Description Of Each Process - Scotsman BC0530 Service Manual

BC0530 Service Manual

Description of Each Process

The following sequence begins with the cuber as
shipped from the factory with the water plate(s) closed
and ready to begin a normal ice making cycle.
Fill: The water solenoid valve will be energized only
until the water level reaches the highwater FLOAT,
and the water pump will run when the water plate is
closed.
Freeze: Once the water fill cycle has been completed,
the water solenoid valve will remain de-energized
until the following harvest cycle. The water level in the
liquid level probe tube lowers as the water is frozen,
but no additional water will be introduced during the
freeze cycle. The control stream runs continuously
during the freeze cycle with the water returning to
the water tank through the hole which can be seen
through the control stream box to the left of the dam
in the box. The control stream is a "safety valve" to
ensure the ability to initiate harvest rather than an ice
quality control, and it should never need to go over
the dam for more than 15 seconds before harvest
begins.
Note: No water, other than condensation, should drip
or run to the drain pan from the control stream or from
the water tank during the freeze cycle. The water level
in the liquid level probe tube must get below the level
of the low float to initiate the harvest cycle. If there is
an excess of water in the water tank, the water pump
outlet pressure increases when the evaporator cells
are full, and the control stream rises and flows over
the dam to the drain pan to evacuate the liquid level
control tube.
Lower: When the water level in the liquid level
probe tube is below the low water level probe the
controller senses the absence of continuity between
the probes. Power is applied to the defrost valve coil
allowing hot gas to circulate through the evaporator.
The evaporator begins to defrost, and the water plate
begins to open immediately. When the cam arm down
switch is activated the water plate will stop.
Harvest: As long as the evaporator remains cold, the
water plate(s) remain in the open position with the
water solenoid valve de-energized. The defrost valve
remains energized, and the evaporator become warm
enough to release the ice which drops by gravity into
the ice storage area.
Raise: After the ice is out and the evaporator warms
to the reset temperature required by the controller the
actuator motor will be energized to close the water
plate. The water solenoid valve will be energized to
begin the water fill for the next ice-making cycle, the
defrost valve will be de-energized, and the evaporator
will begin to cool.
Ice Bin Full: When the level of ice reaches the
bin probe, the ice maker stops automatically, and it
remains off until the bin probe warms up when the ice
level is lowered.
Cleaning Mode: All of the cuber operational
components except refrigeration are able to function
with the make ice/clean switch in the clean position.
Simply placing this switch in the cleaning position
does not complete the cleaning and sanitizing of the
cuber. Instructions pertaining to the cleaning of a
machine can be found in this manual.
Note: The frequency of the need for cleaning is
determined by the supply water characteristics. The
cuber should be cleaned no less frequently than once
each 6 months, and it may require more frequent
cleaning. The requirement for sanitizing frequency
may be contained in local health code regulations.
Water Plate Closure Problems: If the plate
up switch is not properly actuated, due to mis-
adjustment, weak springs, or an obstruction to the
water plate travel, such as ice which did not slide
off of the plate, the actuator motor will immediately
reverse and re-open the water plate.
Shutdown-High Pressure: All models are provided
with a high pressure cutoff which interrupts power
only to the compressor, and to the condenser fan
motor, when the high-side pressure rises to the cutoff
setting 425psig (AUTO RESET AT 300PSIG). When
this happens be sure there is sufficient airflow, a clean
condenser, and a properly functioning fan motor.
March 2020
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