Lennox 13HPX User manual

Page 1
©2014 Lennox Industries Inc.
Dallas, Texas, USA
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
WARNING
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.
NOTICE !
For more in-depth information, consult the Installa
tion and Service Procedures manual, available as
Corp. 0619-L4 on DaveNet or through the Technical
Support department at 800-453-6669.
INSTALLATION
INSTRUCTIONS
Merit®Series 13HPX Units
HEAT PUMP
506727-01
3/2014
Supersedes 6/2013
GENERAL
This 13HPX outdoor heat pump is designed for use with
HFC-410A refrigerant only. This unit must be installed with
an approved indoor air handler or coil. See the Lennox
13HPX Product Specifications bulletin for approved indoor
component match ups.
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.
Installation and service must be performed by a licensed
HVAC professional installer (or equivalent) or a service
agency.
STEP 1 -- SETTING THE UNIT -- CLEARANCES
NOTES:
Service clearance of 30 in. (762 mm) must be maintained on
one of the sides adjacent to the control box.
Clearance to one of the other three sides must be 36 in. (914
mm)
Clearance to one of the remaining two sides may be 12 in.
(305 mm) and the final side may be 6 in. (152 mm).
A clearance of 24 in. must be maintained between two units.
48 in. (1219 mm) clearance required on top of unit.
See
NOTES
See NOTES
See NOTES
See
NOTES
CONTROL
BOX
FIGURE 1
Litho U.S.A.

Page 2
A
B
SIDE
VIEW
UNIT DIMENSIONS - INCHES (MM)
FIGURE 2
TABLE 1
UNIT DIMENSIONS
Model No. A B
13HPX-018-230 24-1/4 (616) 33-1/4 (845)
13HPX-024-230 24-1/4 (616) 33-1/4 (845)
13HPX-030-230 28-1/4 (718) 29-1/4 (743)
13HPX-036-230 28-1/4 (718) 37-1/4 (946)
13HPX-042-230 28-1/4 (718) 43-1/4 (1099)
13HPX-048-230 28‐1/4 (718) 33-1/4 (845)
13HPX-060-230 28‐1/4 (718) 37-1/4 (946)
STEP 1 -- SETTING THE UNIT
(CONTINUED) -- Unit Placement
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take care
while handling this equipment.
WARNING
To prevent personal injury, as well as damage to panels,
unit or structure, observe the following:
While installing or servicing this unit, carefully stow all
removed panels so that the panels will not cause injury to
personnel, objects or nearby structures. Also, take care to
store panels where they will not be subject to damage
(e.g., being bent or scratched).
While handling or stowing the panels, consider any
weather conditions (especially wind) that may cause
panels to be blown around and damaged.
CAUTION
Before attempting to perform any service or maintenance,
turn the electrical power to unit OFF at disconnect switch.
NOTICE !
Roof Damage!
This system contains both refrigerant and oil. Some
rubber roofing material may absorb oil, causing the
rubber to degrade. Failure to follow this noticecould
result in damage to roof surface.
IMPORTANT !
This model is designed for use in check / expansion
valve systems only. An indoor expansion valve ap
proved for use with HFC-410A refrigerant must be or
dered separately and installed prior to operating the
system.
IMPORTANT !
Exhaust vents from dryers, water heaters and furnaces
should be directed away from the outdoor unit. Pro
longed exposure to exhaust gases and the chemicals
contained within them may cause condensation to
form on the steel cabinet and other metal components
of the outdoor unit. This will diminish unit performance
and longevity.
INSTALL UNIT AWAY
FROM WINDOWS
TWO 90_ELBOWS INSTALLED IN LINE SET
WILL REDUCE LINE SET VIBRATION
PLACEMENT
FIGURE 3
Install unit level or, if on a slope, maintain slope tolerance of 2 degrees
(or 2 inches per 5 feet [50 mm per 1.5 m]) away from building structure.
GROUND LEVEL
MOUNTING
SLAB
BUILDING
STRUCTURE DISCHARGE AIR
SLAB MOUNTING
FIGURE 4

