Service Guide

29
9) Defrost–The defrost icon turns on and "dEF" is displayed during defrost. There is a
5-min. minimum defrost time and a 1-hr.maximum defrost time.
1a) Time-Initiated: 5-hr. cumulative Comp run time defrost timer starts. Once 5-hr.
cumulative Comp run time defrost timer terminates (Comp energized more than
5hrs.).
1b) Manually-Initiated: To initiate a manual defrost, press the manual defrost button on
display.
Defrost icon turns on and "dEF" is displayed. DH energizes. If on, Comp and
EvapFM icons turn off. Comp, ConFM, EvapFM, MH, and PH de-energize.
2a) Time-Initiated Defrost-Termination:
(1) DTh warms to 45°F (7.2°C). Defrost icon and "dEF" continues. DH de-energizes.
3-min. Comp delay timer starts, 7-min. EvapFM delay timer starts, and 18-min.
temperature display delay timer starts.
(2) 3-min. Comp delay timer terminates. "dEF" continues. Defrost icon turns off and
Comp icon turns on. Comp, ConFM, MH, and PH energize.
(3) 4 min. later, 7-min. EvapFM delay timer terminates. Comp, ConFM, "dEF," MH,
and PH continue. EvapFM icon turns on and EvapFM energizes. Note that the
7-min. EvapFM delay time is a maximum; if the defrost thermistor cools to 25°F
(-3.9°C) before the 7-min. EvapFM delay timer terminates, EvapFM icon turns on
and EvapFM energizes.
(4) 11-min. later, 18-min. temperature display delay timer terminates. "dEF" is
replaced by cabinet temperature.
2b) Manually-Initiated Defrost-Termination:
(1) DTh warms to 45°F (7.2°C). Defrost icon and "dEF" continue. DH de-energizes.
3-min. Comp and EvapFM delay timer starts, and 15-min. temperature display
delay timer starts.
(2) 3-min. Comp delay timer terminates. "dEF" continues. Defrost icon turns off,
Comp and EvapFM icons turn on, and Comp, ConFM, EvapFM, MH, and PH
energize.
(3) 12-min. later, 15 min. temperature display timer terminates. "dEF" is replaced by
cabinet temperature.
Defrost Diagnosis:
1) Time-Initiation or Manual Initiation: 5-hr. Comp cumulative run time defrost timer
terminates or CM defrost button pressed.
(1) CM Diagnosis: Conrm defrost icon turns on, "dEF" is displayed, and Comp and
EvapFM icons turn off. If not, replaceCM. Next, check that CM C1 (V) and CM
F5 (W/BU) do not have 115VAC to neutral (W). If 115VAC is present, replaceCM.
Check for 115VAC at CM H4 (O) to neutral (W). If 115VAC is not present, replace
CM.
(2) DH Diagnosis: Conrm DH energizes (amp draw). If not, check for 115VAC at
DT (BK) to neutral (W). If 115VAC is not present, check DT continuity. If open, let
cool and reset. If DT does not close, replace DT. If DT is closed, check DH amp
draw and continuity.
(3) Comp and ConFM Diagnosis: Conrm Comp and ConFM de-energize.
If not, check for 115VAC at CR#6(R) to neutral (W). If 115VAC is present,
replace CR.