Hoshizaki KM-501MAH, KM-501MRH, KM-501MWH Features, Maximum Water Supply Period 6 minutes

2. Features

a)Maximum Water Supply Period – 6 minutes

Inlet water valve opening, in the harvest cycle, is limited by the harvest timer. The water valve cannot remain open longer than the maximum period. The water valve can close in less than six minutes if the harvest cycle is completed.

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 dip switches 9 & 10.

The 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 thermistor 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 reset button on the control board must be pressed with power on to reset the safety.

d)Low Water Safety

If the pump motor is operated without water, the mechanical seal can fail. To prevent this type of failure, 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 pump motor from mechanical seal failure.

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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