Page 3
13HPX SERIES
STEP 2 -- REFRIGERANT PIPING -- Flush
ing 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).
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.
TABLE 2
REFRIGERANT LINE SET — INCHES (MM)
Model
Field
Connections Recommended Line Set
Liquid
Line
Vapor
Line
Liquid
Line
Vapor
Line L15 Line Sets
-018
3/8 in.
(10
mm)
3/4 in.
(19
mm)
3/8 in.
(10
mm)
3/4 in.
(19
mm)
L15-41 — 15 ft. -
50 ft. (4.6 m - 15
m)
-024
-030
-036
-042 3/8 in.
(10
mm)
7/8 in.
(22
mm)
3/8 in.
(10
mm)
7/8 in.
(22
mm)
L15-65 — 15 ft. -
50 ft. (4.6 m - 15
m)
-048
-060
3/8 in.
(10
mm)
1-1/8
in. (29
mm)
3/8 in.
(10
mm)
1-1/8
in. (29
mm)
Field Fabricated
NOTE — Some applications may required a field provided 7/8” to 1-1/8”
adapter
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.
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).
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
Fire, Explosion and Personal Safety Haz
ard. Failure to follow this warning could re
sult in damage, personal injury or death.
Never use oxygen to pressurize or purge re
frigeration lines. Oxygen, when exposed to
a spark or open flame, can cause fire and/or
an explosion, that could result in property
damage, personal injury or death.
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.
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.

Page 4
ANCHORED HEAVY NYLON
WIRE TIE OR AUTOMOTIVE
MUFFLER‐TYPE HANGER
STRAP LIQUID LINE TO
VAPOR LINE
WALL
STUD
LIQUID LINE
NON-CORROSIVE
METAL SLEEVE
VAPOR LINE - WRAPPED
IN ARMAFLEX
AUTOMOTIVE
MUFFLER‐TYPE HANGER
REFRIGERANT LINE SET — TRANSITION
FROM VERTICAL TO HORIZONTAL
Line Set Isolation — The following illustrations are
examples of proper refrigerant line set isolation:
STRAPPING
MATERIAL (AROUND
VAPOR LINE ONLY)
TAPE OR
WIRE TIE
WIRE TIE (AROUND
VAPOR LINE ONLY)
FLOOR JOIST OR
ROOF RAFTER
TAPE OR
WIRE TIE
To hang line set from joist or rafter, use either metal strapping material
or anchored heavy nylon wire ties.
8 FEET (2.43 METERS)
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.
FLOOR JOIST OR
ROOF RAFTER
REFRIGERANT LINE SET — INSTALLING
HORIZONTAL RUNS
NOTE — Similar installation practices should be used if line set is
to be installed on exterior of outside wall.
PVC
PIPE
FIBERGLASS
INSULATION
CAULK
OUTSIDE
WALL
VAPOR LINE WRAPPED
WITH ARMAFLEX
LIQUID
LINE
OUTSIDE WALL LIQUID LINE
VAPOR LINE
WOOD BLOCK
BETWEEN STUDS
STRAP
WOOD BLOCK
STRAP
SLEEVE
WIRE TIE
WIRE TIE
WIRE TIE
INSIDE WALL
REFRIGERANT LINE SET — INSTALLING
VERTICAL RUNS (NEW CONSTRUCTION SHOWN)
LINE SET INSTALLATION
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.
NON-CORROSIVE
METAL SLEEVE
IMPORTANT — Refrigerant lines must not contact structure.
NON-CORROSIVE
METAL SLEEVE
8 FEET (2.43 METERS)
IMPORTANT — Refrigerant lines must not contact wall
FIGURE 5

