KitchenAid KBFA20ER, Technical Education

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3-1
PRODUCT OPERATION
THEORY OF OPERATION
TEMPERATURE MANAGEMENT
The KitchenAid French Door Bottom-Mount
Refrigerator uses a thermistor in each cooling
compartment to maintain proper tempera-
tures. An electronic control, mounted in the
unit compartment, monitors the thermistors in
each compartment. As the freezer temperature
warms, the control energizes the compressor
and evaporator fan motors to cool the com-
partment.
When the refrigerator temperature rises and
warms the refrigerator thermistor, the control
energizes the mechanical air damper motor to
move it to the open position. At the same time,
the evaporator fan motor begins to run to bring
cool air up from the freezer. As noted above,
the compressor will run as needed based on
the temperature in the freezer compartment,
but the evaporator fan motor can run without
the compressor when the refrigerator is calling
for cooling.
REFRIGERATOR
DAMPER OPERATION
When the refrigerator compartment warms
and cooling is required, power is applied to the
YL/RD wire on the damper switch. The damper
motor runs until the damper switch changes
to the normally open (N.O.) position, and the
motor stops with the damper door fully open.
Power remains on the YL/RD wire as long as
cooling is required.
When the proper temperature is reached in the
refrigerator compartment, the electronic control
switches power to the BU/RD wire. The motor
runs until the damper switch closes into the
normally closed (N.C.) position, and the motor
stops with the damper door fully closed.
Power will always be applied to either the BU/RD
(temperature satisfied and the damper door is
closed), or the YL/RD (calling for cooling and
the damper door is open). The maximum open-
ing or closing time is 36 seconds.