Liquid Line Valve
•
Remote only. Opened by the controller to start a freeze cycle. Closed to shut unit off. Line
voltage coil.
Hot Gas Valve(s)
•
Operated by the controller in parallel with the harvest assist solenoid. Cycles on and off at
the beginning of a restart. Energized throughout the harvest cycle. Line voltage coil.
Controller
•
Senses ice thickness, water level, water temperature, discharge temperature. Controls
compressor contactor, fan motor, water pump, inlet water valve, hot gas valve, purge
valve, harvest assist solenoid. Indicates status and component operation. 12 volt.
Transformer
•
12 volt secondary, supplies power to controller only.
Water Level Sensor
•
Three probe conductivity sensor. Bottom probe is common, mid probe is refill sump, top
probe is full sump. Refill can occur at any time.
Ice Thickness Sensor
•
Single wire conductivity sensor. Circuit made from controller to ground to controller when
water contacts a probe suspended over ice plate. Signals ready for harvest.
Curtain Switch(es)
•
Magnetic reed switch. Normally open, switch is closed when magnet is nearby. Models
with two evaporators have two curtain switches. Single switch can be connected to either
J8 or J7 of controller. Curtains may be removed in the freeze cycle without affecting
controller operation. A curtain removed during harvest will cause the controller to terminate
harvest and shut the unit off. Two curtain models require both curtains to open to
terminate harvest, and if either one remains open for 30 seconds that signals the controller
to shut the unit off on bin full.
Water temperature sensor.
•
Thermistor inserted into the water pump discharge hose. Reported temperature used by
the controller to determine anti-slush cycle start time.
January 2010 Page 33
Electrical Component Details
