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PRINCIPLE OF OPERATION
How it works
In the SCOTSMAN Modular Cubers the water
used to make the ice is kept constantly in
circulation by an electric water pump which primes
it to the self propeller spray bar nozzles from
where it is diverted into the inverted mold cups of
the evaporator (Fig. B).
A small quantity of the sprayed water freezes into
ice; the rest of it cascades by gravity into the
sump assembly below for recirculation.
FREEZING CYCLE (Fig. A)
The hot gas refrigerant discharged out from the
compressor reaches the condenser where, being
cooled down, condenses into liquid.
Flowing into the liquid line it passes through the
drier filter, then it goes all the way through the
capillary tube where, due to the heat exchanging
action, it looses some of its heat content so that
its pressure and temperature are lowered as
well.
Next the refrigerant enters into the evaporator
serpentine (which has a larger I.D. then the
capillary) and starts to boil off; this reaction is
emphasized by the heat transferred by the
sprayed water.
The refrigerant then increases in volume and
changes entirely into vapor.
The vapor refrigerant then passes through the
suction accumulator (used to prevent that any
small amount of liquid refrigerant may reach the
compressor) and through the suction line.
In both the accumulator and the suction line it
exchanges heat with the refrigerant flowing into
the capillary tube (warmer), before to be sucked
in the compressor and to be recirculated as hot
compressed refrigerant gas.
The freezing cycle is controlled by the evaporator
temperature sensor (which has its probe in contact
with the evaporator serpentine) that determines
the length of its first portion of the cycle.
When the temperature of the evaporator
serpentine drops to a pre-set value, the evaporator
sensor probe changes its electrical resistance
allowing a low voltage current (12 volts) to flow to
the P.C. BOARD which in turn activates an
electronic timer.
The timer, which is built-in the P.C. BOARD,
takes over from the evaporator temperature
sensor, the control of the freezing cycle up to its
completion.
NOTE.
The change of the electric potential of
the evaporator sensor with the consequent
activation of the timer (Time mode) is signalled
by the glowing-up of the RED LED located
beside the FREEZING yellow one in the front
of the P.C. BOARD.
MXG-S 327 A
MXG-S 327 W
MXG-M 327 A
ON
ON
OFF
ON
OFF
ON
ON
ON
OFF
ON
MXG-M 327 W
MXG-M 327 W
MXG-L 327 A
MXG-L 327 W
MXG-S 427-437 A
MXG-S 427-437 W
MXG-M 427-437 A
ON
ON
OFF
ON
OFF
ON
ON
ON
OFF
ON
MXG-M 427-437 W
MXG-L 427-437 A
MXG-L 427-437 W
TAB. A
DIP SWITCH FACTORY SETTING COMBINATIONS PER MODEL AND VERSION
DIP SWITCH
1
2
3
4
5
6
7
8
9
10
FREEZING CYCLE
DEFROST
CYCLE
DEFR. CYCLE
ADD. TIME
15/30
°
AIR
WATER
Summary of Contents for MXG 327
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