Service Manual

13
b) Freezer
1. Startup/Cool Down
MH and PH energize. There is a slight delay before cabinet temperature appears on
DMand Comp, ConFM, and EvapFM energize.
2. Cool Down Achieved
CM monitors cooling of the cabinet via CTh. CTh cools to 3
°F (1.7°C) below setpoint.
EvapFM, MH, and PH continue. Comp and ConFM de-energize.
3. Cool Down Restart
CTh warms to 3
°F (1.7°C) above setpoint. EvapFM, MH, and PH continue. Comp and
ConFM energize.
4. Defrost
"dEF" is displayed during defrost. There is a 5-minute minimum defrost time and a 1-hour
maximum defrost time.
a) Temperature/Time Initiation: DTh cools to 32
°F (0°C), then a 4-hour cumulative Comp
run timer starts. Once 4-hour cumulative Comp run timer terminates and DThis at or
below 32°F (0°C), defrost begins. DH energizes, MH and PH continue, Comp, ConFM,
and EvapFM de-energize.
b) Manual Initiation: Manual defrost may be initiated by pressing and holding the lower
button until "dEF" appears on DM. MH and PH continue. DH energizes, Comp, ConFM,
and EvapFM de-energize.
c) Termination
(1) After Temperature/Time Initiation: DTh warms to 59
°F (15°C). 3-minute Comp
delay timer starts, 8-minute EvapFM delay timer starts, and 13-minute temperature
display delay timer starts. MH and PH continue, DHde-energizes.
3-minute Comp delay timer terminates. Comp and ConFM energize. 5 minutes
later, 8-minute EvapFM delay timer terminates and EvapFM energizes. 5 minutes
after EvapFM energizes, 13-minute temperature display delay timer terminates and
cabinet temperature returns to DM.
(2) After Manual Initiation: DTh warms to 59°F (15°C). MH and PH continue, DH
de-energizes. 3-minute Comp/EvapFM delay timer starts, 13-minute temperature
display delay timer starts.
3-minute Comp/EvapFM delay timer terminates. Comp, ConFM, and EvapFM
energize. 10minutes later, 13-minute temperature display delay timer terminates
and cabinet temperature returns to DM.
Note: There is a 4-hour minimum defrost interval.
Legend: CM–control module; Comp–compressor; ConFM–condenser fan motor;
CTh–cabinet thermistor; DH–defrost heater; DM–display module;
DTh–defrost thermistor; EvapFM–evaporator fan motor; MH–mullion heater;
PH–perimeter heater