TM 9-4120-399-14
Table 4-3. Unit Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
W i t h unit operating in COOL mode, check the condition of
Step 9.
refrigerant in sight glass.
If color is yellow or a light hue of chartreuse, or if numerous
bubbles appear, turn air conditioner OFF. Contact your supervisor.
REDUCED HEATING CAPACITY.
5.
Check that all doors, windows and other openings in the room or
Step 1.
enclosure are tightly closed.
Tightly close all openings.
If control panel is remotely located, check to be sure that sensing
Step 2.
bulb is not near a light bulb or some type of heat producing
equipment.
Turn off or move heat source, or move the remote control panel per
Check that the evaporator inlet and outlet louvers are properly
Step 3.
adjusted.
Adjust louvers properly.
Check to be sure that excessive cold, outside air is not being
Step 4.
introduced through the fresh air damper.
Fully close damper then, if condition improves, adjust properly.
Check air flow out of evaporator outlet louver.
Step 5.
If air flow volume is low:
a. Adjust intake (return air) guard louvers.
b. Clean and service or replace conditioned air filter element.
c. Clean evaporator coil.
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