Lennox 2SHP13 Series User manual

506875-01 Page 1 of 23Issue 1139
Installation and servicing of air conditioning equipment
can be hazardous due to internal refrigerant pressure
and live electrical components. Only trained and
qualified service personnel should install or service
this equipment. Installation and service performed by
unqualified persons can result in property damage,
personal injury, or death.
WARNING
Sharp metal edges can cause injury. When installing
the unit, use care to avoid sharp edges.
WARNING
Risk of electrical shock. Disconnect all remote power
supplies before installing or servicing any portion of the
system. Failure to disconnect power supplies can result
in property damage, personal injury, or death.
WARNING
The equipment covered in this manual is to be installed by trained and experienced service and
installation technicians. Improper installation, modification, service, or use can cause electrical
shock, fire, explosion, or other conditions which may cause personal injury, death, or property
damage. Use appropriate safety gear including safety glasses and gloves when installing this
equipment.
WARNING
TABLE OF CONTENTS
INSTALLATION .....................................................2
START-UP .......................................................... 11
OPERATION ...................................................... 15
MAINTENANCE .................................................17
HOMEOWNER INFORMATION ........................ 18
WIRING DIAGRAM ............................................ 21
WARRANTY ......................................................23
These instructions must be read and understood completely before attempting installation.
INSTALLATION AND MAINTENANCE INSTRUCTIONS
2SHP13 Series
with Dry Nitrogen Holding Charge
Split System Heat Pump
*P506875-01*
(P) 506875-01

Page 2 of 23 506875-01Issue 1139
INSTALLATION
Torque Table
Table 1
Compressor Bolts 90 in. lbs.
#10 Machine Screws 28 in. lbs.
#8 Machine Screws 16 in. lbs.
Sheet Metal Screws 16 in. lbs.
Service Port Caps 8 ft. lbs.
Stem Caps 8 ft. lbs.
Fastener Torque
Figure 1
Installation Clearances
* A service clearance of 30" must be maintained on one of the
sides adjacent to the control box. Clearance to one of the other
three sides must be 36". Clearance to one of the remaining two
sides may be 12" and the final side may be 6".
Aclearance of 24" must be maintained between units.
48" clearance required on top of unit. Maximum soffit overhang is
36".
General
This heat pump, which will also be referred to in this
instruction as the outdoor unit, uses HCFC-22
refrigerant.
This outdoor unit is intended as a replacement outdoor
component for use in residential systems which include
an existing indoor coil which is functioning properly. It is
NOT intended for new installations.
•shipped from the factory with nitrogen holding charge
that must be purged from the unit;
•designed for use with HCFC-22 refrigerant only;
•designed for use in systems that use check / thermal
expansion valve (H2TXV). See the 2SHP13 product
specification sheet for approved check / expansion
valve match ups and application information.
Important: The heat pump must have properly matched
system components including indoor unit and refrigerant
metering device. Mismatched equipment may have an
impact on the operation, performance, reliability, and
warranty of the heat pump system.
Inspection of Shipment
Upon receipt of equipment, carefully inspect it for possible
shipping damage. If damage is found, it should be noted
on the carrier’s freight bill. Take special care to examine
the unit inside the carton if the carton is damaged. Any
concealed damage discovered should be reported to the
last carrier immediately, preferably in writing, and should
include a request for inspection by the carrier’s agent.
If any damages are discovered and reported to the carrier
DO NOT INSTALL THE UNIT, as claim may be denied.
Check the unit rating plate to confirm specifications
are as ordered.
Location of Unit
Outdoor units operate under a wide range of weather
conditions; therefore, multiple factors must be considered
when positioning the unit. The unit must be positioned to
give adequate clearances for sufficient airflow and
serviceing. Refer to Figure 1 for installation clearances.
•Place a sound-absorbing material, such as Isomode,
under the unit if it will be installed in a location or
position that will transmit sound or vibration to the
living area or adjacent buildings.
•Install the unit high enough above the ground or roof
to allow adequate drainage of defrost water and prevent
ice buildup.
•In heavy snow areas, do no locate the unit where drifting
snow will occur. The unit base should be elevated
above the depth of average snows.
NOTE: Elevation of the unit may be accomplished by
constructing a frame using suitable materials. If a support
frame is constructed, it must not block drain holes in unit
base.
•When installed in areas where low ambient
temperatures exist, locate unit so winter prevailing
winds do not blow directly into outdoor coil.

