4. Controls and Adjustments
The cabinet and rail temperatures are updated every 30 seconds. The control board is supplied with a service jumper on the K151 connector. Only the temperature setpoint and the temperature scale ("F5") may be adjusted with this connector in place. To view or adjust other selections, see "II.D.5. Service Menu."
a)Switch Settings
Power Switch "OFF": Unit off (both cabinet and rail).
Power Switch "ON": Cabinet temperature is displayed and cabinet cooling begins. Cabinet fans and perimeter heaters are on and run continuously (except during defrost). Rail Cooling Switch "OFF": Rail cooling off, cabinet cooling continues.
Rail Cooling Switch "NORMAL: Designed for use when the rail cover is open. Rail temperature display on and rail cooling begins. The rail fans operate continuously. Rail Cooling Switch "LOW": Designed for use when the rail cover is closed. Rail temperature display is on and rail cooling begins. The rail fans operate intermittently when "F9" is at the factory default setting. For access and adjustments to the "F9" setting, see "II.D.5. Service Menu."
Note: A Hoshizaki OEM rail cooling switch must be used if replacing the rail cooling switch. For details see "IV.M. Rail Cooling Switch."
b)Temperature Display
The temperature display can be changed between Fahrenheit and Celsius. To change the temperature display, press and hold the cabinet "SET" button and the "SERVICE USE ONLY" button for 5 seconds. "F0" appears in the display screen. Press the up arrow button until "F5" appears in the display screen. "F5" is the only service menu selection accessible with the service jumper in place.
Press the cabinet "SET" button to view the temperature display setting. Press the up or down arrow button to switch between F° and C°. Press the cabinet "SET" button to save the new setting. Press the cabinet "SET" button and the "SERVICE USE ONLY" button for 5 seconds to return to normal temperature display.
"SET" buttons used to view current temperature settings. Cabinet "SET" button used with "SERVICE USE ONLY" button to enter and exit the service menu.
"MANUAL DEFROST" 
button used to initiate
a manual defrost.
"UP" and "DOWN" arrow buttons used to change temperature settings, scroll through the service menu, and to change menu settings.
"SERVICE USE ONLY" button used with cabinet "SET" button to enter and exit the service menu.
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