N4H7T: 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. NASA001LS, 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
Refer to
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
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).