Page 5
13HPX SERIES
STEP 2 -- REFRIGERANT PIPING -- Removing Existing Indoor Metering Device
SENSING
LINE
TEFLON®RING
FIXED ORIFICE
BRASS NUT
LIQUID LINE ASSEMBLY
(INCLUDES STRAINER)
LIQUID LINE ORIFICE HOUSING
DISTRIBUTOR TUBES
DISTRIBUTOR
ASSEMBLY
REMOVE AND DISCARD
WHITE TEFLON®SEAL
(IF PRESENT)
A. On fully cased coils, remove the coil access and plumbing panels.
B. Remove any shipping clamps from the liquid line and distributor as
sembly.
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.
D. Remove and discard fixed orifice, valve stem assembly (if present)
and Teflon®washer as illustrated above.
E. Use a field-provided fitting to temporarily reconnect the liquid line to the
indoor unit's liquid line orifice housing.
TYPICAL EXISTING FIXED ORIFICE
REMOVAL PROCEDURE
(UNCASED COIL SHOWN)
TYPICAL EXISTING EXPANSION VALVE REMOVAL
PROCEDURE (UNCASED COIL SHOWN)
TWO-PIECE PATCH PLATE
(UNCASED COIL ONLY)
VAPOR
LINE
DISTRIBUTOR
ASSEMBLY
DISTRIBUTOR
TUBES
LIQUID
LINE
MALE EQUALIZER
LINE FITTING
EQUALIZER
LINE
CHECK
EXPANSION
VALVE
TEFLON®
RING
STUB END
TEFLON®
RING
SENSING BULB
LIQUID LINE
ORIFICE
HOUSING
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
A. On fully cased coils, remove the coil access and plumbing panels.
B. Remove any shipping clamps from the liquid line and distributor
assembly.
C. Disconnect the equalizer line from the check expansion valve
equalizer line fitting on the vapor line.
D. Remove the vapor line sensing bulb.
E. Disconnect the liquid line from the check expansion valve at the
liquid line assembly.
F. Disconnect the check expansion valve from the liquid line orifice
housing. Take care not to twist or damage distributor tubes during
this process.
G. Remove and discard check expansion valve and the two Teflon®
rings.
H. Use a field-provided fitting to temporarily reconnect the liquid line
to the indoor unit's liquid line orifice housing.
LOW HIGH
EXISTING
INDOOR
UNIT
GAUGE
MANIFOLD
CYLINDER CONTAINING
CLEAN HCFC-22 TO BE
USED FOR FLUSHING
(Positioned to deliver liquid
refrigerant)
LIQUID LINE SERVICE
VALVE
INLET
DISCHARGE
TANK
RETURN
CLOSED
OPENED
RECOVERY
CYLINDER
RECOVERY MACHINE
NEW
OUTDOOR
UNIT
VAPOR LINE
SERVICE VALVE
VAPOR
LIQUID
1
A. HCFC-22 cylinder with clean refrigerant (positioned to deliver liquid
refrigerant) to the vapor service valve.
B. HCFC-22 gauge set (low side) to the liquid line valve.
C. HCFC-22 gauge set center port to inlet on the recovery machine with an
empty recovery tank connected to the gauge set.
D. Connect recovery tank to recovery machine per machine instructions.
CONNECT GAUGES AND EQUIPMENT FOR
FLUSHING PROCEDURE
A
B
C
D
B
OR
FLUSHING LINE SET
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
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. 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.
D. 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.
The line set and indoor unit 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.
1A
2
3
1B
FIGURE 6

