TM 9-4120-378-14
Table 5-1. Direct Support Troubleshooting - Continued
Malfunction
Test or Inspection
Corrective Action
2.
COMPRESSOR STARTS, BUT STOPS AT ONCE - "SHORT CYCLES" - Continued
Step 3.
Check for proper operation of condenser fan and motor.
Step 4.
Turn off power; short-circuit ("jumper") the HIGH pressure switch. Turn on power.
For maximum of 12 seconds, cycle compressor to see whether compressor
operates normally.
Do not exceed 12-second operating time for compressor, or vacuum may
be formed in suction side or refrigeration system and damage it.
Check dehydrator to see that it is not sweating, frosting or cold to the touch.
Step 5.
Check refrigerant system for leaks using a halogen or electronic leak detector.
Step 6.
Refrigerant charge may be low, as indicated by bubbles in liquid sight indicator, or
non-condensable gas may have entered system,
If refrigerant charge is low, but no leaks are found, discharge and purge system,
repair or replace leaking component, and recharge. (Refer to paragraphs 5.9
through 5.15.)
Install pressure gages in system (paragraph 5.4) and check system pressures to
Step 7.
see whether an overcharge of refrigerant is indicated.
If overcharge is indicated, partially discharge the system and retest. (Refer to
3.
INSUFFICIENT COOLING
Feel dehydrator to see whether it is cold to the touch, or is frosted or sweating.
Step 1.
Step 2.
Check input and discharge sides of solenoid valves for temperature difference.
Abnormally cold discharge indicates leakage or obstruction.
5-3