Ice Making Sequence Of Operation; Safety Limits - Manitowoc NEO UD0140A Manuel D'instructions

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 - Water flowing across the evaporator freezes
and builds 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.
• 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. The control
board automatically initiates a freeze sequence when
these times are exceeded.
14

SAFETY LIMITS

Safety limits are stored and indicated by the control
board. The number of cycles required to stop the ice
machine varies for each safety limit.
Safety limits can be reset by pressing the On/Off button
and starting a new ice making cycle.
A safety limit is indicated by an energized Service Light
on the touch pad. Refer to Section 5 if you receive a
safety limit indication.
• Safety Limit 1 - If the freeze time reaches 45 minutes,
the control board automatically initiates a harvest
cycle. After 6 consecutive 45-minute freeze cycles
occur, the ice machine stops.
• Safety Limit 2 - If the harvest time reaches 3.5
minutes, the control board automatically energizes
the water pump and extends the harvest cycle
another 3.5 minutes (7 minutes total). After 7 minutes
the ice machine automatically starts a new freeze
cycle. If 3 consecutive 7 minute harvest cycles occur,
the ice machine stops.
• Safety Limit 3 - If the freeze time reaches 4 minutes
and water is not sensed, the ice machine stops and
initiates a 30 minute delay period. The ice machine
will automatically restart at the end of the 30 minute
delay period. If 100 consecutive failures occur the ice
machine stops.
Part Number 040002909 Rev01 4/15
Section 3