Electrical/Refrigeration - Scotsman MF 88 Service Manual

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As it evaporates, it absorbs heat from the
evaporator and whatever is in contact with it
(such as the water inside it). After the evaporator,
the refrigerant, now a low pressure vapor, goes
through the heat exchanger and suction line
back to compressor, where the cycle is repeated.

ELECTRICAL/REFRIGERATION

The MF/MFN 88 Flakers are designed to operate
at 400 Volts. 50 Hertz, threephase plus neutral.
Special voltage requirements are available on
special order.
Therefore, always CHECK NAMEPLATE for
electrical information BEFORE proceeding with
electrical wiring connections to the Icemaker.
Cold ambient temperatures and interruptions in
water supply are conditions that can cause
excessively hard ice and overloads within the
Freezer Assembly, which is directly trasmmitted
to the Drivemotor; and in turn, will cause the
intervention of Drive Motor Current limiter.
Master Switch turn the unit ON and OFF every
time is switching KT2 time delay relay keep on, in
operation the drive motor for 18'.
Spout Switch is mounted on the top of the Ice
Spout and is actuated by the movement of the
spring retained pressure plate. The spout switch
acts as a back-up safety switch, should the
termostatic Control Bulb fail and cause ice to
jam-up in the ice spout. The switch will shutoff the
ice maker when actuated. The Spout Switch can
be manually tested by pressing upward the
pressure plate.
There are other safety controls in the machine
and are:
Liquid Line - Solenoid Valve
Necessary to stop refrigerant flow when not
desired to be located on the liquid line past the
drier is electrically connected to compressor contactor
or relay to stopflooding the evaporator and suctionside
during compressor off periods. Supplied.
The low-water pressure Switch functions to
discontinue the ice making process whenever
incoming water pressure is reduced to below
0.3 bar (4 PSI). The switch will automatically
restart the icemaking process when the water
pressure is increased to 1 bar (14 PSI).
EPR valve. Evaporator Pressure Regulating
Valve. this valve maintains a constant pressure
on evap. Inlet regardless of the pressure on the
outlet so it keeps the evaporator temperature
above a pre-determined value preventing
dangerous freeze-up conditions (KVP).
Sight Glass
A sight glass is intalled in the liquid line. The sight
glass will show bubbles if the system is low on
refrigerant.
Solenoid valve delay timer (KT1)
Delays the opening of the liquid valve by 18 min.
at every start up of the ice maker.
Gear motor delay timer (KT2)
Delays gear motor STOP by 18 min. at every trip
OFF of the ice maker.
3 - phases monitoring relay (F1)
On the power in of the machine check and assure
correct Wiring - rotation of the gear motor.
Drive Motor Current Relay - Gavazzi DIB71 (KA1)
It senses the intensity at the drive motor, should
this exceed its Amps setting point as per here
below chart, tripping OFF the entire machine.
MF 88 - MFN 88
400V
HYS 6
LEVEL 80% - 1,6 Amps 50% - 2,5 Amps
DELAY 2 sec.
Dip switch (under cover):
400 V all in ON position
230 V dip Sw 1 in OFF position, 2
position.
CONTROL CONSOLE
Located on the front panel is a virtual control
console that monitors unit performance auto-
matically. Any interruption or significant reduction
in water or electrical supplies causes an instant
stop to the operation of the modular flaker.
At the same time a warning light is activated on
the control console telling the user of the ice
makers stoppage and also the reason why.
Whenever any stoppage accured, its cause
should be diagnosed and corrected the cause of
the stoppage should be diagnosed and corrected
also the reason why.
IN OPERATION
LOW WATER PRESSURE
SPOUT SWITCH
BIN FULL
PHASES CTL.
DRIVE MOTOR RELAY
The Drive Motor Bonfiglioli mod. BN80A4
0.55 Kw Volts 230/400 Ph 3 Hz 50 Amps
2.65-1.53 RPM 1410 thermally protected.
Provides power through speed reducer to turn
auger.
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230V
6
2 sec.
6 in ON