Table 4-2. Unit Maintenance Troubleshooting

TM 5-4120-393-14

Table 4-2. Unit Maintenance Troubleshooting

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. AIR CONDITIONER DOES NOT START IN ANY MODE.

Step 1. Check to see if input power has been disconnected.

Connect input' power.

Step 2. Make sure that power is 208 volt; 3 phase, 50/60 hertz.

Connect correct input power.

Step 3. Check to see if compressor circuit breaker is tripp ed.

Slowly PULL AND PUSH TO RESET CIRCUIT BREAKER.

Step 4. Check for loose or damaged electrical connectors or damaged wires in wiring harnesses.

Tighten or replace connectors, or repair damaged wires.

Step 5. Check op eration of Circuit Breaker (CB).

Test Circuit Breaker (CB). (See para 4-42). Replace circuit breaker if defective.

Step 6. Check operation of control power transformer (T).

Test transformer. (See para 4-49.) Replace transformer if defective.

Step 7. Check operation of RFI filters (FL1 thru 4) and dc rectifier assembly (CR).

Test filters and rectifier. Replace defective filter(s) or rectifier. (See para 4-52 and 4-53.)

Step 8. Check all terminals and internal wiring in junction boxes for tightness and damage.

Tighten terminals or repair wiring as necessary. (See para 4-41 and 4-47.)

Step 9. Check operation of mode selector switch (S).

Test switch. (See para 4-38). Replace switch if defective.

4-36