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Test points:
The Horizon PC board incorporates on-board test points that can be used to determine various electrical
outputs. The test point holes allow a standard probe to be inserted for quick voltage measurement. For 208-230
systems, use TP-4 (L2) as the common for testing outputs for solenoids, motors, etc.
Time delay and self-flushing jumpers:
The duration of the Time Delay period, the time between normal shut down and restart, is jumper selectable.
Jumpers J33 and J34 can be used to select a time delay value of either 1/2, 1, 2, or 3 hours. The factory default
setting is 1 hour. Jumper J32 sets the self-flushing interval to 2 or 6 hours of compressor run time, and J31
either enables or disables self-flushing feature. The factory default setting is enabled flushing every 2 hours.
Error faults:
The Horizon PC board monitors various operating parameters including high pressure, auger gearmotor
amperage limits, clogged drain, and high 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.
Note:
there are two types of LO WATER and HI AMPS errors as listed below.
Soft errors:
HI AMPS: The PC board monitors the amperage of the auger motor. Should the gear motor experience current
draw above the 3.8 amps limit the machine will shut down and the TIME DELAY, HI AMP, and SERVICE LED’s
will be illuminated. After the time delay the machine will restart and the TIME DELAY, HI AMP, and SERVICE
LED’s will clear.
HI WATER: A sensor in the water reservoir is positioned at the very top of the reservoir cap. Should water rise to
this high alarm sensor, a soft error will occur. The machine will operate with this alarm active, however the water
feed solenoid will not be on. The alarm will turn off should water recede from the sensor.
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 120 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.
Hard error:
HI AMPS:
1. “Two strikes” feature.
If the gearmotor has a second HI AMP occurrence during the countdown period
(6 hours after a HI AMP time delay) a hard error will occur and the HI AMP and SERVICE LED’s will be
illuminated.
2. No current. To prevent the refrigeration system from running without gearmotor rotation the PC board will
indicate HIGH AMP and SERVICE if the drive relay is energized and there is no current draw.
HI PRESSURE: Should the refrigeration pressure rise above 425 psi, a hard error will occur. Even if pressure
fall-back below the reset point of 295 psi, the error will not clear and the machine will not restart.
DRAIN CLOG: The drain clog sensor, located in the plastic drain pan behind the drain solenoid, 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
rise to the sensor, especially during a self-flushing purge cycle.
LO WATER:
1. There is a sensor in the water reservoir that reaches down to the very bottom. The machine will not start if
water is not present at this sensor.
2. A hard error will occur should water not be present within 60 seconds of power up or if the sensors are
disconnected or damaged.
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 compressor is labeled COMP/SOL.
