Service Manual

17
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 at 4 hours of cumulative compressor run time
for 25-
min. 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: CM–Control Module; 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.