Harvest Cycle - Scotsman NW458 Service Manual

above 25℃ and shorter time required when
temperature are below 25 ℃ . Average
complete cycle time is about 22 min.

HARVEST CYCLE

1. During the harvest cycle the components in
operation are:
• Hot Gas valve
• Water Drain/Purge Valve
• Water Pump for the first 40"
• Compressor
and both
• Machine Under Power
• Machine in Operation
2. 30 seconds after the beginning of the
Harvest Cycle, the Water Inlet Solenoid Valve
is energized for 10 seconds only in order to
have a short flush of fresh water into the sump
while the Water Pump is still in operation.
3. The Fan Motor remains in OFF mode
unless the Condenser Sensor probe rise up to
more then 38℃ (same set up as per end of
freezing cycle).
4. When the ice plate is falling down from the
evaporator, the magnetic switch is activated
for a while providing the signal to the PC
Board to restart a new freezing cycle.
5. Observe first ice cube harvest and check
size of ice cubes; if an adjustment is required
thread down or out screw NO.1 as shown on
below illustration.
This screw position determines the distance
between the sensor reeds and the egg-crate
evaporator thus keeping the ice cube at a
proper thickness.
NOTE: This type of machine produce an
"ICE PLATE" that breaks when falls down
into the storage bin. Setting the ice thickness
sensor in order to have single ice cubes may
cause malfunction of the machine.
6. Observe second and third cube harvest.
Check if size and shape combination is correct.
In areas where extreme problem water
conditions exist,
equipment is recommended.
NOTE: If water
"demineralized" the ice thickness sensor
might not be able to sense the water on its
reeds, thereby it will not switch the unit on
harvest cycle.
A safety system built in the P.C. Board
switches the unit on harvest cycle whenever
the freezing period gets longer than 30' or
40'.
NOTE: To assure a correct operation of the
machine the water must have a minimum
electrical conductivity of 20 us.
7. Check operation of magnetic switch
controlling it by keeping open the bottom end
of plastic deflector for more than 30 seconds.
The machine must switch off at storage bin full.
Release the plastic deflector. The machine
should restart in the freezing cycle mode
within few seconds going through a 3' delay
time.
8. Place again all cabinet panels and screws
previously removed.
9. Thoroughly explain to owner/user the
significant specifications of the ice maker start-
up, reset and operation, going through the
procedures in the operating instructions.
Answer all questions about the ice maker by
the owner and inform the owner himself of the
name and telephone number of the authorized
service agency serving him.
17
filtering or purifying
used is too soft,