TM9-4120-400-14
TROUBLESHOOTING - continued
Table 4-2.
MALFUNCTION
TEST OR INSPECTION
C O R R E C T I V E ACTION
3 . CONDENSER FAN FAILS TO OPERATE.
Step 1. Check operation of condenser fan motor. (See para 4-44.)
Test motor. Replace motor if defective.
Step 2. Check electrical connections and wiring. (See fig. 4-4 and para 4-20.)
Tighten or replace connectors, or repair or replace damaged wires.
Step 3. Check fan for binding. (See para 4-44.)
Relieve binding or replace fan.
Step 4. Test condenser fan relay. (See fig. 4-4 and para 4-32.)
Replace bad relay.
Step 5. (Three phase units only.) Check phase sequence relay. (See para 4-30.)
Replace bad relay.
INSUFFICIENT COOLING.
Step 1. Check to see that MODE SELECTOR switch is properly positioned.
Set switch to COOL.
Step 2. Check sight-glass liquid level indicator that refrigerant is colorless and clear. Yellow, milky or bubbly
refrigerant indicates low level or excessive moisture.
Notify supervisor.
Step 3. Inspect evaporator and condenser coil for did.
Clean coil with 25-30 psi compressed air. (See para 4-45 and 4-48.)
Step 4. Inspect evaporator return air filter for dirt. (See para 4-13.)
Clean filter.
Step 5. Inspect mist eliminator for dirt. (See para 4-16.)
Remove, clean, and/or replace mist eliminator.
Step 6. Check for obstructions to airflow.
Remove any obstructions to airflow (evaporator and condenser sides).
4-32
