AIR CONDITIONING - CONT - TM-55-1905-223-24-170053

TM 55-1905-223-24-17

Table 2-2. Troubleshooting - CONT

Malfunction

Test or Inspection

Corrective Action

AIR CONDITIONING - CONT

WARNING

Shock Hazard. Wear protective gloves when checking voltage.

STEP 4.

Check for overload trip due to low voltage.

Check voltage to the unit (paragraph 2-17). Find and correct cause of low voltage (TM 55-

1905-223-24-18).

WARNING

Turn power OFF.

STEP 5.

Check for dirty electrical control contacts on the thermostat or defective thermostat.

Clean contacts with soft bristle brush as required. If contacts are burned or pitted, replace

the thermostat. (Refer to TM 55-1905-223-10 for location and operation of thermostats.)

STEP 6.

Check to see if high pressure control switch is open due to high head (discharge) pressure.

Locate and correct the cause of high head pressure. Refer to Item 8 of this table.

STEP 7.

Check for open contact on internal overload protector in compressor (A/C-1 and 3).

Allow time for compressor to cool and automatically reset. If it does not reset when cooled

down, check for "open" or "short" in compressor (paragraph 2-17).

STEP 8.

Check for defective compressor or compressor motor.

Test compressor or compressor motor for a "short" or "open" condition (paragraph 2-17).

16.

Compressor or compressor motor hums but does not start.

STEP 1.

Check for broken wiring.

Visually check for broken wire correct as required.

STEP 2.

Check for pitted or burned contacts in circuit breaker or defective circuit breaker.

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