GH7T: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
3
In Long-Line Applications, Install Liquid-Line 
Solenoid Valve (LSV)
For refrigerant piping arrangements with equivalent lengths greater than
80 ft. (24.38 m)  and/or when elevation difference  between  indoor  and
outdoor unit is greater than ±20 ft. (±6.10 m), follow all requirements of
the  Residential  Piping  and  Long-Line  Guideline.  If  required  by
Long-Line  Guideline,  install  LSV  kit,  part  no.  KHALS0401LLS,
specifically designed for R-410A refrigerant heat pumps. LSV should be
installed within 2 ft. (0.61 m) of outdoor unit with flow arrow pointing
toward outdoor unit. Follow the Installation Instructions included with
accessory kit. 
IMPORTANT: Flow arrow must point toward outdoor unit. 
Make Piping Connections
Outdoor  units  may  be  connected  to  indoor  section  using  accessory
tubing package or field-supplied refrigerant grade tubing of correct size
and  condition.  For  tubing  requirements  beyond  80  ft  (24.4  m),
substantial  capacity  and  performance  losses  can  occur.  Following  the
recommendations  in  the  Residential  Piping  and  Long  Line  Guideline
will  reduce these losses.   Refer to Table 1 for accessory requirements.
Refer to Table 2 for field tubing diameters.
There are no buried-line applications greater than 36 in. (914.4 mm)
If refrigerant tubes or indoor coil are exposed to atmosphere, they must
be evacuated to 500 microns to eliminate contamination and moisture in
the system.
Outdoor Unit Connected to Factory Approved Indoor 
Unit:
Outdoor unit contains the correct system refrigerant charge for operation
with  factory  approved,  AHRI  rated,  indoor  unit  with  highest  sales
volume when connected by 15  ft (4.57 m) of field-supplied or factory
accessory  tubing  and  factory-supplied  filter  drier.    Check  refrigerant
charge for maximum efficiency.
Service Valves
Service valves are closed and plugged  from the factory. Outdoor  units
are shipped with a refrigerant charge sealed in the unit. Leave the service
valves closed until all other refrigerant system work is complete or the
charge will be lost. Leave the plugs in place until line set tubing is ready
to be inserted.
Heat pumps require a piston metering device in the liquid service valve
for proper heating operation. Piston is shipped in the piston body of the
liquid service valve, temporarily held in place with a plastic cap. Do not
remove the plastic cap until line set tubing is ready to be installed.
Refer to Fig. 4 and follow these steps for piston installation:
1. Remove plastic cap holding piston in piston body of liquid service
valve.
2. Check  that  piston  size  (stamped  on  side  of  piston)  matches  with
number listed on unit rating plate. Return piston to piston body of
liquid service valve (either direction).
3. Find plastic bag taped to unit containing copper adapter tube, brass
nut, and plastic washer.
4. Install plastic washer in the seat inside piston body.
5. Fit brass nut onto adapter tube and install tube onto liquid service
valve. Tighten nut finger tight, then wrench additional ½ turn only
[15-ft  lbs  (20.3  N-m)].  Over  tightening  may  damage  the  plastic
washer and service valve’s piston body.
A14235
Fig. 4 – Liquid Service Valve with Heating Piston and Adapter Tube
Table 1 – Accessory Usage
Accessory
Required for Low Ambient
Cooling Applications 
(Below 55°F / 12.8°C)
Required for Long Line 
Applications
*
*. For tubing line sets between 80 and 200 ft. (24.38 and 60.96 m)  and/or 20 ft. (6.09 m) vertical differential, refer to Residential Piping and Longline Guideline.
Required for Sea Coast
Applications
(within 2 miles/3.2 km)
Compressor Start Assist Capacitor and Relay Yes Yes No
Crankcase Heater Yes (standard) Yes (standard) No
Evaporator Freeze Thermostat Yes No No
Hard Shutoff TXV
Yes
(standard w/factory approved
indoor unit)
Yes
(standard w/factory approved
indoor unit)
Yes
(standard w/factory approved
indoor unit)
Isolation Relay Yes No No
Liquid Line Solenoid Valve No
See Residential Piping
and Long Line Guideline
No
Low-Ambient Pressure Switch Yes No No
Support Feet Recommended No Recommended
WARNING
!
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could result in personal injury or death.
Relieve  pressure  and  recover  all  refrigerant  before  system  repair  or
final unit disposal. 
Use  all  service  ports  and  open  all  flow-control  devices,  including
solenoid valves.
Federal  regulations  require  that  you  do  not  vent  refrigerant  into  the
atmosphere.    Recover  refrigerant  during  system  repair  or  final  unit
disposal
CAUTION
!
UNIT DAMAGE HAZARD
Failure  to  follow  this  caution  may  result  in  equipment  damage  or
improper operation.
If ANY refrigerant tubing is buried, provide a 6-in (152.4 mm). vertical
rise  at  service  valve.    Refrigerant  tubing  lengths  up  to  36-in    (914.4
mm). may be buried without further special consideration.  Do not bury
lines longer than 36 in (914.4 mm).