Ice Making Sequence Of Operation - Manitowoc NEO U0140 Series Installation, Operation And Maintenance Manual

Operation

Ice Making Sequence of Operation

NOTE: The On/Off button must be depressed and the ice
damper must be closed before the ice machine will start.
Water Purge Cycle
The ice machine purges any remaining water from the
water trough down the drain.
Freeze Cycle
Prechill - The refrigeration system chills the evaporator
before water flow over the evaporator starts. The water inlet
valve energizes during the pre-chill and remains on until
the ice thickness float switch is satisfied.
Freeze - With water trough thermistor , the following
sequence occurs in the frezze cycle:
• When the water temperature reaches 34°F, the water
pump will de-energize for 25 seconds, then re-
energizes.
• When the water pump restarts the water inlet solenoid
energizes for 7 seconds.
• Water flowing across the evaporator will start to freeze
and build ice on the evaporator. After a sheet of ice
has formed, the harvest float switch signals the control
board to start a harvest cycle.
Freeze - Without water trough thermistor , the following
sequence occurs in the frezze cycle:
• At 3.75 minutes the water pump de-energizes for 25
seconds , then re-energizes.
• When the water pump restarts the water inlet solenoid
energizes for 7 seconds.
• Water flowing across the evaporator will start to freeze
and build ice on the evaporator. After a sheet of ice
has formed, the harvest float switch signals the control
board to start a harvest cycle.
Harvest Cycle
Any remaining water is purged down the drain as
refrigerant gas warms the evaporator. When the evaporator
warms, the sheet of cubes slides off the evaporator and into
the storage bin. If all cubes fall clear of the ice damper, the
ice machine starts another freeze cycle.
Full Bin Cycle
If the ice damper is held open by ice cubes, the ice machine
shuts off. When the ice damper closes, the ice machine
starts a new cycle at the water purge.
Control Board Timers
The control board has the following non-adjustable timers:
• The ice machine is locked into the freeze cycle for 6
minutes before a harvest cycle can be initiated.
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• The maximum freeze time is 45 minutes, at which time
the control board automatically initiates a harvest
sequence.
• The maximum harvest time is 7 minutes. When harvest
is complete the control board automatically initiates a
freeze sequence.
• If the ice damper does not open and close within
the 7 minute harvest cycle, the ice machine enters
a water thaw cycle for 170 seconds. If the damper
does not open and close within the 170 second thaw
cycle, a second thaw cycle starts. The control board
automatically initiates a freeze sequence when the thaw
cycle(s) is complete.
Part Number: 040005890 Rev 04 02/19
Section 3