Hoshizaki KM-40B, Service Manual

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starts after the thermistor temperature reaches 2°C. After this period, the freeze cycle
operation is transferred to the float switch for freeze termination. During the first 5
minutes of freeze, confirm that the evaporator temperature drops. After the minimum
freeze period, disconnect the float switch at the 2-pin connector attached to the red
wires. See Fig. 2 for general location. The unit should immediately switch to the drain
cycle. Diagnosis: If the evaporator is not cold, check to see if the hot gas valve is
still open or if the expansion valve (on KM-80B only) is not opening properly, if the
water valve is continuing to fill the reservoir, if there are improper unit pressures or an
inoperative compressor. If the unit remains in freeze with the float switch removed,
replace the board.
Note: Normal freeze cycle will last 20 to 40 minutes depending on model and
conditions. Cycle times and pressures should follow performance data provided
in this manual.
6) Drain Cycle – The compressor remains energized, the hot gas valve energizes, the
fan motor de-energizes. The drain valve energizes, allowing water to drain from the
tank for 20 seconds. This removes contaminants from the water tank. Diagnosis: If
the drain valve does not open, check the circuit. Check for proper voltage. If water
does not drain out, check and clean the tubing at the drain valve and then check and
clean the valve assembly.
7) Normal Harvest Cycle – same as the initial harvest cycle – Return to step 4.
Note: Unit continues to cycle until bin control is satisfied or power is turned off. (The
drain cycle can be adjusted to occur every cycle, or every 2, 5, or 10 cycles. The
factory default is every 10 cycles.) The unit always restarts at the 1 minute fill
cycle.