Horizon HCD700R/N, HMD700R/N Ice Machines
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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.
Comp/Sol output:
The output for the liquid line solenoid valve is labeled COMP/SOL.
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.