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Freezer and Fresh Food Heated Defrost
Following pre-chill, the heated freezer and heated
fresh food defrost cycle is initiated where both
heaters will be on at the same time.
The 3-way valve will move to the A position. The
compressor will turn off. The condenser, freezer, fresh
food, and ice box fans will turn off.
The freezer defrost heater remains on until the freezer
evaporator is 50
˚
F (defrost termination temperature)
or the maximum defrost time of 45 minutes is
reached.
The fresh food defrost heater remains on until the
fresh food evaporator is 45
˚
F (defrost termination
temperature) or the maximum defrost time of 45
minutes is reached.
If either the fresh food or freezer defrost heater’s
ON time exceeds the normal defrost threshold of
approximately 20 minutes, the defrost is considered
abnormal. Abnormal defrost forces both the fresh
food and freezer into pre-chill after 6 hours of
compressor run time (door openings not counted).
During defrost, if power is interrupted, the refrigerator
will restart in the dwell state if the freezer evaporator
temperature is above 50
˚
F (defrost termination
temperature).
After both defrost heaters turn off, the refrigerator will
enter the dwell cycle.
Dwell Cycle
After both defrost heaters have cycled off, the unit
will enter the dwell cycle.
During the dwell cycle, the compressor and fans
will remain off. The 3-way valve will move to the
A position (both fresh food and freezer open) and
remain there for the entire cycle.
Dwell cycle will terminate after 7 minutes.
At the end of the dwell cycle, the compressor run
timer for adaptive defrost is reset to 0 hours and the
refrigerator enters the post-dwell cycle.
If power is interrupted during the dwell cycle and the
freezer temperature is greater than 50
˚
F (the freezer
defrost termination temperature), the dwell cycle
will start over.
Note:
Pull down will start if the freezer
temperature is over 60°F.
Post Dwell Cycle
Upon completion of the dwell cycle, the unit will enter
the post-dwell cycle.
The 3-way valve will move to either the A or B
position, depending upon whether the fresh food
temperature is satis
fi
ed.
The compressor and condenser fan will start, but the
fresh food fan, freezer fan, and ice box fan will remain
off.
Post-dwell cycle will end when the freezer and
fresh food evaporators reach the post dwell exit
temperature of -10
˚
F, or the post-dwell time of 10
minutes has expired.
Upon exit of post-dwell cycle, the control system
will now operate all cooling components by its logic
and restarts the compressor run timer for adaptive
defrost.
Refrigerator Operation Summary
Models operate as follows:
• Pull down occurs when the refrigerator is
powered up and freezer is above 60
˚
F.
• Cooling operation is the normal cycling of
temperatures whether the last defrost was
normal or abnormal.
• Fresh food cycle defrost occurs when the 3-way
valve turns off refrigerant
fl
ow to the fresh food
evaporator, but the freezer continues to cool.
• Pre-chill occurs before freezer heated defrost.
• Fresh food defrosts occur 32, 64, and 96 hours
from the previous freezer and fresh food heated
defrost.
• Freezer heated defrost occurs every 96 hours of
compressor run time.
• Dwell occurs after every heated defrost cycle.
• Post dwell occurs after every dwell cycle.
