Johnson Controls HMH7 Series User manual

Johnson Controls Ducted Systems
Installation Manual: HMH7 Series - 17
SEER Horizontal Discharge Modulating
Heat Pump
York International Corporation, 5005 York
Drive, Norman, OK 73069
2021-02-03
6046972-UIM-A-0221
Supersedes: Nothing
A

2 Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump
Johnson Controls Ducted Systems

Contents
ContentsGeneral.................................................................................... 5
Safety....................................................................................... 5
Inspection......................................................................... 5
Limitations........................................................................ 6
Piping considerations...................................................... 6
Unit installation...................................................................... 8
Transportation and handling......................................... 8
Selecting a location for installation............................... 8
Installing the drain elbow and drain hose.................... 9
Installing the outdoor unit............................................ 10
Affixing the brand label................................................. 10
Precautions for brazing of lines................................... 11
Connecting the refrigerant lines.................................. 11
Refrigerant charging..................................................... 12
Electrical connections.......................................................... 13
Connecting HMH72B24 and HMH72B36 wiring......... 15
Connecting HMH72B48 and HMH72B60 wiring......... 16
Electrical data................................................................. 17
Performing a test run.................................................... 17
Technical information.......................................................... 18
Refrigerant cycle............................................................ 18
Wiring diagrams............................................................. 22
Control board................................................................. 24
Field settings.................................................................. 28
Running a parameter query......................................... 29
Oil trap............................................................................. 30
Control mode.................................................................. 31
Sensor parameter.......................................................... 31
Troubleshooting................................................................... 32
Checking components................................................... 32
Fault codes...................................................................... 35
Troubleshooting guide.................................................. 46
Start-up sheet....................................................................... 49
Johnson Controls Ducted Systems
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 3

4 Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump
Johnson Controls Ducted Systems

General
Read all sections of this manual and keep the manual
for future reference.
WARNING: Cancer and Reproductive Harm –
www.P65Warnings.ca.gov.
The units are tested in accordance with the following:
The outdoor units are designed to be connected to a
matching indoor coil with sweat connect lines. This unit
is to be matched with one ducted indoor unit and is not
designed for application in a ductless configuration.
Refer to the Technical Guide for permissible system
configurations. Sweat connect units are factory charged
with refrigerant for a nominal sized matching indoor coil
plus 15 ft of field-supplied lines.
Safety
Read these safety precautions carefully to ensure correct
installation.
Note the following:
• You must match the outdoor unit with an indoor unit
with refrigerant R-410A.
• Use the specified filter drier on the liquid pipe when
connecting the units.
• Carefully file the indoor and outdoor unit manuals
away for future reference.
Understand and pay particular attention to the signal
words DANGER, WARNING, or CAUTION.
DANGER indicates an imminently hazardous situation,
which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation,
which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation,
which, if not avoided may result in minor or moderate
injury. It is also used to alert against unsafe practices and
hazards involving only property damage.
WARNING
Incorrect installation may create a condition where the
operation of the product could cause personal injury
or property damage. Incorrect installation, adjustment,
alteration, service, or maintenance can cause injury
or property damage. Refer to this installation manual
for assistance or for additional information, consult a
qualified contractor, installer, or service agency.
CAUTION
This heat pump uses R-410A refrigerant. R-410A
systems operate at higher pressures than R-22
systems. Do not use R-22 service equipment
or components on R-410A equipment. Service
equipment must be rated for R-410A.
CAUTION
This product must be installed in strict compliance
with the enclosed installation instructions and any
applicable local, state, and national codes including,
but not limited to building, electrical, and mechanical
codes.
Inspection
Inspect the unit immediately after receiving it for possible
damage during transit, including copper distributor lines
that may have shifted and are touching either copper
lines or the cabinet. If damage is evident, the extent of the
damage must be noted on the carrier’s delivery receipt.
A separate request for inspection by the carrier’s agent
must be made in writing. Contact the local distributor for
more information.
Requirements for installing or servicing R-410A
equipment
• Gauge sets, hoses, refrigerant containers, and
recovery system must be designed to handle the POE
type oils, and the higher pressures of R-410A.
• Manifold sets must be high side and low side with
low side retard.
• All hoses must have a 700 psig service pressure
rating.
• Leak detectors must be designed to detect HFC
refrigerant.
• Recovery equipment (including refrigerant recovery
containers) must be specifically designed to handle
R-410A.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 5
Johnson Controls Ducted Systems

