Refrigeration Compartment Theory Of Operation - Viking VCSB483D Service Notebook

To avoid electrical shock, which can cause severe personal injury or death, disconnect power to
refrigerator using power switch before servicing. Wires removed during disassembly must be replaced
on proper terminals to insure correct earth ground and polarization. After servicing, reconnect power
using power switch.
If both freezer and fresh food thermistors
are warm, their resistance drop (see table
Refrigeration and Freezer Thermistor in
Temperature Control Section) and the
electronic signals are sent to initiate
operation of the evaporator fan motor,
compressor, and condenser fan motor and
for operation of the fresh food fans. Once
the signal is sent for operation of the
compressor, the adapter board sends a 3mA,
5VDC square wave frequency signal to the
inverter in order to start the compressor
motor at the specified speed (See table on

Refrigeration Compartment Theory of Operation

WARNING
page 5 in this document for appropriate
values). As the fresh food thermistor warms,
resistance decreases allowing low voltage
signal to be sent to the electronic control. The
electronic control sends a low voltage signal
to semiconductor switch for DC fresh food fan
to begin operating. The fresh food fan then
circulates freezer
compartment.
As the fresh food thermistor cools, the
resistance increases. The increased resistance
blocks low voltage signal to electronic control,
interrupting circuit to DC fresh food fan.
33
air into fresh food