monitowoc UG018, Installation, Operation And Maintenance Manual

Section 3

Operation

Part Number 040003628 08/13

3-5

Ice Making Sequence of Operation

INITIAL START-UP

1.

Water Inlet and Pressure Equalization

Turn the toggle switch to”ON” positon,the water fill valve 

and harvest valve are energized, 210 seconds later, the 

water fill valve is de-energized. 20seconds after the 

harvest valve solenoid is energized, the compressor is 

energized. 300seconds after the compressor is 

energized, the harvest valve solenoid is de-energized, 

the water pumpand the fan motor are 

energized,machine goes into freeze cycle. 

2.

Freeze Cycle

The pump sprays water into the inverted cups. The 

water freezes layer by layer, until an ice cube forms in 

each cup.
When the”water temperature”is equal to or less than 2 

℃

for more than 5 seconds, control will read

the” liquid line temperature” and dip switch setting , get 

the” freeze postpone time” and “fan shut off time”.Board 

will shut the Fan before the end of the freeze cycle to 

assist harvest. When the ” freeze postpone time” has 

elapsed, the harvest cycle is initiated.

3.

Harvest Cycle

The compressor continues to operate and the water 

pump is de-energized. The hot gas valve energizes, 

allowing hot gas to enter and warm the evaporator. The 

water valve is also energized, aiding with harvest, as 

well as filling up the sump with fresh water for a new 

freeze cycle.
at the point of 2 minutes to freeze end , board will read 

the ” liquid line temperature”again and calculate the 

“harvest time”
The ice falls from the cups and is directed into the bin by 

the ice chute. The harvest cycle continues until the 

harvest time has elapsed,then machine goes into a new 

freeze cycle

4.

Automatic Shut-Off

When the storage bin is full, the ice will come in contact 

with the bin thermostat which is located inside the bin. 

The machine will stop after approximately 45seconds of 

continuous ice contact with the bin thermostat probe.
The ice machine remains off until a 3 minutes delay has 

elapsed and enough ice has been removed from the 

storage bin to allow the ice to fall clear of the bin 

thermostat probe. As the ice clears the probe, the bin 

thermostat warms up and the machine starts another 

freeze cycle.

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