Welbilt FB081TF, Service Manual

Page: 22 / 96

22 Part Number REV00 04/08/2020
Operation Section 3
REFRIGERATED CABINET OPERATION
Default temperature set point = 1.1°C / 34° F with a 2.2°C /
4° F Differential.
Default Cabinet Settings
Normal Operations
The microprocessor control board controls the cabinet
temperature based on the input received from the cabinet
temperature thermistor. The thermistor value is compared to
the control board set point. When the reach-in temperature is
equal or greater than the set point (plus half the differential),
the compressor relay closes, provided the following
conditions are satisfied:
• Power has been uninterrupted to the control board for
a 3 minute period.
OR
• The 3 minute compressor time delay has expired. The
delay period starts after the compressor has run and
then cycles off.
The compressor relay opens when the reach-in temperature
is less than the set point (minus half the differential).
EVAPORATOR & CONDENSER FAN MOTOR OPERATION
The condenser fan motor and compressor share the
same relay. The evaporator fan motor relay is energized
continuously and the evaporator fan runs continuously.
OPERATION IN THE CLEAN/SANITIZE CYCLE
During the weekly cleaning/sanitize cycle, the evaporator fan
motor relay and the condenser fan motor/compressor relay
remain energized.
ADAPTIVE DEFROST
After 3 hours of cumulative compressor run time, the
compressor will be de-energized for fifteen (15) minutes.
HIGH TEMP ALARM
High temp alarm will display when product thermistor
is above 5.5°C / 42°F for 30 minutes and the following
conditions are satisfied:
• 3 hours since power is applied
• 1 hour since cleaning cycle
Error display will reset when the temperature reaches 5°C /
41°F or below.