506875-01 Page 3 of 23Issue 1139
•Locate unit away from overhanging roof lines which
would allow water or ice to drop on, or in front of, coil
or into unit.
Slab Mounting
When installing a unit at grade level, install on slab high
enough above grade so that water from higher ground will
not collect around the unit (see Figure 2). Slab should
have a slope tolerance away from the building of 2° or 2"
per 5'. This will prevent ice from building up under the
unit during a defrost cycle. Refer to following roof mounting
section for barrier construction if unit must face prevailing
winter winds.
Figure 2
Slab Mounting
Discharge Air
Mounting Slab
Ground Level
Building
Structure
Roof Mounting
Install unit at a minimum of 6" above surface of the roof to
avoid ice buildup around the unit. Locate the unit above a
load bearing wall or area of the roof that can adequately
support the unit. Consult local codes for rooftop
applications.
If unit coil cannot be mounted away from prevailing winter
winds, a wind barrier should be constructed (see Figure
3). Size the barrier at least the same height and width as
the outdoor unit. Mount barrier 24" from the sides of the
unit in the direction of the prevailing winds.
Electrical Wiring
All field wiring must be done in accordance with the
National Electrical Code (NEC) recommendations,
Canadian Electrical Code (CEC) and CSA Standards, or
local codes, where applicable.
Unit must be grounded in accordance with national
and local codes. Failure to ground unit properly can
result in personal injury or death.
WARNING
Line voltage is present at all components when unit is
not in operation on units with single pole contractors.
Disconnect all remote electric power supplies before
opening access panel. Unit may have multiple power
supplies. Failure to disconnect all power supplies could
result in personal injury or death.
WARNING
Figure 3
Wind Barrier Construction
Refer to the furnace or blower coil Installation Instructions
for additional wiring application diagrams and refer to unit
rating plate for minimum circuit ampacity and maximum
overcurrent protection size.
1. Install line voltage power supply to unit from a properly
sized disconnect switch. Any excess high voltage
field wiring should be trimmed or secured away from
the low voltage field wiring.
2. Ground unit at unit disconnect switch or to an earth
ground. To facilitate conduit, a hole is in the bottom
of the control box. Connect conduit to the control box
using a proper conduit fitting. Units are approved for
use only with copper conductors. 24V Class II circuit
connections are made in the low voltage junction box.
A complete unit wiring diagram is located inside the
unit control box cover (see also pages 20 and 21 of
this instruction).

Page 4 of 23 506875-01Issue 1139
Thermostat Designations
(Some connections may not apply. Refer to
specific thermostat and indoor unit.)
Without Auxiliary Heat
With Auxiliary Heat
Do not connect C (common) connection between indoor unit and
thermostat except when required by the indoor thermostat. Refer
to thermostat installation instructions. C (common) connection
between indoor unit and outdoor unit required for proper operation.
Figure 4
3. Install room thermostat on an inside wall that is not
subject to drafts, direct sunshine, or other heat
sources.
4. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit (see Figure 4).
5. Do not bundle any excess 24V control wire inside
control box. Run control wire through installed wire
tie and tighten wire tie to provide low voltage strain
relief and to maintain separation of field-installed low
and high voltage circuits.
Refrigerant Piping
Field refrigerant piping consists of liquid and suction lines
from the outdoor unit (sweat connections) to the indoor
coil (flare or sweat connections).
Select line set diameters from Table 2 to ensure that oil
returns to the compressor. Size vertical suction riser to
maintain minimum velocity at minimum capacity.
Recommended line length is 50' or less. If more than 50'
line set is required, contact Technical Services at (800)
515-3501. Table 2 shows the diameters for line sets up
to 100' although vertical lift applications and trapping
requirements need to be reviewed with Technical Services
for line sets over 50'.
Refrigerant Line Set Diameters (in.)
For installations eceeding 50’, contact Technical
Services at [phone].
Table 2

