COMPRESSOR WILL NOT START - TM-5-4120-369-140042

TM 5-4120-369-14

Troubleshooting - Continued

Table 4-2.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

COMPRESSOR WILL NOT START

Set circuit breakers to ON position. Turn mode selector switch to COOL

Step 1.

position and temperature selector switch to COOLER position.

Reset controls properly.

Check for defective or tripped compressor internal overload switch.

Step 2.

Set circuit breaker and mode selector switch to off. Disconnect main power

cable for at least 45 minutes; then, reconnect cable and reset controls. If

condition continues, report deficiency to Direct Support maintenance.

Check for loose electrical connections or faulty wiring.

Step 3.

Tighten loose connections. Repair faulty wiring.

Test for open control circuit by means of continuity check (paragraph 4-32).

Step 4.

Report open-circuit condition to Direct Support maintenance.

Check to see if contacts on high or low pressure cutout switch are open.

Step 5.

Reset pressure switches. If condition continues, report deficiency to

Direct Support maintenance.

Step 6.

Test control circuit breaker and compressor circuit breaker for faulty

operation.

Replace defective circuit breaker (paragraph 4-27).

Test control transformer and rectifier for defective opertion.

Step 7.

Replace defective transformer (paragraph 4-28) and defective rectifier

(paragraph 4-29).

Step 8.

Test for defective time delay relay.

Replace defective relay (paragraph 4-27).

Test for defective compressor relay.

Step 9.

Replace defective relay (paragraph 4-27).

Step 10.

Check to see if compressor motor is defective. Test for open or

grounded winding (paragraph 4-35).

Report motor-fault condition to Direct Support maintenance.

COMPRESSOR STARTS BUT CUTS OUT ON OVERLOAD

Step 1.

Check for high pressure due to improper condenser coil air flow.

Verify proper operation of condenser

Clean condenser coil and louvers.

fans and louvers.

4-7