Service Manual

SCCG50 & SCCP50
Service Manual
November 2008
Page 20
Water System
The controller uses a Water Sensor to check
for the presence of water in the reservoir and to
measure the conductivity of the water.
The water sensor consists of two stainless steel
probes located in a holder next to the water pump.
The probes sense the conductivity of the water.
The higher the mineral content of the water,
the better it can conduct electricity. The control
system is capable of sensing water as clean as
10 microSiemens/cm.
If the controller cannot sense water and the bin
thermostat is closed the controller will power the
inlet water solenoid valve to ll the reservoir. The
water ll is timed. There is a maximum amount of
time allowed from the time the controller turned on
the inlet water valve until the water sensor signals
to the controller. That time is 2 1/2 minutes. If water
is not sensed within 2 1/2 minutes, the controller
will not proceed with an ice making cycle. Instead it
will blink the Water light and try lling the reservoir
in 20 minutes.
Reservoir water dilution
The process of making ice from circulating water
causes the pure water to freeze rst, because it
freezes at the warmest temperature. The remaining
water will develop an increasing concentration
of minerals. If that mineral concentration were
allowed to continue, eventually the ice machine
would become coated with mineral scale.
To combat the mineral build up, the reservoir
water is diluted with fresh water every cycle. The
controller adds enough water to ll the reservoir
and extra water to overll it. The extra water drains
out through the standpipe in the reservoir.
The controller keeps the inlet water solenoid valve
open until the evaporator temperature set point is
reached, plus some extra time. The extra time is
either pre-set or automatically determined by the
controller.
Evaporator
Pump
Reservoir
Drain
Freeze Cycle Water Schematic
Harvest Cycle Water Schematic
Standpipe
Inlet Water Solenoid Valve