Defrost Cycles - GE PSH23PGR Series Technical Service Manual

Temperature can cause some fan speed
variation. Fan speed can vary +/- 5%, depending
on the temperature, with higher temperatures
causing slightly higher speeds.
Condenser fan speed is controlled by Pulse
Width Modulation (PWM), the same method used
to control fan speeds for the evaporators.
13.6 VDC
12.0 VDC
0 VDC
Super High Speed (12.0 VDC measured)
13.6 VDC
10.5 VDC
0 VDC
High Speed (10.5 VDC measured)
13.6 VDC
7.5 VDC
0 VDC
Medium Speed (7.5 VDC measured)
13.6 VDC
5.5 VDC
0 VDC
Low Speed (5.5 VDC measured)

Defrost Cycles

Fresh Food Evaporator Defrost Cycle
The refrigerator utilizes a forced air cycle defrost
method (no electric heater) to remove frost from
the fresh food evaporator. Fresh food air that is
above freezing temperature circulates thru the
coil and melts any accumulated frost. Note that
during fresh food defrost, the compressor may
still be running, cooling only the freezer section.
Fresh Food Normal Defrost
The fresh food section cools until the fresh food
thermistor is satisfi ed.
If both freezer and fresh food thermistors are
satisfi ed, the compressor cycles off. If the freezer
still requires cooling, the main control board
rotates the 3-way valve to stop refrigerant fl ow to
the fresh food evaporator. Even though refrigerant
fl ow has stopped in the fresh food evaporator, the
fresh food fan continues to run at low speed.
The system is designed to run the fan until the
fresh food evaporator thermistor reaches 35°F.
Once this temperature is reached, the fan
continues to run for an additional 5 minutes.
Under normal conditions, the defrost time takes
approximately 30 minutes. The maximum time
the fan runs in low speed is 60 minutes. If the
evaporator thermistor has not reached 35°F after
60 minutes, the control switches to extended
defrost #1.
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