B. Control Board Check

Before replacing a CB that does not show a visible defect and that you suspect is bad, always conduct the following check procedure. This procedure will help you verify your diagnosis. Always choose a neutral (W wire) to establish a good neutral connection when checking AC voltage (115VAC).

Startup and Cool Down:

1)Press the power button for 2 sec. to turn off the appliance.

2)Unplug the appliance from the electrical outlet.

3)Remove the top panel. Check all wiring connections. Confirm that the power cord, EvapFM, Comp, DS, and CTh are all properly connected to CB and ground connection (GND) is properly connected to the frame.

4)Secure the top panel to prevent it from falling over when checking voltages and

CB items.

5)Secure (tape) DS in the door closed position.

6)Plug the appliance back in. °F LED turns on. Diagnosis: Confirm that °F LED is on. If not, check CB POWER connector for 115VAC. If 115VAC is not present, check power supply and power cord connection. If 115VAC is present and °F LED is not on, replace CB.

7)Press the power button for 2 sec. to turn on the appliance.

8)Check that CT LEDs and EvapFM icon turn on. If not, check for 115VAC at the POWER connector on CB. If 115VAC is not present, check power cord and power supply.

If 115VAC is present, and DM is not on (°F and CT LEDs and EvapFM icon), replace CB.

9)If °F and CT LEDs are on but EvapFM icon is not, confirm DS is engaged (pushed in, contacts open). Check across DS for 5VDC. If 5VDC is not present, check DS activation lever and DS continuity. Note: DS contacts are open when DS is engaged (door closed). If 5VDC is present, check CB EvapFM connector for 12VDC. If 12VDC is not present, replace CB. If 12VDC is present, check EvapFM wiring connector for loose connection, EvapFM continuity, and fan blade for binding.

10)Defrost:

This appliance defrosts every 6 hrs. for 30 min. Defrost is an off-cycle defrost.

a)Manual Defrost Initiation: To initiate a manual defrost, press and hold the "+" button until the defrost icon turns on. 30‑min. DT starts. EvapFM continues. If Comp run time < 3 min., Comp icon and Comp continue until 3-min. Comp run timer terminates. Once 3-min. Comp run timer terminates, Comp icon turns off, Comp de‑energizes, and 30-min. DT starts. Diagnosis: If defrost icon is on, confirm that Comp de‑energizes. If not, confirm Comp run time > 3 min. If Comp continues after 3-min. Comp run timer terminates, replace CB.

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Hoshizaki HR24A service manual Control Board Check, Startup and Cool Down, Defrost
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HR24A specifications

The Hoshizaki HR24A is an advanced refrigeration unit designed to meet the cooling needs of commercial kitchens and food storage facilities. Known for its reliability and efficiency, this model showcases several innovative features that set it apart in the competitive market of commercial refrigeration.

One of the standout characteristics of the Hoshizaki HR24A is its robust construction. Built with a durable stainless steel exterior, it not only adds aesthetic appeal but also ensures longevity and resistance to corrosion and wear. The interior is designed for easy cleaning, with rounded corners that minimize the buildup of grime and food particles.

The HR24A offers an impressive storage capacity, making it ideal for establishments with high-volume food storage requirements. With a temperature range typically between 33°F and 38°F, the unit maintains optimal conditions for preserving perishables such as meats, dairy, and vegetables. This precision in temperature control is essential for maintaining food safety and quality.

One of the key technologies integrated into the Hoshizaki HR24A is its advanced refrigeration system. Utilizing a highly efficient compressor and a fan-assisted cooling feature, the unit ensures rapid temperature recovery even in busy kitchen environments. This is crucial during peak hours when door openings are frequent, as it helps maintain consistent internal temperatures.

Energy efficiency is another hallmark of the HR24A. It is designed with environmentally friendly refrigerants and complies with Energy Star standards, which can lead to significant cost savings over time through reduced electricity consumption. This commitment to environmental responsibility makes it an attractive option for eco-conscious businesses.

In terms of user-friendliness, the HR24A is equipped with digital controls and adjustable shelving, allowing for customized organization according to specific storage needs. The LED lighting inside the unit provides excellent visibility, making it easy to locate items quickly, which is particularly beneficial during busy service periods.

Overall, the Hoshizaki HR24A combines durability, efficiency, and functionality, making it an exceptional choice for anyone seeking a reliable refrigeration solution in a commercial kitchen setting. Whether used in restaurants, hotels, or catering businesses, its impressive features and state-of-the-art technology continue to meet the demanding requirements of the foodservice industry.
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