROANCE
WITH
NATIONAL
AND LOCAL
CODES.

RTI4

w
AI32

LI
REVERSING

VALVE

A
EQUIPMENT
GROUND

•

COMPRESSOR
CONTACTOR

SENSOR,

OUTDOOR

N UNIT
mRmANGEMENT.

TEMP

(OPTIONAL)

LINE
VOLTAGE
FIELD
INSTALLED
CLASS
II
VOLTAGE
FIELD
INSTALLED

LZ_

Figure

14. Typical

Low-Voltage

Field Wiring

GROUNDLUG

CONTROLBOX

_'-

CONTACTOR

DEFROST CONTROL
BOARD (DCB)
GROUND
-''_/

208-230/60/1

L_)NNN
TOoXR
t LYs'<
oTE_

OPERATION

L1
"__

L2
K1-1 COMPRESSOR

_[3_/

CAPACITOR

CONTACTOR

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 plate for minimum circuit ampacity and maximum over-current

Figure 15. Typical High-Voltage Field Wiring

Page 8
505328M

04/08

(Unit Panel)

protection size.

This section providesinformationon installationor
replacement
ofexistinglinesets.If linesetsarenotbeing
installed
or replace,thenproceedto Brazing Connections

Line sets for heat pump applications can not be installed
underground. For more information see the Lennox
Refrigerant Piping Design and Fabrication Guidelines, or
contact Lennox Technical Support Product Applications
for assistance.
Table 3. Refrigerant Line Sets
Valve Sizes
Recommended Line Set

on page 11.
If refrigerant lines are routed through a wall, seal and
isolate the opening so vibration is not transmitted to the
building, Pay close attention to line set isolation during
installation of any HVAC system. When properly isolated
from building structures (walls, ceilings, floors), the
refrigerant lines will not create unnecessary vibration and
subsequent sounds.
REFRIGERANT

Model

-030
--036
-042

-060

MATCHING WITH NEW OR EXISTING INDOOR COIL
AND LINE SET

IMPORTANT

Vapor

Liquid

Vapor

Line

3/8 in.
(10mm)

3/4 in.
(19mm)

3/8 in
(10mm)

3/4 in.
(19mm)

L15-41
15-50ft.
(5 - 15 m)

3/8 in.

7/8 in

3/8 in.

7/Sin

(10mm)

(22mm)

(10mm)

(22mm)

L15-65
15 - 50 ft.
(5-15m)

3/8 in.
(10 ram)

1-1/8 in,
(29 ram)

3/8 in.
(10 ram)

1-1/8 in,
(29 ram)

Field
Fabricated

-024

LINE SET

Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections) to the indoor unit
coil (flare or sweat connections). Use Lennox L15 (sweat,
non41are) series line sets, or use field-fabricated
refrigerant lines as listed in table 3.

L15
LineSets

Liquid

INSTALLING LINE SET
Line
Set
Isolation--This
reference
illustrates
procedures, which ensure proper refrigerant line set
isolation:
•

Installation of line sets on
illustrated in figure 16.

•

Installation of line sets on vertical
in figure 17 on page 10.

•

Installation of a transition from
horizontal
vertical is illustrated in figure 18 on page 10.
TO HANG LINE SET FROM JOIST OR RAFTER,
USE EITHER METAL STRAPPING MATERIAL OR
ANCHORED
HEAVY NYLON WIRE TIES.
STRAPPING
(AROUND

runs is illustrated
to

WIRE TIE (AROUND
VAPOR LINE ONLY

8 FEET

METAL
SLEEVE

_._

TAPE OR
WIRE TIE

STRAP THE VAPOR LINE TO THE
JOIST OR RAFTER AT 8 FEET
INTERVALS
THEN STRAP
THE
LIQUID LINE TO THE VAPOR LINE.

FLOOR JOIST OR
ROOF RAFTER

Number of elbows and if there is a rise or drop of the
piping.

MATERIAL

TAPE OR

Line set diameters for the unit being installed (from
table 3)

runs

VAPOR LINE
ONLY)

When installing refrigerant lines longer than 50 feet, see
the Lennox Refrigerant Piping Design and Fabrication
Guidelines, or contact Lennox Technical Support Product
Applications
for assistance.
To obtain the correct
information from Lennox, be sure to communicate the
following points:

Model (XP15) and size (e.g. -060) of unit.

horizontal

_ _%
_-

Figure 16. Refrigerant Line Sets: Installing
Horizontal Runs

Page 9
XP15 SERIES

IMPORTANT
- MUST
OUTSIDE
WALL
REFRIGERANT
LINES
NOT
CONTACT
WALL.
VAPOR
LINE
LIQUID
LINE

ANCHORED
HEAVY
NYLON
WIRE
TIE

WALL
STUD
NOTE
-SIMILAR
INSTALLATION
PRACTICES
SHOULD
BE
USED
IFLINE
SET
ISTO
BE
INSTALLED
ON
EXTERIOR
OF
OUTSIDE
WALL.

STRAP
LIQUID
LINE
TO
VAPOR
LINE
JID
LINE
METAL
SLEEVE
VAPOR
-WRAPPED
INLINE
ARMAFLEX
AUTOMOTIVE
MUFFLER-TYPE
HANGER

VAPOR
LINE
WRAPPED
WITH
ARMAFLEX
WALL
STUD
IMPORTANT!
REFRIGERANT
LINES
MUST
NOT
CONTACT
STRUCTURE.

IUID
LINE
TO
VAPOR
LINE
LIQUID
LINE

PVC
_
CAULK
PIPE FIBERGLASS
INSULATION

VAPOR
WRAPPED
METAL
SLEEVE
INLINE
ARMAFLEX

Figure 17. Refrigerant Line Sets: Installing Vertical
Runs (New Construction Shown)

Figure 18. Refrigerant Line Sets: Transition from
Vertical to Horizontal

REMOVE CAP AND CORE FROM
BOTH LIQUID AND SUCTION
SERVICE PORTS

CUT AND DEBUR

SERVICE PORT MUST BE
OPEN TO ALLOW EXIT
POINT FOR NITROGEN

INDOOR

UNIT

SUCTION

LINE

SERVICE
/VALVE
UNIT
outdoor

_QU_D
UNE

SERV_CEJ
VALVE

INSTALL CORE ONLY FOR
3OTH SERVICE PORTS after they
have coolED.

Figure 19. Brazing Connections
Page 10
505328M

04/08

ISOLATION GROMMETS
Locate the provided isolation grommets Slide grommets
onto vapor and liquid lines Insert grommets into mullion to
isolate refrigerant lines from sheet metal edges

Use the following procedure to braze the line set to the new
outdoor unit Figure 19 is provided as a general guide for
preparing to braze the line sets to the outdoor unit
Before brazing, remove the access panel as illustrated in
figure 11; then remove the narrow piping panel to prevent
burning off the paint as illustrated in figure 20

underneath the valve body to protect the base paint,
Also, shield the light maroon R-410A sticker.
5. Flow regulated nitrogen (at 1 to 2 psig) through the
refrigeration gauge set into the valve stem port
connection on the liquid line service valve and out of
the valve stem port connection on the vapor service
valve. The CTXV metering device at the indoor unit
coil will allow low pressure nitrogen to flow through the
system,)
Note: Use silver alloy brazing rods with five or six percent
minimum silver alloy for copper-to-copper brazing or 45
percent silver alloy for copper-to-brass or copper-to-steel
brazing,
6. Braze the line set to the liquid line service valve. Turn
off nitrogen flow, Repeat procedure starting at
paragraph 4 for brazing the vapor line set to service
valve,
After brazing the vapor line set to the service valve,
disconnect gauge from service port, remove wrapping and
replace service port cores.

REMOVE TWO SCREWS
AND REMOVE PANEL
BEFORE BRAZING

LINE SET
CONNECTION
POINTS

Remove the existing HCFC-22 refrigerant flow control
orifice or thermal expansion valve from the indoor coil.
Existing devices are not approved for use with HFC-410A
refrigerant and may prevent proper flushing. Use a
field-provided fitting to reconnect lines, See figure 23 on
page 13 for disassembly and typical removal instructions.

