Page 1
INSTALLATION
E2006 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.
IMPORTANT
This unit must be matched with an indoor coil as
specified in Lennox’ Engineering Handbook.
Coils previously charged with R−22 must be flushed.
XC15 Outdoor Unit
XC15 outdoor units use R−410A refrigerant. This unit must
be installed with a matching indoor coil and line set as outlined in the Lennox Engineering Handbook. XC15 outdoor
units are designed for use in expansion valve (TXV) systems only. Refer to the Lennox Engineering Handbook for
expansion valve kits which must be ordered separately.
INSTRUCTIONS
XC15 Series Units
CONDENSING UNITS
505,095M
01/06
Table of Contents
XC15 Outdoor Unit 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shipping And Packing List 1. . . . . . . . . . . . . . . . . . . . . . . .
Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Information 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Unit 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing Panels 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refrigerant Piping 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flushing Existing Line Set and Indoor Coil 9. . . . . . . . . .
Refrigerant Metering Device 10. . . . . . . . . . . . . . . . . . . . .
Manifold Gauge Set 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Valves 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leak Testing 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Evacuation 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Start−up 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refrigerant Charging 13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Operation 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 18. . . . . . . . . . . . . . . . . . . . . . . . . . .
XC15 Start−Up and Performance Check List 19. . . . . . . .
Homeowner’s Information − Maintenance 19. . . . . . . . . .
Thermostat Operation 20. . . . . . . . . . . . . . . . . . . . . . . . . . .
Sound Reduction Cover & Assembly Procedure 20. . . .
General Information
When servicing or repairing HVAC components, ensure
the fasteners are appropriately tightened. Table 1 shows
torque values for fasteners, and for port and valve caps.
Litho U.S.A.
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.
Shipping and Packing List
1 − Assembled XC15 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.
01/06 505,095M
*2P0106* *P505095M*
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 #8 16 in.− lb. 2 NM
Compressor bolts 90 in.− lb. 10 NM
Gauge port seal cap 8 ft.− lb. 11 NM
These instructions are intended as a general guide and do
not supersede national or local codes in any way. Consult
authorities having jurisdiction before installation.
Page 1
Page 2
Unit Dimensions − inches (mm) and Parts Arrangement
TOP VIEW
39−1/2
(1003)
18
(457)
DISCHARGE AIR
9−1/4
(234)
13−1/2
(343)
10−1/2
(267)
CONTACTOR
SYSTEM OPERA-
TION MONITOR
RUN CAPACITOR
DISCHARGE LINE
VAPOR VALVE AND
GAUGE PORT
VAPOR LINE
LOW PRESSURE
SWITCH
FILTER DRIER
ELECTRICAL
INLETS
37 (940)
[−024 thru −042]
47 (1194)
[−048 and −060]
35−1/2
(902)
OUTDOOR FAN
COMPRESSOR
AND SOUND
REDUCTION
COVER (SEE
PAGE 20 FOR
COVER
INFORMATION)
COMPRESSOR
TERMINAL
PLUG
HIGH
PRESSURE
SWITCH
10−3/8 (264)
SUCTION
LINE
INLET
LIQUID
LINE
INLET
SIDE VIEW ACCESS VIEW
Setting the Unit
CAUTION
In order to avoid injury, take proper precaution when
lifting heavy objects.
4−7/16
(113)
21−1/8 (537)
[−024 thru −042]
31−1/8 (791)
[−048 and −060]
18−5/8
(473)
8 (203)
1 (25)
Figure 1
Refer to unit dimensions for sizing mounting slab, platforms or supports. Refer to figure 2 for installation clearances.
Service Panel Clearance
A service clearance of 30" (762 mm) must be maintained
on the access panel side of the unit (see figure 2).
505095M 1/3/06
Page 2
Page 3
Installation Clearances
(as noted)
(as
noted)
30 in. (762−mm)
*A service clearance of 30" (762 mm) must be maintained on
the access panel side of the unit. Clearance to one of the other three sides must be 36" (914 mm). Clearance to one of the
remaining two sides may be 12" (304 mm) and the final side
may be 6" (152 mm).
A clearance of 24" (610 mm) must be maintained between
two units. 48" (1219 mm) clearance required on top of unit.
Maximum soffit overhang is 36" (914 mm).
(as
noted)
Figure 2
Roof Mounting
Install unit at a minimum of 4 inches above the surface of
the roof. Care must be taken to ensure weight of unit is
properly distributed over roof joists and rafters. Either redwood or steel supports are recommended.
Removing Panels
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
Slab Mounting
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. See figure
3. Slab may be level or have a slope tolerance away from
the building of not more than 2 degrees or 2 inches per 5
feet (51 mm per 1524 mm).
Slab Mounting At Ground Level
BUILDING
STRUCTURE
MOUNTING
SLAB
INSTALL UNIT LEVEL OR, IF ON A SLOPE, MAINTAIN SLOPE TOLERANCE OF 2
DEGREES (OR 2 INCHES PER 5 FEET [51 MM PER 1.5 M]) AWAY FROM
BUILDING STRUCTURE.
Figure 3
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.
Access Panel
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.
Page 3
XC15 SERIES
Page 4
Remove and reinstall the access panel as described in figure 4.
Access Panel
Removing/Installing Louvered Panels
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.
Remove 4 screws to
remove panel for
accessing compressor
and controls.
Install by positioning
panel with holes
aligned; install screws
and tighten.
Figure 4
Louvered Panels
CAUTION
Physical contact with metal edges and corners can
result in personal injury. Be aware of, and use caution when working with panels.
Remove the louvered panels as follows:
1. Remove 2 screws, allowing the panel to swing open
slightly.
2. Hold the panel firmly throughout this procedure.
Rotate bottom corner of panel away from hinge corner
post until lower 3 tabs clear the slots (see figure 5, Detail B).
3. Move panel down until lip of upper tab clears the top
slot in corner post (see figure 5, Detail A).
Position and Install PanelPosition the panel almost
parallel with the unit (figure 5, Detail D) with the screw
side" as close to the unit as possible. Then, in a continuous
motion:
S Slightly rotate and guide the LIP of top tab inward (fig-
ure 5, Details A and C); then upward into the top slot
of the hinge corner post.
S Rotate panel to vertical to fully engage all tabs.
S 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.
