INSTALLATION
INSTRUCTIONS
E2013 Lennox Industries Inc.
Dallas, Texas, USA
Merit® Series 13ACX Units
AIR CONDITIONER
506945-01
5/2013
Supersedes 7/2012
Litho U.S.A.
WARNING
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.
WARNING
Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
The State of California has determined that this product
may contain or produce a chemical or chemicals, in very
low doses, which may cause serious illness or death. It
may also cause cancer, birth defects, or reproductive
harm.
CAUTION
Before attempting to perform any service or maintenance,
turn the electrical power to unit OFF at disconnect switch.
GENERAL
This 13ACX outdoor unit is designed for use with HFC-410A
refrigerant only. This unit must be installed with an approved
indoor unit. See the Lennox 13ACX Product Specifications
bulletin (EHB) for approved indoor component match ups.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take care
while handling this equipment.
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
STEP 1 -- SETTING THE UNIT -- Clearances
MINIMUM CLEARANCE
ABOVE UNIT
CLEARANCE ON ALL SIDES — INCHES (MILLIMETERS)
6 (152)
NOTES:
48 (1219)
S
S
Clearance to one of the other three
sides must be 36 inches (914mm).
30 (762)
12 (305)
Clearance to one of the remaining
two sides may be 12 inches
(305mm) and the final side may be
6 inches (152mm).
LINE SET
CONNECTIONS
36 (914)
MINIMUM CLEARANCE BETWEEN TWO UNITS
ACCESS
PANEL
24 (610)
LINE SET
CONNECTIONS
FIGURE 1
7/2012
506945-01
Page 1
*2P72012*
*P506945-01*
IMPORTANT — Refrigerant lines must not contact structure.
LINE SET
Line Set Isolation — The following illustrations are
examples of proper refrigerant line set isolation:
INSTALLATION
REFRIGERANT LINE SET — INSTALLING
VERTICAL RUNS (NEW CONSTRUCTION SHOWN)
NOTE — Insulate liquid line when it is routed through areas where the
surrounding ambient temperature could become higher than the
temperatureof the liquid line or when pressure drop is equal to or greater
than 20 psig.
REFRIGERANT LINE SET — TRANSITION
FROM VERTICAL TO HORIZONTAL
ANCHORED HEAVY NYLON
IMPORTANT — Refrigerant lines must not contact wall
WIRE TIE OR AUTOMOTIVE
MUFFLER‐TYPE HANGER
AUTOMOTIVE
MUFFLER‐TYPE HANGER
OUTSIDE WALL
LIQUID LINE
VAPOR LINE
WALL
STUD
WIRE TIE
INSIDE WALL
STRAP
WOOD BLOCK
BETWEEN STUDS
STRAP LIQUID LINE TO
VAPOR LINE
NON-CORROSIVE
METAL SLEEVE
WIRE TIE
LIQUID LINE
NON-CORROSIVE
METAL SLEEVE
WOOD BLOCK
WIRE TIE
VAPOR LINE - WRAPPED
IN ARMAFLEX
STRAP
REFRIGERANT LINE SET — INSTALLING
HORIZONTAL RUNS
SLEEVE
To hang line set from joist or rafter, use either metal strapping material
or anchored heavy nylon wire ties.
WIRE TIE (AROUND
VAPOR LINE ONLY)
VAPOR LINE WRAPPED
WITH ARMAFLEX
8 FEET (2.43 METERS)
OUTSIDE
WALL
STRAPPING
MATERIAL (AROUND
VAPOR LINE ONLY)
FLOOR JOIST OR
LIQUID
LINE
ROOF RAFTER
TAPE OR
WIRE TIE
8 FEET (2.43 METERS)
PVC
PIPE
CAULK
NON-CORROSIVE
METAL SLEEVE
FIBERGLASS
INSULATION
STRAP THE VAPOR LINE TO THE JOIST
OR RAFTER AT 8 FEET (2.43 METERS)
INTERVALS THEN STRAP THE LIQUID
LINE TO THE VAPOR LINE.
TAPE OR
WIRE TIE
NOTE — Similar installation practices should be used if line set is
to be installed on exterior of outside wall.
FLOOR JOIST OR
ROOF RAFTER
FIGURE 5
Page 3
13ACX SERIES
STEP 2 -- REFRIGERANT PIPING -- Flushing Existing Line Set and Indoor Coil
Flush the existing line set per the following
instructions. For more information, refer to the
Installation and Service Procedures manual available
on DaveNet. CAUTION - DO NOT attempt to flush and
re-use existing line sets or indoor coil when the system
contains contaminants (i.e., compressor burn out).
