Scotsman EC 46, Service Manual

Page: 12 / 28

Page 12
Page 12
OPERATING INSTRUCTIONS
START UP
After having correctly installed the ice maker and
completed the plumbing and electrical
connections, perform the following “Start-up” pro-
cedure.
A. Withdraw the condenser air filter then
remove the unit front panel and locate the cleaning
switch on the control box.
B. Set the cleaning switch in the cleaning
position. This will close the electrical circuit to the
water inlet valve and to the hot gas valve
C. Switch ON the power line disconnect switch
and push the green button switch. Unit will start
up in charging cycle mode. During this cycle the
components energized are:
WATER INLET SOLENOID VALVE
HOT GAS SOLENOID VALVE
The Water pump and the Fan motor in the air
cooled versions, are also in operation.
D. Let unit stay in charging cycle for about
three/four minutes till water is coming out from
the drain hose, then move the cleaning switch to
the operation position.
NOTE.
During the charging cycle, the water
inlet solenoid valve is energized. The water
flows through the valve to the back side of the
evaporator platen and then down to fill up the
icemaker sump for the next freezing cycle.
OPERATIONAL CHECKS
E. The unit now starts its first freezing cycle
with the following components in operation:
COMPRESSOR
WATER PUMP
FAN MOTOR in air cooled version
F. 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 cup molds; also make sure
that the plastic curtain is hanging freely and there
is not excessive water spilling through it.
G. The ice making process takes place
thereby, with the water sprayed into the molds
that gets gradually refrigerated by the heat
exchanged with the refrigerant flowing into the
evaporator serpentine.
H. When the evaporator temperature reaches
a preset value the evaporator thermostat or cube
size control changes its contacts; the freezing
cycle ends and starts the defrost or harvest cycle.
Freezing time will range between 20 and 22
minutes in a 21
°
C ambient temperature. Longer
time for temperature above, shorter when below.
Average complete cycle range is about 23 to 25
minutes.
I. Check, during the first defrost/harvest
cycle, that the incoming water flows correctly
into the sump in order to re-fill it and the surplus
overflows through the overflow drain tube.
J. As soon as the water into the Sealed Water
Reservoir reaches the maximum level, the two
metal pins close the electrical contact through
the water, transmitting a low voltage current to
the PC Board.
The PC Board energises the Water Drain Pump
for 8 seconds pumping out most of the water
contained into the Sealed Water Reservoir.
K. Check the texture of ice cubes just released.
Right size must have a small depression (about
5-6 mm) in their crown.
If not, wait for the second defrost/harvest cycle
before performing any adjustment.
L. If required, the length of the freezing cycle
can be modified by turning the knob of the cube
size control or evaporator thermostat located in
front of the control box until the desired size is
achieved.
If the ice cubes are shallow and cloudy, it is
possible that the ice maker runs short of water
during the end of the freezing cycle or, the quality
of the supplied water requires the use of an
appropriate water filter or conditioner.
M. During the defrost or harvest cycle hold a
handful of ice cubes against the bulb of the
storage bin thermostat; the icemaker switch OFF
in about one-two minutes.
Take out the ice from the storage bin thermostat.
The ice maker should restart automatically in
three-four minutes.
NOTE. The bin thermostat is factory set at
1
°
C (35
°
F) OUT and 4
°
C (39
°
F) IN.
N. Re-fit the unit front panel then instruct the
owner/user on the general operation of the ice
machine and about the cleaning and care it
requires.