Figure 20. Piping Panel Removal

WARNING

After the line set has been connected to both the indoor
and outdoor units, check the line set connections at both
the indoor and outdoor units unit for leaks. Use the
following procedure to test for leaks:

IMPORTANT

_WARNING

WARNING

1. Cut ends of the refrigerant lines square (free from
nicks or dents). Debur the ends. The pipe must remain
round, do not pinch end of the line.
2. Remove service cap and core from both the vapor and
liquid line service ports.

AWARNING

3. Connect gauge low pressure side to liquid line service
valve,
4. To protect components during brazing, wrap a wet
cloth around the liquid line service valve body and
copper tube stub and use another wet cloth
Page 11
XP15 SERIES

WARNING

OUTOOORO.,T

SERVICE

VALVE

REMOVE SERVICE
PORT CAP

REMOVE

PORT CORE

Figure 21. Typical Service Valve Port Core Removal

A IMPORTANT
1 Connect an HFC410A manifold gauge set high
pressure hose to the vapor valve service port
(Normally the high pressure hose is connected to the
liquid line port; however, connecting it to the vapor port
better protects the manifold gauge set from high
pressure damage.)

A IMPORTANT

2 With both manifold valves closed connect the cylinder
of HFC410A refrigerant to the center port of the
manifold gauge set Open the valve on the HFC 410A
cylinder (vapor only)
3 Open the high pressure side of the manifold to allow
HFC 410A into the line set and indoor unit
4 Weigh in a trace amount of HFC410A
[,4 trace
amount is a maximum of two ounces (57 g) refrigerant
or three pounds (31 kPa) pressure].
5, Close the valve on the HFC-410A cylinder and the
valve on the high pressure side of the manifold gauge
set.
6. Disconnect the HFC-410A cylinder,
7, Connect a cylinder of dry nitrogen with a pressure
regulating valve to the center port of the manifold
gauge set,

A CAUTION

8, Adjust dry nitrogen pressure to 150 psig (1034 kPa),
9, Open the valve on the high side of the manifold gauge
set in order to pressurize the line set and the indoor unit,

A IMPORTANT

10, After a few minutes, open one of the service valve
ports and verify that the refrigerant added to the
system earlier is measurable with a leak detector,
11, After leak testing disconnect
ports,

gauges from service

Remove both of the outdoor unit's service port cores (liquid
and vapor) as illustrated in figure 21,

If new lines are used then proceed to Installing New
Refrigerant Metering Device. Otherwise proceed with the
following procedure,

Page 12
505328M

04/08

REQUIRED EQUIPMENT
Equipment required to flush the existing line set and indoor
unit coil:
•

6, 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.

Two clean HCFC-22 recovery bottles,

•

Oilless recovery machine with pump-down feature,

•

Two gauge
HFC-410A),

sets

(one

for

HCFC-22;

one

for

XP15 units are used in check thermal expansion valve
(CTXV) systems only, See the indoor unit coil installation
instructions and the Lennox Engineering Handbook for
approved CTXV match-ups and application information.
Table 3 on page 9 lists liquid and vapor line sizes and
corresponding line sets,
(Uncased Coil Shown)_

TWO PIECE PATCH
PLATE(UNCASED
COIL ONLY)

ORIFICE
HOUSING

OR
I EXPA )RI FIC E _""_
NSION VALVE
I

(SEE NOTE)

TUBES

RECOVERY

MACHINE

NOTE - The inverted HCFC-22 cylinder must contain at least the same
amount of refrigerant as was recovered from the existing system.

Figure 22. Typical Flushing Connection
PROCEDURE
1, Verify that the existing HCFC-22 refrigerant flow
control device has been removed before continuing
with flushing procedures. Existing devices are not
approved for use with HFC-410A refrigerant and may
prevent proper flushing.
2, Connect an HCFC-22 cylinder with clean refrigerant to
the vapor service valve. Connect the HCFC-22 gauge
set to the liquid line valve. Connect a recovery
machine with an empty recovery tank to the gauge set
as illustrated in figure 22.
3, 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
existing system line set and indoor unit coil.
4, 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 unit coil before it enters the recovery machine,
5, 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. Allow the
recovery machine to pull a vacuum on the system,
NOTE - A single system flush should remove all of the
mineral oil from the existing refrigerant lines and indoor
unit 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 a
vacuum on the system at the end of the procedure.

ACCESS FITTING
(NO VALVE CORE)

On smaller vapor lines, bulb may be
mounted on top or side-mounted (preferably at 3 o'clock position).
On 518" and larger lines, mount bulb
approximately at the 4 or 8 o'clock positions; never mount on bottom of line.

@clock

NOTE - If necessary, remove HCFC-22 flow control device (fixed
orifice/check expansion valve) from existing line set before installing HFC-410A approved expansion valve and o-ring.

Figure 23. Typical Metering Device Installation
The thermostatic expansion valve or check / thermostatic
expansion valve, can be installed internal or external to the
indoor coil. In applications where an uncased coil is being
installed in a field provided plenum, install the CTXV and
provide an access for field servicing of the CTXV. Refer to
Figure 23 for reference during installation of CTXV,

Page1
XP15 SERIES

1, On fully cased coils, remove the coil access and
plumbing panels,

LIQUID AND VAPOR
SERVICE VALVES

2, Remove any shipping clamps holding the liquid line
and distributor assembly,

DO NOT INSTALL
CAPS AT THIS TIME

O TOOO .

3. Using two wrenches, disconnect liquid line from
distributor. Take care not to twist or damage distributor
tubes during this process,

INSTALL SERVICE
PORT CORES

Figure 24. Typical Service Valve Port Core
Installation

4, Remove and discard RFC bullet and Teflon washer,
5. Remove and discard cap from the equalizer line port
on the vapor line. Check for valve core in port fitting
and if installed, remove from port.

WARNING

6. Install one of the provided Teflon washers around the
stubbed end of the CTXV,
7. Attach the stubbed end of the kit valve to the distributor
assembly.
8. Place the remaining Teflon washer around the other
end of the CTXV.
9. Attach the liquid line to the CTXV.
10. Attach the sensing bulb of the CTXV in the proper
orientation to the vapor line using the clamp an screws
provided with the CTXV,

A IMPORTANT

11. Connect the equalizer line from the CTXV to the
equalizer vapor port on the vapor line.
12. To prevent against any possibility of water damage,
properly insulate all parts of the CTXV assemble that
may sweat due to temperature differences between
the valve and its surrounding ambient temperatures.
13. The expansion/check valve can be installed internally
in coil blowers, or external or internal to indoor coil only
applications,
Expansion valves equipped with Chatleff type fittings are
available from Lennox, Refer to the Engineering
Handbook for CTXV kits for use with specific match-ups.

Evacuating the system of non-condensables is critical for
proper operation of the unit. Non-condensables
are
defined as any gas that will not condense under
temperatures and pressures present during operation of
an air conditioning system. Non-condensables and water
vapor combine with refrigerant to produce substances that
corrode copper piping and compressor parts.
1. Connect manifold gauge set to the service valve ports
as follows:
•

Table 4. Indoor CTXV Kits
Model

Kit Number

XP15-024 and -036

49L24

XP15-048 and -060

91M02

3. Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set,
4. Open both manifold valves and start the vacuum
pump.
5. Evacuate the line set and indoor unit to an absolute
pressure
of 23,000 microns (29.01 inches of
mercury).

A IMPORTANT

If the indoor unit being installed came with a fixed orifice
type metering device, remove that orifice and install the
CTXV as illustrated in figure 23.

Re-install both of the outdoor unit's service port cores
(liquid and vapor) as illustrated in figure 24.