WARNING
Polyol ester (POE) oils used with HFC-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.
NOTE - When installing refrigerant lines longer than 50 feet,
refer to the Refrigerant Piping Design and Fabrication
Guidelines manual available on DaveNet (Corp. 9351-L9),
or contact the Technical Support Department Product
Application group for assistance.
IMPORTANT !
Some scroll compressors have an internal vacuum
protector that will unload scrolls when suction pres-
sure goes below 20 psig. A hissing sound will be
heard when the compressor is running unloaded.
Protector will reset when low pressure in system is
raised above 40 psig. DO NOT REPLACE COMPRES-
SOR.
IMPORTANT !
If this unit is being matched with an approved line set
or indoor unit coil that 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 HFC-410A
refrigerant. Residual mineral oil can act as an insula-
tor, preventing proper heat transfer. It can also clog
the expansion device and reduce system perfor-
mance and capacity.
LIQUID LINE FILTER DRIER INSTALLATION
The filter drier (one is shipped with each 13ACX unit) must
be field installed in the liquid line between the outdoor unit's
liquid line service valve and the indoor coil's metering device
(fixed orifice or TXV) as illustrated in figure 6. This filter drier
must be installed to ensure a clean, moisture-free system.
Failure to install the filter drier will void the warranty. A
replacement filter drier is available from Lennox. See
Brazing Connections page 7 for special procedures on
brazing filter drier connections to the liquid line.
Failure to properly flush the system per this instruc-
tion and the detailed Installation and Service Proce-
dures manual will void the warranty.
WARNING
When using a high pressure gas such as
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).
Typical Liquid Line Filter Drier Installation
BRAZE CONNECTION POINTS
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.
LIQUID
LINE
LIQUID LINE
LINE
SERVICE VALVE
LIQUID LINE
OUTDOOR
FILTER DRIER
UNIT
FIGURE 6
TABLE 2
REFRIGERANT LINE SET — INCHES (MM)
Valve Size Connections
Recommended Line Sets
Model Number (-xx*)
Liquid Line
Suction Line
L15 Line Set Model Line Set Length
Catalog Number
89J52
L15-26-20
L15-26-25
L15-26-35
L15-26-50
L15-41-20
L15-41-30
L15-41-40
L15-41-50
L15-65-30
L15-65-40
L15-65-50
20 feet (6.1 m)
25 feet (9.1 m)
35 feet (12.2 m)
50 feet (15.2 m)
20 feet (6.1 m)
30 feet (9.1 m)
40 feet (12.2 m)
50 feet (15.2 m)
30 feet (9.1 m)
40 feet (12.2 m)
50 feet (15.2 m)
89J53
13ACX-018-230
13ACX-024-230
3/8” (10 mm)
5/8“ (16 mm)
89J54
89J55
89J56
13ACX-030-230
13ACX-036-230
13ACX-042-230
89J57
3/8” (10 mm)
3/8” (10 mm)
3/4” (19 mm)
7/8” (22 mm)
89J58
89J59
89J60
13ACX-048-230
13ACX-060-230
89J61
89J62
* Applicable to all minor revision numbers unless otherwise specified.
** Some applications may required a field-provided 1-1/8” to 7/8” adapter.
Page 4
STEP 2 -- REFRIGERANT PIPING -- Removing Existing Indoor Metering Device
TYPICAL EXISTING FIXED ORIFICE
REMOVAL PROCEDURE
(UNCASED COIL SHOWN)
TYPICAL EXISTING EXPANSION VALVE REMOVAL
PROCEDURE (UNCASED COIL SHOWN)
OR
1B
1A
STUB END
TWO-PIECE PATCH PLATE
(UNCASED COIL ONLY)
LIQUID LINE
ORIFICE
HOUSING
DISTRIBUTOR TUBES
EXPANSION
VALVE
LIQUID LINE ORIFICE HOUSING
DISTRIBUTOR
TUBES
®
TEFLON
RING
®
TEFLON RING
FIXED ORIFICE
BRASS NUT
®
TEFLON
RING
SENSING
LINE
DISTRIBUTOR
ASSEMBLY
DISTRIBUTOR
ASSEMBLY
EQUALIZER
LINE
REMOVE AND DISCARD
®
WHITE TEFLON SEAL
(IF PRESENT)
LIQUID LINE ASSEMBLY
(INCLUDES STRAINER)
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
A
B
On fully cased coils, remove the coil access and plumbing panels.
Remove any shipping clamps from the liquid line and distributor as-
sembly.