506875-01 Page 5 of 23Issue 1139
Installing Refrigerant Line
During the installation of an air conditioning system, it is
important to properly isolate the refrigerant line to prevent
unnecessary vibration. Line set contact with the structure
(wall, ceiling, or floor) may cause objectionable noise when
vibration is translated into sound. As a result, more energy
or vibration can be expected. Close attention to
line set isolation must be observed.
Following are some points to consider when placing and
installing a high-efficiency outdoor unit:
Placement
Be aware that some localities are adopting sound
ordinances based on how noisy the unit is at the neighbor’s
home, not at the original installation. Install the unit as
far as possible from the property line. When possible, do
not install the unit directly outside a bedroom window.
Glass has a very high level of sound transmission. Figure
5 shows how to place the outdoor unit and line set to
reduce line set vibration.
Figure 5
Outside Unit Placement and Installation
Line Set Isolation
Illustrations on the pages 6 and 7 demonstrate procedures
which ensure proper refrigerant line set isolation. Figure
6 shows how to install line sets on horizontal runs. Figure
7 shows how to make a transition from horizontal to
vertical. Figure 8 shows how to install line sets on vertical
runs.
Brazing Connection Procedure
1. Cut ends of refrigerant lines square (free from nicks
or dents). Debur the ends. The pipe must remain
round; do not pinch end of line.
2. Before making line set connections, use 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% silver alloy
for copper-to-copper brazing or 45% silver alloy for
copper-to-brass or copper-to-steel brazing) which are
rated for use with HCFC-22 refrigerant.
4. Remove the Schrader core assemblies before brazing
to protect them from damage due to extreme heat.
Replace the cores when brazing is complete.
5. Wrap a wet cloth around the valve body and copper
tube stub to protect them from heat damage during
brazing. Wrap another wet cloth underneath the valve
body to protect the base paint.
6. Braze the line set to the service valve. Quench the
joints with water or a wet cloth to prevent heat damage
to the valve core and opening port. The tube end
must stay bottomed in the fitting during final
assembly to ensure proper seating, sealing, and
rigidity.
7. Install the factory-supplied fixed orifice (or thermal
expansion valve which is sold separately and which
is approved for use with HCFC-22 refrigerant) in the
liquid line at the indoor coil.
Refrigerant Metering Device
2SHP13 units are designed for use with either fixed orifice
or TXV systems. Refer to the appropriate following section
for information on installing the chosen refrigerant metering
device.
Fixed Orifice Systems
2SHP13 units are shipped with a fixed orifice refrigerant
metering device. Replace the existing indoor unit fixed
orifice with the orifice supplied with this unit. Place the
supplied fixed orifice sticker on the indoor cabinet after
installation. See Table 3 on page 7 for the proper fixed
orifice size for each unit. In nonstandard applications,
the provided fixed orifice may not be appropriately sized.
Install the fixed orifice as shown in Figure 9 on page 7.
Do not twist distributor cap tubes when loosening the
seal nut from the orifice housing. Use wrench to back up
the distributor.

Page 6 of 23 506875-01Issue 1139
Figure 7
Refrigerant Line Sets: Transition from Vertical to Horizontal
Anchored
Heavy Nylon
Wire Tie
Wall
Stud
Metal Sleeve Vapor Line Wrapped
in Armaflex
–
Liquid Line
Wall
Stud
Automotive
Muffler-Type
Hanger
Strap Liquid
Line to Vapor
Line
Metal Sleeve
Vapor Line Wrapped
in Armaflex
–
Liquid Line
Strap Liquid
Line to Vapor
Line
Figure 6
Refrigerant Line Sets: Installing Horizontal Runs
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)
8’
8’
Tape or Wire Tie
Strap the vapor line to the joist or rafter
at 8 intervals then strap the liquid line
to the vapor line.
’
Floor Joist or
Roof Rafter
Metal Sleeve
Floor Joist or Roof Rafter
Tape or Wire Tie
Wire Tie
(around vapor line only)

506875-01 Page 7 of 23Issue 1139
Figure 8
Refrigerant Line Sets: Installing Vertical Runs (new construction shown)
Outside Wall
Wood Block
Between Studs
IMPORTANT: Refrigerant
lines must not contact wall.
Vapor Line Liquid Line
Wire Tie
Inside Wall
Strap
Sleeve
Wire Tie
Wire Tie
Strap
Wood Block
Sleeve
Vapor Line Wrapped
with Armaflex
Liquid Line
Caulk
PVC Pipe Fiberglass
Insulation
Outside Wall
IMPORTANT:
Refrigerant
lines must not
contact structure.
NOTE: Similar installation practices
should be used if line set is to be
installed on exterior of outside wall.
Metering Device Installation
Figure 9
If necessary, remove R22 flow control device (fixed
orifice/thermal expansion valve) from existing line
set before installing R-410A approved orifice or
expansion valve.
Fixed Orifice Data
Table 3

Page 8 of 23 506875-01Issue 1139
Expansion Valve Systems
Expansion valves equipped with Chatleff-type fittings are
available from the manufacturer. See Table 4 for proper
TXV for each unit.
To install an expansion valve (see Figure 9 on page 7):
1. Separate the distributor assembly and remove the
piston orifice and used teflon seal. Insert nozzle end
of the expansion valve along with a new teflon seal
into the distributor and tighten to 20 – 30 ft. lbs. Use
backup wrench on all wrench flats. Overtightening
will crush the teflon seal and may cause a leak.
2. Attach liquid line portion of distributor assembly along
with new teflon seal to the inlet of the expansion valve.
Tighten to 20 – 30 ft. lbs. Use backup wrench on all
wrench flats. Overtightening will crush the teflon
seal and may cause a leak.
3. Connect the external equalizer line to the equalizer
port on the suction line and tighten to 8 ft. lbs.
4. Strap the superheat sensing bulb to the suction
header. If installing an expansion valve on an indoor
coil that previously used a fixed orifice, be sure to
remove the existing fixed orifice. 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
When checking the unit charge, use a manifold gauge
set that is equipped with “low loss” hoses. Do not use a
manifold gauge set with anything other than a “low loss”
hose
.
Liquid and Suction Line Service Valves
The liquid line and suction line service valves (see Figure
10) and service ports are used for leak testing, evacuating,
charging, and checking charge.
Each valve is equipped with a service port which has a
factory-installed Schrader valve. Aservice port cap
protects the Schrader valve from contamination and serves
as the primary leak seal.
To Access the Schrader Port:
1. Remove the 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 an additional 1/6 turn.
To Open Liquid or Suction Line Service Valve:
1. Remove stem cap with an adjustable wrench.
2. Use a service wrench with a hex-head extension to
back the stem out counterclockwise as far as it will
go. Use a 3/16" hex head extension for liquid line
service valves and a 5/16" extension for suction line
service valves.
3. Replace the stem cap. Tighten finger tight, then
tighten an additional 1/6 turn.
Table 4
TXV Data
Figure 10
Service Valve

