Lennox Signature XP15-024 User manual

06/09 505,328M
*2P0609* *P505328M*
Page 1
E2009 Lennox Industries Inc.
Dallas, Texas, USA
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and
service must be performed by a qualified installer or
service agency.
CAUTION
Physical contact with metal edges and corners
while applying excessive force or rapid motion can
result in personal injury. Be aware of, and use
caution when working near these areas during
installation or while servicing this equipment.
IMPORTANT
This unit must be matched with an indoor coil as
specified in Lennox’ Engineering Handbook.
Coils previously charged with HCFC−22 must be
flushed.
IMPORTANT
The Clean Air Act of 1990 bans the intentional
venting of refrigerant (CFCs, HCFCs AND HFCs) as
of July 1, 1992. Approved methods of recovery,
recycling or reclaiming must be followed. Fines
and/or incarceration may be levied for
noncompliance.
INSTALLATION
INSTRUCTIONS
Dave Lennox Signature®
Collection XP15 Units
HEAT PUMP UNITS
505,328M
06/09
Supersedes 05/09
Table of Contents
XP15 Outdoor Unit 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shipping and Packing List 1. . . . . . . . . . . . . . . . . . . . . .
Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Information 2. . . . . . . . . . . . . . . . . . . . . . . . . . .
Recovering Refrigerant from Existing System 4. . . . .
Positioning New Outdoor Unit 5. . . . . . . . . . . . . . . . . .
Removing Panel 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Connections 7. . . . . . . . . . . . . . . . . . . . . . . . .
New or Replacement Line Set 9. . . . . . . . . . . . . . . . . . .
Brazing Line Set Connections 11. . . . . . . . . . . . . . . . . . .
Removing Existing Refrigerant Metering Device 11. . .
Testing for Leaks 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing Service Valve Port Core 12. . . . . . . . . . . . . .
Flushing Existing System 12. . . . . . . . . . . . . . . . . . . . . . .
Installing New Refrigerant Metering Device 13. . . . . . .
Installing Service Valve Port Core 14. . . . . . . . . . . . . . .
Evacuating the System 14. . . . . . . . . . . . . . . . . . . . . . . . .
Start−Up Procedures 15. . . . . . . . . . . . . . . . . . . . . . . . . . .
System Operations 19. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lennox System Operation Monitor (LSOM) 19. . . . . . .
Defrost System 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Homeowner Information 26. . . . . . . . . . . . . . . . . . . . . . . .
Start−Up and Performance Checklist 28. . . . . . . . . . . . .
XP15 Outdoor Unit
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.
Shipping and Packing List
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.
Litho U.S.A.

Page 2
505328M 06/09
Unit Dimensions −− Inches (mm)
4−5/8
(117)
39−1/2
(1003) 35−1/2
(902)
18−1/2
(470)
8 (203)
1 (25)
4−7/16
(113)
LIQUID LINE
INLET
VAPOR LINE
INLET
ELECTRICAL INLETS
BASE WITH ELONGATED LEGS
SIDE VIEW ACCESS VIEW
DISCHARGE AIR
37 (940)
[−024 thru −042]
47 (1194)
[−048 and −060]
16−7/8
(429)
8−3/4
(222)
26−7/8
(683)
3−3/4 (95)
30−3/4
(781)
3−1/8
(79)
UNIT SUPPORT
FEET
OUTDOOR FAN
RUN CAPACITOR
COMPRESSOR
COMPRESSOR
SOUND DOME
COMPRESSOR
TERMINAL PLUG
LOW PRESSURE
SWITCH
HIGH PRESSURE
SWITCH
CONTACTOR
DEFROST CONTROL
SYSTEM
OPERATION MONITOR
VAPOR VALVE AND
GAUGE PORT
DISCHARGE LINE
REVERSING VALVE
VAPOR LINE
FILTER DRIER
XP15 Parts Arrangement
WARNING
This product and/or the indoor unit it is matched
with may contain fiberglass wool.
Disturbing the insulation during installation,
maintenance, or repair will expose you to fiberglass
wool dust. Breathing this may cause lung cancer.
(Fiberglass wool is known to the State of California
to cause cancer.)
Fiberglass wool may also cause respiratory, skin,
and eye irritation.
To reduce exposure to this substance or for further
information, consult material safety data sheets
available from address shown below, or contact
your supervisor.
Lennox Industries Inc.
P.O. Box 799900
Dallas, TX 75379−9900
General Information
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 Recommended Torque
Service valve cap 8 ft.− lb. 11 NM
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. 11 NM