LIP
SCREW
HOLES
Detail A
Detail B
Detail C
ROTATE IN THIS DIRECTION;
THEN DOWN TO REMOVE PANEL
MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO PARALLEL WITH THE UNIT
AS POSSIBLE) WHILE INSTALLING PANEL.
ANGLE MAY BE TOO
EXTREME
PREFERRED ANGLE
FOR INSTALLATION
HOLD DOOR FIRMLY TO THE HINGED
SIDE TO MAINTAIN
FULLY−ENGAGED TABS
Detail D
Figure 5
Electrical
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).
505095M 1/3/06
Page 4
Page 5
Refer to the furnace or blower coil installation instructions
color coded, temperature
for additional wiring application diagrams and refer to unit
nameplate for minimum circuit ampacity and maximum
overcurrent protection size.
1. Install line voltage power supply to unit from a properly
sized disconnect switch. See figure 6.
Typical Field Wiring Diagram
GND
L1
L2
208−230/60/1
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.
Figure 6
2. Ground unit at unit disconnect switch or to earth
ground.
3. Connect conduit to the unit via the bottom hole using
a proper conduit fitting.
NOTE − Units are approved for use only with copper
conductors. 24V, Class II circuit connections are
made in the low voltage junction box. Refer to figure 7
for field wiring diagram. A complete unit wiring diagram is located on the back side of the access panel.
NOTE − For proper voltages, select thermostat wire
gauge per the following chart:
Wire run length AWG # Insulation type
less than 100’ (30m) 18
more than 100’ (30m) 16
color−coded, temperature
rating 35ºC minimum
4. Install room thermostat (ordered separately) on an inside wall approximately in the center of the conditioned
area and 5 feet (1.5 m) from the floor. It should not be
installed on an outside wall or where it can be affected
by sunlight, drafts or vibrations.
5. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit. See figure 7.
6. LSOM L Terminal WiringConnect L terminal of the
room thermostat to the L (Brown) field wire connection.
7. LSOM Installation VerificationVerification procedures are described in System Operation under System Operation Monitor (see Page 16).
NOTE − Wiring the module incorrectly will cause false
LED codes. Table 8 (see page 17) describes LED operation when the module is incorrectly wired and the
action required to correct the problem.
Typical Wiring Diagram
Figure 7
Page 5
XC15 SERIES
Page 6
Refrigerant Piping
If the XC15 unit is being installed with an indoor coil and line
set, make the refrigerant connections as outlined in this
section. f an existing line set and/or indoor coil is going to
be used to complete the XC15 system, refer to this section,
as well as the flushing section which follows.
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections) to the indoor coil
(flare or sweat connections). Use Lennox L15 (sweat, non−
flare) series line sets as shown in table 2 or use field−fabricated refrigerant lines. Valve sizes are also listed in table 2.
Table 2
Refrigerant Line Sets
Valve Sizes Recommended Line Set
Liquid
Model
−024
−030
−036
−042
−048
−060 3/8 in.
Line
3/8 in.
(10 mm)
3/8 in.
(10 mm)
(10 mm)
Vapor
Line
3/4 in.
(19 mm)
7/8 in
(22 mm)
1−1/8 in.
(29 mm)
Liquid
Line
3/8 in
(10 mm)
3/8 in.
(10 mm)
3/8 in.
(10 mm)
Vapor
Line
3/4 in.
(19 mm)
7/8in
(22 mm)
1−1/8 in.
(29 mm)
L15
Line Sets
L15−41
15 − 50 ft.
(5 − 15 m)
L15−65
15 − 50 ft.
(5 − 15m)
Field
Fabricated
1. PlacementSome localities are adopting sound ordi-
nances based on the unit’s noise 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 (see figure 8).
Outside Unit Placement and Installation
Install unit
away from
windows
Two 90° elbows installed in line
set will reduce line set vibration.
NOTE − When installing refrigerant lines longer than 50
feet, contact Lennox Technical Support Product
Applications for assistance. To obtain the correct
information from Lennox, be sure to communicate the
following points:
S Line set diameters for the unit being installed (from
table 2)
S Model (XC15) and size of unit (e.g. −060).
IMPORTANT
Matching XC15 with new Indoor Coil and Line
SetIf an existing indoor coil equipped with an
RFCI metering device is being replaced, also install
a new liquid line prior to installing the XC15 unit.
Installing Refrigerant Line
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
noises. Also, consider the following when placing and
installing a high−efficiency outdoor unit:
Figure 8
2. Line Set IsolationThe following illustrations dem-
onstrate procedures which ensure proper refrigerant
line set isolation. Figure 10 shows how to install line
sets on horizontal runs. Figure 11 shows how to make
a transition from horizontal to vertical. Figure 12 shows
how to install line sets on vertical runs.
Installing Isolation Grommets
Locate the isolation grommets (provided). Slide grommets
onto vapor and liquid lines. Insert grommets into mullion to
isolate refrigerant lines from sheet metal edges.
WARNING
Polyol ester (POE) oils used with R−410A refrigerant absorb moisture very quickly. It is very important that the refrigerant system be kept closed as
much as possible. DO NOT remove line set caps or
service valve stub caps until you are ready to make
connections.
505095M 1/3/06
Page 6
Page 7
Brazing Connection Procedure
Before brazing, remove the access panel (see figure 4);
then remove the narrow piping panel to prevent burning off
the paint (see figure 9).
Piping Panel Removal
Remove 2
screws and remove panel
before brazing.
PIPING
Line set
connection
points.
PANEL
Figure 9
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. When making line set connections, use 1 to 2 psig dry
nitrogen to purge the refrigerant piping. This will help
to prevent oxidation and the introduction of moisture
into the system.
3. Use silver alloy brazing rods (5 or 6 percent minimum
silver alloy for copper−to−copper brazing or 45 percent
silver alloy for copper−to−brass or copper−to−steel
brazing) which are rated for use with R−410A refrigerant. While brazing-in the line set connections, wrap a
wet cloth around the valve body and the copper tube
stubs.
4. Quench the joints with a wet cloth to prevent possible
heat damage to the valve core and opening port.
NOTE − The tube end must stay bottomed in the fitting
during final assembly to ensure proper seating, sealing and rigidity.
5. Install the thermal expansion valve in the liquid line at
the indoor coil.
