Service Manual

18
2) Defrost Termination: DTh warms to 44°F (6.6°C). If not, conrm DTh status. See
"II.D. Thermistor Check." If DTh is in proper range, 3-min. Comp delay timer starts.
Once 3-min. Comp delay timer terminates, Comp icon turns on and Comp and
ConFM energize. 15-min. temperature display timer starts. Once 15-min. temperature
display timer terminates, "dEF" is replaced by cabinet temperature on display.
(1) 3-min. Comp delay timer terminates: 3 min. after DTh warms to 44°F (6.6°C),
conrm Comp icon turns on and Comp and ConFM energize. If not, conrm
cabinet temperature is warm enough for Comp operation. Next, check for
115VAC at CM1 (C) (V) to neutral(W). If115VAC is not present, check CTh
status. See "II.D. Thermistor Check." If CTh ohm reading is in proper range,
Comp icon is on, and 115VAC is not present at CM 1 (C) (V), replace CM.
If 115VAC is present, check for 115VAC at CUR (V). If 115VAC is present at
CM1 (C) (V) to neutral (W) and not at CUR (V), check HPS continuity.
See "1.5)g) HPS Activation" above. If HPS is closed and 115VAC present, check
for 115VAC at condensing unit power supply cord (BK) to neutral (W).If 115VAC
is not present at condensing unit power supply cord (BK), replace condensing
unit power supply cord. If 115VAC is present at condensing unit power supply
cord (BK) and ConFM is energized but Comp is not, check for 115VAC at Comp
external protector to neutral (W). If 115VAC is not present, give time for external
protector to cool and reset. If Comp external protector does not reset, replace
Comp external protector. If 115VAC is present on both Comp external protector
wires, check run capacitor, start capacitor, start relay, and Comp motor windings.
If ConFM is not energized, check ConFM fan blades for binding and motor
winding continuity. If Comp does not start, replace condensing unit.
(2) 15-min. temperature display delay timer terminates: 15 min. after Comp
icon turns on and Comp and ConFM energize, "dEF" is replaced by cabinet
temperature on display. If not, replace CM.
Legend: CL–cabinet light; CM–control module; Comp–compressor; ConFM–condenser fan
motor; CTh–cabinet thermistor; DCD–direct current driver; DS–door switch;
DTh–defrost thermistor; EvapFM–evaporator fan motors; HPS–high-pressure
switch; TXV–thermostatic expansion valve; CUR–condensing unit receptacle