Normal Harvest Cycle - Hoshizaki KMD-850MAH Service Manual

5. Normal Harvest Cycle

LEDs 1, 4, and 2 are on. Comp, FMR, and HGV remain energized and WV opens. PM
stops. As the evaporator warms, the thermistor reaches 48°F (9°C). The control board
then receives the thermistor's 3.9 kΩ signal and starts the harvest timer. When the
harvest timer completes its countdown, the harvest cycle is complete. The minimum total
time allowed by the board for a complete harvest cycle is 2 minutes. WV is energized
during harvest for a maximum of 6 minutes or the length of harvest minus 50 seconds,
whichever is shorter. LED 4 goes off when WV closes. PM energizes and runs for the
last 50 seconds of harvest. LED 3 comes on when PM energizes. At the end of harvest,
the control board checks the position of F/S and proceeds to the freeze cycle if it is
closed or calls for a 1-minute fill if it is open.
The unit continues to cycle through freeze and harvest cycles until the bin control
activates (opens) and shuts the unit down.
Note: To prevent incomplete batches of ice from forming on the evaporator, the control
board will only shut down the machine within the first 5 minutes of the freeze
cycle. If ice pushes the bin control actuator in (open) after the first five minutes of
the freeze cycle, the control board will allow the machine to complete the freeze
cycle and the following harvest cycle before shutting down the machine.
Legend: Comp–compressor; DV–Drain Valve; FMR–remote fan motor; FMS–self-contained
fan motor; F/S–float switch; HGV–hot gas valve; LLV–liquid line valve;
PM–pump motor; SR–service relay; WV–inlet water valve
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