Table 4-2. Troubleshooting - TM-5-4120-355-140042

TM 5-4120-355-14

Table 4-2. Troubleshooting

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

COMPRESSOR STARTS BUT GOES OUT ON OVERLOAD

Step 1. Listen if condenser fan is operating.

Check motor leads and power line going to motor. Correct as required.

Step 2. Condenser coil may be blocked.

Clean condenser coil

LITTLE OR NO HEATING CAPACITY

Step 1. Check if selector switch is at HEAT.

Set switch to HEAT.

Step 2. Check if there is sufficient air movement over evaporator.

Clean air filter.

Step 3. Check electrical connections to heater.

Correct heater wiring.

SUCTION PRESSURE INADEQUATE

Step 1. Check sight glass for appearance of flash gas.

Add refrigerant.

LOW SUCTION AND DISCHARGE PRESSURES

Step 1. Check sight glass for appearance of flash gas.

Report lack of refrigerant to higher maintenance.

Step 2. Check if air filter is clean.

Clean air filter.

Section VII. Radio Interference Suppression

This section is not applicable to this equipment.

Section VIII. Maintenance of Housing Assembly

4-14. General

The air conditioner is constructed with removable aluminum panels. The front access panel provides access to the

junction box, control panel, and access fittings. A discharge grille protects the evaporator and controls the direction of

discharge of conditioned air. The intake grille protects the air conditioning filter and regulates the amount of air returned

to the unit. The condenser coil grille and fan guard protects the condenser coil and fan. A fresh air inlet screen permits the

entry of outside air and is controlled by the damper door with the control spring and chain. The cover panel covers the top

of the unit.

WARNING: Disconnect the air conditioner from power source before performing any maintenance on the components

of the unit.

4-10