Limitations
Install the unit in accordance with all national, state, and
local safety codes, and the following limitations:
• Observe the limitations for the indoor unit, coil, and
appropriate accessories.
• Do not install the outdoor unit with any duct work in
the air stream. The outdoor fan is the propeller type
and is not designed to operate against any additional
external static pressure.
• Observe the maximum and minimum conditions for
operation to ensure a system that gives maximum
performance with minimum service.
Table 1: Minimum and maximum operating limit
conditions
Outdoor coil °F (°C) Indoor coil °F (°C)
Air
temperature DB cool DB heat WB cool DB heat
Minimum 35 (2) -5 (-21) 57 (14) 50 (10)
Maximum 122 (50) 75 (24) 72 (22) 80 (27)
Note: See the NOTICE in the Reduced capacity
conditions section.
Reduced capacity conditions
NOTICE
Inverter temperature protection
If excessive inverter temperatures are sensed, the
compressor speed/capacity is reduced until an
acceptable condition is reached. When the inverter
temperature returns to an acceptable level, the system
returns to normal operation.
NOTICE
Overcurrent and undercurrent protection
If a low or high current condition is sensed, the
compressor speed/capacity is reduced until an
acceptable current level is reached. When the system
reaches an acceptable current level, the compressor
and fan return to normal operating conditions.
NOTICE
Overvoltage and undervoltage protection
If a low or high supply voltage condition is sensed
(below 187 VAC or above 265 VAC), the compressor
speed/capacity is automatically reduced until an
acceptable voltage level is reached. When an
acceptable voltage level is sensed, the system
automatically returns to a normal state of operation.
NOTICE
Low ambient protection
Cooling mode: The unit automatically adjusts to
maintain cooling operation in outdoor ambient
conditions down to 35°F (2°C). The unit reduces
capacity and low ambient protection (cooling mode) or
cycles off if asked to provide cooling when the outdoor
temperature is at or below these conditions. Heating
mode: The unit provides compressor heat down to an
outdoor ambient temperature of -5°F (-29°C). As the
outdoor ambient temperature reduces, available heat
reduces for all air source heat pumps.
Piping considerations
When using more than 15 ft of interconnecting tubing,
see Table 2 for charging. For long-line applications,
interconnecting lines over 100 ft must be installed with
liquid line solenoid. Refer to the Piping Application Guide
for more information.
Figure 1: Refrigerant piping
Table 2: Refrigerant piping
Maximum
pipe length
(L)
Maximum
height
difference
(H)
Additional
refrigerant
- exceeding
15 ft (4.6 m)
Model
ft (m) ft (m) oz/ft (g/m)
HMH72B24 164 (50) 98 (30) 0.38 (11)
HMH72B36 246 (75) 98 (30) 0.38 (11)
HMH72B48,
HMH72B60 246 (75) 98 (30) 0.60 (17)
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump6
Johnson Controls Ducted Systems

