Bryant R-22 service manual ReversingValve Cooling Mode or Defrost, Mode, Solenoid Energized

NEW SOLENOID COIL

3 PORT DESIGN

A91457

4TH PORT

4 PORT DESIGN

A91456

Fig. 46—Reversing Valve

If valve is defective:

1.Shut off all power to unit and remove all charge from system.

5.Use slip couplings to install new valve with stubs back into system. Even if stubs are long, wrap valve with a wet rag to prevent overheating.

2. Check valve design. If valve is of the 3-port design and new

replacement is of the 4-port design, replacement of the

solenoid coil and wire leads is necessary. Valve bodies are

interchangeable, but solenoid and wires are not. Three-port

reversing valve and solenoid coil with leads must be used

6.After valve is brazed in, check for leaks. Evacuate and charge system. Operate system in both modes several times to be sure valve functions properly.

together. New solenoid coil cannot be used on a 3-port

valve.

Four-port reversing valve uses solenoid with quick-connect

terminals for leads connection. Old solenoid coil cannot be

used on 4-port reversing valve. If for any reason a new wire

cord is not available, cut the leads on the old solenoid coil

as close to the coil as possible. Terminate the leads with 2

female 1/4-in. quick-connects. Connect terminals to new

solenoid and tape connection to insulate and provide

moisture barrier. Replace these wires as soon as wire cord

is available. See RCD (Replacement Component Catalog)

for proper cord part number.

3. Remove solenoid coil from valve body. Remove valve by

cutting it from system with tubing cutter. Repair person

should cut in such a way that stubs can be easily rebrazed

TO OUTDOOR

COIL

TP-4

FROM COMPRESSOR

DISCHARGE LINE

FROM INDOOR COIL VIA SERVICE VALVE ON OUTDOOR COIL

TO ACCUMULATOR

TP-3TP-2

TP-1

back into system. Do not use hacksaw. This introduces

chips into system that cause failure. After defective valve is

removed, wrap it in wet rag and carefully unbraze stubs.

Save stubs for future use. Because defective valve is not

overheated, it can be analyzed for cause of failure when it

is returned.

4. Braze new valve onto used stubs. Keep stubs oriented

correctly. Scratch corresponding matching marks on old

valve and stubs and on new valve body to aid in lining up

new valve properly. When brazing stubs into valve, protect

valve body with wet rag to prevent overheating.

—40—

A88342

Fig. 47—Reversing Valve (Cooling Mode or Defrost

Mode, Solenoid Energized)

VII. THERMOSTATIC-EXPANSION VALVES (TXV)

The types of TXVs used in condensing-unit and heat-pump systems are as follows:

Rapid-Pressure Balance (RPB)—Has a special bleed port that allows rapid bleed-through of pressure after system shutdown until pressure equalization occurs within approximately 1 to 2 minutes.