506875-01 Page 9 of 23Issue 1139
To Close Liquid or Suction Line Service Valve:
1. Remove the stem cap with an adjustable wrench.
2. Use a service wrench with a hex-head extension to
turn the stem clockwise to seat the valve. Tighten
firmly.
3. Replace the stem cap. Tighten finger tight, then
tighten an additional 1/6 turn.
Suction Line (Ball Type) Service Valve
Suction line (ball type) service valves function the same
way as the other valves; the difference is in the
construction (see Figure 11).
The ball valve is equipped with a service port with a factory-
installed Schrader valve. Aservice port cap protects the
Schrader valve from contamination and serves as the
primary seal.
Ball Type Service Valve
(Valve Open)
Figure 11
Use adjustable wrench. To open, rotate stem counter-
clockwise 1/4 turn (90°). To close, rotate stem clockwise 1/
4 turn (90°).
Leak Testing
After the line set has been connected to the indoor and
outdoor units, the line set connections and indoor unit
must be checked for leaks.
Using an Electronic Leak Detector
1. Connect the high pressure hose of the manifold gauge
set to the suction valve service port. (Normally the
high pressure hose is connected to the liquid line port;
however, connecting it to the suction ports helps to
protect the manifold gauge set from damage caused
by high pressure.)
2. With both manifold valves closed, connect the cylinder
of HCFC-22 refrigerant. Open the valve on the HCFC-
22 cylinder (vapor only).
3. Open the high pressure side of the manifold to allow
HCFC-22 into the line set and indoor unit. Weigh in a
trace amount of HCFC-22. (A trace amount is a
maximum of 2 oz. of refrigerant or 3 lbs. pressure.)
Close the valve on the HCFC-22 cylinder and the valve
on the high pressure side of the manifold gauge set.
Disconnect the HCFC-22 cylinder.
4. Connect a cylinder of nitrogen with a pressure
regulating valve to the center port of the manifold gauge
set. When using high pressure gas such as
nitrogen for this purpose, be sure to use a
regulator that can control the pressure down to 1
or 2 psig.
5. Adjust nitrogen pressure to 150 psig. Open the valve
on the high side of the manifold gauge set to pressurize
the line set and the indoor coil.
Evacuation
Evacuating the system of noncondensables is critical for
proper operation of the unit. Noncondensables are defined
WARNING
Refrigerant can be harmful if inhaled. Refrigerant must
always be used and recovered responsibly. Incorrect
or irresponsible use of refrigerant can result in personal
injury or death.
WARNING
Never use oxygen to pressurize refrigeration or air
conditioning systems. Oxygen will explode on
contact with oil and could cause personal injury or
death.

Page 10 of 23 506875-01Issue 1139
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.
WARNING
Do not use a compressor to evacuate a system. Avoid
deep vacuum operation. Extremely low vacuums can
cause internal arcing and compressor failure. Danger
of equipment damage. Damage caused by deep
vacuum operation will void warranty.
Use a thermocouple or thermistor electronic vacuum gauge
that is calibrated in microns. Use an instrument that reads
down to 50 microns.
1. Open liquid and suction line service valves on outdoor
unit.
2. Connect the manifold gauge set to the service valve
ports as follows:
•Low pressure gauge to suction line service valve
•High pressure gauge to liquid line service valve
3. Connect micron gauge.
4. Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set.
5. Open both manifold valves and start vacuum pump.
6. Evacuate the system to a minimum of 500 microns
or lower. 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 pressure.
A rapid rise in pressure indicates a relatively large
leak. If this occurs, the leak testing procedure must
be repeated.
7. When 500 microns or lower is maintained, close the
manifold gauge valves, turn off the vacuum pump, and
disconnect the manifold gauge center port hose from
the vacuum pump. Attach the manifold gauge center
port hose to a nitrogen cylinder with pressure regulator
set to 150 psig and purge the hose. Open the manifold
gauge valves to break the vacuum in the system.
Close the manifold gauge valves.
8. 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 system.
9. Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the system
until 500 microns is maintained
9. Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the system
until 500 microns is maintained within a 20-minute
period after shutting off the vacuum pump and closing
the manifold gauge valves.
10. When the requirements above have been met,
disconnect the manifold hose from the vacuum pump.