Liquid-line filter drier
This unit requires a bi-flow liquid line filter drier installed
external to the unit. This is included in the wiring
accessory kit HMH7AK001 required for installation.
R-410A filter-drier
Source 1 Part Number
Apply with models
S1-404101 All
NOTICE
Using a larger than specified line size could result
in oil return problems. Using too small a line results
in loss of capacity and other problems caused by
insufficient refrigerant flow. For the heat pump,
maintain level horizontal refrigerant lines between the
indoor unit and the outdoor unit to facilitate sufficient
oil return.
Add-on replacement/retrofit
When using this unit as a replacement for an existing
R-410A unit, these are matched systems. Replace
the indoor coil and the outdoor unit. Perform the
following steps to ensure correct system operation and
performance.
1. Change out the indoor coil to an approved R-410A
coil/air handling unit combination with the
appropriate metering device.
2. Change out the lineset when replacing an R-22 unit
with an R410A unit to reduce cross-contamination of
oils and refrigerants. If change-out of the lineset is
not practical, take the following precautions:
a. Inspect the lineset for kinks, sharp bends, or
other restrictions, and for corrosion.
b. Determine if there are any low spots that
might be serving as oil traps.
c. Flush the lineset with a commercially available
flush kit to remove as much of the existing oil
and contaminants as possible.
3. If replacing the outdoor unit because of a
compressor burnout, replace the refrigeration lines
or, at a minimum, thoroughly flush the lines with a
commercially available flush kit.
WARNING
Never install a suction-line filter drier in the liquid line
of an R-410A system. Failure to follow this warning
can cause a fire, injury, or death.
Precautions for line installation
Adhere to the following during line installation:
• Connect the outdoor unit to the indoor coil using
field supplied refrigerant grade (ACR) copper tubing
that is internally clean and dry. Units must only be
installed with the tubing sizes for approved system
combinations as specified in the Tabular Data Sheet.
The charge given is applicable for total tubing
lengths up to 15 ft (4.6 m).
• Install the refrigerant lines with as few bends as
possible. Ensure not to damage the couplings or
kink the tubing. Use clean hard drawn copper tubing
where no appreciable amount of bending around
obstruction is necessary. If soft copper must be
used, ensure to avoid sharp bends that may cause a
restriction.
• Install the lines so that they do not obstruct service
access to the coil, indoor section, or filter.
• Isolate the refrigerant lines to minimize noise
transmission from the equipment to the structure.
• Insulate the vapor line with a minimum of 1/2-in.
foam rubber insulation (Armaflex or equivalent).
Insulate liquid lines that may be exposed to direct
sunlight, high temperatures, or excessive humidity.
• Tape and suspend the refrigerant lines correctly. Do
not allow tube metal-to-metal contact. See Figure 2.
Figure 2: Installation of vapor line
• Use PVC piping as a conduit for all underground
installations as shown in Figure 3. Keep buried lines
as short as possible to minimize the build up of liquid
refrigerant in the vapor line during long periods of
shutdown.
Figure 3: Underground installation
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 7
Johnson Controls Ducted Systems