NOTE − Expansion valve (not provided; obtain separately) must be approved for use with R−410A refrigerant.
To hang line set from joist or rafter,
use either metal strapping material
or anchored heavy nylon wire ties.
STRAPPING MATERIAL
(Around vapor line only)
TAPE OR WIRE TIE
Refrigerant Line Sets: Installing Horizontal Runs
WIRE TIE
(Around vapor line only)
8 feet
FLOOR JOIST OR
ROOF RAFTER
TAPE OR WIRE TIE
8 feet
Strap the vapor line to the joist or rafter
at 8 ft. intervals then strap the liquid line
to the vapor line.
METAL
SLEEVE
FLOOR JOIST OR ROOF RAFTER
Figure 10
Page 7
XC15 SERIES
Page 8
ANCHORED
HEAVY NYLON
WIRE TIE
Refrigerant Line Sets: Transition From Vertical To Horizontal
AUTOMOTIVE
MUFFLER-TYPE
HANGER
WALL
STUD
METAL
SLEEVE
Strap Liquid
Line To Vapor Line
LIQUID
LINE
VAPOR LINE − WRAPPED
IN ARMAFLEX
WALL
STUD
METAL
SLEEVE
Strap Liquid Line
To Vapor Line
LIQUID
LINE
VAPOR LINE − WRAPPED
IN ARMAFLEX
Figure 11
Refrigerant Line Sets: Installing Vertical Runs (new construction shown)
NOTE − Similar installation practices should be used if line set is to be installed on exterior of outside wall.
OUTSIDE WALL
WOOD BLOCK
BETWEEN STUDS
IMPORTANT - Refrigerant
lines must not contact wall.
LIQUID LINEVAPOR LINE
WIRE TIE
INSIDE WALL
IMPORTANT!
Refrigerant
lines must
not contact
structure.
505095M 1/3/06
VAPOR LINE WRAPPED
WITH ARMAFLEX
OUTSIDE WALL
PVC PIPE
FIBERGLASS
INSULATION
LIQUID
LINE
CAULK
STRAP
SLEEVE
WIRE TIE
WOOD BLOCK
WIRE TIE
STRAP
SLEEVE
Figure 12
Page 8
Page 9
Flushing Existing Line Set & Indoor Coil
Flushing Procedure
WARNING
Danger of fire. Bleeding the refrigerant charge from only the high side
may result in the low side shell and
suction tubing being pressurized. Application of a brazing torch while
pressurized may result in ignition of
the refrigerant and oil mixture − check
the high and low pressures before unbrazing.
CAUTION
This procedure should not be performed on systems which contain contaminants (Example: compressor burn out).
IMPORTANT
If this unit is being matched with an approved line
set or indoor coil which was previously charged
with mineral oil, or if it is being matched with a coil
which was manufactured before January of 1999,
the coil and line set must be flushed prior to installation. Take care to empty all existing traps. Polyol
ester (POE) oils are used in Lennox units charged
with R−410A refrigerant. Residual mineral oil can
act as an insulator, preventing proper heat transfer. It can also clog the expansion device, and reduce the system performance and capacity.
Failure to properly flush the system per the instructions below will void the warranty.
Required Equipment
Equipment required to flush the existing line set and indoor
coil:
S two clean R−22 recovery bottles,
S oil−less recovery machine with pump-down feature,
S 2 gauge sets (one for R−22; one for R−410A).
IMPORTANT
The Environmental Protection Agency (EPA) prohibits the intentional venting of HFC refrigerants
during maintenance, service, repair and disposal of
appliance. Approved methods of recovery, recycling or reclaiming must be followed.
1. Remove existing R−22 refrigerant using the following,
appropriate procedure (see figure 13):
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 R−22 refrigerant
to flush the system −
D Disconnect all power to the existing outdoor unit.
D Connect to the existing unit, a clean recovery cyl-
inder and the recovery machine according to the
instructions provided with the recovery machine.
D Remove all R−22 refrigerant from the existing sys-
tem. Check gauges after shutdown to confirm that
the entire system is completely void of refrigerant.
D Disconnect the liquid and vapor lines from the ex-
isting outdoor unit.
If the existing outdoor unit is equipped with
manual shut−off valves AND you plan to use NEW
R−22 refrigerant to flush the system −
D Start the existing R−22 system in the cooling mode
and close the liquid line valve.
D Pump all of the existing R−22 refrigerant back into
the outdoor unit. (It may be necessary to bypass
the low pressure switches to ensure complete refrigerant evacuation.)
D When the low side system pressures reach 0 psig,
close the vapor line valve.
D 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.
D Disconnect the liquid and vapor lines from the ex-
isting outdoor unit.
2. Remove the existing outdoor unit. Set the new R−410A
unit and follow the brazing connection procedure (see
page 7) to make line set connections.
Page 9
XC15 SERIES
Page 10
Inverted R−22 Cylinder
(Contains clean R−22 to
be used for flushing)
Flushing Connections
Vapor Line
EXISTING
INDOOR COIL
RECOVERY CYLINDER
EXISTING VAPOR LINE
EXISTING LIQUID LINE
Service Valve
Liquid Line
Service Valve
Tank Return
Inlet
Discharge
RECOVERY MACHINE
Figure 13
3. Make low voltage and line voltage connections to the
new outdoor unit. Do NOT turn on power to unit or
open the outdoor unit service valves at this time.
4. Remove the existing refrigerant flow control orifice or
thermal expansion valve before continuing with flushing procedures. Existing devices are not approved for
use with R−410A refrigerant and may prevent proper
flushing. Use a field−provided fitting to reconnect lines.
IMPORTANT
The line set and indoor coil must be flushed with
at least the same amount of clean refrigerant that
previously charged the system. Check the charge
in the flushing cylinder before proceeding.
5. Remove the pressure tap valve cores from the XC15
unit’s service valves. Connect an R−22 cylinder with
clean refrigerant to the vapor service valve. Connect
the R−22 gauge set to the liquid line valve. Connect a
recovery machine with an empty recovery tank to the
gauge set.
6. Set the recovery machine for liquid recovery and start
the recovery machine. Open the gauge set valves to
allow the recovery machine to pull a vacuum on the existing system line set and indoor coil.
7. Invert the cylinder of clean R−22 and open its valve to
allow liquid refrigerant to flow into the system through
the vapor line valve. Allow the refrigerant to pass from
the cylinder and through the line set and the indoor coil
before it enters the recovery machine.
