Selected Electrical Components - Scotsman UC2024 Series Service Manual

UC2024 and UC2724 Service Manual

Selected Electrical Components

Controller
The controller is the part that operates the machine. It is
connected to:
• Pressure controls
• Hot gas valve
• Evaporator thermistor
• Sump water thermistor
• Sensing plate switch
• Contactor coil
• Water pump
• Inlet water valve
• Fan motor (if air cooled)
• Master switch
• Transformer
Compressor
Vapor pump that forces refrigerant thru the system
Water pump
When powered, it circulates water over the evaporator
plate
Inlet water valve
When energized, it opens to let water into the sump.
Evaporator thermistor
Attached to the evaporator refrigerant outlet tube, the
resistance is checked by the controller to determine
when the ice is nearly ready for harvest.
Sump water thermistor
Inserted into the water pump hose, its resistance is
checked by the controller to determine when the water
pump should be temporarily stopped to avoid slush in
the sump.
Pressure controls
There are two, high pressure cut out and fan motor
on air cooled models. The high pressure cut out stops
operation if discharge pressure is too high. The fan
motor pressure control cuts the fan off when discharge
pressure is low and switches it back on when it has
increased.
Sensing plate switch
Normally open, closes when the magnet on the sensing
plate is next to it. Controls the harvest cycle and the on
off operation of the machine.
November 2019
Page 18