Nortek SH3ME4M Series User manual

SPLIT SYSTEM HEAT PUMP FOR MANUFACTURED HOUSING
*SH3ME4M SERIES – 1RP24K, 1RP30K, 1SP36K, 1SP42K, 1SP48K (2, 2.5, 3, 3.5 & 4 TON) -
SINGLE PHASE MODELS WITH BRAZED CONNECTIONS
14.3 SEER2
INSTALLATION INSTRUCTIONS
IMPORTANT
ATTENTION INSTALLERS:
It is your responsibility to know this product better than your customer.This includes being able to install the product
according to strict safety guidelines and instructing the customer on how to operate and maintain the equipment for
the life of the product. Safety should always be the deciding factor when installing this product and using common
sense plays an important role as well. Pay attention to all safety warnings and any other special notes highlighted in
the manual. Improper installation of the unit or failure to follow safety warnings could result in serious injury, death,
or property damage.
These instructions are primarily intended to assist qualified individuals experienced in the proper installation of this
appliance. Some local codes require licensed installation/service personnel for this type of equipment. Please read all
instructions carefully before starting the installation. Return these instructions to the customer’s package for future
reference.
DO NOT DESTROY. PLEASE READ CAREFULLY & KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.
IMPORTANT SAFETY INFORMATION......................2
HEAT PUMP INSTALLATION ....................................3
General Information ...................................................3
Before You Install this Unit.........................................3
Packaging Removal ...................................................3
Locating the Heat Pump ............................................3
Clearance Requirements ...........................................3
Ground Level .............................................................3
Roof Mount ................................................................3
Accessory Mounting Kits............................................3
INSTALLATION/VERIFICATION OF THE
SYSTEMS EXPANSION DEVICE...............................4
Connecting Refrigerant Tubing Between the Indoor
& Outdoor Unit ...........................................................4
Coupling the Line-Set to the Unit................................4
REFRIGERANT CHARGING ......................................4
ELECTRICAL WIRING ...............................................5
Pre-Electrical Checklist ..............................................5
Line Voltage ...............................................................5
Grounding ..................................................................6
Thermostat Connections............................................6
Low Voltage Connections ..........................................6
START UP & ADJUSTMENTS ...................................6
Pre-Start Check List...................................................6
Start-Up Procedures ..................................................6
Operating Temperatures............................................7
Air Circulation - Indoor Blower ...................................7
Short Cycle Protection
System Cooling..........................................................7
System Heating..........................................................7
Defrost Control Board Test Pins
Charging the Unit in AC Mode ...................................7
If the outdoor temperature is 65 degrees F
or higher:..................................................................7
If the outdoor temperature is between
35 degrees F and 65 degrees F ..............................8
If the outdoor temperature is below
35 degrees F............................................................8
HEAT PUMP MAINTENANCE....................................9
Panel Removal...........................................................9
Panel Installation........................................................9
ELECTRICAL DIAGRAMS & TABLES ......................10
Figure 6. Wiring Diagram for *SH3ME4M Units
with Rotary Compressors (2.0 & 2.5T) .....10
Figure 7. Wiring Diagram for *SH3ME4M Units
with Scroll Compressors
(3.0, 3.5 & 4.0T).........................................11
INSTALLATION CHECKLIST.....................................12
REPLACEMENT PARTS ............................................12

2
WARNING:
The information listed below must be followed
during the installation, service, and operation
of this unit. Unqualified individuals should
not attempt to interpret these instructions or
install this equipment. Failure to follow safety
recommendations could result in possible
damage to the equipment, serious personal
injury or death.
• The installer must comply with all local codes and
regulations which govern the installation of this type of
equipment. Local codes and regulations take precedence
over any recommendations contained in these instructions.
Consult local building codes and the National Electrical
Code (ANSI) for special installation requirements.
• All electrical wiring must be completed in accordance with
local, state and national codes and regulations and with
the National Electric Code (ANSI/NFPA 70) or in Canada
the Canadian Electric Code Part 1 CSA C.22.1.
• This equipment contains liquid and gaseous refrigerant
under high pressure. DO NOT USE ANY PORTION OF THE
CHARGE FOR PURGING OR LEAK TESTING.Installation
or servicing should only be performed by qualified trained
personnel thoroughly familiar with this type equipment.
• Fully annealed, refrigerant grade copper tubing should be
used when installing the system. Refrigerant suction line
tubing should be fully insulated.
• Installation of equipment may require brazing operations.
Installer must comply with safety codes and wear
appropriate safety equipment (safety glasses, work gloves,
fire extinguisher, etc.) when performing brazing operations.
• Installation of this equipment will require the use of
refrigerant line-sets with quick connect couplings. Use
only Nortek approved couplings or line-sets for these
connections.
• Follow all precautions in the literature, on tags, and on
labels provided with the equipment. Read and thoroughly
understand the instructions provided with the equipment
prior to performing the installation and operational checkout
of the equipment.
• When refrigerant tubing and electrical wiring penetrates a
structures envelope, the openings should be made to be
suitably water-tight after their installation.
• This unit is designed for outdoor installations only and
should be positioned as shown on page 3.
IMPORTANT SAFETY INFORMATION
INSTALLER: Please read all instructions before servicing
this equipment. Pay attention to all safety warnings and any
other special notes highlighted in the manual. Safety markings
are used frequently throughout this manual to designate a
degree or level of seriousness and should not be ignored.