Page 6
STEP 2 -- REFRIGERANT PIPING -- Brazing Procedures
ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND SUCTION / VAPOR LINE SERVICE
VALVES
OUTDOOR
UNIT
LIQUID LINE
VAPOR LINE
LIQUID LINE SERVICE
VALVE
SUCTION /
VAPOR LINE
SERVICE
VALVE
ATTACH
GAUGES
INDOOR
UNIT
SUCTION / VAPOR SERVICE PORT MUST BE
OPEN TO ALLOW EXIT POINT FOR NITROGEN
A. Connect gauge set low pressure side to
liquid line service valve (service port).
B. Connect gauge set center port to bottle of
nitrogen with regulator.
C. Remove core from valve in suction / vapor
line service port to allow nitrogen to escape.
NITROGEN
HIGHLOW
USE REGULATOR TO FLOW
NITROGEN AT 1 TO 2 PSIG.
B
A
C
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
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.
CUT AND DEBUR CAP AND CORE REMOVAL
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.
12
ANGLE-TYPE SERVICE
VALVE
SERVICE
PORT
CORE
SERVICE PORT
CAP
SERVICE
PORT
CORE
SERVICE
PORT CAP
CUT AND DEBUR
LINE SET SIZE MATCHES
SERVICE VALVE CONNECTION
COPPER TUBE
STUB
SERVICE VALVE
CONNECTION
REFRIGERANT LINE
DO NOT CRIMP SERVICE VALVE
CONNECTOR WHEN PIPE IS
SMALLER THAN CONNECTION
REDUCER
3
BALL-TYPE SERVICE
VALVE
LINE SET SIZE IS SMALLER
THAN CONNECTION
FIGURE 7
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.
Wash hands with soap and water after handling brazing
alloys and flux.
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.

Page 7
13HPX SERIES
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
LIQUID LINE SERVICE VALVE
LIQUID LINE
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.
WATER-SATURATED
CLOTH
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.
6
SUCTION / VAPOR LINE
WATER-SATURATED
CLOTH
SUCTION / VAPOR LINE
SERVICE VALVE
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.
WHEN BRAZING LINE SET TO
SERVICE VALVES, POINT FLAME
AWAY FROM SERVICE VALVE.
PREPARATION FOR NEXT STEP
7
WRAP SERVICE VALVES
To help protect service valve seals during brazing, wrap water-saturated cloths around service valve bodies and copper tube stubs. Use
additional water-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
WARNING
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.
FIGURE 8

Page 8
STEP 2 -- REFRIGERANT PIPING -- Installing Indoor Expansion Valve
This outdoor unit is designed for use in systems that include an expansion valve metering device (purchased separately) at
the indoor coil. See the 13HPX 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.
TWO-PIECE
PATCH PLATE
(UNCASED
COIL ONLY)
VAPOR
LINE
LIQUID LINE
ORIFICE
HOUSING
DISTRIBUTOR
TUBES
LIQUID LINE
MALE EQUALIZER LINE
FITTING (SEE
EQUALIZER LINE
INSTALLATION FOR
DETAILS)
SENSING
LINE
EQUALIZER
LINE
CHECK/
EXPANSION
VALVE
TEFLON®
RING
(Uncased Coil Shown)
Sensing bulb insulation is required if
check/expansion valve is installed external
to the coil casing. See sensing bulb
installation for bulb positioning.
STUB
END
TEFLON®
RING
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
DISTRIBUTOR
ASSEMBLY
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.
12
ON LINES SMALLER THAN
7/8”, MOUNT SENSING
BULB AT EITHER THE 3 OR
9 O'CLOCK POSITION.
12
BULB
VAPOR LINE
VAPOR LINE
NOTE — NEVER MOUNT THE SENSING BULB
ON BOTTOM OF LINE.
BULB
BULB
BULB
VAPOR LINE
FLARE NUT
COPPER FLARE
SEAL BONNET
MALE BRASS EQUALIZER
LINE FITTING
FLARE SEAL CAP
OR
123
4
5
6
7
8
9
10
11 12
1/2 Turn
SENSING BULB INSTALLATION
EQUALIZER LINE INSTALLATION
123
4
5
6
7
8
9
10
11 12
1/8 Turn
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.
B. Remove the field-provided fitting that temporarily reconnected
the liquid line to the indoor unit's distributor assembly.
INDOOR EXPANSION VALVE INSTALLATION
C. Install one of the provided Teflon®rings around the
stubbed end of the check/expansion valve and use re
frigerant oil to lightly lubricate the connector threads
and exposed surface of the Teflon®ring.
D. Attach the stubbed end of the check/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.
E. Place the remaining Teflon®washer around the other
end of the check expansion valve. Lightly lubricate
connector threads and expose surface of the Teflon®
ring with refrigerant oil.
F. Attach the liquid line assembly to the check expansion
valve. Finger tighten, then use an appropriately sized
wrench to turn an additional 1/2 turn clockwise as illus
trated in the figure above or tighten to 20 ft-lb.
A. Attach the vapor line sensing bulb in the proper orienta
tion as illustrated below using the clamp and screws
provided.
B. NOTE - Though it is preferred to have the sensing bulb
installed on 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 check/expansion bulb before insulating the sensing bulb.
C. Connect the equalizer line from the check/expansion
valve to the equalizer vapor port on the vapor line. Fin
ger tighten the flare nut, then tighten an additional 1/8
turn (7 ft-lbs) as illustrated to the right.
FIGURE 9