NOTE - During the early stages of evacuation, it is
desirable to close the manifold gauge valve at least once to
determine if there is a rapid rise in sure 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 pressure in a
vacuum is equal to atmospheric pressure minus vacuum
pressure,
6. When the absolute pressure reaches 23,000 microns
(29.01 inches of mercury), close the manifold gauge

Page 14
505328M

04_8

low pressure gauge to vapor line service valve

•
high pressure gauge to liquid line service valve
2. Connect micron gauge.

valves,turnoffthevacuumpumpanddisconnect
the
manifoldgaugecenterporthosefromvacuumpump.
Attachthemanifoldcenterporthosetoa drynitrogen
cylinderwithpressureregulator
setto 150psig(1034
kPa)andpurgethe hose.Openthe manifoldgauge
valvestobreakthevacuumin thelinesetandindoor
unit.Closethemanifoldgaugevalves,
7, Shutoff the dry nitrogencylinderand removethe
manifoldgaugehosefromthe cylinder.Openthe
manifoldgaugevalvestoreleasethedrynitrogen
from
thelinesetandindoorunit,
8, Reconnect
themanifoldgaugeto thevacuumpump,
turnthepumpon,andcontinue
toevacuate
thelineset
andindoorunituntilthe absolutepressuredoesnot
riseabove500microns(29.9inchesofmercury)
within
a 20-minute
periodaftershuttingoffthevacuumpump
andclosingthemanifoldgaugevalves.
9, Whenthe absolutepressurerequirement
abovehas
beenmet, disconnectthe manifoldhosefrom the
vacuumpumpandconnectit to anuprightcylinderof
HFC-410A
refrigerant,
Openthemanifold
gaugevalve
1 to2 psiginordertoreleasethevacuuminthelineset
andindoorunit,
10, Close manifoldgauge valvesand shut off the
HFC-410A
cylinderandremovethe manifoldgauge
set,
SERVICING
UNITSDELIVERED
VOIDOFCHARGE
If thesystemisvoidofrefrigerant,
cleanthesystemusing
theprocedure
described
below,
1, Usenitrogentopressurize
thesystemandcheckfor
leaks,Repairallleaks,
2, Evacuatethe systemto removeas muchof the
moistureaspossible,
3, Usenitrogento breakthevacuumandinstalla new
filterdrierinthesystem.
4, Evacuatethe system again. Then, weigh the
appropriate
amountof HFC-410A
refrigerant
as listed
on unitnameplate
intothesystem.
5, Monitorthe systemto determinethe amountof
moistureremainingin theoil.It maybenecessary
to
replacethefilter drierseveraltimesto achievethe
requireddrynesslevel.If systemdryness is not
verified,the compressorwill fail in the future.

4, Replace the stem caps and tighten as specified in
Operating Service Valves on page 3.
5, Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit's
nameplate. If not, do not start the equipment until you
have consulted with the power company and the
voltage condition has been corrected,
6, Set the thermostat for a cooling demand. Turn on
power to the indoor indoor unit and close the outdoor
unit disconnect switch to start the unit.
7, Recheck voltage while the unit is running. Power must
be within range shown on the nameplate,
8, Check system for sufficient refrigerant by using the
procedures
listed under Testing and Charging
System,
TESTING AND CHARGING SYSTEM
This system uses HFC-410A refrigerant which operates at
much higher pressures than HCFC-22. The pre-installed
liquid line filter drier is approved for use with HFC-410A
only, Do not replace liquid line filter drier with components
designed for use with HCFC-22,
NOTE - This unit is NOT approved for use with coils which
use capillary tubes as a refrigerant metering device,
SETTING UP TO CHECK CHARGE
1. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HFC-410A.
2. Connect the manifold gauge set to the unit's service
ports as illustrated in figure 25,
•

low pressure gauge to vapor service port

•

high pressure gauge to liquid service port

COOLING MODE INDOOR AIRFLOW

HEATING MODE INDOOR AIRFLOW CHECK
Blower airflow (CFM) may be calculated by energizing
electric heat and measuring:
•

temperature rise between the return air and supply air
temperatures at the indoor coil blower unit,

•

voltage supplied to the unit,

•

amperage being drawn by the heat unit(s),

Then, apply the measurements taken in following formula
to determine CFM:
Amps x Volts x 3.41

CFM =

IMPORTANT

CHECK

Check airflow using the Delta-T (DT) process as illustrated
in figure 26 on page 16.

1.08 x Temperature

CALCULATING

rise (F)

CHARGE

If the system is void of refrigerant, first, locate and repair
any leaks and then weigh in the refrigerant charge into the
unit, To calculate the total refrigerant charge:

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 to release the refrigerant
charge (contained in outdoor unit) into the system,

Amount
specified
on
nameplate

Adjust amount for
variation in
line set length
(table in figure 27)
+

Additional charge
specified per
indoor unit
match-up
(tables 6 through 11)

Total
charge

Page15
XP15 SERIES

OUTDOOR

NOTE - ARROWS
INDICATE
DIRECTION OF REFRIGERANT

UNIT

DISTRIBUTOR

CHECK
EXPANSION
VALVE

REVERSING

DRIER

LOW HIGH
[
PRESSURE
PRESSURE

FLOW

VALVE

OUTDOOR

CO,L

MUFFLER

INDOOR UNIT

_:[tGAUGE
MANIFO%D
1]:_
HFC-410
ADRUM

LINE
I
VALVE

VAPOR
VALVE

COMPRESSOF
J2

CHECK

LINE

EXPANSION

VALVE -INDOOR
COIL

NOTE- Use gauge ports on vapor line valve and liquid valve for evacuating refrigerant
lines and indoor coil. Use vapor gauge port to measure vapor pressure during charging,

Figure

25. XP15 Cooling

Cycle (Showing

DT
24 24 24 23 23 22 22 22 20 19 18 17 16
23 23 23 22 22 21 21 20 19 18 17 16 15
22 22 22 21 21 20 19 19 18 17 16 15 14
21 21 20 19 19 18 17 16 16 15 14 13

Temp.
l
of air
I 80
entering,_ I 78
indoor _ I ==
coil °F _'?1tu
I

"- 17421

14
13
12

DRY
BULB

expressed

2. Find temperature drop across coil--Measure
the coil's dry
bulb entering and leaving air temperatures
(A and C). Temperature

Drop

3. Determine

LEILI9 _LaL_d

are

Connections)

Formula:

(TDrop) = A minus

if fan needs adjustment--If

the difference

between

the measured
TDrop and the desired DT (TDrop-DT)
is within
+_3°, no adjustment
is needed. See examples:
Assume DT =
15 and A temp. = 72 °, these C temperatures
would necessi-

19 °

All temperatures

Manifold

1. Determine
the desired DT--Measure
entering air temperature using dry bulb (A) and wet bulb (B). DT is the intersecting value of A and B in the table (see triangle).

20 19 18 17 17 161L55_15 14 13 12 11 10
20
19 19 18 18 17 17 16 15 15 14 13 12 11 10
57 58 59 60 61 62 63 64 65 66 67 68 69 70 I

72
70
Wet-bulb °F

Gauge

iNDOOR

WET

COiL

BULB

in °F

EI(3LIUII_:

C°

TDrop-

°F

ACTION

53°

Increase

58°

-1

(within +3° range)

62 °

-5

Decrease

4. Adjust the fan speed--See
crease/decrease
fan speed.

indoor

the airflow
no change

the airflow

unit instructions

to in-

Changing air flow affects all temperatures;
recheck temperatures to confirm that the temperature
drop and DT are within
+_30.

Figure 26. Checking

Indoor Airflow over Evaporator Coil using Delta-T Chart

WEIGH
Refrigerant

Liquid

Line

Set Diameter
3t8" (9.5 mm)

L_NNOX

Charge

per Line Set Length

Ounces
adjust

from

3 ounce

15 feet (4.6 m) line set*

@:L,
Figure 27. Using Weigh In Method

Page 16
04/08

3. Conduct
leak check;
previously outlined.

evacuate

HIHIIIJI|I[I

NOTE
line length
length isis less
greater
ft. (4.6
m), add this
amount.- *If
If line
than than
15 ft.15(4.6
m), subtract
this
amount.