• Pack fiberglass insulation and a sealing material such
as permagum around refrigerant lines where they
penetrate a wall to reduce vibration and retain some
flexibility.
Additional refrigerant charge
The outdoor unit is precharged with enough R-410A
refrigerant for the outdoor unit, the smallest indoor unit,
and 15 ft of lineset. Additional refrigerant per foot of
additional lineset is 0.38 oz for the 24k and 36k models,
and 0.60 oz for the 48k and 60k models (see Table 2).
Refer to the Tabular Data Sheet for more information on
precharge amount and indoor combinations.
CAUTION
When installing the pipe through the wall, secure a cap
at the end of the pipe. Do not place the pipe directly on
the ground.
Unit installation
If installing the unit on a hot sun exposed roof or a
paved ground area that is seasonally hot, raise the unit
sufficiently above the roof or ground to avoid taking the
accumulated layer of hot air into the outdoor unit, which
can cause the unit to derate prematurely.
Transportation and handling
1. Route two lifting slings under the unit as shown
in Figure 4. If there are no packaging materials,
protect the unit with cloth or paper. See Figure 5.
Figure 4: Handling with packaging
Figure 5: Handling without packaging
2. Ensure the unit is balanced and, if safe to do so,
carefully lift the unit up.
Selecting a location for installation
Adhere to the following when selecting a location for
installation:
• Install and anchor the unit on a solid base that is 2 in.
above grade and does not shift or settle, which could
cause strain on the refrigerant lines and possible
leaks. Maintain the clearances shown in Figure 6
and install the unit horizontally in a level position.
The base pad must not come in contact with the
foundation or side of the structure because sound
may transmit to the residence.
• Before starting the installation, select and check the
suitability of the location for the indoor and outdoor
units.
• Ensure that the outdoor unit is installed in an
appropriate location that limits exposure to wind,
rain, snow accumulation, and direct sunlight.
• Locate the outdoor unit away from bedroom
windows or other rooms where sound might be
objectionable.
• Provide ample clearance from shrubs to allow
adequate air to pass across the outdoor coil without
leaves or branches being pulled into the fan.
• Ensure that the outdoor unit has sufficient clearance
for air entrance to the outdoor coil, air discharge,
and service access.
• Keep the length of the refrigerant tubing between
the outdoor unit and the indoor coil as short as
possible to avoid capacity and efficiency losses.
Observe all limitations and clearance requirements.
• Elevate the unit sufficiently to prevent any blockage
of the air entrances by snow in areas where snow
may accumulate. Check the local weather bureau for
the expected snow accumulation in your area.
• Isolate the unit from rain gutters to avoid any
possible wash out of the foundation.
WARNING
The outdoor unit must not be installed in an area
where mud or ice could cause personal injury.
Roof installation
When installing units on a roof, the structure must
be capable of supporting the total weight of the unit,
including a pad, lintels, and rails, which must be used to
minimize the transmission of sound or vibration into the
conditioned space.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump8
Johnson Controls Ducted Systems

Wall mount installation
Ensure to mount the outdoor unit on a solid base that
is sloped to shed water, secure from settlement, and
isolated from the structural foundation or walls to prevent
sound and vibration transmission into the living space.
On occasion, site conditions may require the use of
direct wall mounted brackets to locate and support the
outdoor unit. In these applications, ensure to address unit
base pan support, structural integrity, safe access and
serviceability, as well as the possible sound and vibration
transmission into the structure. Wall mounting requires
three mounting brackets and is best served by a properly
engineered solution. Refer to the Price Pages for the
specific part number for your application.
Avoid the following places for installation where damage
to the outdoor section may occur:
• Where there is machine oil
• Coastal regions where the equipment is prone to
atmospheric corrosion
• Near hot springs where the equipment is prone to
sulfide gas corrosion
• In proximity to high-frequency or wireless
equipment
Figure 6: Minimum clearances when selecting a
location
Note: When operating the outdoor section in low
ambient conditions, follow these instructions:
• Never install the outdoor unit in a place where
its air inlet/outlet side may be exposed directly
to wind.
• To prevent exposure to wind, install the
outdoor unit with its air inlet side facing the
wall.
• To prevent exposure to wind, install a baffle
board on the air outlet side of the outdoor unit.
Installing the drain elbow and drain
hose
About this task:
Condensate water may drain from the outdoor unit when
the unit operates in heating mode. To avoid adverse
conditions in the area around the unit, install the included
drain elbow and a drain hose to drain out the condensate
water. Install the drain elbow and drain the hose before
the indoor and outdoor units are connected.
1. Connect the drain hose (field-supplied, 15 mm
inside diameter) as shown in Figure 7.
Figure 7: Drainage
Note: Do not use a drainage elbow in colder
climates. The drain may freeze and cause the
fan to stop running.
NOTICE
Heat pumps defrost periodically resulting in water
drainage. The unit must not be located where
water drainage may freeze and create a hazardous
condition, such as sidewalks and steps.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 9
Johnson Controls Ducted Systems

