Features; A) Maximum Water Supply Period - 6 Minutes; B) Harvest Backup Timer And Freeze Timer; C) High Temperature Safety - Hoshizaki KMD-901MWH Service Manual

2. Features

a) Maximum Water Supply Period – 6 minutes
The inlet water valve will be open during harvest for 6 minutes or the length of harvest
minus 50 seconds, whichever is shorter.

b) Harvest Backup Timer and Freeze Timer

The harvest backup timer shuts down the icemaker if, for two cycles in a row, the harvest
cycle takes more than 20 minutes to complete. The control board will signal this problem
using 2 beeps every 3 seconds.
The freeze timer shuts down the icemaker if, for two cycles in a row, the freeze cycle
takes longer than the time specified to complete. The control board will signal this
problem using 3 beeps every 3 seconds. The time is factory set using S4 dip switch 9 &
10.
The "ALARM RESET" button on the control board must be pressed with power on to
reset either of these safeties.

c) High Temperature Safety

The temperature of the suction line in the refrigeration circuit is limited by the high
temperature safety. This protects the unit from excessively high temperatures. If the
evaporator temperature rises above 127 ± 7°F (53 ± 4°C), the control board reads a
.804 kΩ signal from the thermistor and operates the safety. This shuts down the circuit
and the icemaker automatically stops.
The control board will signal this problem using 1 beep every 3 seconds. The "ALARM
RESET" button on the control board must be pressed with power on to reset the safety.

d) Low Water Safety

The control board checks the position of the float switch at the end of the initial one
minute water fill cycle and at the end of each harvest cycle. If the float switch is in the up
position (electrical circuit closed), the control board changes to the ice making cycle. If
the float switch is in the down position (electrical circuit open), the control board changes
to additional one minute water fill cycles until water enters the sump and the float switch
closes. When the float switch closes, the control board changes to the ice making cycle.
The unit will not start without adequate water in the sump. This serves as a low water
safety to protect the water pump.
For water-cooled model, if the water is shut off, the unit is protected by the high pressure
switch.

e) High Voltage and Low Voltage Cut-outs

The maximum and minimum allowable supply voltages of this icemaker are limited by
the high voltage and low voltage cut-outs.
If miswiring (especially on single phase 3 wire models) causes excessive voltage
(147Vac ±5% or more) on the control board, the high voltage cut-out shuts down the
circuit in 3 seconds and the icemaker automatically stops. The control board will signal
this problem using 7 beeps every 3 seconds.
The icemaker also automatically stops in cases of insufficient voltage (92Vac ±5% or
less). The control board will signal this problem using 6 beeps every 3 seconds.
When the proper supply voltage is resumed, the icemaker automatically starts running
again.
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