506875-01 Page 11 of 23Issue 1139
START-UP
Refrigerant Charge Adjustment
*If line length is greater than 15 ft., add this amount.
If line length is less than 15 ft., remove this amount.
Table 5
Liquid Line Set
Diameter
Oz. per 5 ft. adjust
from 15 ft. line set *
3/8 in. 3 oz. per 5 ft.
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.
CAUTION Mineral oils are not compatible with R-410A. If oil must
be added, it must be a polyolester oil.
IMPORTANT
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, attach HCFC-22 cylinder
to system through gauge set, and weigh in liquid
refrigerant.
4. Replace the stem caps and secure finger tight, then
tighten an additional 1/6 of a turn.
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit
nameplate. If not, do not start equipment until the
power company has been consulted and the voltage
condition corrected.
6. Set thermostat for cooling demand, turn on power to
indoor blower and close the outdoor unit disconnect
switch to start the unit.
7. Recheck unit voltage with unit running. Power must
be within range shown on unit nameplate.
Refrigerant Charging
The unit rating plate has been marked with a recommended
system charge. This charge is based on a matching indoor
coil and outdoor coil with 15' line set. For varying lengths
of line set, refer to Table 5 for refrigerant charge adjustment.
Optimizing System 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 unit’s refrigerant metering device and 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 valve
ports as follows (see Figure 12):
• Low pressure gauge to suction line service valve
• High pressure gauge to liquid line service valve
2. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HCFC-22.
3. If room temperature is below 70°F, set the room
thermostat to call for heat. This will create the
necessary load for properly charging the system in
the cooling cycle.
4. Use a digital thermometer to record the outdoor
ambient temperature.
5. When the heating demand has been satisfied, switch
the thermostat to cooling mode with a set point of
68°F. When pressures have stabilized, use a digital
thermometer to record the liquid and suction line
temperatures.
6. The outdoor temperature will determine which charging
method to use. Proceed with the appropriate charging
method.

Page 12 of 23 506875-01Issue 1139
Charge Using Weigh-In Method (Fixed Orifice/TXV
Systems)
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, first locate and repair any leaks then
use the weigh-in method to charge the unit.
1. Recover the refrigerant from the unit.
2. Conduct a leak check, then evacuate as previously
outlined.
3. Weigh in the charge according to the total amount
shown on the unit nameplate.
If weighing facilities are not available or if unit is being
charged during warm weather, follow one of the other
procedures outlined below.
Charge Using Subcooling Method (TXV Systems) –
Outdoor Temperatures 65°F or Above
If charging a TXV system when the outdoor ambient
temperature is 65°F or above, the subcooling method can
be used to charge the unit.
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. For
best results, use the same digital thermometer to
check both the outdoor ambient and the liquid line
temperatures.
Figure 12
Use gauge ports on suction line valve and liquid line valve for evacuation refrigerant lines and
indoor coil. Use suction gauge to measure suction pressure during charging.
Cooling Cycle
2. At the same time, record the liquid line pressure
reading.
3. Use a temperature/pressure chart for HCFC-22 to
determine the saturation temperature for the liquid
line pressure reading.
4. Subtract the liquid line temperature from the saturation
temperature (according to the chart) to determine
subcooling.
_____ ° Saturation Temperature °F
-
_____ ° Liquid Line Temperature °F
=
_____ ° Subcooling Value °F
5. Compare the subcooling value with those shown in
Table 6. If subcooling is greater than shown, recover
some refrigerant. If subcooling is less than shown,
add some refrigerant.
Charge Using Superheat Method (Fixed Orifice
Systems) – Outdoor Temperatures 65°F or Above
1. With the manifold gauge hose on the suction service
port and the unit operating stably, use a digital
thermometer to record the suction line temperature.
2. At the same time, record the suction line pressure
reading.