Installing the outdoor unit
1. Use washers when fastening the outdoor section at
the foundation bolts.
2. When fastening the outdoor section with the
foundation bolts, ensure that the anchoring
locations are as shown in Figure 8.
3. Fasten the outdoor section as shown in Figure 9.
4. Make sure to fasten the outdoor unit tightly and in
a horizontal position to prevent noise.
5. Do not drain condensate onto public places as this
may lead to slippery surfaces.
6. Use a strong base, made of concrete or similar, that
positions the outdoor section at least 2 in. from
the ground. This keeps the outdoor section dry
and reduces the chance of corrosion, which could
reduce the life span of the outdoor section. See
Figure 10.
Table 3: Anchoring locations
A B C D E F d
Model in. (mm) in. (mm) in. (mm) in. (mm) in. (mm) in. (mm) in. (mm)
HMH72B24 33 7/8 (860) 12 3/16 (310) 21 11/32 (542) 13 7/16 (341) 14 1/2 (368) 6 5/8 (168) 7/16–11/16
(11–17)
HMH72B36,
HMH72B48,
HMH72B60
37 3/8 (950) 13 3/8 (340) 22 7/8 (580) 14 15/16 (380) 16 1/4 (414) 7 1/4 (185) 5/8 (15)
Figure 8: Anchoring locations
Figure 9: Securing the unit
Note: If the bolt is too long or impedes any
future movement of the unit, cut it to a more
appropriate length.
Figure 10: Concrete base
Affixing the brand label
1. Find the brand label in the plastic bag attached to
the unit carton.
2. Remove the label backing and affix the brand label
in the area marked A in Figure 11, centered 1/2 in.
immediately below the tooling mark on the front
panel.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump10
Johnson Controls Ducted Systems

Figure 11: Brand label location
Precautions for brazing of lines
All outdoor unit and indoor coil connections are copper-
to-copper and must be brazed with a phosphorous-
copper alloy material such as Silfos-5 or equivalent. Do
not use soft solder. The outdoor units have reusable
service valves on both the liquid and vapor connections.
The total system refrigerant charge is retained within
the outdoor unit during shipping and installation. The
reusable service valves are provided to evacuate and
charge per this instruction. Serious service problems can
be avoided by taking adequate precautions to ensure an
internally clean and dry system.
CAUTION
The indoor coil is under inert gas pressure. Relieve
pressure from the coil by depressing the Schrader
core at the end of the suction manifold stub out. Dry
nitrogen must always be supplied through the tubing
while it is being brazed because the temperature
required is high enough to cause oxidation of the
copper, unless an inert atmosphere is provided.
The flow of dry nitrogen must continue until the joint
cools. Always use a pressure regulator and safety
valve to insure that only low pressure dry nitrogen
is introduced into the tubing. Only a small flow is
necessary to displace air and prevent oxidation.
Precautions for brazing of the service valve
• Wrap a wet rag around the service valve to prevent
heat damage, as shown in Figure 12.
• Protect all painted surfaces, insulation, and plastic
base during brazing.
• After brazing, cool the joint with a wet rag.
WARNING
This is not a backseating valve. The service access
port has a valve core. Opening or closing the valve
does not close the service access port. If the valve
stem is backed out past the chamfered retaining
wall, the O-ring can be damaged, causing leakage or
system pressure that could force the valve stem out of
the valve body, possibly causing personal injury.
Figure 12: Brazing the service valve
Connecting the refrigerant lines
About this task:
The valve can be opened by removing the plunger cap
and fully inserting a hex wrench into the stem, then
backing out counter-clockwise until the valve stem just
touches the chamfered retaining wall.
1. Remove the cap and Schrader core from both the
liquid and vapor service valve service ports at the
outdoor unit. Connect low pressure nitrogen to the
liquid line service port.
2. Braze the liquid line to the liquid valve at the
outdoor unit. Ensure to wrap the valve body with a
wet rag. Allow the nitrogen to continue flowing.
3. Carefully remove the plugs from the liquid and
vapor connections at the indoor coil.
4. Braze the liquid line to the indoor coil liquid
connection. Nitrogen should be flowing through
the indoor coil.
5. Slide the grommet away from the vapor connection
at the indoor coil. Braze the vapor line to the
indoor coil vapor connection. After the connection
has cooled, slide the grommet back into original
position.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 11
Johnson Controls Ducted Systems

