Manitowoc UG Series, Technician'S Handbook

Page: 32 / 128

32 Part Number: 040006847 12/19
Ice Making Sequence of Operation
INITIAL START-UP
1.
Water Inlet and Pressure Equalization
Turn the toggle switch to the “ON” position, the water fill
valve and harvest valve are energized, and 300 seconds
later, the water fill valve is de-energized. 20 seconds after
the harvest valve solenoid is energized, the compressor is
energized. 300 seconds after the compressor is energized,
the harvest valve solenoid is de-energized, the water pump
and the fan motor are energized, and the machine goes
into freeze cycle.
2.
Freeze Cycle
As the ice making process begins, 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 in the sump is equal to or
less than 2 °C for more than 5 seconds, the control board
will read the settings of “liquid line temperature” and dip
switch and obtain the “freeze postpone time” and “fan
shut off time”. Before the end of the freeze cycle, the
control board may shut off the fan motor to assist harvest.
When the “freeze postpone time” has elapsed, the harvest
cycle is initiated.