MAINTENANCE OF ENVIRONMENTAL CONTROL SUBSYSTEM

TM 55-1905-223-24-17

(8) If compressor is inoperative, or system cannot be operated, use the migration method given

for the self-contained units (A/C-1 and 3), except, connect gauge manifold to both suction

and discharge valves and open both handwheels on the manifold when letting refrigerant

pass into empty container.

WARNING

DO NOT overfill R-22 containers.

NOTE

Both service valves must be opened clockwise three or four turns when using the

above migration method.

The migration method may be a slow process.

(9) When using any method of removing refrigerant the R-22 container must be weighed

periodically to make sure it is not being overfilled.

(10)

When possible, use the system compressor to remove refrigerant charge as follows:

(a) Connect the gauge manifold from the compressor discharge valve service port to the

refrigerant container and purge the lines. Note the maximum allowable refrigerant

container weight.

(b) Place the refrigerant container in ice. Place the compressor in normal system

operation. Turn the discharge service valve in a few turns to open the service port,

open the refrigerant container valve and the gauge manifold so that discharge gas can

enter the cold container, with the discharge pressure registering on the manifold high

pressure gauge.

WARNING

DO NOT close the valve on the receiver outlet.

WARNING

DO NOT OVERFILL CONTAINER. Use additional containers as necessary.

container frequently to check the progress in filling. Continue bypassing a portion of

the discharge gas into the refrigerant container until it is filled to its weight capacity.

Use additional containers as necessary.

(d) When a major portion of the refrigerant has been removed, system pressures may fall

so low that refrigerant can no longer be efficiently transferred. To remove the

remainder of the refrigerant, disconnect the refrigerant cylinder and vent the remaining

refrigerant to the atmosphere.

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