17
8)
Cool Down Achieved
–CTh cools to 3°F (1.7°C) below setpoint. EvapFM and MH
continue. Comp and ConFM de-energize.
Diagnosis
: Confirm Comp and ConFM
de-energize. If not, and Comp and ConFM were energized longer than 2 min., check
CTh status. See "II.D. Thermistor Check." If CTh ohm reading is in range and Comp
and ConFM continue longer than 2 min., check for 115VAC at CM C1 (R) to neutral (W).
If 115VAC is present, replace CM. If 115VAC is not present and Comp and ConFM
continue, check for 115VAC at CR #1 (R). If 115VAC is present, replace CR.
9)
Defrost–
Cabinet temperature is displayed during defrost. There is a 20-min. minimum
defrost time, a 1-hr. maximum defrost time, and a 2-hr. minimum defrost interval.
1a)
Time-Initiated
: When 2-hr. cumulative Comp run timer terminates, defrost starts (off
cycle). EvapFM and MH continue. Comp and ConFM de-energize.
1b)
Manually-Initiated
: To initiate a manual defrost, press the manual defrost button
on display. Defrost icon turns on and, if energized, Comp and ConFM de-energize.
Cabinet temperature is displayed during defrost.
2)
Defrost Termination
: DTh warms to 40°F (4.4°C). EvapFM and MH continue. Comp
and ConFM energize.
Defrost Diagnosis
:
a)
Defrost Initiation
:
Has DTh cooled to 8.6°F (-13°C) or lower? Confirm DTh status.
See "II.D. Thermistor Check."
If DTh is in proper range or manual defrost initiated,
confirm Comp and ConFM de-energize. If not, check for 115VAC at CM C1 (R) to
neutral (W). If 115VAC is present and DTh is within proper range, replace CM. If there
is no voltage at CM C1 (R) to neutral (W) and Comp and ConFM do not de-energize,
check for 115VAC at CR #1 (R) to neutral (W). If 115VAC is present at CR #1 (R) to
neutral (W) and DTh is within proper range, replace CR.
b)
Defrost Termination
: Has DTh warmed to 40°F (4.4°C)? If not yet confirmed,
confirm DTh status. See "II.D. Thermistor Check." If DTh is in proper range, have
Comp and ConFM energized? If not, see "7d) Comp and ConFM Diagnosis" above.
Legend:
CM
–control module;
Comp
–compressor;
ConFM
–condenser fan motor;
CR
–compressor relay;
CTh
–cabinet thermistor;
DS
–door switch;
DSR
–door switch
relay;
DTh
–defrost thermistor;
EvapFM
–evaporator fan motors;
HPS
–high-pressure switch;
MH
–mullion heater;
TXV
–thermostatic expansion valve