505328M

2. Compare unit pressures with table
Normal Operating Pressures,

4. Weigh in the unit nameplate charge plus
any charge required for line set differences
over feet,

per 5 feet (g per 1.5 m)

per 5' (85 g per 1.5 m)

1. Check Liquid and suction line pressures

This nameplate is for illustration purposes
only. Go to actual nameplate on outdoor
unit for charge information.

the airflow as illustrated in figure 26 to be sure the indoor airflow is as
1 Check
required. (Make any air flow adjustments before continuing with the following

8UBCOOLING

procedure.)
2 Measure outdoor ambient temperature; determine whether to use cooling
or heating mode to check charge.
3 Connect gauge set.

4 Check Liquid and Vapor line pressures. Compare pressures with Normal
Operating Pressures table 5, (The reference table is a general guide. Expect
minor pressure variations. Significant differences may mean improper charge or
other system problem. )

USE COOLING
MODE
60°F (15 °) -USE HEATING
MODE

Set thermostat for heat/cool demand, depending on mode being used:
Using cooling mode--When the outdoor ambient temperature is 60°F (15°C) and
above. Target subcooling values in table below are based on 70 to 80°F (21-27°C)
indoor return air temperature;
if necessary, operate heating to reach that
temperature range; then set thermostat to cooling mode setpoint to 68°F (20°C).
When pressures have stabilized, continue with step 6.

Using heating mode--When the outdoor ambient temperature is below 60°F (15°C).
Target subcooling values in table below are based on 65-75°F (18-24°C) indoor
return air temperature; if necessary, operate cooling to reach that temperature range;
then set thermostat to heating mode setpoint to 77°F (25°C). When pressures have
stabilized, continue with step 6.

SAT o
LIQ o SC o

mode

6 Read the liquid line temperature; record in the LIQ ° space.
7 Read the liquid line pressure; then find its corresponding temperature in the
temperature/pressure
chart listed in table 12 and record it in the SAT° space.
8 Subtract LIQ° temp. from SAT° temp. to determine subcooling; record it in SC° space.
9 Compare SC° results with table below, being sure to note any additional charge for
line set and/or match-up.
10 If subcooling value is greater than shown in tables 6 through 11 for the applicable unit,
remove refrigerant; if less than shown, add refrigerant.
11 If refrigerant is added or removed, repeat steps 6 through 10 to verify charge.
Figure 28. Using Subcooling Method
Table 5. Normal Operating Pressure - Liquid +10 and Vapor +5 PSIG*

IMPORTANT
|lliiliTo]ilv/_-I

IP.|l[[o]i[-.lllilllii['4-"[_]l)i]

I[:t-$"]!ll':-.t-lliiL.]Iv|i[_

""""'""

:--,).-4i[:[_rlrl_irilrlll_l_-41[-4i[_-4.111i!11i1,¢

_-"ll .F'[|[o]i[..'!ll_-'l[i-']'_ilil

il"""T
XP15-024

XP15-030

..aidI vo o.

i,_.]i|l[ill_l[q

1['4i[_:t-11

II
XP15-036

I vo o.

XP15-042

XP15-048

I vo o...aidI Vo o.

XP15-060

I Vo o.

HEATINGOPERATION
20 (-7.0)

315

308

284

293

312

349

30 (-1.0)

340

317

296

312

332

375

40 (4.4)

364

339

313

321

353

384

394

115

359

107

326

106

337

103

374

110

406

107

50 (10)
COOLING

OPERATION

65 (18.3)

237

141

250

141

260

139

265

141

242

139

255

136

75 (23.9)

274

143

292

143

298

141

309

144

279

140

297

138

85 (29.4)

319

145

336

145

344

143

360

147

322

142

343

140

95 (35.0)

364

147

385

147

393

145

408

149

370

144

392

142

105 (40.6)

415

149

438

148

446

148

462

151

423

147

447

145

115 (49.0)

469

152

497

151

506

150

522

154

479

149

510

148

*These are most-popular-match-up
pressure& Indoor match up, indoor air quality, and indoor load cause pressures
**Temperature of the air entering the outdoor coi!.

to vary.

Page 17
XP15 SERIES

Table 6. XP15-024

Table 9. XP15-042

Target
Subcooling
Heat
Cool
(+5OF)
(+1OF)
14
6

INDOOR MATCHUPS
CH23-51

*Add
charge
Ib
0

oz
14

INDOOR

Target
Subcooling
Heat
Cool
(+5OF)
(+1OF)
7
7

MATCHUPS

CH33-62D

*Add
charge
Ib
0

oz
13

CBX27UH-030-230

CBX27UH-042-230

CB3OU-31
CBX32M-030

15
15

5
5

O
O

1
1

CBX27UH-048-230
CB3OU-51*P

9
9

4
4

O
O

11
11

CBX32M-036

CBX32M-048

CBX32MV-024/030
CBX32MV-036

15
13

5
6

O
2

O
4

CBX32MV-048
C33-44C

9
13

4
4

O
O

11
O

CH33-42
CR33-48

14
38

6
7

O
3

14
1

CH33-44/48B,
CH33-49C

12
9

4
4

O
O

5
12

CR33-48

6
13

6
6

1
1

15
15

CX34-38 SN# 6007 and after
CX34-38 before SN# 6007

4
13

4
4

O
O

CX34-43
CX34-44/48B

12
13

4
4

O
O

5
O

CX34-31
CX34-38
CX34-38

SN# 6007 and after
before SN# 6007

Table 7. XP15-030
Target
Subcooling
Heat
Cool
(+5OF)
(+1OF)
13
5

INDOOR MATCHUPS
CH23-51

*Add
charge
Ib
0

oz
4

-48C

CX34-50/60C

Table 10. XP1 _-048
Target
Subcooling
Heat
Cool
(+5OF)
(+1OF)
21
4

*Add
charge

CBX27UH-030-230
CBX27UH-036-230

12
13

5
5

0
0

10
8

INDOOR

CB30U-31
CB30U-41/46

14
12

5
5

0
0

0
10

CH23-68
CBX27UH-048-230

CBX32M-030

CBX32M-036
CBX32MV-024/030

12
14

5
5

0
0

10
0

CBX27UH-060-230
CB3OU-51*P

12
22

4
4

O
O

11
3

CBX32MV-036

CB3OU-65*P
CBX32M-048

12
22

4
4

O
O

3
3

CR33-48
CX34-38 SN# 6007 and after

31
5

4
5

0
0

13
8

CBX32M-060

CX34-38
CX34-43

13
9

5
5

0
1

8
4

CBX32MV-048
CBX32MV-060

22
12

4
4

O
O

3
3

CBX32MV-068

CX34-49

CX34-50/60C

CH33-62D
CX34-49C

12
13

4
4

O
O

8
2

CX34-6OD
CX34-62D

14
12

4
4

O
O

O
5

before SN# 6007

Table 8. XP15-036
INDOOR MATCHUPS
CBX27UH-036-230
CBX27UH-042-230

Target
Subcooling
Heat
Cool
(+5OF)
(+1OF)
13
4

MATCHUPS

*Add
charge
Ib
0

oz
3

Ib
0

oz
12

Table 11. XP15-060
INDOOR

MATCHUPS

Target
Subcooling
Heat
Cool
(+5OF)
(+IOF)

*Add
charge
Ib

CB3OU-41/46
CB3OU-51

13
5

4
5

O
O

3
12

CH23-68
CBX27UH-060-230

28
17

6
6

0
O

CBX32M-042
CBX32M-048

13
5

4
5

O
O

3
12

CB3OU-51*R -65"P

CBX32MV-036
CBX32MV-048

13
5

4
5

O
O

3
12

CBX32M-O48*R -O6O*P
CBX32MV-O48*R -O6O*P

19
19

6
6

O
O

2
2

CH33-62D

C33-44C

CH33-42
CH33-44/48B

14
9

4
4

O
O

1
7

7
5

5
5

O
O

7
12

CH33-48C
CH33-49C
CH33-62D

CR33-48C
CR33-50/60

37
32

4
5

O
O

5
10

CX34-31

4
13

4
4

O
O

3
3

7
13

5
4

O
O

7
3

CX34-38
CX34-38

SN# 6007 and after
before SN# 6007

CX34-43
CX34-44/48
CX34-49

*Amount of charge required in addition to charge shown on unit
nameplate. (Remember to consider lineset length difference.)