MALE EQUALIZER
LINE FITTING
C
Using two wrenches, disconnect liquid line from liquid line orifice hous-
ing. Take care not to twist or damage distributor tubes during this pro-
cess.
VAPOR
LINE
LIQUID
LINE
SENSING BULB
D
E
Remove and discard fixed orifice, valve stem assembly (if present)
®
A
B
On fully cased coils, remove the coil access and plumbing panels.
and Teflon washer as illustrated above.
Remove any shipping clamps from the liquid line and distributor
assembly.
Use a field-provided fitting to temporarily reconnect the liquid line to the
indoor unit's liquid line orifice housing.
C
Disconnect the equalizer line from the expansion valve equalizer
line fitting on the vapor line.
D
E
Remove the vapor line sensing bulb.
CONNECT GAUGES AND EQUIPMENT FOR
FLUSHING PROCEDURE
Disconnect the liquid line from the expansion valve at the liquid line
assembly.
2
CYLINDER CONTAINING
CLEAN HCFC-22 TO BE
USED FOR FLUSHING
(Positioned to deliver liquid
refrigerant)
GAUGE
MANIFOLD
F
Disconnect the expansion valve from the liquid line orifice housing.
Take care not to twist or damage distributor tubes during this
process.
A
®
G
H
Remove and discard expansion valve and the two Teflon rings.
LOW
HIGH
1
Use a field-provided fitting to temporarily reconnect the liquid line
to the indoor unit's liquid line orifice housing.
NEW
OUTDOOR
UNIT
VAPOR LINE
SERVICE VALVE
FLUSHING LINE SET
OPENED
CLOSED
The line set and indoor unit coil must be flushed with at least the same
amountof clean refrigerant that previously charged the system. Check
the charge in the flushing cylinder before proceeding.
EXISTING
INDOOR
UNIT
3
B
LIQUID LINE SERVICE
VALVE
A
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
B
RECOVERY
CYLINDER
TANK
RETURN
set and indoor unit coil.
B
Position the cylinder of clean HCFC-22 for delivery of liquid
refrigerant 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.
C
INLET
D
DISCHARGE
RECOVERY MACHINE
C
D
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 the
system down to 0.
A
HCFC-22 cylinder with clean refrigerant (positioned to deliver liquid
refrigerant)to the vapor service valve.
B
C
HCFC-22 gauge set (low side) to the liquid line valve.
HCFC-22 gauge set center port to inlet on the recovery machine with an
empty recovery tank connected to the gauge set.
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.
D
Connect recovery tank to recovery machine per machine instructions.
FIGURE 7
Page 5
13ACX SERIES
STEP 2 -- REFRIGERANT PIPING -- Brazing Procedures
CAP AND CORE REMOVAL
CUT AND DEBUR
Cut ends of the refrigerant lines square (free from nicks or dents)
and debur the ends. The pipe must remain round. Do not crimp end
of the line.
Remove service cap and core from
both the suction / vapor and liquid line
service ports.
2
1
CUT AND DEBUR
SERVICE PORT
CAP
SERVICE
PORT
CORE
LINE SET SIZE MATCHES
SERVICE VALVE CONNECTION
SERVICE
PORT
CORE
SERVICE VALVE
CONNECTION
SERVICE
PORT CAP
COPPER TUBE
STUB
ANGLE-TYPE SERVICE
VALVE
BALL-TYPE SERVICE
VALVE
REDUCER
DO NOT CRIMP SERVICE VALVE
CONNECTOR WHEN PIPE IS
SMALLER THAN CONNECTION
LINE SET SIZE IS SMALLER
THAN CONNECTION
REFRIGERANT LINE
ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND SUCTION / VAPOR LINE SERVICE
VALVES
3
Flow regulated nitrogen (at 1 to 2 psig) through the low-side refrigeration gauge set into the liquid line service port valve, and out of the suction /
vapor line service port valve.
A
B
C
Connect gauge set low pressure side to
liquid line service valve (service port).
USE REGULATOR TO FLOW
NITROGEN AT 1 TO 2 PSIG.
LOW
HIGH
Connect gauge set center port to bottle of
nitrogenwith regulator.
Remove core from valve in suction / vapor
line service port to allow nitrogen to escape.
ATTACH
GAUGES
B
SUCTION / VAPOR SERVICE PORT MUST BE
OPEN TO ALLOW EXIT POINT FOR NITROGEN
SUCTION /
VAPOR LINE
SERVICE
VALVE
C
VAPOR LINE
OUTDOOR
UNIT
INDOOR
UNIT
NITROGEN
LIQUID LINE SERVICE
VALVE
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
LIQUID LINE
A
FIGURE 8
CAUTION
Brazing alloys and flux contain materials which are
hazardous to your health.