WARNING indicates a potentially hazardous situation that if
not avoided, could result in personal injury or death.
CAUTION indicates a potentially hazardous situation that
if not avoided, may result in minor or moderate injury or
property damage.
WARNING:
Shut off all electrical power to the unit before
performing any maintenance or service on the
system. Failure to comply may result in personal
injury or death.
WARNING:
Unless noted otherwise in these instructions,
only factory authorized parts or accessory
kits may be used with this product. Improper
installation, service, adjustment, or maintenance
may cause explosion, fire, electrical shock or
other hazardous conditions which may result in
personal injury or property damage
WARNING:
*SH3ME4M Split System Heat Pumps are shipped
charged with R410A refrigerant and ready
for installation. If repairs make it necessary
for evacuation and charging, it should only
be attempted by qualified trained personnel
thoroughly familiar with this equipment. Under
no circumstances should the owner attempt to
install and/or service this equipment. Failure to
comply with this warning could result in property
damage, personal injury, or death.
CAUTION:
This unit uses refrigerant R-410A. DO NOT use
any other refrigerant in this unit. Use of another
refrigerant will damage the unit.

3
HEAT PUMP INSTALLATION
General Information
The *SH3ME4M series Heat Pump is designed only for
outdoor rooftop or ground level installations. This unit has been
tested for capacity and efficiency in accordance with AHRI
Standards and will provide many years of safe and dependable
comfort, providing it is properly installed and maintained.
Abuse, improper use, and/or improper maintenance can
shorten the life of the appliance and create unsafe hazards.
To achieve optimum performance and minimize equipment
failure, it is recommended that periodic maintenance be
performed on this unit. The ability to properly perform
maintenance on this equipment requires certain mechanical
skills and tools.
Before You Install this Unit
√The cooling and heating loads of the area to be conditioned
must be calculated and a system of the proper capacity
selected. It is recommended that the area to be conditioned
be completely insulated and vapor sealed.
√Check the electrical supply and verify the power supply
is adequate for unit operation. The system must be wired
and provided with circuit protection in accordance with
local building codes. If there is any question concerning
the power supply, contact the local power company.
√Verify that the indoor thermostat and wiring is correct for
the installation of these units and that any required unit
accessories are on-hand before beginning the installation.
√The indoor section (air handler, furnace, etc) should be
installed before routing the refrigerant tubing. Refer to the
indoor unit's installation instructions for installation details.
√All units are securely packed at the time of shipment and
upon arrival should be carefully inspected for damage prior
to installing the equipment at the job site. Verify coil fins
are straight. If necessary, comb fins to remove flattened
or bent fins. Claims for damage (apparent or concealed)
should be filed immediately with the carrier.
√Please consult your dealer for maintenance information
and availability of maintenance contracts. Please read all
instructions before installing the unit.
Packaging Removal
NOTE: To prevent damage to the tubing connections, carefully
remove the carton and user’s manual from the equipment.
Discard the shipping carton.
Locating the Heat Pump
• Survey the job site to determine the best location for
mounting the outdoor unit.
• Sufficient clearance for unobstructed airflow through the
outdoor coil must be maintained in order to achieve rated
performance. See Figure 1 for minimum clearances to
obstructions.
• Overhead obstructions (Figure 1), poorly ventilated areas,
and areas subject to accumulation of debris should be
avoided.
• The unit should not be placed under roofing or other
overhangs which are not guttered; that would allow water
or ice to fall into the unit’s discharge opening.
• Consideration should be given to availability of electric
power, service access, noise, and shade.
Clearance Requirements
• The general recommendation is for the units to be installed
with 18 inches of clearance on 3 sides and with 24 inches
of clearance for the service access side to the unit’s service
panel.
• For installations that are space constrained, one side of the
unit, adjacent to the service panel, may have its air side
clearance reduced to a minimum of 6 inches. The other
side adjacent to the service panel requires 24 inches for
service access. The remaining two sides, at a minimum
shall require 12 inches of clearance.
• A minimum of 18 inches between two units must be
maintained for proper performance.
Ground Level
• The unit should be installed on a solid base that is level
and located at least 2 inches above grade*. Note: It is
recommended that poured concrete mounting bases
are not attached or adjacent to the building structure or
foundation.
Roof Mount
• The unit may only be installed on a structure that is capable
of supporting the total weight of the unit and its anchorage.
The support for the base of the unit may not slope more
than 1/8 inch per foot. The minimum clearance for the
base of the unit to the roof-line is 2 inches* for residential
applications.
*Note on ground and roof clearances: Heat pump and
other applications should account for the accumulation
of snow and raise the base of the unit accordingly. (At a
minimum, a 6 inch clearance is required.)
Accessory Mounting Kits
• Kits for other mounting methods and accessories can be
found in the technical sales literature for the unit. Or the
literature library on NortekHVAC.com.
Figure 1. Clearance Requirements
24" for
Service Access
12" or 18”
See Note
12" or 18”
See Note
DO NOT
OBSTRUCT
TOP OF UNIT
NOTE: Units require full perimeter clearances.
Installer must maintain 18” between two units.
18” Recommended.
(Minimum allowable clearance
of 6” to structure on
1 side of the unit only.)

4
INSTALLATION/VERIFICATION OF THE
SYSTEMS EXPANSION DEVICE
After outdoor and indoor unit placement has been determined,
refer to the Quick Reference Data sheet for information on the
appropriate TXV metering device to use for the equipment.