8. After all of the liquid refrigerant has been recovered,
switch the recovery machine to vapor recovery so that
Low
Pressure
XC15
UNIT
GAUGE MANIFOLD
NOTE − The inverted R−22 cylinder
must contain at least the same
amount of refrigerant as was recovered from the existing system.
High
Pressure
ClosedOpened
all of the R−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 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.
9. Close the valve on the inverted R−22 drum and the
gauge set valves. Pump the remaining refrigerant out
of the recovery machine and turn the machine off.
10. Use dry nitrogen to break the vacuum on the refrigerant lines and indoor coil before removing the recovery
machine, gauges and R−22 refrigerant drum. Reinstall
pressure tap valve cores into XC15 service valves.
11. Install the expansion valve in the liquid line at the indoor coil.
Refrigerant Metering Device
XC15 units may be used in thermal expansion valve (TXV)
systems only. See the indoor coil installation instructions
and the Lennox Engineering Handbook for approved TXV
match−ups and application information. Table 2 (on
Page 6) lists liquid and vapor line sizes and corresponding line sets.
Expansion valves equipped with Chatleff type fittings are
available from Lennox. Refer to the Engineering Handbook for expansion valves for use with specific match−ups.
If you install an expansion valve with an indoor coil that includes a fixed orifice, remove the orifice before the expansion valve is installed (see figure 14).
505095M 1/3/06
Page 10
Page 11
Metering Device Installation
O−RING
DISTRIBUTOR
NOTE − If necessary, remove R−22 flow control device (fixed
orifice/thermal expansion valve) from existing line set before
installing R−410A approved expansion valve and o−ring.
EXPANSION VALVE &
O−RING (See NOTE)
STRAINER
LIQUID LINE
STUB
Figure 14
IMPORTANT
Failure to remove a fixed orifice when installing an
expansion valve to the indoor coil will result in improper operation and damage to the system.
Manifold Gauge Set
Manifold gauge sets used with systems charged with
R−410A refrigerant must be capable of handling the higher
system operating pressures. The gauges should be rated
for use with pressures of 0 − 800 on the high side and a low
side of 30" vacuum to 250 psi with dampened speed to 500
psi. Gauge hoses must be rated for use at up to 800 psi of
pressure with a 4000 psi burst rating.
To Open Front-Seated Service Valves:
1. Remove stem cap with an adjustable wrench.
2. Use a service wrench with a hex−head extension
(3/16" for liquid-line valve sizes; 5/16" for vapor-line
valve sizes) to back the stem out counterclockwise as
far as it will go.
3. Replace the stem cap. Tighten finger tight, then tighten
according to torque specifications table (page 1).
To Close Front-Seated Service Valves:
1. Remove the stem cap with an adjustable wrench.
2. Use a service wrench with a hex−head extension
(3/16" for liquid-line valve sizes; 5/16" for vapor-line
valve sizes) to turn the stem clockwise to seat the
valve. Tighten it firmly.
3. Replace the stem cap. Tighten finger tight, then tighten
according to torque specifications table (page 1).
Front-Seated Liquid Line Service Valve
SCHRADER
VALV E
[open to line set
when valve is
closed (front
seated)]
(VALVE front-
seated)
To
indoor
coil
SERVICE PORT CAP
SERVICE PORT
(Valve Shown
Closed)
Insert hex wrench
here
STEM
CAP
Service Valves
The liquid line and vapor line service valves (figures 15 and
16) and gauge ports are used for leak testing, evacuating,
charging and checking charge. See table 1 (on page 1) for
torque requirements.
Each valve is equipped with a service port which has a factory−installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.
To Access Schrader Port:
1. Remove service port cap with an adjustable wrench.
2. Connect gauge to the service port.
3. When testing is completed, replace service port cap.
Tighten finger tight, then tighten an additional 1/6 turn.
SERVICE PORT CAP
SERVICE
PORT
To
indoor
coil
To outdoor coil
SCHRADER
VALV E
(Valve Shown
Open)
insert hex wrench
here
STEM
CAP
To outdoor coil
Figure 15
Page 11
XC15 SERIES
Page 12
Vapor Line (Ball Type) Service Valve
Vapor line service valves function the same way as the other valves; the difference is in the construction. These
valves are not rebuildable. If a valve fails, replace it. The
ball valve (shown in figure 16) is equipped with a service
port with a factory−installed Schrader valve. A service port
cap protects the Schrader valve from contamination and
assures a leak−free seal.
Ball−Type Vapor Line Valve (Valve Closed)
To indoor coil
Use Adjustable Wrench
To close: rotate Stem
Counter-clockwise 90°.
To open: rotate Stem
Clockwise 90°.
SERVICE
PORT
SCHRADER
VALV E
SERVICE
PORT CAP
To outdoor coil
BALL
(Shown
closed)
STEM
STEM
CAP
Figure 16
Leak Test with Electronic Leak Detector
1. Connect an R−410A 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.)
2. With both manifold valves closed, connect the cylinder
of R−410A refrigerant to the center port of the manifold
gauge set. Open the valve on the R−410A cylinder (vapor only).
3. Open the high pressure side of the manifold to allow
R−410A into the line set and indoor unit. Weigh in a
trace amount of R−410A. [A trace amount is a maxi-
mum of 2 ounces (57 g) refrigerant or 3 pounds (31
kPa) pressure]. Close the valve on the R−410A cylin-
der and the valve on the high pressure side of the manifold gauge set. Disconnect the R−410A cylinder.
4. Connect a cylinder of dry nitrogen with a pressure regulating valve to the center port of the manifold gauge
set.
5. Adjust dry nitrogen pressure to 150 psig (1034 kPa).
Open the valve on the high side of the manifold gauge
set in order to pressurize the line set and the indoor unit.
6. After a few minutes, open a refrigerant port to ensure
the refrigerant you added is adequate to be detected.
(Amounts of refrigerant will vary with line lengths.)
Check all joints for leaks. Purge dry nitrogen and
R−410A mixture. Correct any leaks and recheck.
IMPORTANT
Leak Testing
After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit
for leaks.
WARNING
Refrigerant can be harmful if it is inhaled. Refrigerant must be used and recovered responsibly.
Failure to follow this warning may result in personal
injury or death.
