Duke 155433P, Installation, Operation, Parts & Maintenance Manual

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E. Emergency Back-Up System
Your oven is equipped with an emergency back-up system
to be used should the computer controller ever
malfunction.
It is intended only to be used to keep you
in operation until a service agent arrives to provide
repairs
.
Operation: Turn power switch to off position. Push the
toggle switch located on the right access panel of the oven
to the up position.
Turn power switch clockwise to cook position. The oven
will now maintain a temperature of 375° by the back up
thermostat. You will need to manually time your bake
cycle until the biscuits are baked. No display will be
illuminated.
Call your local authorized service agent to render
repairs as soon as possible.
F. Troubleshooting
Oven Not Heating
1. Oven heating lamp is off.
2. Digital display in the controller is not lit. (Make
sure backup thermostat control switch is in the
down position.)
3. Check the 24VAC from the transformer. If
voltage is present, replace the controller.
4. If no voltage, check the transformer and
transformer input voltage. Make certain the
correct transformer input voltage taps are used.
Transformer Primary Voltage
Orange 240-L1
Red 208-L1
WHITE 120-L1
BLACK L2
Transformer Secondary Voltage
Yellow-blue 12V (pin 4 & pin3)
Yellow-blue 12V (pin 2 & pin3)
Yellow-yellow 24V (pin 4 & pin 2)
DIGITAL DISPLAY IN THE CONTROLLER IS
LIT, OVEN NOT HEATING
A simple test.
1. Turn the oven off.
2. Disconnect the oven control connector to J1
on the PCB
3. Insert a short insulated jumper wire between
pins 1 and 3 in the oven control connector.
Make sure the wire is insulated and bare wire
cannot touch ground or other metal parts.
(CAUTION: Line voltage present.)
4. Turn the oven on.
5. If the oven heats up, turn the oven off,
remove the jumper from the oven control
connector, and replace the oven control
connector. Check the controller's setpoint. If
the setpoint is correct, replace the controller.
6. If the oven does not heat up, the problem is
within the oven.
7. Turn the oven off.
8. Remove the jumper wire and replace the
connector.
9. Oven Heating Lamp is on. The problem is
within the oven.
OVEN TOO HOT (OVEN STAYS ON)
1. Turn the oven off.
2. Disconnect the oven control connector (J1)
3. Turn the oven on.
4. If the oven heats up, the problem is within the
oven.
5. If the oven does not heat up, turn the oven
off, and replace the oven control connector on
J1, then turn the oven back on. Proceed to 6.
6. Press the ENTER switch to read the oven's
temperature.
7. Indicated temperature is obviously less than it
should be.
8. The thermocouple cable may be shorted, or,
9. The controller may be defective.
10. Replace the temperature probe.
11. If the temperature now indicates the correct
temperature, the problem was the temperature
probe.
12.
If the temperature still indicates lower than
expected, replace the controller
.