Page 18
505328M

04_8

Table 12. HFC-410A Temperature (°F) Pressure (Psig)

EMERGENCY HEAT (AMBER LIGHT)
An emergency heat function is designed into some room
thermostats. This feature is applicable when isolation of the
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
control circuit is isolated from power and field-provided relays
bypass the outdoor thermostats. An amber indicating light
simultaneously comes on to remind the homeowner that the
unit is operating in the emergency heat mode.

°F

Psig

°F

Psig

°F

Psig

°F

Psig

32
33

100.8
102.9

63
64

178.5
181.6

94
95

290.8
295.1

125
126

445.9
451.8

105.0

184.3

299.4

127

457.6

107.1

187.7

303.8

128

463.5

109.2

190.9

308.2

129

469.5

111.4

194.1

312.7

130

475.6

113.6

197.3

100

317.2

131

481.6

115.8

200.6

101

321.8

132

487.8

118.0

203.9

102

326.4

133

494.0

120.3

207.2

103

331.0

134

500.2

122.6

210.6

104

335.7

135

506.5

125.0

214.0

105

340.5

136

512.9

127.3

217.4

106

345.3

137

519.3

129.7

220.9

107

350.1

138

525.8

132.2

224.4

108

355.0

139

532.4

134.6

228.0

109

360.0

140

539.0

137.1

231.6

110

365.0

141

545.6

139.6

235.3

111

370.0

142

552.3

HIGH-PRESSURE SWITCH
XP15 units are equipped with a high-pressure switch that
is located in the liquid line to the compressor. The normally
closed SPST auto-reset switch opens at 590 psi,

142.2

239.0

112

375.1

143

559.1

LOW-PRESSURE

144.8

242.7

113

380.2

144

565.9

147.4

246.5

114

385.4

145

572.8

150.1

250.3

115

390.7

146

579.8

152.8

254.1

116

396.0

147

586.8

XP15 units are equipped with a low-pressure switch that is
located in the vapor line to the compressor. The normally
closed SPST auto-reset switch opens at 25 psi and closes
at 55 psi,

155.5

258.0

117

401.3

148

593.8

158.2

262.0

118

406.7

149

601.0

161.0

266.0

119

412.2

150

608.1

163.9

270.0

120

417.7

151

615.4

166.7

274.1

121

423.2

152

622.7

169.6

278.2

122

428.8

153

630.1

172.6

282.3

123

434.5

154

637.5

175.4

286.5

124

440.2

155

645.0

INSTALLING

Emergency heat is usually used during an outdoor unit
shutdown, but it should also be used following a power
outage if power has been off for over an hour and the
outdoor temperature is below 50°F (10°C), The system
should be left in the emergency heat mode at least six
hours to allow the crankcase heater sufficient time to
prevent compressor slugging.

SINGLE-SPEED CONDENSER FAN MOTOR
The XP15 is equipped with a single-speed condenser fan
motor. The compressor contactor and defrost control
board (DCB) controls the operation of the motor,
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,

SERVICE VALVE CAPS

Disconnect gauge set and re-install all service valve caps.

OUTDOOR
SERVICE

UNIT
VALVE

SWITCH

Replacement filter driers must be suitable for use with
HFC-410A refrigerant,

INSTALL CAPS
_

The LSOM detects the most common fault conditions in
the system. When an abnormal condition is detected, the
LSOM communicates the specific condition through its
ALERT and TRIP lights, The LSOM is capable of detecting
both mechanical and electrical system problems. See
figure 30 for LSOM LED locations.

Figure 29. Installing Service Valve Port Caps

POWER

LED

.....

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
continuously.
THERMOSTAT

TRIP LED

OPERATION

ALERT LED

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,

Figure 30. LSOM

Page 19
XP15 SERIES

Table 13. LSOM LED Troubleshooting

Codes

Status LED
Condition

Status LED
Description

Status LED Troubleshooting

Green Power LED ON

LSOM has power

24VAC control power is present at the LSOM terminal.

Green Power LED OFF

LSOM not powering up

Determine/verify that both R and C LSOM terminals are connected and voltage is present
at both terminals.

Red Trip LED ON

System and compressor
check out OK

Information

1 Verify Y terminal is connected to 24VAC at contactor coil.

Thermostat demand signal
Y1 is present, but
compressor not running

Red Trip and Yellow
Alert LEDs Flashing

2 Verify voltage at contactor coil falls below 0.5VAC when off.
3 Verify 24VAC is present across Y and C when thermostat demand signal is present; if not
present, R and C wires are reversed.
1 Compressor protector is open.
2 Outdoor unit power disconnect is open.
3 Compressor circuit breaker or fuse(s) is open.

NO TE - During 5-minute
delay in LSOM the red trip
LED will be on.

4 Broken wire or connector is not making contact.

Simultaneous flashing,

Indicates that the control circuit voltage is too low for operation.

5 Low pressure switch open if present in the system.
6 Compressor contactor has failed to close.

1 LOW

refrigerant charge.

2 Evaporator blower is not running.
Yellow Alert Flash
Code 1"

Long Run Time - Compressor is running extremely
long run cycles

3 Evaporator coil is frozen.
4 Faulty metering device.
5 Condenser coil is dirty.
6 Liquid line restriction (filter drier blocked if present).
7 Thermostat is malfunctioning.
1 Check high head pressure or discharge line sensor.

Yellow Alert Flash
Code 2*

System Pressure Trip Discharge or vapor pressure
out of limits or compressor
overloaded

2 Condenser coil poor air circulation (dirty, blocked, damaged).
3 Condenser fan is not running.
4 Return air duct has substantial leakage.
5 If low pressure switch is present, see Flash Code 1 information.
1 Thermostat demand signal is intermittent.

Yellow Alert Flash
Code 3*

Short Cycling - Compressor is running only briefly

2 Time delay relay or DCB is defective.
3 If high pressure switch is present, see Flash Code 2 information.
4 If low pressure switch is present, see Flash Code 2 information.
1 Run capacitor has failed.

Yellow Alert Flash
Code 4*

2 Low line voltage (contact utility if voltage at disconnect is low).

Locked Rotor

3 Excessive liquid refrigerant in the compressor.
4 Compressor bearings are seized.
1 Outdoor unit power disconnect is open.
2 Unit circuit breaker or fuse(s) is open.
3 Unit contactor has failed to close.

Yellow Alert Flash
Code 5*

4 High pressure switch is open and requires manual reset.

Open Circuit

5 Open circuit in compressor supply wiring or connections.
6 Unusually long compressor protector reset time due to extreme ambient temperature.
7 Compressor windings are damaged.
1 Run capacitor has failed.
Yellow Alert Flash
Code 6*

Open Start Circuit - Current only in run circuit

Yellow Alert Flash
Code 7*

Open Run Circuit - Current
only in start circuit

1 Open circuit in compressor

Yellow Alert Flash

Welded Contactor

1 Compressor contactor failed to open.

Code 8*

Compressor always runs

2 Thermostat demand signal not connected to LSOM.

Yellow Alert Flash
Code 9*

Low Voltage - Control circuit <17VAC

1 Control circuit transformer is overloaded.

2 Open circuit in compressor start wiring or connections.
3 Compressor start winding is damaged.

start wiring or connec_ons.