506875-01 Page 13 of 23Issue 1139
Table 7
Superheat Values for
Fixed Orifice Systems
(80°DB/67°WB Return Air)
3. Use a temperature/pressure chart for HCFC-22 to
determine the saturation temperature for the suction
line pressure reading.
4. Subtract the saturation temperature (according to the
chart) from the suction line temperature to determine
the superheat.
_____ ° Suction Line Temperature °F
-
_____ ° Saturation Temperature °F
=
_____ ° Superheat Value °F
5. Compare the superheat value with those shown in
Table 7. If superheat is greater than shown, add some
refrigerant. If superheat is less than shown, recover
some refrigerant.
Charge Using Approach Method (TXV Systems) –
Outdoor Temperatures 65°F or Above
The following procedure is intended as a general guide
and is for use on expansion valve systems only. For best
results, indoor temperature should 70°F to 80°F. 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 8 on page 14. 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.
Table 6
Subcooling Values for TXV Systems
Pressures higher than those listed indicate that the
system is overcharged. Pressures lower than those
listed indicate that the system is undercharged. Verify
adjusted charge using the approach method.
4. Use the same digital thermometer used to check
outdoor ambient temperature in Step 1 to check liquid
line temperature. Verify the unit charge using the
approach method.
5. Subtract the outdoor ambient temperature from the
liquid line temperature to determine the approach
temperature.
_____ ° Liquid Line Temperature °F
-
_____ ° Outdoor Ambient Temperature °F
=_____ ° Approach Temperature °F
6. Compare the approach value with those shown in
Table 9 on page 14. If the values to do not agree with
those provided in Table 9, add refrigerant to lower the
approach temperature or recover refrigerant from the
system to increase the approach temperature.
Check Charge Using Normal Operating Pressures
Use Table 8 on page 14 to perform maintenance checks.
Table 8 is not a procedure for charging the system. Minor
variations in these pressures may be due to differences
in installations. Significant deviations could mean that
the system is not properly charged or that a problem
exists with some component in the system.

Page 14 of 23 506875-01Issue 1139
Table 9
Approach Values for TXV Systems
Approach value is the liquid line temperature minus the
outdoor ambient temperature (±1° F).
NOTE: For best results, use the same digital thermometer to
check both outdoor ambient and liquid temperatures.
Table 8
L - Liquid S - Suction
Values provided above are typical pressures. Indoor unit matchup, indoor air quality equipment, and indoor load will cause pressures to vary.
Normal Operating Pressures

506875-01 Page 15 of 23Issue 1139
OPERATION
Outdoor unit and indoor blower cycle on demand from
the room thermostat. When the thermostat blower switch
is moved to the ON position, the indoor blower operates
continuously.
Filter Drier
The unit is equipped with a bi-flow filter, If replacement is
necessary, replace with one of similar design.
Crankcase Heater
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.
Emergency Heat Function (Room Thermostat)
An emergency heat function is designed into some room
thermostats. This feature is applicable when isolation of
outdoor unit is required or when auxiliary electric heat is
stage by outdoor thermostats. When the room thermostat
is placed in the emergency heat position, the outdoor
unit control circuit is isolated from power and the field-
supplied relays bypass the outdoor thermostats. An
amber indicating light simultaneously comes on to remind
the homeowner that the unit is operating in the emergency
heat mode.
Emergency heat is usually used during an outdoor
shutdown, but it should also be used following a power
outage if power has been off for over an hour and the
outdoor temperature is below 50°F. System should be
left in the emergency heat mode at least 6 hours to allow
the crankcase heater sufficient time to prevent compressor
slugging.
Defrost System
The defrost system includes two components: the defrost
thermostat and the defrost control.
Defrost Thermostat
The defrost thermostat is located on the liquid line between
the check/expansion valve and the distributor. When the
defrost thermostat senses 42°F or cooler, the thermostat
contacts close and send a signal to the defrost control
board to start the defrost timing. It also terminates defrost
when the liquid line warms up to 70°F.
Defrost Control
The defrost control board includes the combined functions
of time/temperature defrost control, defrost relay,
diagnostic LEDs and terminal strip for field wiring
connections (see Figure 13).
Figure 13
Defrost Control Board

