Manual Defrost; Cabinet Control Alarm Safeties; 1A. Cabinet Control Module: 4A7178-01 - Hoshizaki Steelheart Series Service Manual

C. Manual Defrost
The cabinet control module does not have the function enabled for manual defrost.
The rail control dial is used for this function. To manually initiate or terminate a defrost
cycle: Turn the rail control dial clockwise to put the control dial 9 setting in the 12 o'clock
position, pause for 3 to 5 sec., then turn the rail control dial counterclockwise to any
position below setting 7 in the 12 o'clock position. Defrost initiates or terminates within 5
sec. See Fig.11.
Note: When defrost is manually initiated, it continues through the normal defrost cycle
unless manually terminated. Compressor must be on for a minimum of 2 min. to
initiate defrost and off for a minimum of 2 min. to terminate defrost.
D. Cabinet Control Alarm Safeties

1a. Cabinet Control Module: 4A7178-01

PR46B: L-5 to M50052H, M50073K and Later; (-D2): ALL
PR60B: L-5 to M50007H, M50025L and Later; (-D4): ALL
PR67B(-D2)(-D4): ALL
PR93B(-D2)(-D4)(-D6): ALL
These alarms give information in the event the cabinet area is operating out of
acceptable parameters. Should one of the alarms occur, follow the instructions in the
table below to address the alarm. The alarm code and alarm icon flash with audible
alarm. To silence the alarm, press and release any button.
Alarm Code Problem
Cabinet Thermistor Malfunction Alarm
Cabinet thermistor has failed.
(-)E1
High Temperature Alarm
Cabinet temperature has remained above
57°F (13.9°C) for more than 1 hour.
Hi
Low Temperature Alarm
Cabinet temperature has remained below
20°F (-6.6°C) for more than 1 hour.
Lo
12 o'clock
Control Knob
Clockwise
Alarm Signals
12 o'clock
Fig. 11
Counterclockwise
Corrective Action/Reset Details
Check Cabinet Thermistor.
Steady tone. To silence the alarm, press and release
any button.
Cabinet Fan(s) cycle 5 min. on, 5 min. off.
-E1 - Cabinet thermistor out of place or open.
E1 - Cabinet thermistor shorted.
Check for open doors/drawers, dirty air filter and/or
condenser.
Steady tone. To silence the alarm, press and release
any button. The alarm icon stays on.
Automatically resets when temperature returns to
normal.
Check Rail Control Module, Rail Thermistor, and Rail
Light Sensor.
Steady tone. To silence the alarm, press and release
any button. The alarm icon stays on.
Automatically resets when temperature returns to
normal.
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