Verify that the installed expansion device matches those
requirements or install the correct expansion device. Outdoor
heat-pump units have the correct outdoor expansion device
pre-installed at the factory. Verify that the TXV provided
with the indoor unit matches the requirements in the Quick
Reference Data. The correct expansion device or kit is
available for all approved Nortek listed applications from
the parts department.
Connecting Refrigerant Tubing Between the Indoor
& Outdoor Unit
CAUTION:
When connecting refrigerant line-sets together,
it is highly recommended that dry nitrogen be
flowing through the joints during brazing to
prevent internal oxidation and scaling. Copper
oxides, internal to the system can damage the
compressors bearings and seals, block small
orifices and microchannels or otherwise damage
components.
CAUTION:
When performing brazing operations always
protect the system components and seals from
the possibility of heat damage. Remove all
caps, plugs and Schrader valve cores on piping
system components just prior to assembly and
brazing. Use good brazing practices to protect
components from the heat and flame of the
brazing torch.
After outdoor and indoor unit placement has been determined,
route refrigerant tubing between the equipment in accordance
with sound installation practices.
• Refrigerant tubing should be routed in a manner that
minimizes the length of tubing and the number of bends in
the tubing. If precise forming of refrigerant lines is required,
a copper tubing bender is recommended. Avoid sharp bends
and contact of the refrigerant lines with metal surfaces.
• Refrigerant tubing should be supported in a manner that the
tubing will not vibrate or abrade during system operation.
• Tubing should be kept clean of foreign debris during
installation.
• Every effort should be made by the installer to ensure that
the field installed refrigerant containing components of
the system have been installed in accordance with these
instructions and sound installation practices to insure
reliable system operation and longevity.
• The maximum recommended interconnecting refrigerant
line lengths is 75 ft. and the vertical elevation difference
between the indoor and outdoor sections should not exceed
20 ft.
• A filter dryer is provided with the unit and must be installed
in the liquid line of the system. If the installation replaces a
system with a filter dryer already present in the liquid line,
the filter dryer must be replaced with the one supplied with
the unit. The filter dryer must be installed in strict accordance
with the manufacturer’s installation instructions.
• Optional equipment such as liquid line solenoid valves,
low ambient, etc., should be installed in strict accordance
with the manufacturer’s installation instructions.
• After the completion of all brazing operations and when
the components have been properly cooled, replace all the
seals, Shrader cores and caps which had been previously
removed. It is recommended that all seals be either
lubricated with a light coat of refrigerant oil. Always verify
that oil applied matches the oil type listed on the compressor
nameplate. A thread sealant which is compatible with
the system refrigerant and oil can be sparingly applied if
desired.
CAUTION:
If repairs are necessary to the refrigerant line-
set or indoor setup after the initial installation,
then when servicing, cover or seal openings to
minimize the exposure of the refrigerant system
to air to prevent accumulation of moisture and
other contaminants.
REFRIGERANT CHARGING
After refrigerant line connections and expansion device
installation are completed, it is required that you leak check
and evacuate the indoor section and all line connections
(using proper methods) before finalizing the full system
refrigerant charge.
WARNING:
*SH3ME4MSplitSystemHeatPumps are shipped
charged with R410A refrigerant and ready
for installation. If repairs make it necessary
for evacuation and charging, it should only
be attempted by qualified trained personnel
thoroughly familiar with this equipment. Under
no circumstances should the owner attempt to
install and/or service this equipment. Failure to
comply with this warning could result in property
damage, personal injury, or death.
Note: additional charging instructions located near the end
of this document. (See page 7)
• Refer to the Quick Reference Data sheet for additional
charging information for this unit with the approved Nortek
indoor units. For reference, these units are listed in the
AHRI Directory with all approved combinations of indoor
coils and units. Installing these outdoor units on systems
that combine it with an indoor coil or unit not listed there, is
not recommended. When approved combinations of indoor

5
operate within the airflow and other operational parameters
prescribed in all of the units provided instructions and
technical specifications.
• Installation of this outdoor unit with other, non-listed
indoor unit combinations may require different airflows,
expansion devices, charge values and system setup from
the instructions provided here and with this unit. Nortek
does not recommend the use of this product in unlisted
combinations, and the system performance and efficiency
values of unlisted unit combinations may be different than
the listed product combinations.
• *SH3ME4M outdoor units with non-AHRI listed indoor coils
are not recommended. Deviations from rated airflows or
non-listed combinations may require modification to the
expansion device and refrigerant charging procedures for
proper and efficient system operation.
• The refrigerant charge can be checked and adjusted through
the service ports provided external to the outdoor unit. Use
only gage line sets which have a “Schrader” depression
device present to actuate the valve.
• An automatic high-pressure switch is factory-installed
installed in these units and is located on the discharge
line after the unit's compressor. This switch is designed to
protect the system when very high pressures occur during
abnormal conditions. Under normal conditions, the switch
is closed. If the system pressure rises to 650 psig, then
the switch will open and de-energize the contactor coil
in the outdoor unit. The switch will close again once the
liquid pressure decreases to 460 psig and allow the unit
to restart.
• An automatic low-pressure switch is factory-installed
on these units and is located on the suction line. This
auto-reset switch is designed to protect the system from
abnormal operation and events that could otherwise harm
the compressor. When the refrigeration system is at normal
pressures, the switch will be closed. If the compressor
suction pressure falls below 20 psig, the switch will open.
