Prechill Cycle (1400'S And 1800'S); Freeze Cycle; Harvest Cycle; Fan Control - Cornelius XAC 1444 Service Training Manual

Xtreme Ice Training Manual

PRECHILL CYCLE (1400'S AND 1800'S)

1. After the water fill cycle is complete, the water pump turns on.
2. When the water temperature reaches 40_F, the pump turns off.
3. After one minute, the pump comes back on.
4. After another ten seconds, the fill valve opens.
5. Once the water level reaches the maximum level, the fill valve closes.
FIGURE 8

FREEZE CYCLE

1. Ten seconds after the fill valve turns off, the microprocessor records the water level.
2. Using the recorded high water level, the calibration level and the ice thickness level, the micropro-
cessor calculates a harvest level.
3. The microprocessor monitors the water level until it reaches the harvest level.
NOTE: There are two revisions of control boards that have a five minute timer built into the freeze
cycle. This timer prevents the unit from going into a defrost cycle until the compressor has been
running for a minimum of five minutes.
The control board revisions number are: 100592 CRN; 100795 CRN.
NOTE: As ice builds on the evaporator the water level in the water pan drops. This is called
batch harvesting.

HARVEST CYCLE

1. The hot gas solenoid opens, the dump solenoid opens, and the water pump remains running for 15
seconds.
2. The microprocessor monitors the proximity switches waiting for the circuit to open.
3. Once all of the proximity switch circuits have opened, the hot gas solenoid closes.
4. The microprocessor monitors the proximity switches to close.
5. Once all the proximity switch circuits close, the harvest cycle terminates.
NOTE: When the pressure inside, the pressure sensor pick up lowers to a predetermined value,
the pressure transducer starts the harvest cycle.

FAN CONTROL

1. Fan control operates when the hot gas solenoid is closed.
2. The fan turns off when the condenser temperature is below 88_F.
3. The fan turns on when the condenser temperature is above 100_F.
October 17, 2005 15 TP00952