Manitowoc IB1096YC, Installation, Operation And Maintenance Manual

Page: 36 / 99

Operation Section 3
36
Part Number 000007924 5/14
Ice Making Sequence Of Operation
Ice machines and storage bins produce and store ice for
human consumption and product cooling.
NOTE: 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.
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.
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 60 minutes at which
time the control board automatically initiates a
harvest sequence.
• The maximum harvest time is 3.5 minutes. The
control board automatically initiates a freeze
sequence when these times are exceeded.
SAFETY LIMITS
Safety limits are stored and indicated by the control
board after three cycles. The number of cycles required
to stop the ice machine varies for each safety limit.
• Safety Limit 1 - If the freeze time reaches 60 minutes,
the control board automatically initiates a harvest
cycle. If 6 consecutive 60-minute freeze cycles occur,
the ice machine stops.
• Safety Limit 2 - If the harvest time reaches 3.5
minutes, the control board automatically returns the
ice machine to the freeze cycle. If 500 consecutive
3.5 minute harvest cycles occur, the ice machine
stops.
A safety limit is indicated by a flashing control board light
labeled SL1 or SL2. Refer to section 5 if you receive a
safety limit indication.
SAFE OPERATION MODE
Allows the ice machine to operate up to 72 hours if the
ice thickness probe and/or water level probe sensors
fail.
•
When the control board starts the safe mode an alert
is flashed on the LCD display to notify the end-user
they have a production problem.
• The control board automatically initiates and
monitors the safe mode. The control will
automatically exit the safe mode if a normal signal is
received from the input.
• After 72 hours the control board will enter a standby
mode and turn off.