WARNING
Danger of explosion: Can cause injury or death, or equipment damage.
Never use oxygen to pressurize a refrigeration or air conditioning system.
Oxygen will explode on contact with
oil and could cause personal injury.
When using a high pressure gas such
as dry nitrogen to pressurize a refrigeration or air conditioning system,
use a regulator that can control the
pressure down to 1 or 2 psig (6.9 to
13.8 kPa).
505095M 1/3/06
Leak detector must be capable of sensing HFC refrigerant.
Evacuation
Evacuating the system of noncondensables is critical for
proper operation of the unit. Noncondensables are defined
as any gas that will not condense under temperatures and
pressures present during operation of an air conditioning
system. Noncondensables and water vapor combine with
refrigerant to produce substances that corrode copper piping and compressor parts.
IMPORTANT
Use a thermocouple or thermistor electronic vacuum
gauge that is calibrated in microns. Use an instrument
that reads from 50 microns to at least 23,000 microns.
1. Connect manifold gauge set to the service valve ports
as follows:
D low pressure gauge to vapor line service valve
D high pressure gauge to liquid line service valve
2. Connect micron gauge.
3. Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set.
4. Open both manifold valves 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 mercu-
Page 12
Page 13
ry). 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 absolute pressure.
A rapid rise in pressure indicates a relatively large
leak. If this occurs, repeat the leak testing procedure.
NOTE − The term absolute pressure means the total
actual pressure within a given volume or system,
above the absolute zero of pressure. Absolute 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
valves, turn off the vacuum pump and disconnect the
manifold gauge center port hose from vacuum pump.
Attach the manifold center port hose to a dry nitrogen
cylinder with pressure regulator set to 150 psig (1034
kPa) and purge the hose. Open the manifold gauge
valves to break the vacuum in the line set and indoor
unit. Close the manifold gauge valves.
WARNING
Danger of Equipment Damage. Avoid deep vacuum operation. Do not use compressors to evacuate a system. Extremely low vacuums can cause
internal arcing and compressor failure. Damage
caused by deep vacuum operation will void warranty.
7. Shut off the dry nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold
gauge valves to release the dry nitrogen from the line
set and indoor unit.
8. Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line set
and indoor unit until the absolute pressure does not
rise above 500 microns (29.9 inches of mercury) within
a 20−minute period after shutting off the vacuum pump
and closing the manifold gauge valves.
9. When the absolute pressure requirement above has
been met, disconnect the manifold hose from the vacuum pump and connect it to an upright cylinder of
R−410A refrigerant. Open the manifold gauge valves
to break the vacuum from 1 to 2 psig positive pressure
in the line set and indoor unit. Close manifold gauge
valves and shut off the R−410A cylinder and remove
the manifold gauge set.
Start−Up
IMPORTANT
If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start−up to prevent compressor damage as a result of slugging.
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.
4. Replace the stem caps and secure finger tight, then
tighten an additional one-sixth (1/6) of a turn.
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 the power company and the voltage
condition has been corrected.
6. Set the thermostat for a cooling demand. Turn on power to the indoor blower 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.
Refrigerant Charging
This system is charged with R−410A refrigerant which operates at much higher pressures than R−22. The provided
liquid line filter drier is approved for use with R−410A. Do
not replace it with components designed for use with R−22.
This unit is NOT approved for use with coils which use cap-
illary tubes as a refrigerant metering device.
Factory Charge
Units are factory charged with the amount of R−410A refrigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15 ft.
(4.6 m) line set. For varying lengths of line set, refer to table
3 for refrigerant charge adjustment.
Table 3
Refrigerant Charge per Line Set Lengths
Liquid Line
Set Diameter
3/8 in. (9.5mm) 3 ounces per 5 feet (85 grams per 1.52 meter)
*Add the amount shown if line length is greater than 15’ (4.57m), subtract the amount shown if less than 15’.
Ounces per 5 feet (grams per 1.52 meter)
adjust from 15 ft. (4.57m) line set*
IMPORTANT
Mineral oils are not compatible with R−410A. If oil
must be added, it must be a polyol ester oil.
The compressor is charged with sufficient polyol
ester oil for approved line set lengths.
Units Delivered Void of Charge
If the system is void of refrigerant, clean the system using the procedure described below.
1. Use dry nitrogen to pressurize the system and check
for leaks. Repair leaks, if possible.
2. Evacuate the system to remove as much of the moisture as possible.
3. Use dry nitrogen to break the vacuum and install a new
filter drier in the liquid line.
4. Evacuate the system again. Then, weigh the appropriate amount of R−410A refrigerant (listed on unit nameplate) into the system.
Page 13
XC15 SERIES
Page 14
IMPORTANT
Charge adjustments may be required to allow for
longer line sets and coil volumes. Check for proper
charge using charging information in this manual.
5. Monitor the system to determine the amount of moisture remaining in the oil. Use test kit 10N46 to verify
that the moisture content is within the kit’s dry color
range. It may be necessary to replace the filter drier
several times to achieve the required dryness level. If
system dryness is not verified, the compressor
will fail in the future.
Checking Charge
The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur
in the colder months. The method of charging is determined by the outdoor ambient temperature.
Measure the liquid line temperature and the outdoor ambient temperature as outlined below:
1. Connect the manifold gauge set to the service valves:
D low pressure gauge to vapor valve service port
D high pressure gauge to liquid valve service port
Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of R−410A .
2. Set the room thermostat to call for heat. This will
create the necessary load for properly charging the
system in the cooling cycle.
3. Record outdoor ambient temperature using a digital
thermometer.
4. When the heating demand has been satisfied, switch
the thermostat to cooling mode with a set point of 68ºF
(20ºC). When pressures have stabilized, use a digital
thermometer to record the liquid line temperature.
5. The outdoor temperature will determine which charging method to use. Proceed with the appropriate
charging procedure.
Charge Using Weigh-in MethodOutdoor Temper-
ature < 65ºF (18ºC)
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, first, locate and repair any leaks and
then weigh in the refrigerant charge into the unit.
1. Recover the refrigerant from the unit.
2. Conduct leak check; evacuate as previously outlined.
3. Weigh in the unit nameplate charge. If weighing facilities are not available or if charging the unit during
warm weather, use one of the following procedures.