If the compressor suction pressure then rises to 35 psig,
the switch will automatically re-close.
• These outdoor heat-pump units have an Anti-short cycle
control incorporated into the defrost control board. This
control will only allow the compressor to restart 5 minutes
after the last call for operation was terminated.
• These outdoor heat-pumps units have been configured
with a compressor crankcase heater (CCH) that will
operate when the compressor is not energized. It is highly
recommended to allow the CCH to operate for 24 hours
prior to the initial unit start-up.
• These outdoor heat-pump units have been configured
with an outdoor thermostat switch in the control panel
compartment for compliance with US 24 CFR § 3280.714
(2022) requirements on Manufactured Housing Applications
with electrical resistance heating means. The SPST switch
will be open when ambient temperatures are above 40F and
will close at 25F. Refer to the Low Voltage Connections
Section for additional information.
• These heat-pump units have an additional Schrader port
on the compressor suction line located on the lower service
panel of the unit, above the refrigerant line connections.
This will allow a qualified technician to make a suction DP
measurement across the system accumulator and reversing
valve, or for the true compressor SH to be measured.
ELECTRICAL WIRING
WARNING:
To avoid risk of electrical shock, personal
injury, or death, disconnect all electrical power
to the unit before performing any maintenance
or service. The unit may have more than one
electrical supply.
Label all wires prior to disconnection when
servicing the unit. Wiring errors can cause
improper and dangerous operation.
• All electrical connections must be in compliance with
all applicable local codes and ordinances, and with
the current revision of the National Electric Code
(ANSI/NFPA 70).
• For Canadian installations the electrical connections and
grounding shall comply with the current Canadian Electrical
Code (CSA C22.1 and/or local codes).
Pre-Electrical Checklist
√Verify that the voltage, frequency, and phase of the supply
source match the specifications on the unit rating plate.
√Verify that the service provided by the utility is sufficient
to handle the additional load imposed by this equipment.
Refer to the unit wiring label for proper voltage wiring.
√If replacing an existing unit, verify that the: current wiring,
unit disconnect and circuit breaker is properly sized and
rated for the new units requirements. Verify that information
with the MCA and MOP values on the unit nameplate.
√Verify factory wiring is in accordance with the unit wiring
diagrams Figure 6 (page 10)and Figure 7 (page 11).
Inspect for loose connections.
Line Voltage
• A wiring diagram is located on the inside cover of the
electrical box of the outdoor unit. The installer should
become familiar with the wiring diagram before making
any electrical connections to the outdoor unit.
• An electrical disconnect must be located within sight of and
readily accessible to the unit. This switch shall be capable
of electrically de-energizing the outdoor unit.
• Line voltage to the unit should be supplied from a dedicated
branch circuit containing the correct fuse or circuit breaker
for the unit. Incoming field wiring and minimum size of
electrical conductors and circuit protection must be in
compliance with information listed on the outdoor unit
data label. Any other wiring methods must be acceptable
to authority having jurisdiction.
• The outdoor unit requires electrical connections for its
incoming line voltage wiring, its safety ground wiring and
the low voltage control circuit wiring. Refer to the wiring
diagram for identification and location of outdoor unit
field wiring interfaces Figure 6 (page 10)and Figure 7
(page 11). Make all electrical connections in accordance
with all applicable codes and ordinances.
• Overcurrent protection must be provided at the branch
circuit distribution panel and sized as shown on the unit
rating label and according to applicable local codes. See
the unit rating plate for minimum circuit ampacity (MCA)
and maximum overcurrent protection (MOP) limits.

6
• Provide power supply for the unit in accordance with the
unit wiring diagram, and the unit rating plate. Connect the
line-voltage leads to the terminals on the contactor inside
the control compartment.
• Use only copper wire for the line voltage power supply to
this unit in strict accordance of the NEC (ANSI/NFPA 70),
applicable local codes, and the instructions provided with
the equipment. Use proper code agency listed conduit
and a conduit connector for connecting the supply wires
to the unit. Use of rain tight conduit is recommended.
• Optional equipment requiring connection to the power or
control circuits must be wired in strict accordance of the
NEC (ANSI/NFPA 70), applicable local codes, and the
instructions provided with the equipment.
Grounding
WARNING:
The unit cabinet must have an uninterrupted or
unbroken electrical ground to minimize personal
injury if an electrical fault should occur. Do not
use gas piping as an electrical ground!
This unit must be electrically grounded in accordance with
local codes or, in the absence of local codes, with the National
Electrical Code (ANSI/NFPA 70) or the CSA C22.1 Electrical
Code. Use the grounding lug provided in the control box for
grounding the unit.
Thermostat Connections
• Thermostat connections should be made in accordance
with the instructions supplied with the thermostat and the
indoor equipment.
Low Voltage Connections
• The outdoor unit is designed to operate from a 24 VAC
Class II control circuit. The control circuit wiring must comply
with the current provisions of the NEC (ANSI/NFPA 70)
and with applicable local codes having jurisdiction.
• The low voltage wires must be properly connected to the
units low voltage terminal block.
Thermostat
Red
White
Black
Air Handler
Outdoor
Heat
Pump
OUT
IN
R
W
C
O
Y
R
G
C
O
Y
O
C
R
W2
W2
Y1
IN
Green
G
W2
E
ODT
(Optional)
Figure 2. Typical Thermostat Connections
START UP & ADJUSTMENTS
Pre-Start Check List
√Verify that the outdoor unit is installed according to all
instructions in this document.
