Part Number: 040006019 Rev. 01 09/18
17
Sequence of Operation
Ice Making Sequence
of Operation
Control Board Relays
1
Compressor
2
Hot Gas Valve
Water Fill Valve
3
Water Pump
Fan Motor
Length of
“ON” Time
Start-up*
1. Water Purge
2. Refrigeration System
Start-up
off
on
on
2.9 Minutes
(175 Seconds)
on
on
off
5 Seconds
3. Freeze Cycle
on
off
on
Automatically
determined
4. Harvest Cycle
on
on
off
Automatically
determined
5. Auto Shut-off
off
off
off
Until bin thermostat
re-closes
*Initial Start-up or Start-up After Automatic Shut-off.
INITIAL START-UP OR START-UP AFTER AUTOMATIC SHUT-OFF
1. Water Purge
The water fill valve and the hot gas valve are energized
for 2.9 minutes (175 seconds). This ensures that the ice
making cycle starts with fresh water, and that the refrigerant
pressures are equalized prior to refrigeration system start-up.
2. Refrigeration System Start-up
The compressor starts 2.9 minutes (175 seconds) after
the water fill valve and hot gas valve are energized. (The
water fill valve and hot gas valve remain energized for 5
seconds during compressor start-up, and then shut off.) The
compressor remains on throughout the entire freeze and
harvest cycles.
3. Freeze Cycle
The condenser fan motor and water pump are energized and
remain on throughout the entire freeze cycle. An even flow
of water is directed across the evaporator and into each cube
cell, where it freezes.
The control system automatically determines the length
of the freeze cycle by monitoring the temperature of the
refrigeration system liquid line.
4. Harvest Cycle
The condenser fan motor and water pump de-energize. The
water fill valve energizes to purge the water in the water
trough. The hot gas valve also energizes at the beginning
of the harvest cycle to divert hot refrigerant gas into the
evaporator. The hot refrigerant gas warms the evaporator,
causing the cubes to slide, as a sheet, off the evaporator and
into the ice storage bin.
The control system automatically determines the length
of the harvest cycle, based on the temperature of the
refrigeration system liquid line at the end of the freeze cycle.
At the end of the harvest cycle, the ice machine returns to
another freeze cycle.
5. Automatic Shut-off
The ice machine shut-off is controlled by the level of ice in
the ice storage bin. When the bin is full, ice cubes contact
the bin thermostat bulb holder, which cools down and opens
to stop the ice machine. The ice machine remains off until
enough ice has been removed from the bin. This causes the
thermostat bulb holder to warm and close, restarting the ice
machine. When the ice machine restarts, it returns to the
start-up sequence.
Section 3
Operation