May 2008
Page 18
CU1526, CU2026, CU3030
Service Manual
Electrical Sequence - Air or Water Cooled
Power connected, unit previously switched Off.
Control board does a self check. If the self check fails, the unit displays an E and no further action will
occur.
If the self check passes, the controller will display a 0, the curtain light(s) will be ON and the Power and
Sump Empty lights will be ON.
Pushing and releasing the On button will start the ice making process.
The display will begin to blink F. The component indicator lights will switch on and off to match the
following process:
•
The purge valve opens and the water pump starts to empty the reservoir. This is done to discharge
any excess water from ice melting into the reservoir.
•
The hot gas valve and the harvest assist solenoid are energized.
•
The float valve will open to fill the reservoir. The water valve can open any time the water level is
low.
•
After a few seconds the purge valve closes and the pump shuts off.
•
When the reservoir is full the compressor switches on. Five seconds after the compressor starts
the hot gas valve and the harvest assist solenoid are de-energized.
Light Information: The display shows a non-blinking F. The Power and Status Lights will be Green. The
compressor, fan motor, water pump, sump full and one or two curtain switch lights will be ON.
The air cooled model's fan motor will start to turn when the discharge pressure has built up to the fan
pressure control's cut in point. This is about 15 seconds after the compressor starts.
The Freeze cycle continues. The compressor, water pump, fan motor and curtain indicator lights will be
ON. When the reservoir water temperature falls to a certain preset point, the water pump will shut off for
30 seconds. This is the anti-slush period. At this time the controller checks the conductivity of the water
in the reservoir for the auto-purge feature. After the water pump restarts the Sump Full light will go out
and neither sump lights will be on for the rest of the freeze cycle.
When the ice has built up enough so that the water flowing over the evaporator comes into continuous
contact with the ice level sensor, the Ready to Harvest light will begin to blink on and off. When it has
been On continuously for 5 seconds, the controller will switch the machine into a Harvest cycle.