2 Compressor start winding is damaged.

2 Low line voltage (contact utility if voltage at disconnect is low).

*Flash code number corresponds to a number of LED flashes, followed by a pause, and then repeated. Reset ALER Tflash code by removing 24VAC power
from LSOM; last code will display for 1 minute after LSOM is powered on.
Note: If the unit is equipped with a two-stagged compressor, upon Y2 signal detection and after five seconds, the LSOM will send 24 VAC to the solenoid.
Once the solenoid is fully energized, the L SOM reduces voltage to between 4 to 18 VDC . Every 15 minutes the solenoid voltage will be increase to 24 volts
for a few seconds to ensure solenoid valve is engaged until Y2 signal is no longer present.

Page 20
505328M

04_8

LSOM--LED

Y terminal, If the red LED does not function as
described, refer to table 13 on page 20 to verify the
wiring,
TEST 2:

Functions

A IMPORTANT

1. Disconnect power from the compressor and 24VAC
power from the LSOM
2. Remove the wire from the Y terminal of LSOM and
reapply power to the compressor, allowing the
compressor to run. The yellow alert LED will begin
flashing a code 8 indicating a welded contactor,
3. While the LSOM is off, reattach the wire to the Y
terminal,

See table 13 on page 20 for the complete explanation of
troubleshooting codes.
LED
Color

Function

Description

Green

Power

Indicates voltage within the range of
19-28VAC is present at LSOM connection.

4. Reapply power to the compressor and 24VAC power
to the LSOM; the yellow alert LED will flash the
previous code 8 for one minute and then turn off. If the
yellow LED does not function as described, refer to
table 13 on page 20 to verify the wiring,

Communicates
an abnormal
system
condition through a unique flash code.
The alert LED flashes
a number of

Yellow

Red

Alert

Trip

times
consecutively;
then
pauses;
then
repeats
the
process.
This
consecutive
flashing
correlates
to a
particular abnormal
condition.

Indicates there is a demand signal
from the thermostat but no current to
the compressor is detected by the
LSOM.
Resetting

Alert codes

Manual

DEFROST CONTROL BOARD (DCB) FUNCTION
The DCB measures differential temperatures to detect
when the system is performing poorly because of ice
build-up on the outdoor coil. The DCB self-calibrates when
the defrost system starts and after each system defrost
cycle. The DCB components are illustrated in figure 31.

Alert

can be reset manually

Note - Component

Codes

Locations

or automatically:

DEFROST
TERMINATION
PIN SETTINGS

Cycle the 24VAC power to LSOM off and on. After power up, existing code will display for one
minute and then clear.

rEs_ PI

to monitor the compressor and system. Whentif
conditions return to normal, the alert code is
turned off automatically.

LSOM--L
Terminal Connection
The L connection is used to communicate alert codes to
the room thermostat. On selected Lennox SignatureStat"
thermostats, a blinking check LED will display on the room
thermostat
and
on select
White-Rodgers
room
thermostats, an icon on the display will flash. Either will
flash at the same rate as the LSOM yellow alert LED,
NOTE - ROOM THERMOSTATS WITH SERVICE OR
CHECK LIGHT FEATURE--The
room thermostat may
blink the Check or Service LED or it may come on sofid,
Confirm fault by observing and interpreting the code from
the LSOM yellow alert LED at the unit,
LSOM--Installation
Verification
tests

1. Disconnect power from the compressor and force a
thermostat call for cooling.
2. The red trip LED should turn on indicating a
compressor trip as long as 24VAC is measured at the

LOW
AMBIENT
THERMOSTAT
PINS

rAN

_DIAGNOSTIC
LEDS

DELAY
PINS

REVERSING
VALVE

To verify correct LSOM installation, two functional
can be performed.
TEST 1 :

Manufacturer.

SENSOR
PLUG IN (COIL
AND AMBIENT
SENSORS)

After an alert is detected, the LSOM continues
Automatic

Vary by Board

TEST PINS

o_7

24V TERMINAL
STRIP
CONNECTIONS

0-Ps

PRESSURE
SWITCH
CIRCUIT
CONNECTIONS
¢0_MON

TStPS O_ C _ 0 v_ _2

Figure 31. Defrost Control Board (DCB)
The DCB monitors ambient temperature, outdoor coil
temperature, and total run time to determine when a
defrost cycle is required. The coil temperature probe is
designed 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 DCB 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 DCB initiates defrost cycles.

Page 21
XP15 SERIES

Pressure

Switch

Connections

The unit's automatic reset pressure switches (LO PS - $87
and HI PS - $4) are factory-wired into the DCB on the
LO-PS and HI-PS terminals, respectively.
Pressure
Switch Event Settings
The following are the auto reset event values for low and
high pressures thresholds:
•

High Pressure (auto reset) - trip at 590 psig, reset to
418 psig.

•

Low Pressure (auto reset) - trip at 25 psig, reset to 55
psig.

Five-Strike
Lockout
Safety Function
The five-strike lockout safety function is designed to
protect the unit's compressor from damage. The DCB
monitors for an active state on the DCB's Y1 input as
referenced in figure 31 on page 21. When the Y1 input is
active the internal control logic of the DCB will do the
following:
•
•

•

Count any HI-PS and LO-PS pressure switch trips
(open and close).
If a pressure switch trips four times during the current
active state on the Y1 input, then the DCB's control
logic will reset the pressure switch trip counter to zero
at the end of currently active Y1 input state.
If the pressure switch opens for a fifth time during the
current Y1 input state, the DCB will enter a lockout
condition.

of the temperature range of the sensor, the DCB will not
perform demand defrost operation. The DCB 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 as illustrated
in figure 32 on page 24, considers outdoor 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 DCB will
not perform demand or time/temperature
defrost
operation and will display the appropriate fault code.
Heating and cooling operation will be allowed in this fault
condition.
NOTE - Within a single room thermostat demand, if
five-strikes occur, the DCB will lock out the unit. The DCB's
24 volt power R must be cycled OFF, or the TESTpins on
DCB must be shorted between 1 to 2 seconds to reset the
DCB.
DCB OPERATIONAL

The DCB has four basic operational modes which are
TEST, NORMAL CALIBRATION and DEFROST.
TEST
1. When Y1 is energized and 24V power is being applied
to the DCB, a test cycle can be initiated by: placing the
termination temperature jumper across the Test pins
(P1) for 2 to 5 seconds.

The system will require servicing to determine the cause of
the pressure switch condition. Once the condition has
been rectified, use the following procedure to reset the
DCB.

2. If the jumper remains across the Test pins longer than
five seconds, the DCB will ignore the test pins and
revert to normal operation,
3. The jumper will initiate one cycle per test.

DEFROST SYSTEM SENSORS
Sensors connect to the DCB through a field-replaceable
harness assembly that plugs into the DCB. Through the
sensors, the DCB detects outdoor ambient and coil
temperature fault conditions. As the detected temperature
changes, the resistance across the sensor changes.
Sensor resistance values can be checked by ohming
across pins shown in table 14.
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 14, 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.
Table 14. Sensor Temperature / Resistanc4 Range
Temperature
Range °F (°C)

Resistance values
range (ohms)

Pins/Wire
Color

Outdoor

-35 (-37) to 120
(48)

280,000 to 3750

3 and 4
(Black)

Coil

-35 (-37) to 120
(48)

280,000 to 3750

5 and 6
(Brown)

Sensor

Note: Sensor resistance increases as sensed
decreases.

4, Enter the TEST MODE by placing a jumper across the
TEST pins on the DCB 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.
5, DCB timings are reduced, the low-pressure switch is
ignored and the DCB will clear any active lock out
condition,
6, Each test pin shorting will result in one test event, For
each TEST the jumper must be removed for at least
one second and reapplied, Refer to flow chart
illustrated in figure 33 on page 24 for TEST operation,
NOTE - The Y1 input must be active (ON) and the 0 room
thermostat terminal into DCB must be inactive
NORMAL
The DCB monitors the O line, to determine the system
operating mode (heat/cool), outdoor ambient temperature,
coil temperature (outdoor coil) and compressor run time to
determine when a defrost cycle is required,
CALIBRATION

temperature

Ambient Sensor--The
ambient sensor as illustrated in
figure 32 on page 24 considers outdoor 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

The DCB is considered uncalibrated when power is
applied to the DCB, after cool mode operation, or if the coil
temperature exceeds the termination temperature when it
is in heat mode.
DEFROST
For detail information on DEFROST MODE, see Detail
Defrost Mode Operation on page 26.

