AIR CONDITIONING (Cont) - TM-55-1905-223-24-170212

TM 55-1905-223-24-17

Table 4-1. Troubleshooting - CONT

Malfunction

Test or Inspection

Corrective Action

AIR CONDITIONING - CONT

NOTE

A low discharge pressure (below 170 psig) combined with a high suction pressure

(above 72 psig) indicates a leaky valve plate.

Replace valve plate in semi-hermetic compressor (A/C 2; accommodations) (paragraph 4-

19).

STEP 2.

Check for worn piston rings in semi-hermetic compressor (A/C-2 accommodations).

Replace piston rings (paragraph 4-19).

High suction pressure (above 72 psig).

STEP 1.

Check for clogged suction strainer in semi-hermetic type compressor (A/C-2).

Remove and clean strainer (paragraph 4-19).

STEP 2.

Check for leaky compressor suction valve plate. A higher than normal suction pressure

combined with a discharge pressure lower than normal indicates a leaky valve plate.

Replace compressor suction valve plate (paragraph 4-19).

Lower than normal suction pressure (below 58 psig).

STEP 1.

Check to see if there is sufficient refrigerant.

Add R-22 refrigerant as follows:

WARNING

PRESSURIZED GAS HAZARD. Handle R-22 refrigerant containers with care to

avoid personal injury. Keep containers away from external heat sources. DO NOT

DROP containers. When in use, place containers where they will not be knocked

over.

A/C-2 (Accommodations).

(1)

Shut down compressor and connect a portable gauge manifold to the compressor.

Connect combination (suction) gauge hoseline to the suction service valve

connection. Connect common (middle) hoseline of manifold to a container of new R-

22 refrigerant. Make sure container is in upright position. Purge all connecting hose

lines. Turn on tank to crack hose fitting until refrigerant opens.

4-5