Welbilt FB081TF, Service Manual

Page: 72 / 96

72 Part Number REV00 04/08/2020
Component Check Procedures Section 7
GEAR MOTOR ROTATION SENSOR
Function
The rotation sensor monitors evaporator gear motor speed.
If the gear motor speed drops below 8 pulses per minute
or exceeds 35 pulses per minute the rotation sensor signals
the control board to stop the gear motor and compressor.
Specifications
The sensor monitors gear motor rotation and includes a
time delay and alarm condition.
• At the initial start- up there is a 10 second delay and the
rotational sensor light flashes yellow to indicate a time
delay period.
• The rotation sensor delays sensing for 20 seconds to
allow the gear motor speed to stabilize.
• If the gear motor speed is outside the range the red
sensor light flashes for 10 seconds,. After 10 seconds
the sensor light switches to yellow and monitors motor
speed. If this cycle repeats 8 consecutive times the
sensor goes into an alarm condition - The red sensor
light is on and the ice machine stops until reset.
NOTE: The SAFETY 2 LED on the control board is also
energized.
Light Definition
Yellow Blinking Time Delay Period
Yellow Solid Normal Operation
Red Blinking Fault Time Delay Period
Red Solid Lockout - 8 Consecutive Faults
Remove/Restore Power To Reset
FAN CYCLE CONTROL
Function
Cycles the fan motor on and off to maintain proper
operating discharge pressure.
The fan cycle control closes on an increase, and opens on a
decrease in discharge pressure.
Specifications
Specifications
Refrigerant Type Cut-In (Close) Cut-Out (Open)
R404A 250 ±5
(1723 kPa ±.34)
(17.23 bar ±.34)
200 ±5
(1517 kPa ±.34)
(15.17 bar ±.34)
R290 250 ±5
(1723 kPa ±.34)
(17.23 bar ±.34)
200 ±5
(1517 kPa ±.34)
(15.17 bar ±.34)
Check Procedure
1. Verify fan motor windings are not open or grounded,
and fan spins freely.
2. Connect manifold gauge set to ice machine.
3. Hook voltmeter in parallel across the fan cycle control,
leaving wires attached.
4. Refer to chart below.
FCC Setpoint:
Reading
Should Be:
Fan
Should Be:
Above Cut-In 0 Volts Running
Below Cut-Out Line Voltage Off