Scotsman C2648 - Manual (Page 29)

C2648 Prodigy and Prodigy Plus Service Manual
January 2015
Page 29
Electrical Sequence - Remote Cooled
Power connected, unit previously switched Off.
Control board does a self check. If the self check fails, the unit displays an E and no further action will occur.
If the self check passes, the controller will display a 0, the curtain lights will be ON and the Power and Sump
Empty lights will be ON.
Pushing and releasing the On button will start the ice making process.
The display will begin to blink F. The component indicator lights will switch on and off to match the
following process:
The purge valve opens and one water pump starts to empty the reservoir. This is done to discharge any excess
water from ice melting into the reservoir.
The hot gas valves and the harvest assists are energized by the High Capacity Relay.
The inlet water valve will open to fill the reservoir. The water valve can open any time the water level is low.
After a few seconds the purge valve closes and the pump shuts off.
When the reservoir is full the inlet water valve stops, the liquid line valve is opened and the compressor
switches on. Five seconds after the compressor starts the hot gas valve and the harvest assist solenoid are
de-energized. Both water pumps switch on.
Light Information: The display shows a non-blinking F. The Power and Status Lights will be Green. The
compressor, fan motor, water pump, sump full lights will be ON and all curtain switch lights will be
OFF.
The Freeze cycle continues. When the reservoir water temperature falls to a certain preset point, the
water pumps will shut off for 30 seconds. This is the anti-slush period. At this time the controller checks the
conductivity of the water in the reservoir for the auto-purge feature. After the water pumps restart the Sump Full
light will go out and neither sump lights will be on for the rest of the freeze cycle.
When the ice has built up enough so that the water flowing over the evaporator comes into continuous contact
with the ice level sensor, the Ready to Harvest light will begin to blink on and off. When it has been On
continuously for 3 seconds, the controller will switch the machine into a Harvest cycle.
Indicator Information: The display shows a non-blinking H. The Power and Status Lights will be Green.
The compressor and hot gas valve lights will be ON. After a few seconds the water pump, purge valve
and inlet water valve lights will switch on.
The three harvest assists are connected in parallel with the three hot gas valves. Although energized
throughout the harvest cycle, a harvest assist probe does not move until the ice has become partially loosened
from the evaporator plate by the action of the hot refrigerant gas passing through the evaporator serpentine.
The remote condenser fan motor is powered by the compressor contactor, so it will be operating during the
harvest cycle.
The operating water pump and purge valve will shut off when the purge level setting time has been reached,
either the manual time or the automatic time. The inlet water valve will remain on until it fills the reservoir. The
Ready to Harvest light will switch Off when the ice falls from the evaporator.
Harvest continues until the ice slab is ejected from the evaporator and falls, opening the curtain. When the
curtain opens, the magnetic reed curtain switch opens, breaking the circuit to the controller. If all the curtains
re-close within 30 seconds, the controller switches the machine back into another freeze cycle.
If any curtain switch remains open, the controller shuts the machine down and puts it into a standby position.