√Verify that the indoor unit is appropriate for use with the
refrigerant listed on the outdoor unit. And that it has the
proper design pressure for the outdoor unit equipment
type.
√Verify the indoor unit and thermostat have been installed
in accordance with that equipment’s instructions.
√Verify line voltage power leads are securely connected and
that both indoor and outdoor units are properly grounded.
√Verify that the power supplied by branch circuits for both
the indoor and outdoor equipment is:
• the proper voltage for the equipment, and
• that the overcurrent protection device is properly
sized, and
• that the supply wiring is the correct gauge.
√Verify that the low voltage and thermostat wiring are securely
connected to the proper terminals for all equipment.
√Verify that the low voltage transformer has been properly
connected with that unit’s instructions.
√Verify that the refrigerant line-set has been properly routed
between the units, connected appropriately, is properly
secured and protected from damage, and that it has the
correct piping insulation installed.
√Verify that the refrigerant system and lines are leak free by
inspection with a leak detector or the soap-bubble method.
√Verify that any attached indoor ducting has been properly
installed and sealed.
√Verify that the indoor condensate drain line and trap are
properly installed and functioning.
√Verify that all removable panels have been re-installed,
and all cabinet enclosures and fan guards are secure.
√Verify that the air filters are clean and properly installed.
√Verify that the thermostat is set to the stand-by, or off
setting. And the fan switch is set to automatic or off.
Start-Up Procedures
The thermostat's function mode should be set to OFF and
the fan mode should be set to AUTO. Close all electrical
disconnects to energize the system.
WARNING:
This unit is equipped with a crankcase heater.
Allow 24 hours prior to continuing the start up
procedures to allow for heating of the refrigerant
compressor crankcase. Failure to comply may
result in damage and could cause premature
failure of the system. This warning should be
followed at initial start up and any time the power
has been removed for 12 hours or longer.
Operating Temperatures
This equipment has been designed to operate for a large range
of ambient conditions, however: running the heat-pump in
• For applications utilizing the outdoor thermostatic switch
within these units, the installer shall need to wire in
the switch as appropriate for their application. Refer to
Figure 2 for typical configurations and the unit wiring
diagram as needed.

7
heating mode, at higher than 70°F ambient temperatures may
require the use of a Heat Pump Mild Weather Control Kit.
If an application is expected to require heating operation during
mild ambient temperatures the systems liquid line pressures
should be inspected during these periods of operation. If the
liquid line pressure is 530 psig or greater, then the Heat Pump
Mild Weather Control Kit is required to be installed on the
system. Alternately, the control system could be configured
to utilize the emergency or auxiliary heating means in order
to maintain reliable system operation.
Air Circulation - Indoor Blower
1. Set the thermostat system mode on OFF and the fan mode
to ON.
2. Verify the blower runs continuously. Check the air delivery
at the supply registers and adjust register openings for
balanced air distribution. If insufficient air is detected,
examine ductwork for leaks or obstructions.
3. Set the thermostat fan mode to AUTO and verify the blower
stops running.
Short Cycle Protection
1. Set the thermostat system mode to COOL. Observe the
temperature setting of the thermostat and gradually raise
the set-point temperature until the unit de-energizes.
2. Immediately lower the set point temperature of the
thermostat to its original setting and verify that the indoor
blower is energized and outdoor unit remains de-energized.
3. After approximately 5 minutes, verify the outdoor unit
energizes and the temperature of the discharge air is
cooler than the room temperature.
System Cooling
1. Set the thermostat’s system mode to COOL and the fan
mode to AUTO. Gradually lower the thermostat temperature
setpoint below room temperature and verify the outdoor
unit and indoor blower energize.
2. Verify blower wheel is spinning in direction indicated by
arrow. Feel the air being circulated by the indoor blower
and verify that it is cooler than ambient temperature. Listen
for any unusual noises. If unusual sounds occur, determine
the source of the noise and correct as necessary.
3. Verify HI and LO refrigerant pressures.
4. Allow the system to operate for several minutes and then
set the temperature selector above room temperature.
Verify the fan and compressor cycle off with the thermostat.
NOTE: The blower should also stop unless fan switch is
set to the ON position.
System Heating
1. Set the thermostat's system mode to HEAT and the
temperature mode to below room temperature.
2. Verify the outdoor unit and indoor fan stop running. After
5 minutes, increase the temperature on the thermostat to
it's maximum setting.
3. Verify the outdoor unit and indoor blower energize. Feel
the air being circulated by the indoor blower and verify
that it is warmer than ambient temperature. Listen for any
unusual noises. If unusual sounds occur, determine the
source of the noise and correct as necessary.
Defrost Control Board Test Pins
• Verify the Status Indicator (on the control board) against
the codes listed in Table 1 (page 7) to determine proper
diagnostic description.
• Terminals ‘R’ and ‘C’ must have 18-30 VAC present between
them for proper board operation.
• Board anti-short cycle timer can be bypassed by shorting
the test terminals for less than 1 second while there is a
call for heating or cooling.
• Forced defrost enabled when shorting the test terminals for
more than three seconds while there is a call for heating
or cooling. After short removed, defrost mode will be
terminated when conditions are met.
• Forced defrost can be maintained for up to 11 minutes by
continuously maintaining the short across the test terminals.
