TM 9-4120-408-14
Table 3-1. Operator Troubleshooting Table. (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
2. Insufficient Cooling.
Step 1. Ensure all doors, windows, and other openings in the shelter or enclosure are tightly closed.
Tightly close all openings.
Step 2. Check that the condenser EMI/RFI ventilation panels, fans, and coil are not obstructed or blocked.
Check that evaporator EMI/RFI ventilation panels and fan assembly outlet is not blocked.
Remove obstructions from condenser and evaporator EMI/RFI ventilation panels.
Step 3. Inspect external refrigerant lines for loose connections and damage.
Report loose connection or damaged refrigerant lines to your supervisor.
Step 4. Check operation of temperature control thermostat.
a Turn thermostat switch counterclockwise to maximum COOL setting; then, if condition improves, adjust
thermostat switch to desired setting.
b Notify unit maintenance.
3. Air Conditioner Stops Operating.
Ensure all power connections to the control module, condenser assembly, and evaporator assembly are secure. Inspect
all external power cables for damage.
WARNING
Do not work on equipment with power connected. Electrocution hazard is present. Failure to obey
this warning may result in death or serious personal injury.
a. Disconnect, clean connectors, and reconnect all connectors or connect power from a source supplying 28 vdc.
b. Notify unit maintenance.
4. High Pressure Warning Light on Control Module is Lit.
Inspect refrigerant out line from condenser for damage or kinks which would cause a restriction in refrigerant flow.
Position mode selector switch to OFF to shutdown air conditioner and notify unit maintenance.
5. Low Pressure Warning Light on Control Module is Lit.
Inspect refrigerant out line from evaporator for damage. Turn air conditioner off and notify unit maintenance.
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