Controller Board; Solid-State Control - Hoshizaki KM-320MAH Service Manual

B. Controller Board

1. Solid-State Control

• A HOSHIZAKI exclusive solid-state control is employed in KM-320MAH and
KM-320MWH Modular Crescent Cubers.
• A printed circuit board (hereafter called "controller board") includes a stable and high
quality control system.
• All models are pretested and factory-adjusted.

2. Controller Board

1. Fragile, handle very carefully.
2. A controller board contains integrated circuits, which are susceptible to
failure due to static discharge. It is especially important to touch the metal
part of the unit 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. Do not misconnect K3, K4 and K5,
because the same connector is used for the thermistor and float switch. K4 is
not connected.
5. Always replace the whole board assembly when it goes bad.
6. Do not short out power supply to test for voltage.
Part Number
2A1410-01
Features of Control Products "E" Controller Board
a) Maximum Water Supply Period - 6 minutes
Water solenoid valve opening, in the defrost (harvest) cycle, is limited by the defrost
timer. The water valve cannot remain open longer than the maximum period. The water
valve can close in less than six minutes if the defrost cycle is completed.
b) Defrost Timer
The defrost cycle starts when the float switch opens and completes the freeze cycle.
But the defrost timer does not start counting until the thermistor senses 48°F (9°C) at
the evaporator outlet. The period from the end of the freeze cycle up to the point of the
thermistor's sensing varies depending on the ambient and water temperatures.
CAUTION
Controller Board
Type
HOS-001A (Control Products - 10 Pin)
9