If held for over 11 minutes, the unit will stop and a flashing
‘dF’ will be indicated on the board.
• A continuous display of a fault code will indicate that the
fault is still active.
• A flashing fault code indicates that the fault has been
corrected but remains in memory for troubleshooting
purposes.
• Multiple fault codes are listed in order from the most recent
to the oldest. Only ten codes will be stored in memory.
• Faults will remain in the board memory for seven days
after the last fault is corrected.
• Faults can be cleared from memory by shorting the test
terminal momentarily while there is not a call for heating
or cooling.
Charging the Unit in AC mode
If the outdoor temperature is 65 degrees F or higher:
After completing the refrigerant line connections, leak
checking the system, and evacuating the indoor section
and all line connections (using proper methods), perform
the following steps:
1. Determine the recommended charge addition (if applicable)
for the system being installed. This information is in the
unit’s QRD (Quick Reference Data sheet).
2. Calculate the amount of additional refrigerant needed for
the line set length of the actual installation. This information
is on the first page of the unit’s QRD (Quick Reference
Data sheet).
3. Weigh in the additional charge amounts determined by
step 1 and 2 above.
4. Adjust the charge to match the superheat (for fixed orifice
systems) or subcooling (for TXV systems). There are three
different resources for doing this:
Table 1. Defrost Control Board Status Indicators
STATUS
INDICATOR
STATUS
TYPE
DIAGNOSTIC
DESCRIPTION
C1 Operating Status Cooling, 1st Stage
C2 Operating Status Cooling, 2nd Stage
H1 Operating Status Heating, 1st Stage
H2 Operating Status Heating, 2nd Stage
SC Operating Status Anti Short Cycle Timer
DF Operating Status Defrost
_. Operating Status Power on, no call for operation
01 Fault Pressure switch, low
02 Fault Pressure switch, high
03 Fault Temperature Sensor, Ambient
04 Fault Temperature Sensor, Coil
05 Fault Board
OF
(FLASHING) Input Error Forced defrost - test short applied
longer than 11 minutes

8
a.) The chargecalculator.com website. This will walk
you through the charging process step by step.
b.) The charging tables on the inside of the outdoor
unit’s electrical box cover panel. These tables
provide superheat targets for fixed orifice systems
and subcooling targets for TXV systems. The system
should be charged so that the measured superheat/
subcooling are within 1 degree F of the target listed
in the table.
For fixed orifice systems:
• If your measured superheat at the suction valve is
LESS THAN the recommended superheat value
in the table then REMOVE refrigerant.
• If your measured superheat at the suction valve
is GREATER THAN the recommended superheat
value in the table then ADD refrigerant.
For TXV systems:
• If your measured subcooling at the liquid valve is
LESS THAN the recommended subcooling value
in the table then ADD refrigerant.
• If your measured subcooling at the liquid valve is
GREATER THAN the recommended subcooling
value in the table then REMOVE refrigerant.
c.) The charging tables in the Supplemental Charging
Information, can be found online in the literature
library. The tables can also be accessed by scanning
the QR code on the unit’s electrical panel. The
pressures listed in these tables are for reference only
and are to be used in troubleshooting a system. The
system should be charged to match the superheat
or subcooling targets as previously noted and not
to match the system pressures. Follow the same
procedure described in 4b above.
If the outdoor temperature is between 35 degrees F and
65 degrees F:
After completing the refrigerant line connections, leak
checking the system, and evacuating the indoor section
and all line connections (using proper methods), perform
the following steps:
1. Determine the recommended charge addition (if applicable)
for the system being installed. This information is in the
unit’s QRD (Quick Reference Data sheet).
NOTE: One half of the unit should be covered corner to corner.
Figure 3. Blocked Off Outdoor Fan Discharge
2. Calculate the amount of additional refrigerant needed for
the line set length of the actual installation. This information
is on the first page of the unit’s QRD (Quick Reference
Data sheet).
3. Weigh in the additional charge amounts determined by
step 1 and 2 above.
4. Block off the discharge of the outdoor fan. NOTE: One half
of the unit should be covered corner to corner as shown
in Figure 3.
5. With the unit in cooling mode, Adjust the charge to match
the superheat (for fixed orifice systems) or subcooling (for
TXV systems). There are two different resources for doing
this:
a.) The chargecalculator.com website. This will walk
you through the charging process step by step.
b.) The low ambient charging tables on the inside of
the outdoor unit’s electrical box cover panel. These
tables provide superheat targets for fixed orifice
systems and subcooling targets for TXV systems.
The system should be charged so that the measured
superheat/subcooling are within 1 degree F of the
target listed in the table.
For fixed orifice systems:
• If your measured superheat at the suction valve is
LESS THAN the recommended superheat value
in the table then REMOVE refrigerant.
• If your measured superheat at the suction valve
is GREATER THAN the recommended superheat
value in the table then ADD refrigerant.
For TXV systems:
• If your measured subcooling at the liquid valve is
LESS THAN the recommended subcooling value
in the table then ADD refrigerant.
• If your measured subcooling at the liquid valve is
GREATER THAN the recommended subcooling
value in the table then REMOVE refrigerant
If the outdoor temperature is below 35 degrees F:
After completing the refrigerant line connections, leak
checking the system, and evacuating the indoor section
and all line connections (using proper methods), perform
the following steps:
1. Determine the recommended charge addition (if applicable)
for the system being installed. This information is in the
unit’s QRD (Quick Reference Data sheet).
