Start-Up; Start-Up Cycle; Freezing Cycle - Scotsman NW507 Service Manual

START-UP

START-UP CYCLE

1.Open the water tap/valve and switch ON the
power on the electrical supply line.
2.The models NW307-308-
507-508-457-458-608 enter in
the Start Up cycle with the PC
Board energized,
NW1008/1408 enter
minutes delay time controlled
by PC Board, The LED of ICE
MAKING blinking slow.
In Start Up cycle the LED of
ICE MAKING and BIN FULL
are energized, blinking slow3
minutes for water
clean, then ICE
blinking fast 40 second for
pressure balance.
NOTE:
Model NW 1008/1408 has a crankcase
heater in the compressor. When the main
power to the machine is switched ON, there
is a time delay of 90 minutes during which
only the compressor heater is energized with
Green ICE Making LED Blinking slowly.
However, if the ambient temperature is
higher than 25*C (77*F), PC Board will
automatically bypass this delay.
This time delay can also be bypass by
pressing the bypass switch located at the
back of the machine.
3. During the start up cycle the components in
operation are:
• Hot Gas valve
• Water Drain Valve
• Water Inlet Valve
• Water Pump

FREEZING CYCLE

1. After the start up cycle the machine enters
directly into the freezing cycle with the following
components energized:
• Water Inlet valve
• Compressor
• Fan motor.
and
in 90
system
MAKING
2. The LED energized are:
• Machine under power (steady)
• Machine in ICE MAKING (steady)
3. Water is coming into the water through the
Water Inlet Solenoid Valve till the water
reservoir if filled up to the maximum level
controlled by a Water Level Sensor.
4. 40 seconds later, the Water Pump starts up.
5. After few minutes (3-5) from the start up of
the freezing cycle, the Water Inlet Solenoid
Valve is activated again for few seconds to refill
the water reservoir up to the maximum level so
to reduce any possibility of slush ice formation.
6.In the meantime the condenser sensor starts
to transmit the current to the PC Board keeping
in operation the Fan Motor in ON-OFF mode or
continuously according to the condenser
temperature.
NOTE: Do not remove the evaporator
deflector cover as it will cause the switching
off of the machine at "STORAGE BIN FULL".
7. The machine remains in the freezing cycle
with the ice that become thicker till the two
metal plates of the Ice Thickness Sensor are
covered by the water cascading through the
front surface of the ice plate.
8. When the Power is transmitted back to the
PC Board continuously through the metal
plates of the Ice Thickness Sensor for more
than 6", the machine enters in the Pre-Harvest
or directly into the Harvest Cycle mode
according to:
• FAN MOTOR IN ON-OFF MODE DURING
Rise up the cutting temperature of the
condenser sensor to 38℃ (fan motor off) and
extend the length of freezing cycle by 30" more
the going to harvest cycle.
• FAN MOTOR ALWAYS IN OPERATION
18