Avoid breathing vapors or fumes from brazing operations.
Perform operations only in well-ventilated areas.
Wear gloves and protective goggles or face shield to
protect against burns.
WARNING
Danger of fire. Bleeding the refrigerant
charge from only the high side may result
in pressurization of the low side shell and
suction tubing. Application of a brazing
torch to a pressurized system may result in
ignition of the refrigerant and oil mixture.
Check the high and low pressures before
applying heat.
Wash hands with soap and water after handling brazing
alloys and flux.
Page 6
WRAP SERVICE VALVES
To help protect service valve seals during brazing, wrap water-saturated cloths around service valve bodies and copper tube stubs. Use
additionalwater-saturated cloths underneath the valve body to protect the base paint.
4
FLOW NITROGEN
Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration gauge set into the valve stem port connection on the liquid service valve and
out of the suction / vapor valve stem port. See steps 3A, 3B and 3C on manifold gauge set connections.
5
6
BRAZE LINE SET
Wrap both service valves with water -saturated cloths as illustrated here and as mentioned in step 4, before brazing to line set. Cloths must
remain water-saturated throughout the brazing and cool-down process.
LIQUID LINE SERVICE VALVE
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
IMPORTANT — Allow braze joint to cool. Apply
additional water-saturated cloths to help cool brazed
joint. Do not remove water-saturated cloths until
piping has cooled. Temperatures above 250ºF will
damage valve seals.
WATER-SATURATED
CLOTH
LIQUID LINE
WARNING
SUCTION / VAPOR LINE
SERVICE VALVE
FIRE, PERSONAL INJURY, OR PROPERTY DAMAGE
may result if you do not wrap a water-saturated cloth around
both liquid and suction line service valve bodies and copper
tube stub while brazing the line set! The braze, when
complete, must be quenched with water to absorb any
residual heat.
Do not open service valves until refrigerant lines and
indoor coil have been leak-tested and evacuated. Refer
to Installation and Service Procedures manual found on
DAVENET.
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
SUCTION / VAPOR LINE
WATER-SATURATED
CLOTH
PREPARATION FOR NEXT STEP
After all connections have been brazed, disconnect manifold gauge set from service ports. Apply additional water-saturated cloths to both
services valves to cool piping. Once piping is cool, remove all water-saturated cloths.
7
FIGURE 9
Page 7
13ACX SERIES
STEP 2 -- REFRIGERANT PIPING -- Installing Indoor Expansion Valve
This outdoor unit is designed for use in systems that use either an fixed orifice (RFC) (included with outdoor unit), or
expansion valve metering device (purchased separately) at the indoor coil. See the 13ACX Product Specifications bulletin
(EHB) for approved expansion valve kit match ups. The expansion valve unit 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 expansion valve in a
manner that will provide access for field servicing of the expansion valve. Refer to below illustration for reference during
installation of expansion valve unit. After installation of the indoor coil metering device, proceed to Step 5.
®
C
Install one of the provided Teflon rings around the
stubbed end of the expansion valve and use refrigerant
oil to lightly lubricate the connector threads and ex-
INDOOR EXPANSION VALVE INSTALLATION
®
posed surface of the Teflon ring.
TWO-PIECE
PATCH PLATE
D
Attach the stubbed end of the expansion valve to the
liquid line orifice housing. Finger tighten, then use an
appropriately sized wrench to turn an additional 1/2
turn clockwise as illustrated in the figure to the right, or
tighten to 20 ft-lb.
(Uncased Coil Shown)
1/2 Turn
(UNCASED
STUB
END
LIQUID LINE
ORIFICE
HOUSING
COIL ONLY)
12
EXPANSION
VALVE
1
11
10
2
DISTRIBUTOR
TUBES
9
3
®
®
E
F
Place the remaining Teflon washer around the other
end of the expansion valve. Lightly lubricate connector
TEFLON
RING
4
8
5
7
6
®
threads and expose surface of the Teflon ring with
refrigerantoil.
Attach the liquid line assembly to the expansion valve.
Finger tighten, then use an appropriately sized wrench
to turn an additional 1/2 turn clockwise as illustrated in
the figure above or tighten to 20 ft-lb.
®
TEFLON
RING
SENSING
LINE
DISTRIBUTOR
ASSEMBLY
EQUALIZER
LINE
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
SENSING BULB INSTALLATION
A
Attach the vapor line sensing bulb in the proper orienta-
tion as illustrated below using the clamp and screws
provided.
