Main Power Supply

TM 10-4110-262-13&P

0029 00

Main Power Supply

1. Check input power cable voltage.

2. Check phase-to-phase voltage for 208/230 VAC, phase-to-ground and phase-to-neutral for 120 VAC.

3. Check voltage phase-to-phase on the line side of the compressor contactor.

L1 to L2

208/230 VAC

L1 to L3

208/230 VAC

L2 to L3

208/230 VAC

L1 to ground

120 VAC

L2 to ground

120 VAC

L3 to ground

120 VAC

WARNING

Disconnect all input power. High voltage is present and

electric shock may occur. Failure to comply may result in

serious injury or death to personnel.

4. If no voltage or incorrect voltage is present at terminals L1, L2 or L3, conduct a resistance check from the plug

receptacle to t he individual terminal L1, L2, L3 and plug receptacle pins.

5. Replace defective conductor and/or receptacle if required.

Heater Circuit

1. Adjust the set point to 10 F above box temperature to initiate the heat cycle.

2. If heater rods in evaporator are not hot, check heater overload. If tripped, reset. If it trips again,

check for shorted heater or circuit.

3. If overload is not tripped, check for voltage on load side of overload.

4. If no voltage, check heater contactor control circuit.

0029 00-6