Section D - Air Circulation; Air Circulation Patterns - Electrolux E23CS75DSS0 Service Manual

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Section D - Air Circulation

Automatic Defrost Models
Principals Of Automatic Defrost
Operation
Automatic defrost refrigerators operate on the
principle that moisture or frost transfers or migrates
to the coldest surfaces (evaporator) in the freezer
compartment. For example, a small amount of
water spilled in the freezer compartment will freeze
immediately. However, this ice in time will evaporate
and transfer to the colder surfaces of the freezer
evaporator coil.

Air Circulation Patterns

Automatic defrost models have a single
evaporator in the freezer compartment, and have
forced air cooling in the freezer and refrigerator
compartments.
The "fin and tube" aluminum type evaporator is
located behind the lower back wall of the freezer
compartment. A circulating fan (suction type)
pulls air from the freezer compartment through
the grill in the bottom of the freezer and from the
refrigerator compartment through a duct located
in the separating wall in the bottom rear left hand
corner of the cabinet interior. The air is than drawn
up through the fin and tubes of the evaporator
surface. The cold air is forced into a fan cover and
discharged into the top of the freezer and out the
air discharge under the ice maker. Figure D1. The
air circulating fan operates any time the thermistors
sense the temperature of the food compartment
or the freezer compartment are above the upper
control limit and send the information to the lower
control board. If the food compartment is calling for
cooling the automatic damper in the top of the food
compartment will open and allow cold air to enter
the food compartment. If the food compartment
calls for cooling but the fan is not running, the fan
will start is soon as the damper is open and will
continue to run as long as the food compartment
and/or the freezer compartment call for cooling.
The air circulating fan a 12 V DC fan motor
operates any time the food compartment or the
freezer compartment call for cooling. During the
defrost period, the compressor and circulating fan
do not operate. The power board located under the
freezer behind the grill opens the electrical circuit to
the fan motor and compressor for the defrost cycle.
The lower control board also closes the damper
door that is controlled by a 12 V DC stepper motor
and keeps the damper door closed during the
complete defrost cycle.
Figure D1