Page 3
XP15 SERIES
USING MANIFOLD 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
IMPORTANT
Only use Allen wrenches of sufficient hardness
(50Rc − Rockwell Harness Scale minimum). Fully
insert the wrench into the valve stem recess.
Service valve stems are factory−torqued (from 9
ft−lbs for small valves, to 25 ft−lbs for large valves) to
prevent refrigerant loss during shipping and
handling. Using an Allen wrench rated at less than
50Rc risks rounding or breaking off the wrench, or
stripping the valve stem recess.
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.
1
2
3
4
5
6
7
8
9
10
11 12
1/6 TURN
This illustrates how to use a wrench to tighten caps an additional
1/6 or 1/12 turn clockwise.
1
2
3
4
5
6
7
8
9
10
11 12
1/12 TURN
Figure 1. Cap Tightening Distances
IMPORTANT
To prevent stripping of the various caps used, an
appropriately sized wrench should be used and
fitted snugly over the cap before tightening.
Operating Angle−Type Service Valve
To Access Angle−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:
SWith Torque Wrench: Finger tighten and then
tighten per table 1 on page 2.
SWithout 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:
A valve stem cap protects the valve stem from
contamination and assures a leak−free seal.
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:
SWith Torque Wrench: Tighten finger tight and then
tighten per table 1 on page 2.
SWithout 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.
(VALVE STEM SHOWN
CLOSED) INSERT HEX
WRENCH HERE
SERVICE PORT
SERVICE PORT
CORE
TO OUTDOOR
UNIT
STEM CAP
STEM CAP
VALVE STEM
FRONT-SEATED
TO OUTDOOR
UNIT
SERVICE PORT
CORE
(VALVE STEM
SHOWN OPEN)
INSERT HEX
WRENCH HERE
TO INDOOR
UNIT
SERVICE PORT CAP
SERVICE PORT
SERVICE PORT CAP
TO INDOOR
UNIT
VALVE IS FRONT−SEATED
(CLOSED)
VALVE IS BACK−SEATED
(OPENED)
OPEN TO BOTH
INDOOR AND
OUTDOOR UNITS]
CLOSED TO BOTH
INDOOR AND
OUTDOOR UNITS]
VALVE STEM
BACKED-SEATED
Figure 2. Angle −Type Service Valve

Page 4
505328M 06/09
Operating Ball−Type Service Valve
To Access Ball−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:
SWith Torque Wrench: Finger tighten and then
tighten per table table 1 on page 2.
SWithout 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 Ball−Type Service Valve:
A valve stem cap protects the valve stem from
contamination and assures a leak−free seal.
1. Remove stem cap with a wrench.
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:
SWith Torque Wrench: Finger tighten and then
tighten per table 1 on page 2.
SWithout Torque Wrench: Finger tighten and use 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 valve listed.
Ball (Shown Closed)
Service Port
Core
TOINDOOR UNIT
To outdoor unit
Use Adjustable Wrench To open: rotate Stem Counter-Clock-
wise 90°.To close: rotate Stem clockwise 90°.
Service Port
Service Port
Cap
STEM CAP
Valve Stem
Open to line set when valve
is closed, to both line set
and unit when valve is open.
Figure 3. Ball−Type Service Valve
Recovering Refrigerant from Existing
HCFC−22 System
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:
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.
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.
4. Disconnect the liquid and vapor lines from the existing
outdoor unit.
5. Remove the existing outdoor unit.
NOTE − Use recovery machine instructions for specific
setup requirements.
Manifold GaugesRecovery Machine
Clean Recovery Cylinder Outdoor Unit
Figure 4. Typical Refrigerant Recovery (Method 1)
METHOD 2:
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 −
1. Start the existing HCFC−22 system in the cooling
mode and close the liquid line valve.
2. Pump all of the existing HCFC−22 refrigerant back into
the outdoor unit.
NOTE − It may be necessary to bypass the low pressure
switches to ensure complete refrigerant evacuation.

