TM 9-4120-371-14
Table 4-2. 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.
Make sure that power is 208 volt, 3 phase, 50/60 hertz.
Step 2.
Connect correct input power.
Step 3. Check to see if compressor circuit breaker is tripped.
Slowly PULL out AND PUSH in reset knob TO RESET Circuit Breaker.
Step 4. Check for loose or damaged electrical connectors or damaged wires in wiring harnesses. (See
Tighten or replace connectors, or repair damaged wires.
Step 5. Check fuses. (See para 4-54.)
Replace bad fuse(s).
Step 6. Check operation of the auxiliary switch in circuit breaker (CB1).
Test (CB1) auxiliary switch. (See para 453.) Replace circuit breaker if auxiliary switch is
defective.
Step 7. Check operation of control power transformer (T1).
Test transformer. (See para 452.) Replace transformer, if defective.
Step 8. Check operation of RFI Filter (FL1) and d.c. rectifier (CR1) assembly.
Test filter and rectifier. (See para 4-46 and 455.) Replace defective filter or rectifier.
Step 9. Check all terminals and internal wiring within junction box for tightness and damage.
Tighten terminals, or repair wiring as necessary. (See para 4-51.)
Step 10. Check operation of mode selector switch (S1).
Test switch. (See para 4-42.) Replace switch, if defective.
Step 11. Check that high or low pressure cut-out switches (S6 and S7) are not open.
PUSH and release TO RESET.
Step 12. Reset (PUSH) PRESSURE CUT-OUT switch(s) and restart unit.
If unit does not start, contact direct support maintenance.
