DIRECT SUPPORT TROUBLESHOOTING PROCEDURES - continued

TM 9-4120-430-14

0042 00

A to B should be 230 V ac

A to E should be 120 V ac

B to E should be 120 V ac

FAULT PROCEDURE 2.

COMPRESSOR STARTS, BUT STOPS AT ONCE OR AFTER SHORT RUN

PERIOD. (Due to Tripped Circuit Breaker)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

COMPRESSOR STARTS, BUT STOPS

NOTE

When making test for voltage and phase reading, TB1 terminals 4 and 5 are used with

P1 alternate plug. Refer to WP 0038 00 schematic diagram.

Step 1.

Check compressor for short to ground.

Replace bad compressor or bad lead. (Refer to WP 0059 00.)

Step 2.

Check circuit breaker by observing amperes at moment of trip.

Replace defective circuit breaker. See WP 0027 00.

FAULT PROCEDURE 3.

COMPRESSOR STARTS, BUT STOPS AT ONCE OR AFTER SHORT RUN

PERIOD. (Due to Tripped Low Pressure Switch)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

COMPRESSOR STARTS, BUT STOPS

Step 1.

Leave the unit alone for one minute.

Wait.

Step 2.

After one minute, see if compressor comes on.

Wait and observe when low pressure switch cuts out.

Step 3.

Wait another one minute.

If compressor does not come on, perform continuity test on low pressure switch. Replace

defective switch (WP 0055 00).

NOTE

Sequence of waiting and observing may occur several times depending on temperature.

Step 4.

Perform pressure testing (WP 0051 00) on system to determine if refrigerant is low.

If pressure is low, perform leak check (WP 0047 00) and repair leak (WP 0046 00).

0042 00-3