Page 9
13HPX SERIES
STEP 3 -- LEAK TEST AND EVACUATION
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).
B. 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.
C. Connect a cylinder of nitrogen with a pressure regulating valve to the center port of the manifold gauge
set.
D. 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.
E. 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.
F. After leak testing, disconnect gauges from service ports.
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:
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.
1CONNECT GAUGE SET
2
TEST FOR LEAKS
NOTE — Later in the procedure, the HFC-410A container will be replaced
by the nitrogen container.
LEAK TEST
TO VAPOR
SERVICE VALVE
(ANGLE OR BALL
TYPE)
HFC-410A
MANIFOLD GAUGE SET
OUTDOOR UNIT
HIGH
LOW
NITROGEN
A
B
FIGURE 10

Page 10
STEP 3 -- LEAK TEST AND EVACUATION (CONTINUED)
A. Open both manifold valves and start the vacuum pump.
B. Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).
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:
Close manifold gauge valves.
Close valve on vacuum pump.
Turn off vacuum pump.
Disconnect manifold gauge center port hose from vacuum pump.
Attach manifold center port hose to a nitrogen cylinder with pressure
regulator set to 150 psig (1034 kPa) and purge the hose.
Open manifold gauge valves to break the vacuum in the line set and
indoor unit.
Close manifold gauge valves.
D. 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.
E. 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.
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:
A. Connect low side of manifold gauge set with
1/4 SAE in-line tee to vapor line service valve
B. Connect high side of manifold gauge set to
liquid line service valve
C. Connect available micron gauge connector
on the 1/4 SAE in-line tee.
D. 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.
12
3
4
5
6
7
8
9
1011 12
1/6 TURN
3CONNECT GAUGE SET
4EVACUATE THE SYSTEM
NOTE — Remove cores from service valves (if not already done).
Possible equipment damage.
Avoid deep vacuum operation. Do not use
compressors to evacuate a system.
Extremely low vacuum can cause internal
arcing and compressor failure. Damage
caused by deep vacuum operation will
void warranty.
WARNING !
EVACUATION
Close manifold gauge valves.
Shut off HFC-410A cylinder.
Reinstall service valve cores by removing manifold hose from service valve. Quickly
install cores with core tool while maintaining a positive system pressure.
Replace stem caps and finger tighten them, then tighten an additional one-sixth (1/6)
of a turn as illustrated.
OUTDOOR
UNIT
TO VAPOR
SERVICE VALVE
TO LIQUID LINE
SERVICE VALVE
MICRON
GAUGE
VACUUM PUMP
1/4 SAE TEE WITH SWIVEL
COUPLER
500
MANIFOLD
GAUGE SET
HFC-410A
RECOMMEND
MINIMUM 3/8” HOSE
HIGH
LOW
NITROGEN
A
B
C
D
FIGURE 11