2. Calculate the amount of additional refrigerant needed for
the line set length of the actual installation. This information
is on the first page of the unit’s QRD (Quick Reference
Data sheet).
3. Weigh in the additional charge amounts determined by
steps 1 and 2 above.
4. Return to the system when the outdoor temperature is 35
degrees F or higher and follow the steps defined in step 4
of the “If the outdoor temperature is between 35 degrees
and 65 degrees F" or "If the outdoor temperature is 65
degree F or higher” sections above as applicable.

9
Figure 4. Panel Removal
DETAIL A
DETAIL B
Figure 5. Panel Installation
HEAT PUMP MAINTENANCE
WARNING:
To prevent electrical shock, personal injury, or
death, disconnect all electrical power to the unit
before performing any maintenance or service.
The unit may have more than one electrical
supply.
Proper maintenance is important to achieve optimum
performance from the Heat Pump. The ability to properly
perform maintenance on this equipment requires certain
mechanical skills and tools. If you do not possess these
skills, contact your dealer for maintenance. Consult your
local dealer about the availability of maintenance contracts.
Routine maintenance should include the following:
• Inspect and clean or replace air filters at the beginning of
each heating and cooling season, or more frequently if
required.
• Inspect the condensate drains in the units basepan and
the outdoor coil at the beginning of each cooling season.
Remove any debris. Clean the outdoor coil and louvers
as necessary using a mild detergent and water. Rinse
thoroughly with water.
• To access the outdoor coil on units equipped with louvered
panels, refer to Figure 4 for panel removal and Figure 5
for panel installation.
• Inspect the electrical connections for tightness at the
beginning of each heating and cooling season. Service
as necessary.
• Do not attempt to add additional oil or grease to motors
unequipped with oil tubes or grease fittings. Most outdoor
unit motors are manufactured with sealed, permanently
lubricated bearings that are designed for the life of the
equipment without maintenance.
• The compressor is hermetically sealed and shipped from
the factory with the proper oil charge for most installations.
Lubricating oil should only be added by trained personnel
and is typically only required for long line-sets or tall riser
applications.
Panel Removal
1. Remove screws securing the panel.
2. Slide the panel up towards the top pan in order to clear
the bottom flange from the base pan. See Figure 4.
3. Swing the bottom of the panel out and pull the panel down
to remove it from the unit.
Panel Installation
1. Insert the top corners of side panel flanges into the corner
post channels as shown in Detail A in Figure 5.
2. Slide the panel up into the top pan. (You may need to push
on the center of the panel at the top in order to clear the
top pan edge).
3. Swing the panel in and push down until the panel is resting
on the top edge of the base pan wall as shown in Detail
B.
4. Install screws into the panel to secure it to the unit.

10
Figure 6. Wiring Diagram for *SH3ME4M Units with Rotary Compressors (2.0 & 2.5T)
ELECTRICAL DIAGRAMS & TABLES
OUTDOOR
FAN MOTOR
R
C
CC
(SINGLE PHASE)
FIELD SUPPLY
L1 GRD
L2
GROUNDING
SCREW
T1 T2
L1 L2
CONTACTOR
C
S
R
COMPRESSOR
Y2 IN
FAN2 CCH2CCH1
W2 IN
Y1 IN CR
HOT1
HOT2
(24V COM)
OUTDOOR TEMP
Y1 OUT
RV1
O
LP1LP2HP1HP2
S
CC
DEFROST CONTROL BOARD
C
H
F
DUAL
CAPACITOR
BLACK
YELLOW/ YELLOW BLACK
BLACK/
BLACK WHITE
ORANGE
BLUE
COIL#1 TEMP
RV2
CCH
RVS
HPS
COIL SENSOR
HGBP
AMB SENSOR
Y R O C W2 E
THERMOSTAT
FAN1
W2 OUT
Y2 OUT
BLACK
ODT
LPS
RED/RED BLACK
PEV
BLUE
BLUE
ODT
CC Y2 IN
FAN1 FAN2 CCH2 CCH1
W2 INY1 IN CR
HOT1
HOT2
(24V COM)
OUTDOOR TEMP
Y1 OUT
RV1
O
LP1LP2HP1HP2
COIL#1 TEMP
RV2
Split System Heat Pump (Outdoor Section) Single Phase
WIRING DIAGRAM
NOTES:
1. Disconnect all power before servicing. 2. For supply connections use copper conductors only. 3. Not suitable on systems that exceed 150 volts to ground 4. For replacement wires use conductors suitable for 105˚ C. 5. For ampacities and overcurrent protection, see unit rating plate. 6. Connect to 24 vac/40va/class 2 circuit. See furnace/air handler installation instructions for control circuit and optional relay/transformer kits. 7. Caution: The Low Voltage wiring shall NOT be grounded to this unit.
1. Couper le courant avant de faire letretien. 2. Employez uniquement des conducteurs en cuivre. 3. Ne convient pas aux installations de plus de 150 volt a la terre.
