Component Description - Scotsman CMS1002R User Manual

COMPONENT DESCRIPTION

Compressor Contactor
The compressor contactor carries the compressor
line current. The contactor is wired so any control
in the pilot circuit, such as the bin control, and high
pressure controls, etc., will cause the contactor
holding coil to be de energized, when the control
contact OPENS, thereby breaking the circuit to the
compressor.
Cube Size Control
This reverse acting (closes on temperature fall)
thermostat determines how long the freezing cycle
will be. The cube size control closes its contacts
when the evaporator cools to the set temperature,
starting the timer. A variation in heat load (either
ambient air or incoming water temperature) will
affect the efficiency of the refrigeration system, and
that will vary the length of time it takes the
evaporators to cool to the temperature at which the
cube size control is set to close, which, in turn, will
affect the overall cycle time. See CUBE SIZE
ADJUSTMENT BEFORE attempting to adjust the
control.
Relay
The multi-function, three pole, double throw, relay
plugs into a socket on the printed circuit board in
the control box. The relay functions in part to
by-pass the bin control during the harvest and
freeze cycles, preventing the icemaker from
shutting off in the middle of a cycle. The bypass
action allows only complete freeze and harvest
cycles; the only time that the ice maker can shut
off on bin control is as the end of the harvest cycle.
Timer - Timer & Switch Assembly
The timer begins to turn when activated by the
cube size control. The outer surface, or large
diameter lobe of the timer cam, determines the
length of time for finish freezing of the ice cubes,
while the inner surface, or small diameter lobe,
determines length of the harvest cycle. The
single-pole, double throw microswitch on the timer
controls the power to the plug in relay coil, making
it either the freezing or harvest cycle. The
microswitch is actuated by a cam assembly
directly connected to the timer motor. The timer
cam can be adjusted to vary the defrost time, as
required. One complete rotation of the cam will
take eight minutes. Harvest is preset at 2 and a
quarter minutes.
Hot Gas Solenoid Valve
The hot gas solenoid valve opens only during the
harvest cycle. When it opens, it diverts the hot
discharge gases so that they flow directly into the
evaporator plates, by-passing the condenser and
thermostatic expansion valve. The hot gases warm
the evaporators, releasing the ice cubes from the
ice cube molds. The hot gas solenoid valve is
installed in a branch of the discharge line from the
compressor, and when the timer switches the ice
machine into the harvest cycle, the energized
solenoid coil lifts the valve stem within the valve
body, allowing the hot discharge gas to be diverted
to the evaporators.
High Temperature Cut Out
This temperature sensor is located next to the hot
gas valve, on the outlet side.
During normal operation, it does not affect the ice
machine, but it will shut the machine off if the hot
gas line overheats. It is an automatic reset.
September, 1993
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CMS1002R