MALE EQUALIZER LINE
FITTING (SEE
EQUALIZER LINE
INSTALLATION FOR
DETAILS)
VAPOR
LINE
B
NOTE - Though it is preferred to have the sensing bulb
installedon a horizontal run of the vapor line, installation
on a vertical run of piping is acceptable if necessary.
NOTE — Confirm proper thermal contact between vapor line
and expansion bulb before insulating the sensing bulb.
1/8 Turn
Sensing bulb insulation is required if
expansion valve is installed external to the
coil casing. See sensing bulb installation for
bulb positioning.
12
LIQUID LINE
C
Connect the equalizer line from the expansion valve to
the equalizer vapor port on the vapor line. Finger tighten
the flare nut, then tighten an additional 1/8 turn (7 ft-lbs)
as illustrated to the right.
1
5
11
10
2
9
8
3
4
7
6
ON LINES SMALLER THAN
7/8”, MOUNT SENSING
BULB AT EITHER THE 3 OR
9 O'CLOCK POSITION.
VAPOR LINE
EQUALIZER LINE INSTALLATION
A
Remove and discard either the flare seal cap or flare nut with
copper flare seal bonnet from the equalizer line port on the vapor
line as illustrated in the figure below.
12
BULB
BULB
B
Remove the field-provided fitting that temporarily reconnected
the liquid line to the indoor unit's distributor assembly.
FLARE SEAL CAP
FLARE NUT
VAPOR LINE
ON 7/8” AND LARGER LINES,
MOUNT SENSING BULB AT
EITHER THE 4 OR 8 O'CLOCK
POSITION. NEVER MOUNT
THE SENSING BULB ON
BOTTOM OF LINE.
COPPER FLARE
SEAL BONNET
OR
12
MALE BRASS EQUALIZER
LINE FITTING
BULB
BULB
VAPOR LINE
NOTE — NEVER MOUNT THE SENSING
BULB ON BOTTOM OF LINE.
FIGURE 10
Page 8
STEP 3 -- LEAK TEST AND EVACUATION
LEAK TEST
HIGH
MANIFOLD GAUGE SET
LOW
A
B
TO VAPOR
SERVICE VALVE
(ANGLE OR BALL
TYPE)
NITROGEN
OUTDOOR UNIT
HFC-410A
CONNECT GAUGE SET
1
A
Connect the high pressure hose of an HFC-410A manifold gauge set to the vapor valve service port.
NOTE — 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.
B
With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of
the manifold gauge set.
NOTE — Later in the procedure, the HFC-410A container will be replaced by the nitrogen container.
After the line set has been connected to the indoor and outdoor units, check the line set connections and
indoor unit for leaks. Use the following procedure to test for leaks:
2
TEST FOR LEAKS
A
With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the
manifold gauge set. Open the valve on the HFC-410A cylinder (vapor only).
Open the high pressure side of the manifold to allow HFC-410A into the line set and indoor unit. Weigh in
a trace amount of HFC-410A. [A trace amount is a maximum of two ounces (57 g) refrigerant or three
pounds (31 kPa) pressure.] Close the valve on the HFC-410A cylinder and the valve on the high
pressure side of the manifold gauge set. Disconnect the HFC-410A cylinder.
Connect a cylinder of nitrogen with a pressure regulating valve to the center port of the manifold gauge
set.
B
C
D
E
F
Adjust 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.
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.
After leak testing, disconnect gauges from service ports.
FIGURE 11
Page 9
13ACX SERIES
STEP 3 -- LEAK TEST AND EVACUATION (CONTINUED)
EVACUATION
HIGH
LOW
CONNECT GAUGE SET
NOTE — Remove cores from service valves (if not already done).
3
A
B
C
D
Connect low side of manifold gauge set with
1/4 SAE in-line tee to vapor line service valve
Connect high side of manifold gauge set to
liquid line service valve
MANIFOLD
GAUGE SET
1/4 SAE TEE WITH SWIVEL
COUPLER
Connect available micron gauge connector
on the 1/4 SAE in-line tee.
A
Connect the vacuum pump (with vacuum
gauge) to the center port of the manifold
gauge set. The center port line will be used
later for both the HFC-410A and nitrogen
containers.
500
TO VAPOR
SERVICE VALVE
MICRON
GAUGE
C
NITROGEN
OUTDOOR
UNIT
TO LIQUID LINE
SERVICE VALVE
HFC-410A
B
VACUUM PUMP
RECOMMEND
MINIMUM 3/8” HOSE
D
EVACUATE THE SYSTEM
A
B
Open both manifold valves and start the vacuum pump.
Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).
4
NOTE — During the early stages of evacuation, it is desirable to close the manifold gauge valve at least once. 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 above absolute zero within a given volume or system. Absolute
pressure in a vacuum is equal to atmospheric pressure minus vacuum pressure.
C
When the absolute pressure reaches 23,000 microns (29.01 inches of mercury), perform the following:
S
S
S
S
S
S
S
Close manifold gauge valves.
WARNING !
Possible equipment damage.
Close valve on vacuum pump.
Turn off vacuum pump.
Avoid deep vacuum operation. Do not use
a
Disconnect manifold gauge center port hose from vacuum pump.
compressors to evacuate
system.
Attach manifold center port hose to a nitrogen cylinder with pressure
regulatorset to 150 psig (1034 kPa) and purge the hose.
Extremely low vacuum can cause internal
arcing and compressor failure. Damage
caused by deep vacuum operation will
void warranty.
Open manifold gauge valves to break the vacuum in the line set and
indoor unit.
Close manifold gauge valves.
D
E
Shut off the nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release the
nitrogen from the line set and indoor unit.
Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until the
absolutepressure 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.
F
When the absolute pressure requirement above has been met, disconnect the manifold hose from the vacuum pump and connect it to a
cylinder of HFC-410A positioned to deliver liquid refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in
the line set and indoor unit.
G
Perform the following:
S
S
S
S
Close manifold gauge valves.
Shut off HFC-410A cylinder.
1/6 TURN
12
1
Reinstall service valve cores by removing manifold hose from service valve. Quickly
install cores with core tool while maintaining a positive system pressure.
11
7
2
10
9
8
3
Replace stem caps and finger tighten them, then tighten an additional one-sixth (1/6)
of a turn as illustrated.
4
5
6
FIGURE 12
Page 10
STEP 4 -- ELECTRICAL -- Circuit Sizing and Wire Routing
In the U.S.A., wiring must conform with current local codes and
the current National Electric Code (NEC). In Canada, wiring
IMPORTANT !
must conform with current local codes and the current
Canadian Electrical Code (CEC).
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.
Refer to the furnace or air handler installation instructions for
additional wiring application diagrams and refer to unit
nameplate for minimum circuit ampacity and maximum
overcurrent protection size.
CAUTION
Electrostatic discharge can affect
electronic components. Take care during
unit installation and service to protect the
24VAC TRANSFORMER
Use the transformer provided with the furnace or air handler
for low‐voltage control power (24VAC - 40 VA minimum)
unit's electroniccontrols.Precautionswill
help to avoid control exposure to
electrostatic dischargebyputtingtheunit,
the controland the technicianat the same
electrostatic potential. Touchhandand all
tools on an unpainted unit surface before
performing any service procedure to
neutralize electrostatic charge.
WARNING
ELECTROSTATIC
DISCHARGE
(ESD)
Precautions and
Procedures
Electric Shock Hazard. Can cause injury or
death. Unit must be grounded in
accordance with national and local codes.
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.
SIZE CIRCUIT AND INSTALL SERVICE
DISCONNECT SWITCH
INSTALL THERMOSTAT
Install room thermostat (ordered separately) on an inside
wall approximately in the center of the conditioned area
and 5 feet (1.5m) from the floor. It should not be installed
on an outside wall or where it can be affected by sunlight
or drafts.
Refer to the unit nameplate for minimum circuit ampacity,
and maximum fuse or circuit breaker (HACR per NEC).
Install power wiring and properly sized disconnect switch.
MAIN FUSE BOX/
BREAKER PANEL
THERMOSTAT
SERVICE
DISCONNECT
SWITCH
5 FEET
(1.5M)
NOTE —Unitsareapprovedforuseonlywithcopper
conductors. Ground unit at disconnect switch or
connect to an earth ground.
NOTE — 24VAC, Class II circuit connections are made
in the control panel.
FIGURE 13
Page 11
13ACX SERIES
STEP 4 -- ELECTRICAL (CONTINUED) -- High Voltage and Field Control Wiring
The following illustration provide an example of control wiring connections when using standard thermostat.
ROUTING HIGH VOLTAGE, GROUND AND CONTROL WIRING
FIELD CONTROL WIRING
HIGH VOLTAGE / GROUND WIRES
THERMOSTAT
INDOOR UNIT
Any excess high voltage field wiring should be
trimmed and secured away from any low voltage field
wiring. To facilitate a conduit, a cutout is located in the
bottom of the control panel. Connect conduit to the
control panel using a proper conduit fitting.
