Carrier 38BYC Heat Pump User Manual


 
If TXV installation is required, remove existing AccuRater® from
indoor coil. Refer to Figs. 4 and 5 and install TXV kit as follows:
1. Install suction tube adapter.
2. Install liquid flare-to-sweat adapter.
3. Connect external equalizer tube to fitting on suction tube
adapter.
4. Position sensing bulb on horizontal portion of suction tube
adapter. Secure using supplied hardware.
5. Insulate bulb after installation. (See Fig. 5.)
6. Leak check all connections.
Step 7—Check Outdoor AccuRater® Piston
Check outdoor unit piston. Remove retainer on liquid service valve
and check piston size with matching number listed on outdoor unit
rating plate.
Step 8—Check Defrost Thermostat
Check defrost thermostat to ensure it is properly located and
securely attached. There is a liquid header with a brass distributor
and feeder tube going into outdoor coil. At the end of 1 of the
feeder tubes, there is a 3/8-in. O.D. stub tube approximately 2 in.
long. (See Fig. 6.) The defrost thermostat should be located on stub
tube. Note that there is only 1 stub tube used with liquid header,
and on most units it is the bottom circuit.
Step 9—Make Piping Connections
Relieve pressure and recover all refrigerant before system
repair or final unit disposal to avoid personal injury or death.
Use all service ports and open all flow control devices,
including solenoid valves.
If ANY refrigerant tubing is buried, provide a 6 in. vertical
rise at service valve. Refrigerant tubing lengths up to 36 in.
may be buried without further special consideration. For
lengths longer than 36 in., refer to Application Guideline and
Service Manual — Residential Split System Air Conditioners
and Heat Pumps.
To prevent damage to unit or service valves observe the
following:
•Use a brazing shield.
•Wrap service valves with wet cloth or use a heat-sink
material.
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 50 ft, substan-
tial capacity and performance losses can occur. Following the
recommendations in the Residential Split System Long-Line
Application Guideline will reduce these losses. Refer to Table 1
for field tubing equivalent line length. Refer to Table 2 for
accessory requirements.
For buried line applications greater than 36 in., refer to Table 2 and
Residential Split System Buried Line Application Guideline.
Buried line applications may not exceed 100 ft.
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.
Fig. 4—Typical TXV Installation
A88382
THERMOSTATIC
EXPANSION
VALVE
EQUALIZER
TUBE
SENSING
BULB
COIL
Fig. 5—Positioning of Sensing Bulb
A81032
2 O'CLOCK
10 O'CLOCK
SENSING BULB
STRAP
SUCTION TUBE
8 O'CLOCK
4 O'CLOCK
7
8
IN. OD & SMALLER
LARGER THAN
7
8
IN. OD
Fig. 6—Defrost Thermostat Location
A97517
FEEDER TUBE
DEFROST
THERMOSTAT
STUB TUBE
3