Viking VCSB48, Сервисный журнал, Страница: 12 / 33

12
Electronic Functional Description ( con’t)
1. Critical temperature for freezer is +15
°
F; for
refrigerator critical temperature is +60
°
F.
2. Press Alarm Off pad to turn off alarm.
Thermistor Alarm
Alarm sounds and freezer or refrigerator indicator
light shows and temperature indicators 4 through 7
will turn on in sequence if either thermistor circuit
opens. Refer to Temperature Control Operation
Section and Electronic Testing Section.
1. Press Alarm Off pad to turn off alarm.
2. Alarm will retest for normal operation. If
condition has not been corrected, alarm will
sound again.
Temperature Control Operation
For any temperature setting, outputs will be turned
off/on based on cut-in/cut-out temperature
determined by resistance levels of freezer and
refrigerator thermistors.
Refrigerator and Freezer Thermistor
As temperature decreases, resistance increases.
As temperature increases, resistance decreases.
Open thermistor or thermistor circuit will result in
failure of refrigerator to cool.
Shorted thermistor will cause refrigerator to run 100
percent of time except for defrost cycle.
•
Freezer temperature setting and thermistor value
will determine if compressor/condenser fan and
evaporator fan switches are open or closed.
Compressor/condenser fan switch must be open
for 6 minutes before switch can close again
(compressor dwell time).
•
Refrigerator temperature setting and thermistor
value will determine if fresh food fan switch is
open or closed.
•
Cut-out and cut-in temperature values must be
reached and maintained for 15 seconds before
output state will change (digital delay).
•
Refrigerator and freezer control calibration can
be adjusted in Program Mode B.
Factory set freezer and refrigerator settings