Holding Cabinet – Service Manual
10
DIAGNOSTIC MODE
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Press and hold down the “Temperature” button until you hear a short, double-beep sound.
In this mode all displays indicate temperatures for either the upper or lower heaters for
each bin. Pressing the “Up” and “Down” arrow buttons will select the upper and lower
heaters respectively.
In this mode, pressing the “Time” button will also display the PWM output power duty
cycle. This is shown as a percent for the corresponding heater.
The thermocouple calibration system can only be accessed from within the diagnostic
mode.
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THERMOCOUPLE CALIBRATION SYSTEM
Make sure heater zone to be calibrated is at temperature and stable. Measure actual
temperature and proceed with following procedure.
Enter “Diagnostic Mode” by pressing and holding down the “Temperature” button. After a
second or so, the actual temperatures as measured by holding cabinet are displayed.
Use “Up” or “Down” buttons to select either the upper or lower heating zone for each bin.
Press “Bin” select button to select bin containing heating zone to be calibrated.
Note: Bin display will alternate between showing temperature and calibration offset. As the
calibration offset is changed the temperature displayed will reflect this.
Use the “Up” and “Down” buttons to make the displayed temperature match the actual
temperature as independently measured.
To apply the temperature calibration correctly, press and hold the “Temperature” button
down. While pressing the “Temperature” button, press “Program” button (for 1 second)
until the unit beeps.
Once program in completed the temperature correction is applied and the heater zone will
adjust its temperature. The user interface returns to the actual temperature display.
Once a bin is selected for programming, if no keys are entered for 10 seconds the
calibration mode is terminated and the display returns to actual temperature display mode.
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THERMOCOUPLE FAULT DETECTION
The thermocouple (TC) fault detection logic is disabled for 10 minutes following initial
power application. This allows time for all heating zones to develop enough heat to not
trigger a shorted thermocouple fault.
