Hoshizaki F-450MAH-C service manual Timer Board, Solid-State Control

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3. Timer Board

[a] Solid-State Control

1)A HOSHIZAKI exclusive solid-state control is employed in the self-contained flaker icemakers.

2)A printed circuit board (hereafter called “timer board”) includes a stable and high quality control system.

3)All models are pre-tested and factory-adjusted.

[b] Timer Board

CAUTION

1.Fragile, handle very carefully.

2.A timer board contains CMOS (Complementary Metal-Oxide Semicon- ductor) integrated circuits, which are susceptible to failure due to static discharge. It is especially important to use an anti-static wrist strap when handling or replacing the board.

3.Do not touch the electronic devices on the board or the back of the board to prevent damage to the board.

4.Do not change wiring and connections. Especially, never misconnect terminals.

5.Do not fix the electronic devices or parts on the board in the field. Always replace the whole board assembly when it goes bad.

The icemaker is controlled by the timer board for the following purposes:

1)To prevent the gear motor and the compressor from starting or stopping simultaneously.

2)To reduce remaining ice in the refrigeration casing.

3)To protect the unit in case of low water and low water pressure.

4)To protect the unit in case the bin control causes chattering.

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Contents Modular Flaker Models 450MAH-C Hoshizaki AMERICA, INC Contents Specifications 1. F-450MAH Water TEMP. F 450MAH-C II. General Information Construction Control Box Layout Solid-State Control Timer BoardTimer Board Sequence Part Code Page Page Wiring Diagram 450MAH450MAH-C Sequence of Electrical Circuit Page Compressor starts about 60 sec. after gear motor starts Page Low water except water-cooled model Page Page Page Page Page Timing Chart Gear Motor Relay OFF FAN Motor Flush ICE OFF Upper Lower Bottom Performance Data ICE Production883 891 898 IV. Service Diagnosis No Ice Production Problem Possible Cause Remedy Problem Possible Cause Remedy Low Ice Production Other Removal and Replacement of Components Service for Refrigerant LinesRefrigerant Recovery Evacuation and Recharge R-404ABrazing Removal and Replacement of Compressor Removal and Replacement of Drier Removal and Replacement of Expansion Valve Removal and Replacement of Evaporator Assembly CutterExtruding Head AugerBearing-Lower and Mechanical Seal Gear MotorRemoval and Replacement of Fan Motor Removal and Replacement of Control Water ValveRemoval and Replacement of Flush Water Valve VI. Cleaning and Maintenance Preparing the Icemaker for Long StorageCleaning and Sanitizing Instructions Cleaning SolutionCleaning Procedure Sanitizing Solution Sanitizing Procedure InitialSanitizing Procedure Final Page Maintenance Instructions