Hoshizaki TM-500AAE, Service Manual

Page: 37 / 65

33
[e] OPERATION BOARD
The Operation Board is provided for operation of the icemaker. See “7. OPERATION
BOARD” for details.
[f] CONTROLLER BOARD
The icemaker is controlled by the Controller Board based on the following logic:
1) Ice Production Control
In a low ambient or water temperature condition, the ice production capacity will increase.
Then, the Gear Motor will have a larger torque to scrape off ice, which will overload the
entire icemaking mechanism. To prevent overload, the icemaker controls the fan rotation
speed.
2) Overload Protection
Despite the above control, the icemaker may be overloaded depending on the field
conditions (ex. water quality) or dimensional variation of the components. If the icemaker
is overloaded and the photomicrosensor detects a lower drum rotation speed than normal,
the icemaker will shut down before leading to critical and costly problems, such as with the
icemaking mechanism.
3) Error Code Indication
When the icemaker shuts down with a trouble, an error code will be displayed immediately
to notify the user. To facilitate servicing, ask the user for the applicable error code, and
prepare for the trouble in advance.
4) Flush Timer (Fixed Mounting Only)
The controller board is provided with a timer to count the total operation time up to 12
hours when the icemaker starts flushing. During the flush cycle, the display window will
illuminate “DRAIN”.
As the thin glass icemaker continuously produces ice, the content of substances included
in the icemaking water inside the icemaking unit is three to five times as high as that in
the supplied water. As a result, substances such as calcium, magnesium, and silica
contained in the water will attach and deposit inside the icemaking unit to reduce the ice
production capacity or accelerate wear on the moving parts.
[g] CAPACITOR - XY FILTER
The Capacitor - XY Filter is provided to prevent the Controller Board from signal errors