Ice-O-Matic GEMU090 Series, Service Manual, Page: 10 / 25

Electrical Sequence
Upon power being supplied, all the lights will blink
once and the control system will immediately check
for water in the reservoir. If there is water no further
action will occur until the On/Off button is pushed.
Pushing the On/Off button starts the machine. The
Ice Making light will switch on. The auger motor,
compressor and fan will begin to operate. Those
three components will continue to operate until the
Ice Level Control detects that ice has built up to the
pre-set level. At that point the control system will
begin a shut down process by shutting off the
compressor and fan motor.
After sixty seconds the auger motor will shut off.
The purpose of this is to remove any ice from the
evaporator so the auger motor can restart with
minimal load.
The machine will restart after the ice level has
fallen one inch or more.
Other Control Functions:
To Shut Off: Push and release the On/Off button. If
the machine was off because the bin was full, the
unit will be switched to Off immediately. If the unit
was making ice, the compressor and fan motor will
shut off immediately, and the auger motor shut off
in sixty seconds. To shut the unit off immediately
while making ice, push and HOLD the On/Off
button until it shuts off.
To Clean: See Maintenance section for step by
step process. Pushing the Clean button while the
Ice Making light is On does not start the clean
cycle, it is only active from Off. Pushing the Clean
button from Unit Off starts the clean cycle:
•
Time to Clean light flashes
•
Auger motor operates for twenty minutes
•
Auger motor and compressor operate for
twenty additional minutes
•
Unit shuts off, Time to Clean reminder light
switches Off.
Safety Shut Downs:
Lack of water. It is critical that the unit not operate
without a full charge of water. The water sensor in
the reservoir is used to check continuity through
the water it is in contact with. If there is no water
present, there will be no electrical continuity and
the control system will stop the machine and cause
the Check Water light to blink Red, alerting the
user of a lack of water. When water has returned to
the reservoir, the unit will automatically restart.
Power interruptions: If the power to the machine
failed during normal operation, the machine will
automatically restart after a two minute delay. If the
unit had shut down because of a safety, then the
unit remains in the shut down state.
Auger motor overload: If the auger motor current
exceeds the preset limit for a certain time, the
controller will shut the compressor and auger motor
off. The controller will keep the compressor and
auger motor off for four minutes, then restart them.
The controller records each overload as a strike. It
will erase the strike(s) if the current draw in the
sixty seconds following the restart is below the
preset limit. If within the sixty seconds after the
restart the current again exceeds the limit, the
controller again shuts the machine down and a
second strike is recorded and four minutes later a
second restart occurs. If the current is again
excessive the third time, the unit will stop restarting
and the lights will flash on and off every two
seconds.
Auger motor low current: If the controller senses
the auger motor is not drawing any or minimal
current, it will shut the compressor and auger motor
down for twenty minutes before attempting a
restart. The twenty minutes are intended as time
for the auger motor to cool off if it has shut down on
its internal overload. The controller records that as
a strike. If in the next sixty seconds the auger
motor begins to draw current the strike is erased
and normal operation resumes. If the current is still
low, a second strike is recorded and the unit will
wait another twenty minutes before attempting a
third restart. If the third restart is normal, the strikes
are erased and normal operation is continued. If
the unit fails again, the unit will stop restarting and
the lights will flash twice on and off every two
seconds.
Controller Failure: If all lights are flashing once
every 10 seconds the controller has identified an
internal failure and must be replaced.
Page 8
GEMU090
Service