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is energized but Comp is not, give time for Comp internal protector to cool and reset.
Next, check Comp start capacitor, start relay, and Comp motor windings. If Comp
does not start, replace Comp. If ConFM is not energized, check ConFM fan blades
for binding and motor winding continuity.
If Comp and ConFM are energized and the cabinet does not cool down, check for a
restriction in the refrigeration circuit, correct TXV operation, and correct refrigerant
charge.
e)
HPS Activation
: Confirm ConFM is energized and fan blade turns freely.
Confirm condenser coil is not clogged or restricted. Confirm there are no restrictions
in the refrigeration circuit (TXV and drier). Let refrigeration circuit pressures
equalize. If HPS does not reset and pressures are equalized, replace HPS.
If pressures are not equalized, reclaim refrigerant and diagnose refrigeration circuit
restriction.
8)
Cool Down Achieved
–CTh cools to 3°F (1.7°C) below setpoint. EvapFM continues.
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 or V) 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 or V). 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 continues. 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 or V)
to neutral (W). If 115VAC is present and DTh is within proper range, replace CM.
If there is no voltage at CM C1 (R or V) to neutral (W) and Comp and ConFM do not
de-energize, check for 115VAC at CR #6 (R) to neutral (W). If 115VAC is present at
CR #6 (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:
CL
–cabinet light;
CLS
–cabinet light switch (FGY);
CM
–control module;
Comp
–compressor;
ConFM
–condenser fan motor;
CR
–compressor relay;
CTh
–cabinet thermistor;
DS
–door switch (FS/HS);
DSR
–door switch relay (FS/
HS);
DTh
–defrost thermistor;
EvapFM
–evaporator fan motors;
HPS
–high-pressure switch;
TXV
–thermostatic expansion valve