Charge Using the Approach MethodOutdoor
Temp. >65ºF (18ºC)
The following procedure is intended as a general guide and
is for use on expansion valve systems only. For best results, outdoor temperature should be 70°F (21°C) to 80°F
(26°C). Monitor system pressures while charging.
1. Record outdoor ambient temperature using a digital
thermometer.
2. Attach high pressure gauge set and operate unit for
several minutes to allow system pressures to stabilize.
3. Compare stabilized pressures with those provided in
table 5, Normal Operating Pressures." Minor variations in these pressures may be expected due to differences in installations. Significant differences could
mean that the system is not properly charged or that
a problem exists with some component in the system.
Pressures higher than those listed indicate that the
system is overcharged. Pressures lower than those
listed indicate that the system is undercharged. Continue to check adjusted charge using approach values.
4. Use the same digital thermometer you used to check
the outdoor ambient temperature to check the liquid
line temperature.
5. The difference between the ambient and liquid temperatures should match values given in table 4. If the
values do not agree with the those in table 4, add refrigerant to lower the approach temperature, or recover refrigerant from the system to increase the approach temperature.
Table 4
XC15 Approach Values
_ Liquid Line Temperature
_ Outdoor Temperature
= _ Approach Temperature
Model −024 −030 −036 −042 −048 −060
°F
(°C)*
NOTE − For best results, use the same electronic thermometer to
check both outdoor-ambient and liquid-line temperatures.
*F: +/−1.0°; C: +/−0.5°
10
(5.6)12(6.7)11(6.1)13(7.2)6(3.3)10(5.6)
NOTES −
S R−410A refrigerant cylinders are rose−colored. Refrig-
erant should be added through the vapor valve in the
liquid state.
S Certain R−410A cylinders are identified as being
equipped with a dip tube. These allow liquid refrigerant
to be drawn from the bottom of the cylinder without inverting the cylinder. DO NOT turn this type cylinder upside−down to draw refrigerant.
505095M 1/3/06
Page 14
Page 15
Table 5
XC15 Normal Operating Pressures In psig (liquid +/− 10 and vapor+/− 5 PSIG)*
Model
5F (5C)** Liquid Suction Liquid Suction Liquid Suction Liquid Suction Liquid Suction Liquid Suction
65 (18.3) 239 135 246 135 245 132 260 132 224 129 242 131
70 (21.1) 255 136 266 136 264 133 282 133 241 130 262 132
75 (23.9) 274 137 285 138 285 135 302 134 259 131 282 134
80 (26.7) 293 138 306 139 306 137 325 135 279 133 303 135
85 (29.4) 317 139 328 140 328 137 347 136 301 134 326 136
90 (32.2) 339 140 350 141 352 139 370 137 323 135 349 137
95 (35.0) 362 141 374 142 375 140 395 138 347 137 372 138
100 (37.8) 387 142 399 143 400 141 421 139 372 138 397 140
105 (40.6) 415 144 423 144 425 141 446 141 397 140 422 141
110 (43.3) 440 145 450 145 452 143 475 142 422 141 448 143
115 (46.1) 469 146 477 146 476 144 504 144 449 143 475 146
* These are typical pressures only. Indoor match up, indoor air quality, and indoor load will cause the pressures to vary.
** Temperature of air entering outdoor coil.
−024 −030 −036 −042 −048 −060
Charge Using Subcooling MethodOutdoor Tem-
perature > 65ºF (18ºC)
Use the following method to obtain accurate subcooling
values. Compare the measured subcooling value to the
values given in table 6.
Table 6
XC15 Subcooling Values
(psig ) _ Saturation Temperature
_ Liquid Line Temperature
= _ Subcooling Value
Model −024 −030 −036 −042 −048 −060
°F
(°C)*
NOTE − For best results, use the same electronic thermometer to
check both outdoor-ambient and liquid-line temperatures.
*F: +/−1.0°; C: +/−0.5°
1. With the manifold gauge hose still on the liquid service
port and the unit operating stably, use a digital thermometer to record the liquid line temperature in the
space provided in table 6, and at the same time, record
the liquid line pressure reading in the (psig___)"
space in the table.
2. Use a temperature/pressure chart for R−410A (table 7)
to determine the saturation temperature for the liquid line pressure reading and record that in the space
provided in table 6.
4
(2.2)4(2.2)6(3.3)7(3.9)6(3.3)7(3.9)
3. Subtract the liquid line temperature from the saturation
temperature (according to the chart) to determine the
subcooling value.
4. Compare subcooling value with those in table 6. If subcooling is greater than shown, recover some refrigerant; if less than shown, add some refrigerant.
Charge using Subcooling MethodOutdoor Tem-
perature < 65ºF (18ºC)
When the outdoor ambient temperature is below 65°F
(18°C), use the subcooling method to charge the unit. It
may be necessary to restrict the air flow through the outdoor coil to achieve pressures in the 325−375 psig
(2240−2585 kPa) range. These higher pressures are necessary for checking the charge. Block equal sections of air
intake panels and move obstructions sideways until the liquid pressure is in the 325−375 psig (2240−2585 kPa) range.
See figure 17.
Blocking Outdoor Coil
*Outdoor coil should be blocked one
side at a time with cardboard or plastic
sheet until proper testing pressures
are reached.
cardboard or plastic sheet
*Four−sided unit shown.
Figure 17
Page 15
XC15 SERIES
Page 16
Table 7
R−410A Temperature (°F) − Pressure (Psig)
°F Psig °F Psig °F Psig °F Psig
32 100.8 63 178.5 94 290.8 125 445.9
33 102.9 64 181.6 95 295.1 126 451.8
34 105.0 65 184.3 96 299.4 127 457.6
35 107.1 66 187.7 97 303.8 128 463.5
36 109.2 67 190.9 98 308.2 129 469.5
37 111.4 68 194.1 99 312.7 130 475.6
38 113.6 69 197.3 100 317.2 131 481.6
39 115.8 70 200.6 101 321.8 132 487.8
40 118.0 71 203.9 102 326.4 133 494.0
41 120.3 72 207.2 103 331.0 134 500.2
42 122.6 73 210.6 104 335.7 135 506.5
43 125.0 74 214.0 105 340.5 136 512.9
44 127.3 75 217.4 106 345.3 137 519.3
45 129.7 76 220.9 107 350.1 138 525.8
46 132.2 77 224.4 108 355.0 139 532.4
47 134.6 78 228.0 109 360.0 140 539.0
48 137.1 79 231.6 110 365.0 141 545.6
49 139.6 80 235.3 111 370.0 142 552.3
50 142.2 81 239.0 112 375.1 143 559.1
51 144.8 82 242.7 113 380.2 144 565.9
52 147.4 83 246.5 114 385.4 145 572.8
53 150.1 84 250.3 115 390.7 146 579.8
54 152.8 85 254.1 116 396.0 147 586.8
55 155.5 86 258.0 117 401.3 148 593.8
56 158.2 87 262.0 118 406.7 149 601.0
57 161.0 88 266.0 119 412.2 150 608.1
58 163.9 89 270.0 120 417.7 151 615.4
59 166.7 90 274.1 121 423.2 152 622.7
60 169.6 91 278.2 122 428.8 153 630.1
61 172.6 92 282.3 123 434.5 154 637.5
62 175.4 93 286.5 124 440.2 155 645.0
System Operation
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.
