Service Manual

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(3) EvapFM Diagnosis
UR/WR: EvapFM continues. If not, check for 115VAC at CM
AUX 1 black-smooth(BK-SM) wire to a neutral white (W). If 115VAC is not
present, replace CM.
SR and UF/WF: Conrm EvapFM de-energizes. If not, check for 115VAC at
CM AUX 1 black-smooth (BK-SM) to a neutral white (W). If 115VAC is present,
conrm Comp and ConFM de-energized. Next, check DTh continuity. See "II.D.
Thermistor Check." Replace as needed. If DTh conrmed, replace CM.
(4) DH Diagnosis (SR and UF/WF): Conrm DH energizes. Check for 115VAC at
CM AUX 2 black (BK) wire to a neutral white (W). If 115VAC is present, conrm
Comp, ConFM, and EvapFM de-energized. Next, check DTh continuity. See "II.D.
Thermistor Check." Replace as needed. If DTh conrmed, replace CM.
2) Defrost Termination
Manually Terminated Defrost: Set the CTCD to the off position, then back to
original setting or unplugging and plugging back in to the electrical outlet. Defrost
terminated. If not, replace CM.
Temperature/Time Terminated Defrost
a) UR/WR: DTh warms to 45°F (7.2°C). Conrm continuity of DTh.
See "II.D. Thermistor Check." Replace as needed. If DTh conrmed, replace CM.
Once defrost termination achieved, EvapFM continues. Comp and ConFM energize.
If not, see "4) Startup/Cool down" above.
b) SR: DTh warms to 46°F (7.7°C). DH de-energizes. Conrm continuity of DTh. See
"II.D. Thermistor Check." Replace as needed. If DTh is good and DH continues after
DTh achieves 46°F (7.7°C), replace CM. Comp, ConFM, and EvapFM energize. If
not, see "4) Startup/Cool down" above.
c) UF/WF: DTh warms to 55°F (12.7°C) DH de-energizes. Conrm continuity of DTh.
See "II.D. Thermistor Check." Replace as needed. If DTh is good and DH continues
after DTh achieves 55°F (12.7°C), replace CM. 3-min. DOT starts. 3-min. DOT
terminates. If CTh calling for cooling, Comp, ConFM, PH, and MH energize. Once
evaporator temperature achieves 10°F (-12.2°C) or 3-min. EvapFM delay timer
terminates, EvapFM energizes. If not, see "4) Startup/Cool down" above.
Legend: Comp–compressor; ConFM–condenser fan motor; CLS–cabinet light switch;
CM–control module; CTCD–cabinet temperature control dial; CTh–cabinet
thermistor; DH–defrostheater; DLT–defrost lock-out timer; DST–defrost safety
thermostat; DT–defrost timer; DTh–defrost thermistor; EvapFM–evaporator fan
motor; HPS–high-pressure switch; MH–mullion heater; PH–perimeterheater