Normal Operating Characteristics; Abnormal Operating Characteristics; Liner Protection Mode - GE ZIC36ON Series Technical Service Manual

Adaptive Defrost (Defrost Heater Operation)
After 15 minutes of pre-chill operation, the main
control board turns off the compressor, condenser
fan, and evaporator fan.
During defrost operation, the main control board
monitors the evaporator temperature using
evaporator thermistor inputs. Typically, the
evaporator thermistor will sense a temperature of
45 °F within 20 minutes. When the thermistor
senses 45 °F, the main control board will terminate
defrost heater operation. Maximum defrost cycle
(heater on) time is 40 minutes (main control board
time out).
The defrost system is protected by a defrost
termination thermostat (bimetal switch). The
thermostat opens when the evaporator
temperature raises to 65 °F and closes when the
evaporator temperature lowers to 45 °F.
Adaptive Defrost (Dwell Period)
After defrost heater operation has been terminated
by the main control board, a 5-minute dwell period
occurs. During this period, the compressor,
condenser fan, and evaporator fan remain off. The
remaining frost melting from the evaporator will
continue to drip and drain so that, prior to the
cooling operation, the evaporator will be totally
clear of any moisture. After the 5-minute dwell
period, the unit goes into post dwell.
Adaptive Defrost (Post Dwell)
The post dwell period is designed to cool the
evaporator before circulating air within the
refrigerator. This prevents any residual heat on the
evaporator from being distributed in the freezer.
During this period, the compressor is on and the
condenser fan is on, but the evaporator fan is off.
Post dwell will last 10 minutes or until the
evaporator temperature reaches 30 °F on these
models.
Normal Operating Characteristics That Are
Different from Previous Models
• Evaporator fan running, without compressor or
condenser fan.
•
Post Dwell (Adaptive Defrost), compressor,
and condenser fan on with evaporator fan off
after defrost cycle.
• Liner Protection Mode, fan comes on when the
doors are open for 3 minutes.
• Different sound levels can be heard when the
fan changes speed; however, the fan should
never be heard oscillating between speeds.
• Response time for drastic temperature change
is 2 to 10 minutes. The main control board will
only respond to 8 °F of temperature change
per minute as determined by resistance of
sensor.

Abnormal Operating Characteristics

(Incorrect Operation)
• Rapid fan speed changes, fan takes at least
1 minute to change speeds.
• Compressor running without the condenser
fan. The compressor and condenser fan
should always run at the same time.

Liner Protection Mode

The liner protection mode will activate if either of
the doors has been open for 3 minutes. This
mode will start the evaporator fan on high speed.
This mode is controlled by 2 timers. Timer #1
monitors door-open time. A 3-minute door-open
count begins when the door is opened. If
3 minutes elapse before the door is closed, the
liner protection mode will become active. Once
the door is closed, timer #1 resets and liner
protection mode goes into standby. In standby,
normal fan and damper operations resume and
timer #2 begins a 3-minute door-closed count.
If 3 minutes elapse without a door opening, liner
protection mode will completely deactivate. If a
door is opened within the timer #2 door-closed
count, the remaining time in the door-closed count
will be deducted from the timer #1 door-open
count.
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