Ice Making Sequence Of Operation; Control Board Timers - Manitowoc Indigo NXT Series Installation, Operation And Maintenance Manual

Section 3

Ice Making Sequence of Operation

The power button must be depressed and
the water curtain/ice dampers must be
in place on the evaporator before the ice
machine will start.
Water Purge Cycle
The ice machine purges any remaining
water from the water trough down the
drain.
Prechill Cycle
The refrigeration system cools the
evaporator before the water pump is
energized.
Freeze Cycle
Water flows across the evaporator and the
refrigeration system chills the evaporator.
Ice builds on the evaporator and the freeze
cycle continues until the ice thickness
probe senses a sheet of ice has formed.
The ice thickness probe signals the control
board to start a harvest.
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 water curtain (or ice damper)
the ice machine starts another freeze cycle.
Off Cycle
If the water curtain or ice damper are held
open by ice cubes the ice machine shuts
off. When the water curtain or ice damper
closes, the ice machine starts a new cycle at
the water purge.
Part Number 000014141 Rev 07 2/20

Control Board Timers

The control board has the following non-
adjustable timers:
• The ice machine control board will set
its own install date after 100 freeze and
harvest cycles.
• The ice machine is locked into the freeze
cycle for 6 minutes before a harvest cycle
can be initiated.
• The maximum freeze time is 35
minutes at which time the control
board automatically initiates a harvest
sequence.
• The maximum harvest time is 7 minutes,
the control board will perform a water
thaw cycle and then return the ice
machine to the freeze cycle.
Service Faults
Service Faults are stored and indicated by
the control board after three cycles. The
number of cycles required to stop the ice
machine varies for each Service Fault.
• Long Freeze Cycle - If the freeze time
reaches 35 minutes, the control board
automatically initiates a harvest cycle.
If 6 consecutive 35 minute freeze cycles
occur, the ice machine stops.
• Long Harvest Cycle - If the harvest time
reaches 7 minutes, the control board
automatically returns the ice machine to
the freeze cycle. After 3 consecutive long
harvest cycles the ice machine stops.
Refer to Section 5 if you receive an alert for
Service Fault E01 or E02.
Operation
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