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ture variations and signals them by supplying
current, at low voltage, to the P.C. BOARD.
In case the condenser temperature sensor
detects a temperature at the condenser lower
than +3°C (37°F) that means ambient tempera-
ture too low for the correct unit operation, the
sensor signals to the P.C. BOARD to do not start
up the unit till the ambient temperature rises to
10°C.
In the air cooled versions, in relation to the
different current transmitted, the micro processor
of the P.C. BOARD supplies, through a TRIAC,
the power at high voltage to the fan motor.
In the event the condenser temperature rises
and reaches 60°C or 70 °C according to the
setting of DIP SWITCH number 8 the current
arriving to the micro processor is such to cause an
immediate and total stop of the machine operation.
NOTE. The machine will remain in OFF
mode for one hour then it will restart
automatically.
In case the unit trips OFF again in alarm for
3 times in 3 hours, the machine SHUTS OFF
DEFINITIVELY.
To restart the unit after the shutoff caused by
the hi condenser temperature, it is neces-
sary to switch OFF and ON the power line
main disconnect Switch.
D. ELECTROMAGNETIC SENSOR
(Two on SPN 1205 Model)
This safety device is housed on top of the Drive
Motor (one per each motor on MF 66 model) and
detects - based on Hall Effect principle - the
rotating speed and rotating direction of the drive
Motor.
Should the rotating speed drop below 1300 r.p.m.
t
he magnitude measured by this device is such
to signal to the microprocessor to stop the unit
and light-up the YELLOW LED. The same
reaction occures when the drive motor will tend
to rotate in the wrong direction (counterclockwise)
or when it doesn't rotate at all.
NOTE. The machine will remain in OFF
mode for one hour then it will restart automa-
tically. In case the unit trips OFF again in
alarm for 3 times in 3 hours, the machine
SHUTS OFF DEFINITIVELY. To restart the
unit after the shutoff caused by this safety
device, it is necessary first to eliminate the
cause that has generated the intervention of
the device and then switch OFF and ON the
power line main disconnect switch.
COMPONENTS DESCRIPTION
A. EVAPORATOR TEMPERATURE
SENSOR
The evaporator sensor probe is inserted into its
tube well, which is welded on the evaporator
outlet line, it detects the temperature of the
refrigerant on the way out from the evaporator
and signals it by suppling a low voltage current
flow to the P.C. Board.
According to the current received, the micro-
processor let the ice maker to continue its
operations or not. In case the evaporating tem-
perature, after 10 minutes from the unit start-up,
does not go below -1 °C (30°F) the evaporator
sensor signals to stop immediately the unit
operation, with the blinking of the 5th Warning
YELLOW LED.
NOTE. The machine will remain in OFF mode
for one hour then it will restart automatically.
In case the unit trips OFF again in alarm for
3 times in 3 hours, the machine SHUTS OFF
DEFINITIVELY.
To restart the unit after the shutoff caused by
the hi evaporating temperature, it is neces-
sary to switch OFF and ON the power line
main disconnect Switch.
B. WATER LEVEL SENSOR
This sensor consists of two small stainless steel
rods vertically fitted on the inner face of the
reservoir cover and electrically connected to the
low voltage circuit of the P.C. Board.
When the cover of the reservoir is positioned in
its place the tips of both the rods dip into the
reservoir water transmitting a low power current
throu the same.
NOTE. In the event of shortage of water in
the reservoir or, in case the water used is too
soft (de-mineralized) to cause greater
resistence to the current flow (electrical
conductivity lower than 30
µ
S) this sensor
system causes the shutoff of the machine,
to protect it from running without water or
with an inadequate water quality. In this
situation the YELLOW LED will glow to warn
of the machine shutoff and the reason why.
C. CONDENSER TEMPERATURE SENSOR
The condenser temperature sensor probe,
located within the condenser fins (air cooled
version) or in contact with the tube coil (water
cooled version) detects the condenser tempera