Carrier 38BYG TypicalTXV Installation, DefrostThermostat Location, Positioningof Sensing Bulb

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.

COIL

SENSING

BULB

EQUALIZER

TUBE

THERMOSTATIC

EXPANSION

VALVE

A88382

Fig. 4—Typical TXV Installation

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.

FEEDER TUBE

STUB TUBE

DEFROST

THERMOSTAT

A97517

Fig. 6—Defrost Thermostat Location

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.

10 O'CLOCK

2 O'CLOCK

STRAP

SUCTION TUBE

8 O'CLOCK

7⁄8 IN. OD & SMALLER

SENSING BULB

4O'CLOCK

LARGER THAN 7⁄8 IN. OD

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.

A81032

Fig. 5—Positioning of Sensing Bulb

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

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.

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