Page 16 of 23 506875-01Issue 1139
The control provides automatic switching from normal
heating operation to defrost mode and back. During the
compressor cycle (call for defrost), the control
accumulates compressor run time at 30, 60, 90 minute
fieldadjustable intervals. If the defrost thermostat is closed
when the selected compressor run time interval ends,
the defrost relay is energized and the defrost begins.
Defrost Control Timing Pins
Each timing pin selection provides a different accumulated
compressor run time period during one thermostat run
cycle. This time period must occur before a defrost cycle
is initiated. The defrost interval can be adjusted to 30
(T1), 60 (T2), or 90 (T3) minutes. The defrost timing jumper
is factory installed to provide a 60-minute defrost interval.
If the timing selector jumper is not in place, the control
defaults to a 90-minute defrost interval. The maximum
defrost period is 14 minutes and cannot be adjusted.
A test option is provided for troubleshooting. The test
mode may be started any time the unit is in the heating
mode and the defrost thermostat is closed or jumpered.
If the jumper is in the TEST position at power up, the
control will ignore the test pins. When the jumper is placed
across the TEST pins for 2 seconds, the control will enter
the defrost mode. If the jumper is removed before an
additional 5-second period has elapsed (7 seconds total),
the unit will remain in defrost mode until the defrost
thermostat opens or 14 minutes have passed. If the
jumper is not removed until after the additional 5-second
period has elapsed, the defrost will terminate and the test
option will not function again until the jumper is removed
and reapplied.
Compressor Delay
The defrost board has a field-selectable function to reduce
occasional sounds that may occur while the unit is
cycling in and out of the defrost mode. The compressor
will be cycled off for 30 seconds going in and out of the
defrost mode when the compressor delay jumper is
removed.
NOTE: The 30-second “off” cycle is not functional when
jumpering the TEST pins.
Time Delay
The timed-off delay is 5 minutes long. The delay helps to
protect the compressor from short cycling in case the
power to the unit is interrupted or a pressure switch opens.
The delay is bypassed by placing the timer select jumper
across the TEST pins for 0.5 seconds.
Pressure Switch Circuit
The defrost control includes a low pressure (loss of charge
pressure) switch. Ahigh pressure switch (optional) can
be connected to the board’s HI PS terminals (see Figure
13 on page 15).
During a single demand cycle, the defrost control will lock
out the unit after the fifth time that the circuit is interrupted
by any pressure switch wired to the control board. In
addition, the diagnostic LEDs will indicate a locked-out
pressure switch after the fifth occurrence of an open
pressure switch (see Table 10). The unit will remain locked
out until power to the board is interrupted, then re-
established, or until the jumper is applied to the TEST
pins for 0.5 seconds.
NOTE: The defrost control board ignores input from the
low pressure switch terminals as follows:
•During the TEST mode
•During the defrost cycle
•During the 90-second start-up period
•For the first 90 seconds each time the reversing valve
switches heat/cool modes
If the TEST pins are jumpered and the 5-minute delay
is being bypassed, the LO PS terminal signal is not
ignored during the 90-second start-up period.
Diagnostic LEDs
The defrost board uses two LEDs for diagnostics. The
LEDs flash a specific sequence according to the condition
as shown in Table 10.

506875-01 Page 17 of 23Issue 1139
MAINTENANCE
Before the start of each heating and cooling season, the
following service checks should be performed by a qualified
service technician.
•Inspect and clean outdoor and indoor coils. The
outdoor coil may be flushed with a water hose.
NOTE: It may be necessary to flush the outdoor coil
morefrequently if it is exposed to substances which are
corrosive or which block airflow across the coil (such as
pet urine, cottonwood seeds, etc....).
•Visually inspect the refrigerant lines and coils for leaks.
•Check wiring for loose connections.
•Check voltage at the indoor and outdoor units (with
units operating).
•Check amperage draw at the outdoor fan motor,
compressor, and indoor blower motor. Values should
be compared with those given on unit nameplate.
•Check, clean (or replace) indoor unit filters.
•Check the refrigerant charge and gauge the system
pressures.
•Check the condensate drain line for free and
unobstructed flow. Clean drain line, if necessary.
•Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
•Belt drive blowers: Check drive belt for wwar and
proper tensions.
If insufficient cooling is reported, the unit should be gauged
and refrigerant charge checked (see “Refrigerant
Charging” on page 11).
Before performing maintenance operations on system,
turn the electric power to unit OFF at disconnect
switch(es). Unit may have multiple power supplies.
Electrical shock could cause personal injury or death.
WARNING
Mode Green LED Red LED
No Power
to Board
Normal Operation/
Power to Board
OFF OFF
Anti-Short Cycle
Lockout
Simultaneous Slow Flash
Low Pressure
Switch Fault
Low Pressure
Switch Lockout
High Pressure
Switch Fault
High Pressure
Switch Lockout
Alternating Slow Flash
OFF
OFF
OFF
OFF
Slow Flash
Slow Flash
ON
ON
Table 11
Defrost Control Board Diagnostic LEDs

Page 18 of 23 506875-01Issue 1139
HOMEOWNER INFORMATION
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.
Ask your dealer to show you where the 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.
Disposable filters should be replaced with a filter of the
same type and size. If you are unsure of the filter you
need for your system, contact your dealer.
Many indoor units are equipped with reusable foam filters.
These filters can be cleaned with a mild soap and water
solution. Rinse the filter thoroughly and let dry completely
before returning to unit or grille.
The filter and all access panels must be in place any
time the unit is in operation.
Some systems are equipped with an electronic air cleaner,
designed to remove the majority of airborne particles from
the air passing through the cleaner. If your system
includes an electronic air cleaner, ask your dealer for
maintenance instructions.
Inspect and clean indoor indoor coil. The indoor
evaporator coil is equipped with a drain pan to collect
condensate formaed as the 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
also applies to an auxiliary drain, if one is installed.


