Scotsman BC0530 Service Manual page 18

BC0530 Service Manual
Control Stream: This is a small clear box, divided
into two sections and located on the front face of
the water plate. It is a "safety valve" that ensures
evacuation of the water reservoir so that harvest
cycles will begin without undue delay. Water flowing
into the left section of the box is returned to the water
tank and re-circulated through the system. Water
flowing into the right section of the box is drained out
of the system. The velocity of the stream flowing in
the box, during the ice making cycle, is an indicator
of the water pressure inside the water plate. This
pressure will increase as the ice cubes fill out in the
evaporator, covering the drain holes provided for each
cell. This pressure increase will cause the stream,
normally flowing into the left section of the box, to flow
over the partition and into the right section, draining
the system of excess water.
Adjustment: Turn the Philips head screw located
behind the expansion valve such that the stream of
water falls to the center of the hole in the water plate
control stream box, during the early portion of the ice
making cycle, before the cubes are full.
Water Level Probe Assembly: This assembly
consists of a dual float switch which is positioned
in a clear water level tube. The water level tube is
mounted to the stainless steel bar on the front of the
water plate and is connected to it by a hose. The
water level in the tank is visible in the tube. The water
level float is positioned in the water level tube. The
probe on the left is the harvest or LOW PROBE.
When the water level is low enough to drop that float,
the controller is signaled to start the harvest cycle.
The right side probe is the "HIGH PROBE." When the
water level raises this float the pump will activate, the
water level will lower and then refill back to a second
high water light on the board, this is the secondary
fill. The controller will then de-energize the water inlet
valve and commence ice making mode.
Adjustment: The "Low Float" should be adjusted
so there is 1 1/8 inch of blue stick sticking up out
of the cap. Once set no further adjustment should
be needed. The "High Float" determines how much
water is taken into the system at the beginning of a
cycle. This side should have 1 in of blue stick sticking
out of the top of the cap. Pull up on right side to add
water, push down to decrease water. It is adjusted as
required and the desired fullness (dimple size) of each
cube. Typically all cubes should have a small dimple
at the end of the freeze cycle. Lack of a dimple in the
cubes is an indicator that the water tank level is too
high at the start of the cycle.
Note: Making cubes without a 1/8 dimple will reduce
ice machine capacity and may damage the water
plate surface in extreme cases. If the control stream
is draining water for more than 15 seconds, at the end
of the ice making cycle, the water level in the tank is
Too high. Lower the high probe until proper operation
is evident.
Magnetic Plate Up Switch: This switch is actuated
by the water plate and informs the controller about the
position of the plate—fully up or not fully up. If this
magnetic switch is not actuated when the water plate
closes, because ice is remaining on the water plate
surface, the actuator motor will reverse and reopen
the water plate. This will continue until the surface is
clear.
Magnetic Cam Switch: This switch acts to limit
the clockwise and counterclockwise rotation of the
actuator motor. It informs the controller when the cam
arms are in the "12 o'clock" position (water plate up),
also informs the controller when the cam arms are
in the "7 o'clock" position (water plate down), so the
actuator motor can be de-energized.
Note: The front water plate spring must be on the
left side of the cam hub when the water plate is fully
closed (cam arm in the 12 o'clock position).
Contactor: Provided with all models to carry the
compressor load. The condenser fan motor is also
connected to the contactor. The contactor coil is rated
for line voltage and the contacts are rated for definite
purpose applications (FLA and LRA).
High Pressure Cutoff: A auto reset pressure switch
is provided, which will open the circuit to the contactor
coil if the discharge pressure should reach 425 psig
and reset at 300 psig.
March 2020
Page 18