Lennox Merit Series User manual

©2019 Lennox Industries Inc.
Dallas, Texas, USA
Page 1
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER 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 licensed professional HVAC installer or
equivalent, or service agency.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for noncompliance.
INSTALLATION
INSTRUCTIONS
HEAT PUMP
507876-01
8/2019
Merit®Series 16HPX Units
General
This 16HPX 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. For AHRI Certied
system match-ups and expanded ratings, visit www.Len-
noxPros.com. These instructions are intended as a gen-
eral guide and do not supersede local codes in any way.
Consult authorities having jurisdiction before installation.
NOTICE!
Charging information is given on the charging
procedure sticker on the unit access panel. For
more in-depth information, consult the Installation
and Service Procedures manual on LennoxPros.
com or through the Technical Support department
at 800-453-6669.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.
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
STEP 1 – SETTING THE UNIT – Clearances

Page 2
A
B
SIDE
VIEW
UNIT DIMENSIONS - INCHES (MM)
FIGURE 1
TABLE 1 – Unit Dimensions
Model Numbers A B
16HPX-024 24-1/4 (616) 32-1/2 (826)
16HPX-036 32-1/4 (819) 32-1/2 (826)
16HPX-048 32-1/4 (819) 42-1/4 (1073)
16HPX-060 32-1/4 (819) 42-1/4 (1073)
STEP 1 – SETTING THE UNIT
(Continued) – Unit Placement
NOTICE!
Roof Damage!
This system contains both refrigerant and oil. Some
rubber roong material may absorb oil, causing the
rubber to degrade. Failure to follow this notice could
result in damage to roof surface.
IMPORTANT
This unit must be matched with an AHRI Certied indoor
coil or air handler.
Coils previously charged with HCFC-22 must be ushed.
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.
IMPORTANT
Exhaust vents from dryers, water heaters and furnaces
should be directed away from the outdoor unit. Prolonged
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 90º ELBOWS INSTALLED IN LINE SET
WILL REDUCE LINE SET VIBRATION
PLACEMENT
FIGURE 2
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 3
IMPORTANT
This model is designed for use in check / expansion
valve systems only. An indoor expansion valve approved
for use with HFC-410A refrigerant must be ordered
separately and installed prior to operating the system.
NOTE - An optional Unit Stand-O Kit (94J45) is available
for this unit. Black high-density polyethylene feet raise unit
o of mounting surface away from damaging moisture.
Four feet are furnished per order number.

Page 3
STEP 2 – REFRIGERANT PIPING
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 ushed 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 insulator, preventing
proper heat transfer. It can also clog the expansion
device and reduce system performance and capacity.
Failure to properly ush the system per this instruction
and the detailed Installation and Service Procedures
manual will void the warranty.
Flush the existing line set per the following instructions.
For more information, refer to the Installation and Service
Procedures manual available on LennoxPros.com. CAU-
TION - DO NOT attempt to ush and re-use existing line
sets or indoor coil when the system contains contaminants
(i.e., compressor burn out).
If a new line set is being installed, size the piping per table 1.
TABLE 1
REFRIGERANT LINE SET – INCHES (MM)
Model
Valve 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
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)
-042
-048
-060 3/8 in.
(10 mm)
1-1/8 in.
(28 mm)
3/8 in.
(10 mm)
1-1/8 in.
(28 mm) Field Fabricated
NOTE - Some applications may require a eld-provided 7/8" to
1-1/8"adapter.
NOTE - When installing refrigerant lines longer than 50
feet, refer to the Refrigerant Piping Design and Fabrica-
tion Guidelines manual available on LennoxPros.com
(Corp. 9351-L9), or contact the Technical Support Depart-
ment Product Application group for assistance.
NOTE - For new or replacement line set installation, refer
to Service and Application Note - Corp. 9112-L4 (C-91-4).
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 hazard.
Failure to follow this warning could result in
damage, personal injury or death.
Never use oxygen to pressurize or purge
refrigeration lines. Oxygen, when exposed
to a spark or open ame, can cause re 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 pressure
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 COMPRESSOR.

Page 4
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 -
sembly.
C -Using two wrenches, disconnect liquid line from liquid line
ing. T
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
VALV E
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. Ta ke 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
VALV E
INLET
DISCHARGE
TANK
RETURN
CLOSED
OPENED
RECOVERY
CYLINDER
RECOVERY MACHINE
NEW
OUTDOOR
UNIT
VAPOR LINE
SERVICE VALV E
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 4

Page 5
STEP 2 – REFRIGERANT PIPING – Brazing Procedures
ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND VAPOR LINE SERVICE VALVES
OUTDOOR
UNIT
LIQUID LINE
VAPOR LINE
LIQUID LINE SERVICE
VALV E
VAPOR LINE
SERVICE
VALV E
ATTACH
GAUGES
INDOOR
UNIT
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 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
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 vapor and liquid line service
ports.
12
LIQUID LINE SERVICE
VALV E
SERVICE
PORT
CORE
SERVICE PORT
CAP
SERVICE
PORT
CORE
SERVICE
PORT CAP
CUT AND DEBUR
LINE SET SIZE MATCHES
SERVICE VALVE CONNECTION
DO NOT CRIMP SERVICE VALVE
CONNECTOR WHEN PIPE IS
SMALLER THAN CONNECTION
3
VAPOR LINE SERVICE
VALV E
COPPER TUBE
STUB
REFRIGERANT LINE
REDUCER
SERVICE VALV E
CONNECTION
LINE SET SIZE IS SMALLER
THAN CONNECTION
FIGURE 5
CAUTION
Brazing alloys and ux 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 ux.
WARNING
Danger of re. 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 6
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
VAPOR LINE
WATER-SATURATED
CLOTH
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 VALV ES, 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 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
LennoxPros.com.
FIGURE 6