Page 22
505328M

04/08

MODES

Table 15. Defrost Control Board (DCB) Inputs, Outputs and Configurable

Settings

DCB
Location

DCB Label or
Description

Purpose

Function

TEST

Test Mode

See Test Mode on page 22 for further details.

50, 70, 90, 100

Defrost Temperature Termination Shunt (Jumper) Pins

The DCB as illustrated in figure 31 on page 21 has valid selections
which 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).

24VAC Thermostat Input /
Output

24VAC input/output from indoor thermostat to indoor unit.

24VAC Common

24VAC common

Thermostat

Thermostat service light connection,

24VAC

Thermostat

Input

Controls the second stage operation of the unit,

Thermostat

Input

Reversing valve solenoid.

Thermostat

Input

Controls the operation of the unit,

55, 50, 45, 40

Low Ambient Thermostat Pins

Provides selection of the Y2 compressor lock-in temperature. Valid options are 40, 45, 50 and 55 degrees Fahrenheit,

DIS-YEL

Coil Sensor

(P4-5) Ground connection for outdoor coil temperature
(P4-6) Connection for outdoor coil temperature sensor.

AMB-BLACK

Ambient Sensor

(P4-3) Ground connection for outdoor ambient temperature sensor.
(P4-4) Connection for outdoor ambient temperature sensor.

COIL-BROWN

Discharge Sensor

No discharge sensor is used, replaced by !OK resistor.

DELAY

Service Light

24VAC

The DCB 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.

Delay Mode

NOTE

The 30 second

jumperingthe
P6

TST, PS DF, C, R, O, Y1, Y2

DS1

RED LED

sensor.

off cycle is NOT functional

when

TES T pins on P1.

Factory Test Connectors

No field use.

Diagnostic LED

Valid states for DCB's two LEDs are OFF, ON and FLASHING
which indicate diagnostics conditions that are described in table
16 on page on page 25.

DS2

GREEN LED

FAN

TWO CONNECTORS

Condenser Fan Operation

These two connections provide power for the condenser fan.

O OUT

24 VAC output

24 VAC output connection for reversing valve.
When the low pressure switch trips, the DCB will cycle off the
compressor, and the strike counter in the DCB will count one
strike. The low pressure switch is ignored under the following
conditions:

LO-PS

•

during the defrost cycle and 90 seconds after the termination
of defrost

•

when the average ambient sensor temperature is below 0°F

Low-Pressure Switch

(-18°C)

Y2 OUT

•

for 90 seconds following the start up of the compressor

•

during TEST mode

24 VAC Output

24 VAC output for second stage compressor

Y1 OUT

24 VAC Common Output

HS-PS

High-Pressure

When the high pressure switch trips, the DCB will cycle off the
compressor, and the strike counter in the DCB will count one
strike.

Line output

24VAC service light output,

24V

24 Volt output

24VAC typically used to supply power to the Lennox System
Operation Monitor (LSOM)

24V

Switch

output, switched

solenoid.

24 VAC common
contactor.

for enabling

compressor

Page23
XP15 SERIES

24 TUBES
UP
APRIL 2006)

WIRE
TIE
\

/
12 TUBES
UP

SLEEVE

AMBIENT SENSOR - Extend tip
of plastic sensor just outside of
plastic sleeve.
Place ambient sensor and wire
from DCB inside of plastic sleeve
and route through gap between
corner post and coil support as
shown. Secure with wire tie.

16 TUBES

/
MODELS

-024 AND -036

COIL SENSOR - Clip coil temperature
bend shown on models as follows:
NOTE- No discharge sensor used; replaced by fOK
resistor

MODELS

-048 AND -060

sensor from the DCB on the return

Model -024 and -036:12 tubes up from bottom (11-1/2");
Model -048 and -060 (before April 2006): 16 tubes up from bottom (15-1/2")
Model -048 and -060 (after April 2006): 24 tubes up from bottom (23-1/2")

Figure 32. Heat Pump Unit Sensor Locations

Y1 Active ("0" line inactive)

Short test
pins for
Iongerthan one second
but less than
two
seconds

Clear any short cycle
lockout and five-strike
fault lockout function,
if applicable. No other
functions
will
be
executed and unit will
continue in the mode it
was operating.

Short test pins for more than two seconds
Clear any short cycle lockout and five-strike
fault lockout function, if applicable.

L.finOO0.,N
Mode
II
No further test mode
operation
will
be
executed until the test
short is removed and
reapplied.

.fin.E T,NMode

The DCB 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 reapplied. If no fault exists the unit
will go into DEFROST MODE.

Test pin short REMAINS in place for more than five seconds

The unit will return to HEAT MODE un-calibrated with defrost
timer set for 34 minutes. No further test mode operation will be
executed until the test short is removed and reapplied.

Page 24
04/08

If in DEFROST Mode

The unit will terminate
defrost and enter HEAT
MODE un-calibrated 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
maximum of five seconds

before a

The unit will remain in DEFROST MODE
until termination on time or temperature.

Figure 33. Test Mode

505328M

]

Table 16. DCB Diagnostic LEDs
DS2
Green

DS1
Red

Condition

Possible Cause(s)

Solution
1 Check control transformer

power (24V).

Power problem

Noorpower
C
DCB (24V)
failure.to DCB terminals R and

2 If power is available to DCB and LED(s) do not light,
replace DCB.

SIMULTANEOUS
SLOW FLASH

Normal operation

Unit operating
mode.

None required.

ALTERNATING
SLOW
FLASH

5-minute anti-short cycle delay

Initial powerdemand.
up, safety trip, end of room
thermostat

SIMULTANEOUS
FAST FLASH

Ambient sensor problem

Sensor being detected
time/temperaturedefrost

ALTERNATING
FAST FLASH

Coil sensor problem

Sensor being detected open or shorted or out of temperature range. DCB will not perform demand
or time/temperature defrost operation. (System will still heat or cool).

DCB failure

clear,
replace
Indicates
that DCB.
DCB has internal component failure. Cycle 24 volt power to DCB. If code does not

OFF

FAULT and LOCKOUT CODES

normally or in standby

None required (Jumper TEST pins to override)

open or shorted or out of temperature
operation. (System will still heat or cool).

Low pressure fault

1 Restricted air flow over indoor or outdoor coil.

Low pressure lockout

2 Improper refrigerant charge in system.

OFF

High pressure fault

3 Improper metering device installed or
incorrect operation of metering device.

OFF

High pressure lockout

SLOW
FLASH

Discharge
fault

FAST
FLASH

Discharge line temperature
Lockout

OFF

FAST
FLASH

Discharge sensor fault

FAST
FLASH

OFF

Discharge sensorlockout

SLOW
FLASH

Discharge
fault

FAST
FLASH

Discharge line temperature
lockout

OFF

FAST
FLASH

Discharge sensor fault

FAST
FLASH

OFF

Discharge sensor lockout

line

1 Remove any blockages or restrictions from coils
and/or fans. Check indoor and outdoor fan motor for
proper current draws.

SLOW
FLASH

OFF

DCB will revert

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

OFF

SLOW
FLASH

range.

temperature

4 Incorrect or improper sensor location
or connection to system.

Check system charge using approach and
subcooling temperatures.
Check system operating pressures and compare to
unit charging charts.
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 operation, 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 resistance. If the sensor resistance is not
within range after 90 seconds, the board will count one fault. After five faults, the board will lockout.

temperature
Some heat pump units do not use a defrost line sensor. Therefore this code is not applicable.