POWER
R
R
HEAT
NOTE — Wire tie provides low voltage control wire strain
relief and maintains separation of field-installed low and
high voltage circuits.
W1
Y
W
Y
YELLOW
OUTDOOR UNIT
Y1
COOLING
NOTE — For proper voltages, select thermostat wire
(control wires) gauge per table above.
NOTE — Do not bundle any excess 24VAC control
wires inside control panel.
INDOOR BLOWER
COMMON
G
C
G
C
BLACK
Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit as illustrated.
C
A
Run 24VAC control wires through hole with grommet
and secure with provided wire tie.
WIRE RUN LENGTH
AWG# INSULATION TYPE
B
Make 24VAC thermostat wire connections. Locate
the two wires from the contactor and make
connection using field-provided wire nuts:
LESS THAN 100' (30 METERS) 18
MORE THAN 100' (30 METERS) 16
TEMPERATURE RATING
35ºC MINIMUM.
S
S
Yellow to Y1
Black to C (common)
FIGURE 14
8. Recheck voltage while the unit is running. Power must
be within range shown on the unit nameplate.
STEP 5 -- UNIT START-UP
9. Check system for sufficient refrigerate using the
procedures outlined in under System Refrigerant.
IMPORTANT
OPERATING MANIFOLD GAUGE SET AND SERVICE
VALVES
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.
The liquid and vapor line service valves are used for
removing refrigerant, flushing, leak testing, evacuating,
checking charge and charging.
1. Rotate fan to check for binding.
2. Inspect all factory- and field-installed wiring for loose
connections.
Each valve is equipped with a service port which has a
factory-installed valve stem. Figure 15 provides information
on how to access and operating both angle and ball service
valves.
3. After evacuation is complete, open the liquid line and
suction line service valve stems to release the
refrigerant charge (contained in outdoor unit) into the
system.
Torque Requirements
When servicing or repairing heating, ventilating, and air
conditioning components, ensure the fasteners are
fasteners.
4. Replace the stem caps and tighten to the value listed in
table 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.
IMPORTANT
To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.
6. Connect manifold gauge set for testing and charging
using figure NO TAG as a guideline.
7. Set the thermostat for a cooling demand. Turn on power When servicing or repairing HVAC components, ensure the
torque values for fasteners.
to the indoor indoor unit and close the outdoor unit
disconnect switch to start the unit.
Page 12
TABLE 3. TORQUE REQUIREMENTS
Recommended Torque
gauge set that features low loss anti-blow back fittings.
Parts
Manifold gauge set used with HFC-410A refrigerant
systems must be capable of handling the higher system
operating pressures. The gauges should be rated for use
with pressures of 0 - 800 psig on the high side and a low side
of 30” vacuum to 250 psig with dampened speed to 500 psi.
Gauge hoses must be rated for use at up to 800 psig of
pressure with a 4000 psig burst rating.
Service valve cap
Sheet metal screws
Machine screws #10
Compressor bolts
Gauge port seal cap
8 ft.- lb.
11 NM
2 NM
16 in.- lb.
28 in.- lb.
90 in.- lb.
8 ft.- lb.
3 NM
10 NM
11 NM
Using Manifold Gauge Set
When checking the system charge, only use a manifold
Operating Angle Type Service Valve:
1. Remove stem cap with an appropriately sized 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.
SERVICE PORT CAP
SERVICE PORT CORE
(VALVE STEM SHOWN
CLOSED) INSERT HEX
WRENCH HERE
TO INDOOR
UNIT
(VALVE STEM SHOWN OPEN)
INSERT HEX WRENCH HERE
SERVICE PORT
CORE
STEM CAP
TO OUTDOOR UNIT
ANGLE-TYPE SERVICE VALVE
(FRONT-SEATED CLOSED)
ANGLE-TYPE SERVICE VALVE
(BACK-SEATED OPENED)
When service valve is OPEN, the service port is
open to line set, indoor and outdoor unit.
When service valve is CLOSED, the service port is open
to the line set and indoor unit.
To Access Service Port:
Operating Ball Type Service Valve:
A service port cap protects the service port core from contamination and
serves as the primary leak seal.
1. Remove stem cap with an appropriately sized wrench.
2. Use an appropriately sized wrenched to open. To open valve,
rotate stem counterclockwise 90°. To close rotate stem
clockwise 90°.
