Service Manual

15
1. Startup/Cool Down
1) Check all wiring connections. Conrm the CTh is properly connected.
2. Energize the cooler.
3. Check for 115VAC to neutral (W). If 115VAC is not present, check the Power supply, wire
connections.
4. Check that cabinet temperature is displayed. If not, replace CM.
5. Make sure door is closed.
6. Check that Comp and ConFM energize. If not, check CTh status. See “Thermistor Check.”
If CTh ohm reading is in proper range, check for 115VAC at CM to neutral. If 115VAC is not
present, replace CM.
7. Defrost initiation. Defrost initiation by 6 hours compressor cumulative run time. Conrm
Comp and ConFM de-energize, EvapFM continues on. Check for 115VAC at CM to neutral
for Comp and ConFM, then at CM to neutral for EvapFM. If defrost indicator is on and
115VAC is present, replace CM.
8. Defrost termination, check after a 25 min. that the Comp energizes.
Legend: Controller; Comp–compressor; ConFM–condenser fan motor; CTh–cabinet
thermistor; DS–door switch; DTh–defrost thermistor; EvapFM–evaporator fan motors,
MH–mullion heater; PH–perimeter heater.