Hoshizaki IM-50BAA-LM Service Manual page 51

Water Plate Switch and Cam Switch Operation
1) When harvest cycle starts after freeze cycle, the actuator motor rotates the cam
counterclockwise. But the water tank assembly stays fully closed because ice is frozen
to the lower evaporator.
2) The cam keeps rotating until the cam switch closes (at the angle of 85° where the cam
side touches the water plate), then stops.
3) Then, tap water is supplied to the water plate surface, reaches 7/10" (17 mm) in height,
and overflows to immerse the lower evaporator.
4) Water warms the lower evaporator and raises its temperature up to around 32°F (0°C).
Then, the lower evaporator separates from ice, the water tank assembly opens by its
own weight, and the water plate switch opens.
5) When the water plate switch does not open within a specific time, the control board
operates the actuator motor, and the cam forcibly separates the lower evaporator from
ice, which opens the water tank assembly and water plate switch.
6) When the water plate switch opens, the actuator motor operates to open the water tank
assembly and stop it at a specific angle.
7) Hot gas flows into the upper evaporator to melt the surface of ice stuck there.
* The compressor stops after freeze cycle until the cam switch opens.
Water Plate Switch Positioning
1) To adjust the water plate switch position, loosen the bolts fixing the lever to the side of
the water tank assembly, and move the lever up or down.
2) Check that the water plate switch closes when the water tank assembly is fully closed.
Plastic Washer
50
Evaporator
Screw
Lower Evaporator
Flange Nut,
Spring Washer,
Washer