SCCG50 & SCCP50
Service Manual
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 fill the reservoir. The water fill 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 minutes. If water is not sensed within 2 minutes, the controller will not proceed with an ice making cycle. Instead it will blink the Water light and try filling the reservoir in 20 minutes.
Reservoir water dilution
The process of making ice from circulating water causes the pure water to freeze first, 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 fill the reservoir and extra water to overfill 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
Evaporator
Pump
Reservoir
Drain
Freeze Cycle Water Schematic
Standpipe
Inlet Water Solenoid Valve Harvest Cycle Water Schematic
June 2008
Page 20
