Scotsman CSW45 - Manual (Page 21)

Electrical Sequence
The CSW45’s operation is controlled by an electronic
board. This board takes in data from two thermistors:
The Ice Bin Thermistor and the Evaporator
Thermistor. The two resistances the thermistors
supply, along with the position of the control switch,
determine the cycles of the ice machine.
Start Up
The inlet water valve opens for about two minutes to
fill the reservoir.
The water pump starts and stays on for about a
minute, then shuts off.
Then the inlet water valve opens again for two
minutes. After it closes, the compressor, pump and
fan motor start.
Freeze
The compressor, fan motor and water pump are all
operating and stay in a Freeze cycle until the
evaporator thermistor reaches 6.5
o F. That signals
the control board to place the unit into a harvest
cycle.
Harvest
The compressor and hot gas valve are both powered
during the harvest cycle. The fan and pump are OFF.
The machine stays in the harvest cycle until the
evaporator thermistor senses 52
o
F. If the bin is not
full, the unit goes into another freeze cycle.
Bin Full
The unit will shut down when the ice level sensor
senses a temperature of less than 35
o
F. It will restart
when the thermistor’s temperature increases to 41
o
F.
Clean
The Clean Cycle lasts about 47 minutes. During the
first minute all motors and valves will be switched on
in sequence for 5 seconds each. This includes the
inlet water valve, condenser fan, hot gas solenoid
valve, water spray pump and the compressor. This
early portion of the Clean Cycle doubles as a
diagnostic cycle. The last 46 minutes of the clean the
compressor, water spray pump and hot gas valve will
be on.
July 1999
Page 21
CSW45