10414090
2/17
FIELD WIRING
LEGEND:
LOW VOLTAGE
HIGH VOLTAGE
DUAL CAPACITOR
H
C
F
COMPRESSOR
OUTDOOR FAN MOTOR
R
C
S
L1
T1
L2
T2
DEFROST CONTROL BOARD
208/230V
R
C
SCCH
RVS
LPS
HPS
HGBP
COIL SENSOR
AMB SENSOR
Y ROC W2 E
THERMOSTAT
AMB - Ambient CC - Contactor Coil CCH - Crankcase Heater HGBP - Hot Gas By Pass Valve HPS - High Pressure Switch LPS -Low Pressure Switch ODT - Outdoor Thermostat PEV – Pressure Equalization Valve RVS - Reversing Valve Solenoid
W2 OUT
Y2 OUT
SEE NOTES
6 AND 7
SEE NOTES
6 AND 7
PEV
BROWN
BLACK
BLACK
YELLOW
BLACK BLACK
BLACK
BROWN

11
Figure 7. Wiring Diagram for *SH3ME4M Units with Scroll Compressors (3.0, 3.5 & 4.0T)
OUTDOOR
FAN MOTOR
R
C
CC
C
H
F
DUAL
CAPACITOR
(SINGLE PHASE)
FIELD SUPPLY
L1 GRD
L2
GROUNDING
SCREW
C
S
T1 T2
L1 L2
CONTACTOR
R
COMPRESSOR
Y2 IN
FAN2 CCH2 CCH1
W2 IN
Y1 IN CR
HOT1
HOT2
(24V COM)
OUTDOOR TEMP
Y1 OUT
RV1
O
LP1LP2HP1HP2
S
CC
DEFROST CONTROL BOARD
BLACK
YELLOW/ YELLOW BLACK
BLACK/
BLACK WHITE
ORANGE
BLUE
COIL#1 TEMP
RV2
CCH
RVS
HPS
COIL SENSOR
HGBP
AMB SENSOR
YROC W2 E
THERMOSTAT
FAN1
W2 OUT
Y2 OUT
RED/RED BLACK
BLACK
ODT
LPS
ODT
CC Y2 IN
FAN1 FAN2 CCH2 CCH1
W2 INY1 IN CR
HOT1
HOT2
(24V COM)
OUTDOOR TEMP
Y1 OUT
RV1
O
LP1LP2HP1HP2
COIL#1 TEMP
RV2
Split System Heat Pump (Outdoor Section) Single Phase
WIRING DIAGRAM
NOTES: 1. Disconnect all power before servicing. 2. For supply connections use copper conductors only. 3. Not suitable on systems that exceed 150 volts to ground 4. For replacement wires use conductors suitable for 105˚ C. 5. For ampacities and overcurrent protection, see unit rating plate. 6. Connect to 24 vac/40va/class 2 circuit. See furnace/air handler installation instructions for control circuit and optional relay/transformer kits. 7. Caution: The Low Voltage wiring shall NOT be grounded to this unit.
1. Couper le courant avant de faire letretien. 2. Employez uniquement des conducteurs en cuivre. 3. Ne convient pas aux installations de plus de 150 volt a la terre.
10398350
7/21
FIELD WIRING
LEGEND:
LOW VOLTAGE
HIGH VOLTAGE
DUAL CAPACITOR
H
C
F
COMPRESSOR
OUTDOOR FAN MOTOR
R
C
S
L1
T1
L2
T2
DEFROST CONTROL BOARD
208/230V
R
C
SCCH
RVS
LPS
HPS
HGBP
COIL SENSOR
AMB SENSOR
YROC W2 E
THERMOSTAT
AMB SENSOR - Ambient Sensor CC - Contactor Coil CCH - Crankcase Heater HPS - High Pressure Switch HGBP - Hot Gas By Pass Valve RVS - Reversing Valve Solenoid ODT - Outdoor Thermostat * HARD START KIT (OPTIONAL) LPS -Low Pressure Switch
W2 OUT
Y2 OUT
(Replaces 10252920)
SEE NOTES
6 AND 7
SEE NOTES
6 AND 7
BROWN
BLACK
BLACK
YELLOW
BLACK BLACK
BLACK
BROWN

INSTALLATION CHECKLIST
INSTALLATION ADDRESS:
CITY: STATE:
UNIT MODEL #:
UNIT SERIAL #:
INSTALLER NAME:
CITY: STATE:
Unit Installed Minimum clearances per
Figure 1 (page) 3?YES NO
Has the owner’s information been
reviewed with the customer? YES NO
Has the Literature Package been left
with the unit? YES NO
REFRIGERATION SYSTEM
Was unit given 24 hr warm up period
for crankcase heaters? YES NO
Stage-1 Liquid Pressure (high side):
Stage-1 Suction Pressure (low side):
Specifications & illustrations subject to change without notice or incurring obligations (07/22).
O’Fallon, MO, © Nortek Global HVAC LLC 2022. All Rights Reserved.
REPLACEMENT PARTS
Replacement parts are available through your distributor.
Please have the complete model and serial number of the
unit when ordering replacement parts.
ELECTRICAL:
Capacitors Temperature Limit Switches
Compressors Thermostats
Contactors Time Delay Relays
Pressure Switches Transformers
Relays
MOTORS:
Blower Motor
Fan Motor
COMPONENTS:
Blower Assembly Fan Grille
Cabinet Panels Filter/Driers
Expansion Valves
10434490
(NEW)
ELECTRICAL SYSTEM
Electrical connections tight? YES NO
Line voltage polarity correct? YES NO
Rated Voltage:
Has the thermostat been calibrated? YES NO
Is the thermostat level? YES NO
Is the heat anticipator setting correct?
(If Applicable) YES NO