c) High Temperature Safety - 127 ± 7°F (53 ± 4°C)

The temperature of the suction line in the refrigerant circuit is limited by the high temperature safety.

During the defrost cycle the evaporator temperature rises. The thermistor senses 48°F (9°C) and starts the defrost timer. After the defrost timer counts down to zero, the normal freeze cycle begins. If the evaporator temperature continues to rise, the thermistor will sense the rise in temperature and at 127 ± 7°F (53 ± 4°C) the thermistor operates the high temperature safety.

This high temperature safety shuts down the circuit and the icemaker automatically stops.

This high temperature safety protects the unit from excessive temperature. The control board will beep every 3 seconds. The white 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 controller 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 defrost cycle.

If the float switch is in the up position (electrical circuit closed), the controller board changes to the ice making cycle. If the float switch is in the down position (electrical circuit open), the controller board changes to a one minute water fill cycle before starting the ice making cycle. This method allows for a low water safety shut down to protect the water pump 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 Cut-out

The maximum allowable supply voltage of this icemaker is limited by the high voltage cut-out.

If miswiring (especially on single phase 3 wire models) causes excessive voltage on the controller board, the high voltage cut-out shuts down the circuit in 3 seconds and the icemaker automatically stops. When the proper supply voltage is resumed, the icemaker automatically starts running again. The control board will signal this problem using 7 beeps every 3 seconds.

f) LED Lights and Audible Alarm Safeties

The red LED indicates proper control voltage and will remain on unless a control voltage problem occurs. At startup a 5 second delay occurs while the board conducts an internal timer check. A short beep occurs when the power switch is turned ON or OFF.

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Hoshizaki KM-320MAH, KM-320MWH service manual High Temperature Safety 127 ± 7F 53 ± 4C

KM-320MWH, KM-320MAH specifications

Hoshizaki, a leading manufacturer in the food service equipment sector, offers a diverse range of ice-making machines that excel in efficiency, durability, and innovative technology. Among the notable models are the Hoshizaki MWH KM-515MAH, MWH(-M), MRH KM-901MAH, MRH KM-600MAH, KM-650MAH, and KM-320MAH. Each model brings unique features designed to meet varying commercial ice production needs.

The Hoshizaki MWH KM-515MAH is particularly recognized for its high ice production capacity, generating up to 515 pounds of ice per day. This model incorporates advanced technology that ensures consistent ice quality and purity. The MWH(-M) variant often includes modifications to suit specific operational environments, ensuring reliability in diverse settings.

Similarly, the MRH KM-901MAH stands out with its ability to produce a staggering 901 pounds of ice per day, making it ideal for high-volume establishments. This model is equipped with Hoshizaki's unique "cubelet" technology, producing a soft, chewable ice perfect for beverages. It also features a robust stainless steel construction, enhancing its durability and resistance to corrosion.

The MRH KM-600MAH offers 600 pounds of daily ice output, while the KM-650MAH enhances that capacity to 650 pounds. Both machines prioritize energy efficiency and come with built-in energy-saving modes. These models feature advanced ice sensing technology that monitors production levels to optimize energy consumption and reduce waste.

On the other hand, the KM-320MAH is designed for smaller establishments, with a daily ice production rate of 320 pounds. Despite its smaller footprint, it maintains high production efficiency and is equipped with features like a built-in storage bin, saving space while ensuring a reliable ice supply.

Across these models, Hoshizaki employs various technologies, including air-cooled and water-cooled systems, offering flexibility depending on installation requirements. The ice machines are designed with user-friendly controls and features like self-cleaning capabilities, making maintenance straightforward and less time-consuming.

In summary, Hoshizaki's ice machines, including the MWH KM-515MAH, MRH KM-901MAH, and others, deliver exceptional ice production, durability, and efficiency tailored to meet the demands of any commercial kitchen or service establishment. With a commitment to quality, Hoshizaki continues to be a trusted choice for businesses needing reliable ice-making solutions.