Icematic N21, Service Manual

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GB
20
OPERATING INSTRUCTIONS
START UP
After having correctly installed the ice maker and com-
pleted the plumbing and electrical connections, perform
the following "Start-up" procedure.
A. The model N 21 has to be operated by switching "on"
the master switch on the power line or, in case this last
one has not been fitted, by merely plugging in its elec-
tric cord into an adequate receptacle.
NOTE. The icemaker control is factory set with the
timer microswitches actuators dropped off into the ini-
tial point of the cam slot. This setting position allows a
proper water filling.
The unit starts operating in the "defrost cycle" with the fol-
lowing components being activated:
THE WATER INLET SOLENOID VALVE
THE HOT GAS SOLENOID VALVE
THE COMPRESSOR
THE TIMER MOTOR
B. During the water filling operation, check to see that the
incoming water dribblers, through the evaporator plat-
en dribbler holes, down into the sump reservoir to fill it
up and also that the incoming surplus of water flows
out through the overflow pipe into the drain line.
NOTE. If, in the defrost cycle length, the machine
sump reservoir does not get filled with water up to the
rim of the overflow pipe, remove the front panel and
rotate the shaft of the timer so to cause the dropping
of the two microswitches actuators into the beginning
of the cam slot and check for:
1. The water pressure of the water supply line, it must
be at least 1 bar (14 psig) Minimum (Max 5 bar-70
psig).
2. The filtering device installed in the water line that
may reduce the water pressure below the Minimum
value of 1 bar (14 psig).
3. Any clogging situation in the water circuit like the
inlet water strainer and/or the flow control.
OPERATIONAL CHECKS
C. At completion of the water filling phase the unit initiate
automatically the first freezing cycle with the start up of
(Fig.1):
COMPRESSOR
WATER PUMP
FAN MOTOR (in air cooled version)
D. Check to see through the ice discharge opening that
the spray system is correctly seated and that the water
jets uniformely reach the interior of the inverted mold
cups or the exterior of the evaporator tips; also make
sure that the plastic curtain is hanging freely and there
is not excessive water spilling through it.
E. The ice making process takes place thereby, with the
water sprayed into the molds oron to the tips that gets
gradually refrigerated by the heat exchange with the
refrigerant flowing into the evaporator serpentine.
During the first portion of the freezing cycle, the timer
assy is standing-by with its microswitches actuators
resting on the raised cam profile (position that corre-
spond to the end of the defrost cycle).
F. Then, as the cube size control cut-in point is Reached
by the evaporator temperature the control of the cycle
is passed to the timer assy. Whose raised cam slowly
rotates to continue the freezing cycle (2nd phase) up
to its completition.
The components in operation during this 2nd phase of
the cycle are (Fig.2):
COMPRESSOR
WATER PUMP
FAN MOTOR (in air cooled version)
TIMER MOTOR
G. After about 18÷20 minutes from the beginning of the
freezing cycle, in an hypothetic ambient temperature of
21°C, the defrost cycle takes place with the hot gas
and the water in let valves being simoultaneously acti-
vated.
The electrical components in operation are (Fig.3):
COMPRESSOR
WATER INLET SOLENOID VALVE
HOT GAS VALVE
TIMER MOTOR
H. Check, during the defrost cycle, that the incoming
water flows correctly into the sump reservoir in order to
refill it and that the surplus overflows through the over-
flow drain tube.