Some heat pump units do not use a defrost line sensor. However, on these units a resistor is
installed across pins P4-1 and P4-2. If the resistor is missing or damaged then this fault code will
be displayed.
Some heat pump units do not use a defrost line sensor. Therefore this code is not applicable.

Page 25
XP15 SERIES

DETAILED DEFROST MODE OPERATION

_WARNING

The defrost mode has three basic operational modes
which are defrost cycles, actuation and termination, These
modes are described as follows:
Defrost Cycles--The
demand DCB initiates a defrost
cycle based on either frost detection or time,
Event

Description

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 difference allowed
by the DCB, a defrost cycle will be initiated.
IMPORTANT - The DCB will allow a
greater accumulation of frost and will
initiate fewer defrost cycles than a
time/temperature defrost system.

Time

If six hours of heating mode compressor
run time has elapsed since the last defrost
cycle while the coil temperature remains
below 35°F (2°C), the DCB will initiate a
defrost cycle.

Actuation--When
the reversing valve is de-energized,
the Y1 circuit is energized, and the coil temperature is
below 35°F (2°C), the DCB logs the compressor run time.
If the DCB is not calibrated, a defrost cycle will be initiated
after 34 minutes of heating mode compressor run time.
The DCB will attempt to self-calibrate after this (and all
other) defrost cycle(s),
Calibration
success
depends
on stable
system
temperatures during the 20-minute calibration period. If
the DCB fails to calibrate, another defrost cycle will be
initiated after 90 minutes of heating mode compressor run
time, Once the DCB is calibrated, it initiates a demand
defrost cycle when the difference between the clear coil
and frosted coil temperatures exceeds the maximum
difference allowed by the DCB or after six hours of heating
mode compressor run time has been logged since the last
defrost cycle,
NOTE - If ambient or coil fault is detected, the DCB will not
execute the TEST mode.
Termination--The
defrost cycle ends when the coil
temperature exceeds the termination temperature or after
14 minutes of defrost operation, If the defrost is terminated
by the 14-minute timer, another defrost cycle will be
initiated after 34 minutes of run time,

•

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

•
•

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, Air Filter--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.

See table 16 on page 25 to determine DCB operational
conditions and to diagnose cause and solution to
problems.

Before the start of each heating and cooling season, the
following service checks should be performed by a
qualified service technician. First, turn off electrical power
to the unit prior to performing unit maintenance.
Page 26
04/08

unobstructed flow; clean, if necessary.
Outdoor unit fan motor is prelubricated and sealed. No
further lubrication is needed.
NOTE - If owner reports insufficient cooling, the unit
should be gauged and refrigerant charge checked.
Refer to section on refrigerant charging in this
instruction.

DCB DIAGNOSTICS

505328M

Inspect and clean the outdoor and indoor coils. The
outdoor coil may be flushed with a water hose.

2, Disposable
Filter--Disposable
filters should
replaced with a filter of the same type and size,

NOTE - If you are unsure about the filter required for
your system, call your Lennox dealer for assistance.

IMPORTANT

3, Reusable Filter--Many
indoor units are equipped
with reusable foam filters. Clean foam filters with a

mild soap and water solution; rinse thoroughly; allow
filter to dry completely before returning it to the unit or
grille.
NOTE - The filter and all access panels must be in
place any time the unit is in operation.
4, Electronic
Air
Cleaner--Some
systems
are
equipped with an electronic air cleaner, designed to
remove airborne particles from the air passing through
the cleaner. If your system is so equipped, ask your
dealer for maintenance instructions.
5. Indoor Unit--The
indoor unit's evaporator coil is
equipped with a drain pan to collect condensate
formed as your system removes humidity from the
inside 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.)

IMPORTANT

defrost 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
defrost cycle to satisfy a heating demand; however,
the unit will return to normal operation at the
conclusion of the defrost cycle.
EXTENDED POWER OUTAGE RESTART
PROCEDURE
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
emergency 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 normal
heat pump operation may resume.
THERMOSTAT OPERATION
Though your thermostat may vary somewhat from the
description below, its operation will be similar.

6, Outdoor Unit--Make sure no obstructions restrict
airflow to the outdoor unit. Leaves, trash or shrubs
crowding the unit cause the outdoor unit to work harder
and use more energy. Keep shrubbery trimmed away
from the unit and periodically check for debris which
collects around the unit.
When removing debris from around the unit, be aware
of metal edges on parts and screws. Although special
care has been taken to keep exposed edges to a
minimum, physical contact with metal edges and
corners while applying excessive force or rapid motion
can result in personal injury.
Cleaning of the outdoor unit's coil should be performed
by a trained service technician. Contact your dealer
and set up a schedule (preferably twice a year, but at
least once a year) to inspect and service your heat
pump system.
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 oil-fired furnaces or an
electric furnace which deliver lower volumes of
considerably 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

Temperature

Setting Levers

Most heat pump thermostats have two temperature
selector levers: one for heating and one for cooling. Set the
levers or dials to the desired temperature setpoints for both
heating and cooling. Avoid frequent
temperature
adjustment; 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
indoor blower operation, regardless of whether the
compressor or auxiliary heat are operating. This mode is
required when constant air circulation or filtering is desired.
System Switch
Set the system switch for heating, cooling or auto
operation. The auto mode allows the heat pump to
automatically switch from heating mode to cooling mode to
maintain predetermined comfort settings. Many heat
pump thermostats are also equipped with an emergency
heat mode which locks out heat pump operation and
provides temporary heat supplied by the auxiliary heat.
Indicating

Light

Most heat pump thermostats have an amber light which
indicates when the heat pump is operating in the
emergency heat mode.
Temperature

Indicator

The temperature
temperature.

indicator

displays

the actual

room

Page27
XP15 SERIES

PROGRAMMABLE THERMOSTATS
Your Lennox
system
may be controlled
by a
programmable thermostat, These thermostats provide the
added feature of programmable time-of-day setpoints for
both heating and cooling, Refer to the user's information
manual provided with your particular thermostat for
operation details,

•

Check for any blown fuses or tripped circuit breakers.

•

Make sure unit access panels are in place.

•

Make sure air filter is clean.

•

If service is needed, locate and write down the unit
model number and have it handy before calling.

PRESERVlCE CHECK
If your system fails to operate, check the following before
calling for service:
•
Check to see that all electrical disconnect switches are
ON,

OPTIONAL

•

ACCESSORIES

Optional accessories for the XP15 include the following
(also, see Engineering Handbook for more details):

Make sure the room thermostat temperature selector
and system switch (HEAT, COOL and AUTO) are
properly set,

•

Compressor starter kit

•

Low ambient kit

•

Vapor line drier

•

Wire tie kit

Customer

Address

Indoor Unit Model
Outdoor Unit Model

Serial
Serial

Notes:

START-UP CHECKS
Refrigerant Type:
Rated Load Amps

Actual Amps

Condenser Fan Full Load Amps

Actual Amps:

Rated Volts

Actual Volts

COOLING MODE
Vapor Pressure:
Supply Air Temperature:

Liquid Pressure:
Ambient Temperature:

Return Air Temperature:

HEATING MODE
Vapor Pressure:

Liquid Pressure:

Supply Air Temperature:

Ambient Temperature:

System Refrigerant Charge (Refer to manufacturer's
temperatures.)

Return Air Temperature:

information on unit or installation instructions for required subcooling and approach

Subcooling:

SUBCOOLING

APPROACH

COIL TEMP DROP

Saturated Condensing Temperature (A)
minus Liquid Line Temperature (B)
Approach:
Liquid Line Temperature (A)
minus Outdoor Air Temperature (B)
Indoor Coil Temp. Drop (18 to 22°F)
Return Air Temperature (A)
minus Supply Air Temperature (B)

Page 28
505328M

04/08

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LENNOX Air Conditioner/heat Pump(outside Unit) Manual L0806540

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