6. Protect the vapor valve with a wet rag and braze
the vapor line connection to the outdoor unit.
The nitrogen flow should be exiting the system
from the vapor service port connection. After this
connection has cooled, remove the nitrogen source
from the liquid fitting service port.
7. Replace the Schrader core in the liquid and vapor
valves.
8. Leak test all refrigerant piping connections
including the service port flare caps to ensure they
are leak tight. Do not overtighten (between 40 in.·lb
and 60 in.·lb maximum).
NOTICE
Pressurize the lineset and the indoor coil to 250 psig
with dry nitrogen and leak test with a bubble type leak
detector. Then release the nitrogen charge. Do not
use the system refrigerant in the outdoor unit to purge
or leak test.
9. Evacuate the vapor line, indoor coil, and liquid line
to 500 microns or less.
NOTICE
If a leak is suspected, leak test with dry nitrogen to
locate the leak. Repair the leak and test again. To
verify that the system has no leaks, close the valve
to the vacuum pump suction to isolate the pump and
hold the system under vacuum. Watch the micron
gauge for a few minutes. If the micron gauge indicates
a steady and continuous rise, it is an indication of a
leak. If the gauge shows a rise, then levels off after
a few minutes and remains fairly constant, it is an
indication that the system is leak free but still contains
moisture and may require further evacuation if the
reading is above 500 microns.
10. Release the refrigerant charge into the system.
Open the liquid line service valve by removing the
plunger cap and back out the valve stem counter-
clockwise using a hex head wrench until fully open.
Then, open the vapor line service valve in the same
way. If the service valve is a ball type valve, use an
adjustable end wrench to turn the valve 1/4 turn to
open.
11. Replace the caps on the service ports. Do not
remove the flare caps from the service ports except
when necessary for servicing the system.
12. Replace the plunger caps finger tight, then tighten
an additional 1/12 turn (1/2 hex flat). Ensure to
replace the caps to prevent leaks.
CAUTION
Do not connect manifold gauges unless required to
mitigate an identified issue. Approximately 3/4 oz
of refrigerant is lost each time a standard manifold
gauge is connected.
WARNING
Never attempt to repair any brazed connections while
the system is under pressure. Personal injury could
result.
Refrigerant charging
CAUTION
Refrigerant charging must only be carried out by a
licensed qualified air conditioning contractor.
CAUTION
Compressor damage occurs if the system is
incorrectly charged. On new system installations,
charge the system as instructed in the Tabular Data
Sheet for the matched coil and follow the guidelines in
this instruction.
CAUTION
Do not leave the system open to the atmosphere. Unit
damage could occur due to moisture being absorbed
by the POE oil in the system. This type of oil is highly
susceptible to moisture absorption.
CAUTION
It is unlawful to knowingly vent, release, or discharge
refrigerant into the open air during repair, service,
maintenance, or the final disposal of this unit.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump12
Johnson Controls Ducted Systems