Page 5
XP15 SERIES
3. When the low side system pressures reach 0 psig,
close the vapor line valve.
4. 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.
5. Disconnect the liquid and vapor lines from the existing
outdoor unit.
6. Remove the existing outdoor unit.
Positioning New Outdoor Unit
CAUTION
In order to avoid injury, take proper precaution when
lifting heavy objects.
See Unit Dimensions on page 2 for sizing mounting slab,
platforms or supports. Refer to figure 5 for mandatory
installation clearance requirements.
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
ÍÍÍÍÍÍÍÍÍÍ
See
NOTES
See NOTES
See
NOTES
See NOTES
Control
Box
NOTES:
Service clearance of 30 in. (762 mm) must be maintained on one of
the sides adjacent to the control box.
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)
48 in. (1219 mm) clearance required on top of unit.
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.
Install unit away
from windows
Two 90° elbows installed in line set
will reduce line set vibration.
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.
Mounting
Slab
Building
Structure
GROUND LEVEL
Figure 7. Ground Level Slab Mounting
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 6
505328M 06/09
WIND BARRIER
PREVAILING
WINTER WINDS
24"
(610 mm)
INLET AIR
INLET AIR
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.
ELEVATING THE UNIT
These units are outfitted with elongated−shaped feet as
illustrated in figure 9.
LEG DETAIL
BASE
2" (50.8MM)
SCH 40
FEMALE
THREADED
ADAPTER
Figure 9. Elevated Slab Mounting using Feet
Extenders (Larger Base Units)
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.
With unit positioned at installation site, remove two side
louvered panels to expose the unit base pan. Install the
brackets as illustrated in figure 10 using conventional
practices; replace the panels after installation is complete.
IMPORTANT
Using field−provided stabilizer brackets:
Always use stabilizers when unit is raised above the
factory height. (Elevated units could become
unstable in gusty wind conditions).
Stabilizers may be used on factory height units
when mounted on an unstable or uneven surface.
ONE BRACKET PER SIDE (MIN.); FOR EXTRA STABILITY,
TWO BRACKETS PER SIDE, 2" FROM EACH CORNER.
PLASTIC ANCHOR − USE IF CONCRETE
(HOLE DRILL 1/4"); NOT IF PLASTIC SLAB
(HOLE DRILL 1/8").
COIL
BASE PAN
CORNER POST
STABILIZING BRACKET
(18 GAUGE METAL − 2"
WIDTH; HEIGHT AS
REQ’D)
Slab Side Mounting
#10 1/2" LONG
SELF−DRILLING SHEET
METAL SCREWS
#10 1−1/4" LONG HEX
HD SCREW AND
FLATWASHER
MINIMUM 1
PER SIDE
FOR EXTRA
STABILITY
Deck Top
Mounting
STABILIZING
BRACKET (18
GAUGE METAL − 2"
WIDTH; HEIGHT
AS REQ’D); BEND
TO FORM RIGHT
ANGLE
Figure 10. Installing Stabilizer Brackets
Removing Panels
CAUTION
To prevent personal injury, or damage to panels,
unit or structure, be sure to observe the following:
While installing or servicing this unit, carefully stow
all removed panels out of the way, so that the panels
will not cause injury to personnel, nor cause
damage to objects or structures nearby, nor will the
panels be subjected to damage (e.g., being bent or
scratched).
While handling or stowing the panels, consider any
weather conditions, especially windy conditions,
that may cause panels to be blown around and
battered.

Page 7
XP15 SERIES
REMOVE 4 SCREWS TO REMOVE PANEL FOR
ACCESSING COMPRESSOR AND CONTROLS.
INSTALL BY POSITIONING PANEL WITH HOLES
ALIGNED; INSTALL SCREWS AND TIGHTEN.
Figure 11. Access Panel
Detail A
Detail C
Detail B
ROTATE IN THIS DIRECTION;
THEN DOWN TO REMOVE PANEL
SCREW
HOLES
LIP
IMPORTANT! DO NOT ALLOW
PANELS TO HANG ON UNIT BY
TOP TAB. TAB IS FOR ALIGNMENT
AND NOT DESIGNED TO SUPPORT
WEIGHT OF PANEL.
PANEL SHOWN SLIGHTLY
ROTATED TO ALLOW TOP TAB TO
EXIT (OR ENTER) TOP SLOT FOR
REMOVING (OR INSTALLING)
PANEL.
Figure 12. Removing/Installing Louvered Panels
(Detail A, B and C)
WARNING
Unit must be grounded in accordance
with national and local codes.
Electric Shock Hazard. Can cause
injury or death.
Line voltage is present at all
components when unit is not in
operation on units with single-pole
contactors. Disconnect all remote
electric power supplies before
opening access panel. Unit may have
multiple power supplies.
MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO PARALLEL WITH THE UNIT
AS POSSIBLE) WHILE INSTALLING PANEL.
PREFERRED ANGLE
FOR INSTALLATION
Detail D
ANGLE MAY BE TOO
EXTREME
HOLD DOOR FIRMLY ALONG
THE HINGED SIDE TO MAINTAIN
FULLY−ENGAGED TABS
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 louvered 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:
SSlightly 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.
SRotate panel to vertical to fully engage all tabs.
SHolding 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.
Electrical Connections
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 8
505328M 06/09
Table 2. Wire Run Length
Wire Run Length AWG # Insulation Type
less than 100’ (30m) 18 color−coded, temperature
rating 35ºC minimum
more than 100’ (30m) 16
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
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.
Figure 14. Typical Low−Voltage Field Wiring
GROUND LUG
DEFROST CONTROL
BOARD (DCB)
LENNOX SYSTEM OPERATION
MONITOR (LSOM)
CAPACITOR
GROUND LUG
CONTACTOR
K1−1 COMPRESSOR CONTACTOR
GROUND
L2
208−230/60/1 L1
READ WARNING AND NOTE
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 protection size.
CONTROL BOX
Figure 15. Typical High−Voltage Field Wiring (Unit Panel)

