Operation; Ice Making Sequence Of Operation; Safety Limits - Koolaire KD0250A Installation And Maintenance Manual

Section 3

Ice Making Sequence of Operation

NOTE: The toggle switch must be in the ICE position and the
water curtain 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 and the refrigeration compressor
starts.
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 water curtain, the ice
machine starts another freeze cycle.
Full Bin Cycle
If the water curtain is held open by ice cubes, the ice
machine shuts off and starts a 3-minute delay period. When
the water curtain closes, the ice machine starts a new cycle
at the water purge, provided the 3-minute delay period has
expired.
Part Number 000012545 4/14
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.
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 a flashing Service Light on the
control board.
• 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.
• 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.

Operation

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