Scotsman Ice CU50 System Information, Electrical Sequence, Electrical Components, Bin control

CU50

Service Manual

System Information

Overall:		Electrical Sequence:
•	Refrigerant: 8 oz R-134a	A closed bin thermostat signals to the controller a
•	Compressor: Hermetic, 1300 BTUH,	need for ice. The controller checks for water, if
•	Condenser: Forced draft	water is needed , the controller opens the inlet
		water solenoid valve to fill the reservoir. The hot
•	Fan blade: 5 blade, 7 inch
		gas valve is open to equalize the system. When the
•	Evaporator: Inverted, 24 cube cells. Copper
		reservoir is full, the compressor, fan motor, water
	cups attached to continuous serpentine
		pump are switched on. After 5 seconds the hot gas
•	Metering device: Cap tube
		valve shuts and ice making begins.

•Defrost method: Hot gas bypass with water

	assist	Water is sprayed up into the inverted cup mold. As
•	Spray method: 6 water jets	the water is cooled and ice begins to form in the
•	Water charge: 40 ounces	cups, the temperature of the evaporator will fall.

•Water valve: 115 volt solenoid, .19 GPM

•	Water fill time: Varies with harvest time &	The freeze cycle continues until the temperature of
		the thermistor attached to the evaporator outlet
	purge setting
		tube falls to about zero degrees F. At that point the
•	Spray pump: Pedestal type.
		controller starts a freeze cycle timer, whose default
•	Drain pump: Magnetic drive, controlled by
		time is 10 minutes. At the end of the freeze cycle's
	pressure switch
		timed portion the controller switches to the harvest
•	Purge method: Overflow standpipe	cycle.

•Control method: Electronic

• Cycle control: Thermistor + timers		The harvest cycle begins with the controller
• Freeze cycle timer: 10 minutes, + - 4		stopping the water pump and fan motor. At the
		same time it opens the hot gas valve and the inlet
• Harvest cycle timer: 20 seconds, + - 40
		water solenoid valve. The ice is released by the
• Cube size adjustment: Freeze timer change.
		combination of discharge refrigerant gas entering
• Harvest cycle adjustment: Harvest timer
		the evaporator serpentine and warming up the
	change
		copper, plus the inlet water that flows to the
• Bin control: Thermostat. Opens on		evaporator, floods across the plastic platen to
	temperature fall, Cut Out: 35 degrees F. Cut	warm it up and be pre-chilled for the next cycle. Ice
	In 45 degrees F. Range is adjustable.	cubes drop individually and harvest continues until
		the thermistor attached to the suction line warms
Electrical Components:		up to about 50 degrees F. At that point a harvest
		timer starts, whose default time is 20 seconds. At
•	Compressor	the end of that time the harvest cycle ends and the
•	Fan motor	freeze cycle restarts.

•Spray pump motor

•	Drain pump motor	Bin control.
•	Drain pump switch	The machine's on and off modes are regulated by a
• Inlet water solenoid valve
		bin thermostat. The cap tube for the bin thermostat
•
	Hot gas valve	is in the tube that holds the scoop. The machine
•	Transformer	will only begin ice making when the thermostat's
•	Controller	contacts close. If the contacts re-open before the
•	Water sensor	temperature of the evaporator drops below a preset
		point, the machine will stop. If the temperature is
•	Thermistor
		below that point when the contact s open, the
•	Bin thermostat
		machine will continue through a complete cycle

and stop at the end of the harvest cycle.

March 2010

Page 17