High Pressure Switch
XC15 units are equipped with a high pressure switch that is
located in the liquid line to the compressor. The switch is a
SPST, manual−reset switch that is normal closed. The
switch opens at 590 psi.
Low Pressure Switch
XC15 units are equipped with a low pressure switch that is
located in the vapor line to the compressor. The switch is a
SPST, auto−reset switch that is normal closed. The switch
opens at 40 psi and closes at 90 psi.
Filter Drier
A drier is factory−installed in each XC15 unit. A replacement drier is available from Lennox. Refer to Lennox Repair Part Program.
System Operation Monitor (LSOM)
The diagnostic indicator detects the most common fault
conditions in the air conditioning system. When an abnormal condition is detected, the module communicates the
specific condition through its ALERT and TRIP lights. The
module is capable of detecting both mechanical and electrical system problems. See figure 18 for the system operation monitor.
System Operation Monitor
POWER LED
Y
DATA OUTPUT
CONNECTOR
L
R
C
ALERT LED
TRIP LED
.25" SPADE
CONNECTOR (4)
Figure 18
IMPORTANT
This monitor does not provide safety protection.
The monitor is a monitoring device only and cannot
control or shut down other devices.
LSOMLED Functions
Power LED (green)indicates voltage within the range of
19−28VAC is present at the system monitor power connection.
Alert LED (yellow)communicates an abnormal system
condition through a unique Flash Code the alert LED
flashes a number of times consecutively; then pauses;
then repeats the process. This consecutive flashing correlates to a particular abnormal condition.
Trip LED (red)indicates there is a demand signal from
the thermostat but no current to the compressor is detected by the module.
Refer to table 8 for the complete explanation of troubleshooting codes.
Resetting alert codesAlert codes can be reset manually or automatically:
S Manual reset: Cycle the 24VAC power to LSOM off
and on. After power up, existing code will display for
1 minute and then clear.
S Automatic reset: After an alert is detected, the LSOM
continues to monitor the compressor and system.
When/if conditions return to normal, the alert code is
turned off automatically.
LSOML terminal connection
The L connection is used to communicate alert codes to
the room thermostat. On selected Lennox SignatureStatt
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.
505095M 1/3/06
Page 16
Page 17
NOTE − ROOM THERMOSTATS WITH SERVICE OR
CHECK LIGHT FEATUREThe room thermostat may
blink the Check" or Service" LED or it may come on solid.
Confirm fault by observing and interpreting the code from
the LSOM yellow alert LED at the unit.
not function as described, refer to table 8 to verify the wiring. Disconnect power from the compressor and 24VAC
power from LSOM. 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. Disconnect power
LSOMInstallation verification
To verify correct LSOM installation, two functional tests
can be performed. Disconnect power from the compressor
and force a thermostat call for cooling. The red trip LED
should turn on indicating a compressor trip as long as
24VAC is measured at the Y terminal. If the red LED does
from the compressor and 24VAC power from the LSOM.
While the LSOM is off, reattach the wire to the Y terminal.
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 8 to verify the wiring.
Table 8
System Operation Monitor LED Troubleshooting Codes
Status LED Condition Status LED Description Status LED Troubleshooting Information
Green Power" LED ON Module has power 24VAC control power is present at the module terminal.
Green Power" LED OFF Module not powering up Determine/verify that both R and C module terminals are connected
and voltage is present at both terminals.
Red Trip" LED ON System and compressor
check out OK
Thermostat demand signal
Y1 is present, but compressor not running
Red Trip" & Yellow
Alert" LEDs Flashing
Yellow Alert" Flash
Code 1*
Simultaneous flashing. Indicates that the control circuit voltage is too low for operation.
Long Run Time − Compressor is running extremely
long run cycles
Yellow Alert" Flash
Code 2*
System Pressure Trip −
Discharge or suction pressure out of limits or
compressor overloaded
Yellow Alert" Flash
Code 3*
Yellow Alert" Flash
Short Cycling − Compres-
sor is running only briefly
Locked Rotor
Code 4*
Yellow Alert" Flash
Open Circuit
Code 5*
1
Verify Y terminal is connected to 24VAC at contactor coil.
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.
4
Broken wire or connector is not making contact.
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.
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
High head pressure.
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.
2
Time delay relay or control board is defective.
3
If high pressure switch is present, see Flash Code 2 information.
4
If low pressure switch is present, see Flash Code 1 information.
1
Run capacitor has failed.
2
Low line voltage (contact utility if voltage at disconnect is low).
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.
4
High pressure switch is open and requires manual reset.
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.
.
.
.
table continued on next page
Page 17
XC15 SERIES
Page 18
System Operation Monitor LED Troubleshooting Codes
Status LED Condition Status LED Troubleshooting InformationStatus LED Description
Yellow Alert" Flash
Code 6*
Yellow Alert" Flash
Code 7*
Yellow Alert" Flash
Code 8*
Yellow Alert" Flash
Code 9*
Open Start Circuit − Current
only in run circuit
Open Run Circuit − Current
only in start circuit
Welded Contactor − Com-
pressor always runs
Low Voltage − Control circuit <17VAC
*Flash code number corresponds to a number of LED flashes, followed by a pause, and then repeated. Reset ALERT flash
code by removing 24VAC power from monitor; last code will display for 1 minute after monitor is powered on.