Inspect and clean outdoor coil:
Make sure no obstructions restrict airflow to the outdoor
unit. Leaves, trash, or shrubs crowding the unit can cause
it to work harder and use more energy. Keep shrubbery
trimmed away from the unit and periodically check for
debris which collects around the unit.
The outdoor coil may require frequent cleaning, depending
on environmental conditions. Clean the outdoor coil with
an unpressurized water hose to remove surface
contaminants and debris. It may be necessary to flush
the outdoor coil more frequently if it is exposed to
substances which are corrosive or which block airflow
across the coil (such as pet irome, cottonwood seeds,
etc...).
Heat Pump Operation
Heat pump untis have several characteristics you should
be aware of:
Heat pumps satisfy heating demand by delivering large
amounts of warm air into the living space. This is quite
different from gas-fired, oil-fired, or electric furnaces which
deliver lower volumes of considerably hotter air to heat
the space.
Do not be alarmed if you notice frost on the outdoor coil
in the winter months. Frost develops on the outdoor coil
during the heating cycle when temperatures are below
45° F. An electronic control activates a defrost cycle
lasting 5 to 15 minutes at preset intervals to clear the
outdoor coil of the frost. Ashift in sound type does occur
during the defrost mode.
During the defrost cycle, you may notice steam rising from
the unit. This is a normal occurrence. The thermostat
may engage auxiliary heat during the defrost cycle to
satisby a heating demand. The unit will return to normal
operation at the conclusion of the defrost cycle.
In case of extended power outage....
If the outdoor temperature is belwo 50° F and power to the
outdoor unit has been interrupted for 6 hours or longer,
observe the following when restoring power to the heat pump
system.
Set th e room thermostat selector to the “Emergency Heat”
setting to obtain temporary heat for a minimum of 6 hours.
This will allow system refrigerant pressures a nd
temperatures enough time to return to a stabilized
condition.
In the Emergency Heat mode, all heating demand is
satisfied by auxiliary heat; heat pump operation is locked
out. After a 6 hour “warmup” period, the thermostat can
then be switched to the “Heat” setting and normal heat
operation may resume.
Turn all electric power to unit OFF at disconnect
switch(es) before performing any maintenance
operations on system. Unit may have multiple power
supplies. Electrical shock could cause personal injury
or death.
WARNING

506875-01 Page 19 of 23Issue 1139
Thermostat Operation
Though your thermostat may vary somewhat from the
description below, its operation will be similar.
Temperature Setting Levers
Most heat hump thermostats have two temperature selector
levers: one for heating and one for cooling. Set the levers
or dials to the desired temperature setpoints for both heating
and cooling. Avoid frequent temperature adjustment; turning
the unit off and back on before pressures equalize puts stress
on unit 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 auxiliary
heat are operating. This mode is required when constant
air circulation or filtering is desired.
System Switch
Set the system switch for heating, cooling, or auto operation.
The auto mode allows the heat pump to automatically switch
from heating mode to cooling mode to maintain
predetermined comfort settings. Many heat pump
thermostats are also equipped with an emergency heat mode
which locks out heat pump operation and provides temporary
heat supplied by the auxiliary heat.
Indicating Light
Most heat pump thermostats have an amber light which
indicates when the heat pump is operating in the emergency
heat mode.
Temperature Indicator
The temperature indicator displays the actual room
temperature.
Programmable Thermostats
Your 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 particular thermostat for operation details.
Preservice Check
If your system fails to operate, check the following before
calling for service:
Check to see that all electrical disconnect switches are
ON.
Make sure the thermostat temperature selector is properly
set.
Make sure the thermostat system switch is properly set.
Replace any blown fuses, or reset circuit breakers.
Make sure unit access panels are in place.
Make sure air filter is clean.
Locate unit model number and have it handy before
calling.

Page 20 of 23 506875-01Issue 1139
Start-Up and Performance Checklist
Job Name _______________________________ Job No. ________________ Date ______________
Job Location _____________________________ City ___________________ State ______________
Installer _________________________________ City ___________________ State ______________
Unit Model No.______________ Serial No. ___________________
Service Technician ________________________________________ Nameplate Voltage ______________
Rated Load Ampacity ________ Compressor _______________ Outdoor Fan ___________________
Maximum Fuse or Circuit Breaker ________________________
Electrical Connections Tight? Indoor Filter Clean? Supply Voltage (Unit Off) ________________
Indoor Blower RPM _____________ S.P. Drop Over Indoor (Dry) ____________
Outdoor Coil Entering Air Temperature _____________ Voltage with Compressor Operating _____________
Discharge Pressure ___________ Vapor Pressure ____________
Refrigerant Charge Checked? Outdoor Fan Checked?
Refrigerant Lines: Leak Checked? Properly Insulated?
Service Valves: Fully Opened? Caps Tight?
Thermostat: Calibrated? Properly Set? Level?