Scotsman NW507 Service Manual page 31

plate. The water pump pumps water from the
sump to the tee. From there water is channeled
through the vertical PVC tube to the water
distributors, above the evaporator plate, and
from the holes in the distributor tube water flows
to the cells on one side of the evaporator plate.
Gravity flow returns the unfrozen excess
portion of water to the sump reservoir for
recirculation.
11. Water Purge Solenoid Valve
The Water Outlet Solenoid Valve functions in
conjunction with the water pump to flush-out the
sump assembly as DIP switch #6&#7 setup.
This action cleans-up and rinses the sump
during each harvest
dangerous water minerals concentration.
12. Thermostatic Expansion Valve
The Thermostatic Expansion Valve regulates
the flow of refrigerant to the evaporator and
reduces pressure of liquid refrigerant from
condensing pressure to evaporating pressure.
13. Water pump
The water pump primes the water from the
sump to the water distributor tube and through
the distributing holes it cascades down onto the
evaporator cells by gravity so to be frozen into
clear ice cubes. The water pump remains off
during the first 40" seconds of the freezing cycle
(to avoid any cavitations problem).while it's kept
running during as DIP switch #6&#7 setup.
14. Water inlet solenoid valve - 3/4" male
fitting
The Water Inlet Solenoid valve is energized by
the P.C. Board during the beginning of the
freezing cycle till the water reaches the
maximum level into the sump (controlled by the
Water Level Sensor).
After 3 minutes, from the start up of the freezing
cycle, the Water Inlet Valve is energized again
for a short period to re-fill the sump with water
till again to the maximum level so to minimize
any possibility of slush ice formation
A flow control, fitted into its outlet port, reduces
the pressure of the water flow.
cycle preventing
15. Water level sensor
The Water Level Sensor, located on the upper
right side of the water sump, works in
conjunction with the P.C. Board in order to
control the water level at beginning of the
freezing cycle by receiving a low power current
passing through the water. When the current
reaches the PC Board, the water inlet solenoid
valve is de-energized.
In case the PC Board doesn't receive any
signal(current) as DIP switch #4 setup from the
Water Level Sensor, the PC Board trips OFF
the operation of the machine with the switching
ON of the Water Error LEDs.
16. Start up delay PC Board by-pass switch
Located in the back side of the machine allows
to by-pass the delay time controlled by the
delay PC Board.
WARNING: It is IMPERATIVE to by-
pass the delay time only when sure
of proper warm up of compressor.
17. LED display
Located in the upper and right side of the
machine when remove the front panel.
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1 -- Power light (Green)
2 -- Freezing light (Green)
3 -- Bin full light (Yellow)
4 -- Alarm light (Red)
5 -- High pressure alarm light
(Red)
6 -- Clean light (Red)
7 -- Harvest light (Yellow)
B1 -- Mode button
B2 -- CLEAN button