Follett HCE/HME700A, Operation And Service Manua

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Error faults:
The Horizon PC board monitors various operating parameters including high pressure, auger gearmotor
amperage limits, clogged drain, and low water alarm conditions. There are two types of errors namely “hard” or
“soft”. A hard error is one that shuts the machine off and will not allow restart until the reset button is pressed.
Even cycling power will not reset a hard error. A soft error can either be automatically reset should the condition
rectify, or if power is cycled. Should an error occur, consult the troubleshooting guide in this manual or a Follett
service technician.
Soft errors:
HI AMPS: The PC board monitors the amperage of the auger motor. Should the gear motor experience current
draw above the allowable limit, the machine will shut down and the TIME DELAY and HI AMP will be illuminated.
After the time delay the machine will restart and the TIME DELAY and HI AMP will clear.
LO WATER: During operation, the water level cycles between the normal low and normal high sensors. Should
the water be shut off to a running machine, a soft error will occur. The error sequence is as follows: During
operation, the water level falls to the normal low sensor, and when it does the water feed solenoid is energized.
If water is not detected at the normal low sensor within 10 seconds, a soft error will occur. The machine will shut
down, but the water feed solenoid will remain energized. Should water return, it will fill to the normal low sensor
and the machine will resume normal operation. The error will clear automatically.
HI PRESSURE: Should the refrigeration pressure rise above 425 psi, the machine will shut down and the TIME
DELAY and HIGH PRESSURE will be illuminated. After the time delay, and if the pressure has fallen back below
the reset point of 295 psi, the machine will restart and the TIME DELAY and HIGH PRESSURE will clear.
Hard error:
DRAIN CLOG: The drain clog sensor, located in the chassis, underneath the rear drain pan, will detect the
presence of water just below the top edge of the pan. If water does not properly flow out of the drain pan it will
overflow into the chassis and rise to the sensor (especially during a self-flushing purge cycle). Pressing the reset
button will restart the ice machine.
Relay output indication:
Each relay on the board has an indicator light associated with its output. For example, when the relay for the
water feed solenoid is energized, the adjacent indicator light glows green.
Flushing logic
Flush on fly: For every one (1) hour of ice making time, the machine will open the drain valve for a duration of
60 seconds. While the drain valve is open, the machine will continue to make ice and the water feed valve will
cycle to maintain water level.
Off cycle: At the completion of off-cycle time delay, the machine checks for a cumulative one (1) hour of ice
making time since the last
off-cycle flush. If the cumulative ice making time exceeds one (1) hour, the machine
will open the drain valve for 60 seconds to drain the evaporator in its entirety. It will then refill with water and
begin making ice. If the ice making time is less than 1 hour, the machine will start and begin making ice
without draining the evaporator.