Electrical connections
General information and grounding
Note: This unit uses discrete thermostat wiring. Do
not interface with TTSCC, Hx™ , or Hx™3 thermostat
communication connections. It is possible to
interface with Hx™ or Hx™3 conventional terminals.
CAUTION
This equipment uses an inverter drive that stores
hazardous energy up to 5 min after power is removed.
Wait for more than 5 min before performing electrical
work after power is removed.
NOTICE
Local codes may require use of an ELB (Earth
Leakage Breaker) or RCD (Residual Current Device)
breaker. When required, use a breaker capable of
handling harmonics to prevent failure of the ELB or
RCD breaker.
Field connections wiring
About this task:
All field wiring must be in accordance with national
electrical codes (NEC) and local city codes.
1. Install the correct size weatherproof disconnect
switch outdoors and within sight of the unit, per
local codes.
2. Run the power wiring from the disconnect switch to
the unit.
3. Route the wires from the disconnect through the
power wiring exit provided and into the unit control
box as shown in Figure 15, Figure 16, Figure 17, and
Figure 18 for the various models.
4. Make the power supply connections to the supplied
terminal block.
5. Mount the thermostat 5 ft above the floor, where
it is exposed to normal room air circulation. Do not
place it on an outside wall or where it is exposed to
the radiant effect from exposed glass or appliances,
drafts from outside doors, or supply air grilles.
6. Route the 24-V control wiring (NEC Class 2) from
the outdoor unit to the indoor unit and thermostat.
Keep the low-voltage wiring 4 in. or more away from
the high-voltage wires that are leaving the control
box.
7. Wrap tape along the wire and seal any wiring holes
to prevent entry of condensate water and insects.
Tightly secure the power source wiring using the
cord clamp inside the unit.
8. See the unit-specific connection instructions below.
Table 4: Tightening torque of each screw
Screw Minimum [lb·ft
(N·m)]
Maximum [lb·ft
(N·m)]
M4 0.7 (1.0) 1.0 (1.3)
M5 1.5 (2.0) 1.8 (2.5)
M6 3.0 (4.0) 3.7 (5.0)
M8 6.6 (9.0) 8.1 (11.0)
M10 13.3 (18.0) 21.7 (23.0)
Note: Apply adhesive to rubber bushings when not
using conduit tubes to the outdoor unit.
General electrical checks
• Ensure that the field-selected electrical components
(main power switches, circuit breakers, wires,
conduit connectors, and wire terminals) have
been properly selected according to the electrical
data. Ensure that the components comply with the
National Electrical Code (NEC).
• Ensure the voltage of the power supply is within 10%
of nominal voltage and the ground is contained in
the power supply wires. If not, electrical parts may
be damaged.
• Ensure that the capacity of the power supply is of
sufficient size. If not, an abnormal voltage drop
when starting the unit may prevent the compressor
from operating.
• Ensure that the ground wire is connected.
• Ensure that the electrical resistance is more than
2 MΩ, by measuring the resistance between the
ground and the terminal of the electrical parts. If
the electrical resistance is not more than 2 MΩ, do
not operate the system until the electrical leakage is
found and repaired.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 13
Johnson Controls Ducted Systems

Figure 13: Wiring diagram - HMH7 ACC STD ECM
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump14
Johnson Controls Ducted Systems

Figure 14: Wiring diagram - HMH7 ACC VS ECM
Note:
• Use the B terminal on the thermostat for the reversing valve connection (energized in heat mode).
• The room thermostat must control fossil fuel operation if matched with a gas furnace.
• Refer to wiring and installation kit HMH7AK001 for additional wiring detail on the indoor unit.
Connecting HMH72B24 and HMH72B36
wiring
About this task:
Connect wiring to the unit by completing the following
steps.
1. Unscrew the mounting screws to remove the
electric box cover.
2. Fasten the power supply cable and the low-voltage
cable to the conduit holder using the lock nut.
3. Connect the power supply cable and the low-
voltage cable to the terminal.
4. Fasten the power supply cable and the low-voltage
cable with the cable clamp.
5. Make sure to seal any holes when wiring is
complete. Place the cables side to side (do not
overlap the cables).
6. Re-install the electric box cover when wiring is
complete.
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 15
Johnson Controls Ducted Systems