Page 7
STEP 3 – Install Indoor Expansion Valve
This outdoor unit is designed for use in systems that include a check/expansion valve metering device. See the 16HPX Prod-
uct Specications bulletin (EHB) for approved check/expansion valve kit match-ups and application information. The check/
expansion valve unit can be installed internal or external to the indoor coil. In applications where an uncased coil is being
installed in a eld-provided plenum, install the check/expansion valve in a manner that will provide access for future eld
service of the check/expansion valve. Refer to below illustration for reference during installation of check/expansion valve.
1 -Attach the vapor line sensing bulb in the proper
orientation as illustrated to the right using the clamp and
screws provided.
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 once installed.
2 -Connect the equalizer line from the check expansion
valve to the equalizer vapor port on the vapor line. Finger
tighten the flare nut plus 1/8 turn (7 ft-lbs) as illustrated
below.
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
FURTHER DETAILS)
SENSING
LINE
EQUALIZER
LINE
CHECK
EXPANSION
VALV E
TEFLON®
RING
(Uncased Coil Shown)
Sensing bulb insulation is required if
mounted external to the coil casing. sensing
bulb installation for bulb positioning.
STUB
END
TEFLON®
RING
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
DISTRIBUTOR
ASSEMBLY
3 -Install one of the provided Teflon®rings around the
stubbed end of the check expansion valve and lightly
lubricate the connector threads and expose surface of
the Teflon®ring with refrigerant oil.
4 -Attach the stubbed end of the check expansion valve to
the liquid line orifice housing. Finger tighten and 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.
5 -Place the remaining Te flon®washer around the other
end of the check expansion valve. Lightly lubricate
connector threads and expose surface of the Teflon®
ring with refrigerant oil.
6 -Attach the liquid line assembly to the check expansion
valve. Finger tighten and 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.
ON 7/8” AND LARGER LINES,
MOUNT SENSING BULB AT
EITHER THE 4 OR 8 O'CLOCK
POSITION.
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
12
3
4
5
6
7
8
9
10
11 12
1/2 Turn
SENSING BULB INSTALLATION
EQUALIZER LINE INSTALLATION
12
3
4
5
6
7
8
9
10
11 12
1/8 Turn
1 -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.
2 -Remove the field-provided
sembly.
INDOOR EXPANSION VALVE INSTALLATION
FIGURE 7

Page 8
STEP 4 – LEAK TEST AND EVACUATION
TO VAPOR
SERVICE VALV E
HFC-410A
MANIFOLD GAUGE SET
OUTDOOR UNIT
HIGH
LOW
1
2
A
B
NITROGEN
NOTE - Position
canister to deliver
liquid refrigerant.
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.
CONNECT GAUGE SET
TEST FOR LEAKS
NOTE - Later in the procedure, the HFC-410A container will be replaced by the nitrogen container.
LEAK TEST
FIGURE 8

Page 9
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:
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 VALV E
TO LIQUID LINE
SERVICE VALV E
MICRON
GAUGE
VACUUM PUMP
1/4 SAE TEE WITH SWIVEL
COUPLER
500
MANIFOLD
GAUGE SET
HFC-410A
RECOMMEND
MINIMUM 3/8” HOSE
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.
HIGH
LOW
1
2
3
4
5
6
7
8
9
10
11 12
1/6 TURN
NITROGEN
3
CONNECT GAUGE SET
A
B
C
D
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 !
NOTE -
ister to deliver liquid
refrigerant.
EVACUATION
FIGURE 9

Page 10
STEP 5 – 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 must conform with current local codes and the cur-
rent Canadian Electrical Code (CEC).
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.
24VAC TRANSFORMER
Use the transformer provided with the furnace or air han-
dler for low-voltage control power (24VAC - 40 VA mini-
mum)
WARNING
Electric Shock Hazard. Can cause injury or
death. Unit must be properly 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.
WARNING
Fire Hazard. Use of aluminum wire with this product may
result in a re, causing property damage, severe injury
or death. Use copper wire only with this product.
WARNING
Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit
breaker(s) per Product Specications bulletin (EHB) and
unit rating plate.
WARNING
ELECTROSTATIC
DISCHARGE
(ESD)
Precautions and
Procedures
Electrostatic discharge can a󰀨ect
electronic components. Take care
during unit installation and service to
protect the unit’s electronic controls.
Precautions will help to avoid control
exposure to electrostatic discharge
by putting the unit, the control and the
technician at the same electrostatic
potential. Touch hand and all tools
on an unpainted unit surface before
performing any service procedure to
neutralize electrostatic charge.
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.
NOTE - Units are approved for use only with copper
conductors. Ground unit at disconnect switch or
connect to an earth ground.
SIZE CIRCUIT AND INSTALL SERVICE
DISCONNECT SWITCH
NOTE - 24VAC, Class II circuit connections are made
in the control panel.
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.
THERMOSTAT
5 FEET
(1.5M)
INSTALL THERMOSTAT
SERVICE
DISCONNECT
SWITCH
MAIN FUSE BOX/
BREAKER PANEL
2
1
FIGURE 10