Page 9
XP15 SERIES
New or Replacement Line Set
This section provides information on installation or
replacement of existing line sets. If line sets are not being
installed or replace, then proceed to Brazing Connections
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 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,
non−flare) series line sets, or use field−fabricated
refrigerant lines as listed in table 3.
MATCHING WITH NEW OR EXISTING INDOOR COIL
AND LINE SET
IMPORTANT
Matching XP15 with a New Indoor Coil and Line
SetIf installing a new indoor coil and reusing the
existing line set that included a RFCI liquid line
(small bore liquid line used as a metering device)
then you must change to a standard size liquid line.
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:
SModel (XP15) and size (e.g. −060) of unit.
SLine set diameters for the unit being installed (from
table 3)
SNumber of elbows and if there is a rise or drop of the
piping.
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
Model
Valve Sizes Recommended Line Set
Liquid
Line
Vapor
Line
Liquid
Line
Vapor
Line
L15
Line Sets
−024
3/8 in.
(10 mm)
3/4 in.
(19 mm)
3/8 in
(10 mm)
3/4 in.
(19 mm)
L15−41
15 − 50 ft.
(5 − 15 m)
−030
−036
−042 3/8 in.
(10 mm)
7/8 in
(22 mm)
3/8 in.
(10 mm)
7/8in
(22 mm)
L15−65
15 − 50 ft.
(5 − 15m)
−048
−060 3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
Field
Fabricated
INSTALLING LINE SET
Line Set IsolationThis reference illustrates
procedures, which ensure proper refrigerant line set
isolation:
SInstallation of line sets on horizontal runs is
illustrated in figure 16.
SInstallation of line sets on vertical runs is illustrated
in figure 17 on page 10 .
SInstallation of a transition from horizontal to
vertical is illustrated in figure 18 on page 10.
METAL
SLEEVE
STRAPPING MATERIAL
(AROUND VAPOR LINE
ONLY)
TAPE OR
WIRE TIE
FLOOR JOIST OR
ROOF RAFTER
TAPE OR
WIRE TIE
TO HANG LINE SET FROM JOIST OR RAFTER,
USE EITHER METAL STRAPPING MATERIAL OR
ANCHORED HEAVY NYLON WIRE TIES.
8 FEET
8 FEET
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
WIRE TIE (AROUND
VAPOR LINE ONLY
Figure 16. Refrigerant Line Sets: Installing
Horizontal Runs

Page 10
505328M 06/09
NOTE − SIMILAR
INSTALLATION
PRACTICES SHOULD BE
USED IF LINE SET IS TO
BE INSTALLED ON
EXTERIOR OF OUTSIDE
WALL.
PVC
PIPE FIBERGLASS
INSULATION
CAULK
OUTSIDE
WALL
VAPOR LINE WRAPPED
WITH ARMAFLEX
LIQUID LINE
IMPORTANT!
REFRIGERANT LINES
MUST NOT CONTACT
STRUCTURE.
OUTSIDE WALL
LIQUID LINE
VAPOR LINE
IMPORTANT -
REFRIGERANT LINES MUST
NOT CONTACT WALL.
WOOD BLOCK
BETWEEN STUDS
STRAP
SLEEVE
WOOD BLOCK
STRAP
SLEEVE
WIRE TIE
WIRE TIE
WIRE TIE
INSIDE WALL
Figure 17. Refrigerant Line Sets: Installing Vertical
Runs (New Construction Shown)
STRAP LIQUID LINE
TO VAPOR LINE
METAL SLEEVE
AUTOMOTIVE
MUFFLER-TYPE HANGER
WALL
STUD
VAPOR LINE WRAPPED
IN ARMAFLEX
LIQUID
LINE
ANCHORED HEAVY
NYLON WIRE TIE
STRAP LIQUID LINE
TO VAPOR LINE
WALL
STUD
LIQUID LINE
METAL SLEEVE
VAPOR LINE − WRAPPED
IN ARMAFLEX
Figure 18. Refrigerant Line Sets: Transition from
Vertical to Horizontal
23
4
5
6
outdoor
UNIT
LIQUID LINE
SUCTION LINE
SERVICE
VALVE
SERVICE
VALVE
CUT AND DEBUR ATTACH
GAUGES
WRAP
SERVICE
VALVE
FLOW NITROGEN
NITROGEN
BRAZE LINE SET
1
INSTALL CORE ONLY FOR
BOTH SERVICE PORTS after they
have coolED.
7
INDOOR UNIT
REMOVE CAP AND CORE FROM
BOTH LIQUID AND SUCTION
SERVICE PORTS
SERVICE PORT MUST BE
OPEN TO ALLOW EXIT
POINT FOR NITROGEN
Figure 19. Brazing Connections