1. Remove service port cap with an appropriately sized wrench.
2. Connect gauge set to service port.
3. When testing is completed, replace service port cap and tighten as
follows:
TO INDOOR UNIT
1/6 TURN
S
S
With torque wrench: Finger tighten and
12
6
1
5
11
10
Without torque wrench: Finger tighten and
use an appropriately sized wrench to turn
an additional 1/6 turn clockwise.
2
TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90°.
9
3
BALL (SHOWN
CLOSED)
4
8
7
VALVE
TO CLOSE ROTATE STEM
STEM
Reinstall Stem Cap:
CLOCKWISE 90°.
Stem cap protects the valve stem from damage and serves as the
primary seal. Replace the stem cap and tighten as follows:
SERVICE PORT
1/12 TURN
SERVICE PORT
CORE
S
S
With Torque Wrench: Finger tighten and
12
6
1
5
11
10
SERVICE PORT
CAP
Without Torque Wrench: Finger tight-
en and use an appropriately sized
wrench to turn an additional 1/12 turn
clockwise.
2
9
3
STEM CAP
4
TO OUTDOOR
UNIT
8
7
NOTE — A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque.
FIGURE 15
Page 13
13ACX SERIES
CHECKING AND ADDING SYSTEM
REFRIGERANT
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, soak-
ers, waste water, etc.) will corrode the surface of steel
and aluminum parts, diminish performance and af-
fect longevity of the unit.
The 13ACX unit is factory-charged with enough HFC-410A
refrigerant to accommodate a 15-foot length of refrigerant
piping. Charge should be checked and adjusted using the
tables provided on the charging procedure sticker located on
the unit access panel. Detailed information is provided in the
13ACX Installation and Service Procedures manual
(Corp0625-L5), which is available on DaveNet.
Routine 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.
Homeowners Information
NOTE — The filter and all access panels must be in place
any time the unit is in operation. If you are unsure about the
filter required for your system, call your Lennox dealer for
assistance.
CAUTION
Before attempting to perform any service or mainte-
nance, turn the electrical power to unit OFF at discon-
nect switch.
1. Ask your Lennox dealer to show you where your indoor
unit's filter is located. It will be either at the indoor unit
(installed internal or external to the cabinet) or behind a
return air grille in the wall or ceiling. Check the filter
monthly and clean or replace it as needed.
Cleaning of the outdoor unit's coil should be performed by a
licensed professional service technician (or equivalent).
Contact your dealer and set up a schedule (preferably twice
a year, but at least once a year) to inspect and service your
outdoor unit. The following maintenance may be performed
by the homeowner.
2. Disposable filters should be replaced with a filter of the
same type and size.
3. The indoor 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.)
Outdoor Coil
The outdoor unit must be properly maintained to ensure its
proper operation.
Thermostat Operation
®
See the ComfortSense 7000 thermostat homeowner
manual for instructions on how to operate your thermostat.
S Please contact your dealer to schedule proper inspection
and maintenance for your equipment.
Preservice Check
If your system fails to operate, check the following before
calling for service:
S Make sure no obstructions restrict airflow to the outdoor
unit.
S Grass clippings, leaves, or shrubs crowding the unit can
S
S
S
S
S
S
Verify room thermostat settings are correct.
Verify that all electrical disconnect switches are ON.
Check for any blown fuses or tripped circuit breakers.
Verify unit access panels are in place.
cause the unit to work harder and use more energy.
S Keep shrubbery trimmed away from the unit and
periodically check for debris which collects around the
unit.
Verify air filter is clean.
S Keep snow level below the louvered panels to ensure
If service is needed, locate and write down the unit
model number and have it handy before calling.
proper performance.
Page 14
13ACX Start-Up and Performance Checklist
Customer
Address
Serial
Indoor Unit Model
Outdoor Unit Model
Notes:
Serial
START UP CHECKS
Refrigerant Type:
Rated Load Amps:
Actual Amps
Actual Amps:
Rated Volts
Actual Volts
Condenser Fan Full Load Amps
COOLING MODE
Suction Pressure:
Liquid Pressure:
Ambient Temperature:
Supply Air Temperature:
Return Air: Temperature:
System Refrigerant Charge (Refer to manufacturer's information on unit or installation instructions for required
subcooling and approach temperatures.)
Subcooling:
A
A
A
—
—
—
B
B
B
=
SUBCOOLING
Saturated Condensing Temperature (A)
minus Liquid Line Temperature (B)
Approach:
=
APPROACH
Liquid Line Temperature (A)
minus Outdoor Air Temperature (B)
Indoor Coil Temperature Drop (18 to 22°F)
= COIL TEMP DROP
Return Air Temperature (A)
minus Supply Air Temperature (B)
Page 15
13ACX SERIES
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