Figure 15: HMH72B24 and HMH72B36 wiring
Connecting HMH72B48 and HMH72B60
wiring
About this task:
Connect wiring to the unit by completing the following
steps.
1. Remove the screws, maintenance plate, and the
valve cover.
2. Pass the low-voltage cable and power supply
through the two holes on the right side plate.
3. Fasten the conduit connection to the right side
plate using the lock nut.
4. Connect the low-voltage cable and power supply to
the terminal.
5. Secure the low-voltage cable and power supply
with the clamp tightly.
6. Make sure to seal all holes when wiring is
complete.
7. Replace the maintenance plate and the valve cover
when wiring is complete.
Figure 16: HMH72B48 and HMH72B60 wiring (1)
Figure 17: HMH72B48 and HMH72B60 wiring (2)
Figure 18: HMH72B48 and HMH72B60 wiring (3)
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Johnson Controls Ducted Systems

Electrical data
Table 5: Electrical data
Model
(capacity) Power supply ELB/RCD rated
current (A)*
ELB/RCD fault
current (mA)*
Power source
cable size
Low-voltage
cable size
Circuit
breaker (A)
HMH72B24 208/230 V~ /60
Hz 25 30 3 x 12 AWG 5 x 16 AWG 25
HMH72B36 208/230 V~ /60
Hz 35 30 3 x 10 AWG 5 x 16 AWG 35
HMH72B48,
HMH72B60
208/230 V~ /60
Hz 50 30 3 x 8 AWG 5 x 16 AWG 50
*where required by code
Note: Maximum running current (A): refer to the
nameplate.
Note:
• Follow local codes and regulations when
selecting field wires and ensure all wires are
the minimum wire size.
• When the low-voltage cable is longer than 262
ft (80 m), select a larger wire size.
• Install a main switch and an ELB/RCD for each
system separately. Select a high-response ELB/
RCD that acts within 0.1 s.
NOTICE
When connecting to the terminal block using a
stranded wire, make sure to use the round crimp-style
solderless terminal.
Figure 19: Connecting the power supply
Performing a test run
About this task:
Perform a test run after the refrigerant piping, drain, and
wiring are finished.
CAUTION
The outdoor section is provided with a compressor
and base heater. Check to ensure the main power has
been on for more than 6 h ahead of unit operation to
avoid damage to the compressor.
CAUTION
Do not operate the system until all the checks have
been performed.
1. Check to ensure that the service base valves of the
outdoor unit are fully open.
2. Check to ensure that the electric wires are fully
connected.
3. Use the thermostat to turn on the system and then
proceed with the test run.
4. Turn off the power after the test run is finished.
WARNING
Do not touch any of the parts at the discharge gas
side by hand. The compressor chamber and the pipes
at the discharge side are heated to temperatures
higher than 194°F (90°C).
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Technical information
WARNING
Electrical Shock Hazard
Disconnect and lock out power before servicing. Wait
5 min to ensure that drive capacitors are discharged
before servicing. Use compressor with grounded
system only. Molded electrical plug must be used for
connection to compressor.
WARNING
Burn Hazard
Failure to follow these warnings could result in serious
personal injury or property damage. Ensure that
materials and wiring do not touch high temperature
areas of the compressor. Personal safety equipment
must be used.
CAUTION
Drive Handling
Caution must be used when lifting and installing the
drive. Failure to use caution may result in bodily injury.
Personal safety equipment must be used. Failure to
follow these warnings could result in personal injury or
property damage.
CAUTION
Safety Statements
Only qualified and authorized HVAC or refrigeration
personnel are permitted to install, commission and
maintain this equipment. Electrical connections must
be made by qualified electrical personnel. All valid
standards and codes for installing, servicing, and
maintaining electrical and refrigeration equipment
must be observed.
Refrigerant cycle
Figure 20: Refrigerant flow diagram
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Johnson Controls Ducted Systems

Figure 21: Outdoor unit - HMH72B24
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Johnson Controls Ducted Systems

Figure 22: Outdoor unit - HMH72B36
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Johnson Controls Ducted Systems