Freezing Cycle Operation - Scotsman CME650R Service Manual

FREEZING CYCLE OPERATION

Water from the sump assembly is pumped to the
water distributor system at the top of each
evaporator plate. From the water distributor the
water cascades by gravity over all cells of the plate
and to the sump assembly below.
At the beginning of the freezing cycle, the electrical
circuit is completed to the compressor and the
water pump. The water pump operates
continuously, through both the freezing cycle and
the harvest cycle.
During the freezing cycle, the hot gas solenoid
valve is CLOSED and the water inlet solenoid
valve is CLOSED. When the ice cubes are partially
formed, the cube size control will sense the
temperature at which it is preset to CLOSE. This
will complete the electrical circuit to the timer. The
timer then controls the remainder of the freezing
cycle.
Liquid
Line
Head
Pressure
Control
Valve
Receiver
King
Valve
Fan
Motor
Discharge
Line
Discharge
Coil
Compressor
Crankcase
Heater
Filter/Dryer
Drain
The timer will keep the icemaker operating in the
freezing cycle for a selected length of time. This
will give the ice cubes time to fully form. After that
selected length of time, the timer will switch the
icemaker into the harvest cycle, through the
contacts of the timer assembly microswitch.
Low Temperature Freeze:
When the outside air temperature is low, the Head
Pressure Regulator will close off the liquid line to
the receiver, causing liquid refrigerant to back up
into the condenser until the head pressure builds
up to 240 PSIG. While this is occurring, the head
pressure regulator passes discharge gas into the
receiver to keep the refrigerant flowing.
REFRIGERATION SCHEMATIC
Filter
Heat
Exchange
Liquid
Line Valve
TXV
Water
Pump
Valve
(Closed)
October 1994
Page 17
CME650R
Hot Gas
Valve
(Closed)
Suction
Line
Evaporators