Hoshizaki FTC-120MDA, Service Manual

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30
Operations
1. Compressor functions:
A. Under electric heating defrost mode:
Start condition: Compressor relay closes when both a) and b) or both a) and c) are met.
a) Compressor delay time exceeds the set delay time.
b) Forced refrigeration starts when the room temperature is higher than the set point
temperature.
c) Under non-defrost mode, the room temperature is higher than the set point temperature
+ return difference.
Stop condition: Compressor relay opens when any of the following conditions is met.
a) Room temperature is lower than the set point temperature.
b) At the start of defrost cycle.
c) Forced refrigeration stops.
B. Under thermal defrost mode:
Start condition: Compressor relay closes when both a) and b), both a) and c) or both a)
and d) are met.
a) Compressor delay time exceeds the set delay time.
b) Under non-defrost mode, the room temperature is higher than the set point temperature
+ return difference.
c) Forced refrigeration starts when the room temperature is higher than the set point
temperature.
d) In defrost cycle.
Stop condition: Compressor relay opens when any of the following conditions is met.
a) Room temperature is lower than the set point temperature.
b) At the end of defrost cycle.
c) Forced refrigeration stops, and defrost cycle does not start immediately.
2. Defrost functions:
Defrost relay closes when the following conditions are met.
a) Defrost delay time meets the set delay time.
b) Defrost thermistor temperature is lower than the defrost termination temperature.
c) Defrost cycle ends or manual defrost starts.
Defrost relay opens when any of the following conditions is met.
a) Defrost time runs out.
b) Defrost thermistor temperature is higher than the defrost termination temperature.