Last code will display for 1 minute when power is cycled to module. Power must be on to module for a minimum of 1 minute
for code to clear.
1
Run capacitor has failed.
2
Open circuit in compressor start wiring or connections.
3
Compressor start winding is damaged.
1
Open circuit in compressor start wiring or connections.
2
Compressor start winding is damaged.
1
Compressor contactor failed to open.
2
Thermostat demand signal not connected to module.
1
Control circuit transformer is overloaded.
2
Low line voltage (contact utility if voltage at disconnect is low).
Maintenance
WARNING
Electric shock hazard. Can cause injury or death. Before attempting to perform any service or maintenance, turn
the electrical power to unit OFF at disconnect switch(es). Unit may have
multiple power supplies.
Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each cooling season, check the system as follows:
NOTE − Outdoor fan motor is prelubricated and sealed. No
further lubrication is needed.
1. Clean and inspect the outdoor coil. The coil may be
flushed with a water hose. Ensure the power is turned
off before you clean the coil.
2. Check connecting lines and coils for signs of oil leaks.
3. Check wiring for loose connections.
4. Check for correct voltage at unit (unit operating).
5. Check amp−draw outdoor fan motor.
Unit nameplate _________ Actual ____________ .
NOTE − If owner reports insufficient cooling, the unit
should be gauged and refrigerant charge checked.
Refer to section on refrigerant charging section
(Page 13).
Indoor Coil
1. Clean coil, if necessary.
2. Check connecting lines and coils for signs of oil leaks.
3. Check condensate line and clean, if necessary.
Indoor Unit
1. Clean or change filters.
2. Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
Refer to the unit information service manual for pressure
drop tables and procedure.
3. Check blower for accumulation of dirt or debris.
4. Check all wiring for loose connections
5. Check for correct voltage at unit (blower operating).
6. Check amp−draw on blower motor
Unit nameplate_________ Actual ____________.
Optional Accessories
Optional accessories for the XC15 include the following
(also, see Engineering Handbook for more details):
S Timed-off control
S Low ambient kit
505095M 1/3/06
Page 18
Page 19
XC15 Start−Up & Performance Check List
Customer Address
Indoor Unit Model Serial
Outdoor Unit Model Serial
Notes:
START UP CHECKS
Refrigerant Type:
Rated Load Amps Actual Amps Rated Volts Actual Volts
Condenser Fan Full Load Amps Actual Amps:
COOLING MODE
Suction Pressure: Liquid Pressure:
Supply Air Temperature: Ambient Temperature: Return Air: Temperature:
System Refrigerant Charge (Refer to manufacturer’s information on unit or installation instructions for required subcooling and approach temperatures.)
Subcooling:
Saturated Condensing Temperature (A)
minus Liquid Line Temperature (B)
Approach:
Liquid Line Temperature (A)
minus Outdoor Air Temperature (B)
Indoor Coil Temperature Drop (18 to 22°F)
Return Air Temperature (A)
minus Supply Air Temperature (B)
A B = SUBCOOLING
A B = APPROACH
A B = COIL TEMP
DROP
Homeowner Information − Maintenance
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 FilterAsk your Lennox dealer to show you where
your indoor unit’s filter is located. It will be either at the
indoor unit (installed internal or external to the cabinet)
or behind a return air grille in the wall or ceiling. Check
the filter monthly and clean or replace it as needed.
2. Disposable FilterDisposable filters should be
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
Turn off electrical power to the unit at the
disconnect switch before performing any
maintenance. The unit may have multiple power
supplies.
3. Reusable FilterMany 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 CleanerSome 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 UnitThe 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
Sprinklers and soaker hoses should not be installed
where they could cause prolonged exposure to the
outdoor unit by treated water. Prolonged exposure
of the unit to treated water (i.e., sprinkler systems,
soakers, waste water, etc.) will corrode the surface
of steel and aluminum parts and diminish performance and longevity of the unit.
6. Outdoor UnitMake 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.
Page 19
XC15 SERIES
Page 20
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
System Switch
Set the system switch for heating, cooling or auto operation. The auto mode allows the system to automatically
switch from heating mode to cooling mode to maintain
predetermined comfort settings.
Temperature Indicator
The temperature indicator displays the actual room
temperature.
and set up a schedule (preferably twice a year, but at
least once a year) to inspect and service your air conditioning or heat pump system.
Thermostat Operation
Thermostat operations vary from one thermostat to another. The following provides general operation procedures.
Refer to the user’s information manual provided with your
thermostat for specific operation details.
Temperature Setting Levers
Set the lever or dial to the desired temperature setpoints
for both heating and cooling. Avoid frequent temperature
adjustment; turning the unit offthen back onbefore
pressures can equalize will put unusual stress on the unit’s
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 furnace is operating. This mode is required
when constant air circulation or filtering is desired.
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 thermostat for detailed programming and operation details.
Preservice Check
If your system fails to operate, check the following before
calling for service:
S Check to see that all electrical disconnect switches are
ON.
S Make sure the room thermostat Temperature Selector
and System Switch (Heat, Cool, Auto) are properly
set.
S Check for any blown fuses or tripped circuit breakers.
S Make sure unit access panels are in place.
S Make sure air filter is clean.
S If service is needed, locate and write down the unit
model number and have it handy before calling.
Sound Reduction Cover (SR1) Components and Assembly Procedure
LEFT
TOP
CAP
MIDDLE CABLE TIE
SUCTION
GROMMET
LEFT
SIDE
COVER
BOTTOM CABLE TIE
TOP CABLE TIE
BASE
RIGHT TOP
CAP
RIGHT
SIDE
COVER
DISCHARGE
GROMMET
This diagram identifies the sound reduction
components and shows the correct procedure for
assembling the sound reduction cover:
1. Put SR1 base on unit base pan.
2. Install compressor on base.
3. Cover SR1 base with wet rags to protect against
any brazing material.
4. Braze suction tube.
5. Braze discharge tube.
6. Cool connections to ambient temperature.
7. Perform leak check.
8. Install suction grommet.
9. Install SR1 left and right side covers.
10. Fasten 60" bottom cable tie.
11. Install discharge grommet.
12. Install top caps.
13. Fasten 36" top cable tie.
14. Fasten 36" middle cable tie.
Figure 19
505095M 1/3/06
Page 20
Loading...