Icematic DX 40, Service Manual

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D. P.C. BOARD (Data processor)
The P.C. BOARD, fitted in its plastic box located
in the rear of the unit, consists of two separated
printed circuits one at high and the other at low
voltage integrated with a program selector; of six
aligned LEDS monitoring to the service engineer
the operation of the machine; of one DIP SWITCH
with ten keys; of input terminals for the leads of
the three sensor probes and of input and output
terminals for the leads of the ice maker electrical
wires.
The P.C. BOARD is the brain of the system and
it elaborates, through its Micro Processor, the
signals received from the two sensors in order to
control the operation of the different electrical
components of the ice maker (compressor, water
pump, solenoid valves, etc.).
By turning the program selector it is possible to
put the unit in the following different situations:
CLEANING/RINSING. The water pump is the
only electrical component in operation and it
must be used during the cleaning or the rinsing
procedure of the water system of ice machine.
STAND BY. The unit remain under electrical
power but OUT of operation. It can be used by the
service engineer in order to stop the unit during
the service and inspection operations.
IN OPERATION. The unit is running through the
freezing and defrost cycles stopping automatically
only at full bin situation.
RE-SET. To be selected to resume the unit
operation when the ice maker shuts off due to the
intervention of the security of the P.C. BOARD in
relation to the exceeding time of freezing cycle
portion T1 and T2.
The six LEDS (not visibles trough the panel)
placed in a vertical row in the front of the P.C.
BOARD, monitor, from the top to the bottom, the
following situations:
GREEN LIGHT Unit under electrical power
RED LIGHT Unit shut-off due to P.C. BOARD
security (T1 > 15' o T2 > 45')
RED LIGHT Unit shut-off at full storage bin
RED LIGHT Evaporator sensor at -16
°
C
(3
°
F)
RED LIGHT Evaporator sensor at 0
°
C (32
°
F)
RED LIGHT Compressor under power
COMPONENTS DESCRIPTION
A. EVAPORATOR TEMPERATURE
SENSOR
The evaporator temperature sensor probe,
located in contact with the evaporator serpentine,
detects the dropping of the evaporator tempera-
ture during the freezing cycle and signals it by
supplying a current flow to the Micro Processor of
P.C. BOARD.
According to the current signal and to after how
long this is received, the Micro Processor may or
not give the consent to the ice maker to complete
the freezing cycle.
The low voltage current transmitted, from the
evaporator temperature sensor to the P.C.
BOARD, is signalled by the lighting up of the
fourth (Time T1) and fifth (Time T2) RED LED
placed in the front of the P.C. BOARD to inform
the service engineer, of the normal (regular)
progressing of the freezing cycle.
B. ICE BIN LEVEL SENSOR
The ice bin level temperature sensor, secured to
one of the storage bin walls, stops the operation
of the entire ice maker just at the end of defrost
cycle when its sensing probe (in contact with the
stored ice) reaches the temperature of +2
°
C
(35
°
F) lighting up, in the meantime, the third
RED LED.
Once the ice is removed from the sensing probe,
its temperature progressively rise up and as it
reaches the value of +4.5
°
C (40
°
F) the ice bin
level temperature sensor transmits a low voltage
current flow to the P.C. BOARD so to restart the
operation of the unit.
NOTE.
The ice maker, after the interruption
of its operation due to the ice level control
cut-out, always restarts from the beginnig of
the freezing cycle.
By changing the combination of the DIP SWITCH
Keys number 8 and 9 it is possible to change the
range of the ice level control temperature sensor.
This is shown on table D, keeping its cut out
temperature always at +2
°
C (35
°
F).
C. PHOTOELECTRIC SENSOR
The photoelectric sensor, located behind the
dispenser plastic panel, is electrically connected
to the P.C. BOARD so to provide power to the
auger drive motor when the ice backet is place
close to its sensitivity probe.
As soon as the ice backet is removed from the
dispensing compartment the auger motor stops
immediately.
NOTE. Maximum continuous operating time
of the auger motor is 15 seconds controlled
by the P.C. BOARD.
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