Manitowoc Ice FLAKE/CHIPLET QF0400 - Manual (Page 111)

Section 6 Electrical System
Part No. 80-1214-3 6-49
MOTOR SPEED SENSOR
Function
The motor speed sensor verifies that the gearbox motor
is rotating at the correct speed.
Failure Modes
MOTOR SPEED SENSOR OPEN OR DISCONNECTED
(ICE MACHINE WILL NOT START.)
Performs initial start-up procedure. Ten to 15 seconds
after the ice machine enters Water Flush (1), the ice
machine will initiate an Automatic Shut-Off cycle, flash
the Speed light and remain off for 60 minutes. (Refer to
“Gear Motor Speed” for additional information.)
MOTOR SPEED SENSOR CLOSED OR SHORTED
(ICE MACHINE WILL NOT START.)
Performs initial start-up procedure. Ten to 15 seconds
after the ice machine enters Water Flush (1), the ice
machine will initiate an Automatic Shut-Off cycle, flash
the Speed light and remain off for 60 minutes. (Refer to
“Gear Motor Speed” for additional information.)
Check Procedure
1. Allow time for the evaporator to warm. Disconnecting
power in the Freeze cycle will result in ice build-up
between the evaporator and auger.
2. Verify the motor speed sensor is in place and
securely attached to the motor.
3. Verify the gearmotor run capacitor is functional.
4. Place toggle switch in the OFF position and place an
identifying mark on the evaporator/gearbox coupling.
This will provide a reference point to verify the
coupler is rotating.
Move the toggle switch to the ICE position and verify the
motor shaft and coupling are turning, then observe the
Speed light.
(If the gear motor and coupling will not rotate, the switch
is operating correctly.)
To verify coupling/auger RPM (revolutions per minute):
1. Verify line voltage is within 10% of ice machine
nameplate rating when low RPM is suspected.
2. Verify the gear motor run capacitor is functional.
3. Place identifying mark on coupling.
4. Count coupling revolutions for 2 minutes.
5. Divide coupling revolutions by 2 (example:
31 coupling revolutions ÷ 2 = 15-1/2 RPM).
Minimum revolutions per minute:
QF400 = 9 RPM
QC700 = 15 RPM
QF800 = 15 RPM
QF2200/QF2300 = 11.6 RPM
Speed light is: Cause
On
after 3 to 5 seconds
This is normal operation.
Off
Replace motor
speed sensor.
On after 3 to 5 seconds
and control board
terminates Freeze cycle
Replace control board.
Speed Sensor
QF400
SV2046
Revised 8/2003