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the resistance of the oven sensor, and compares it with
a programmed temperature set into the control. When
the resistance of the oven sensor indicates temperature
in the oven is about 10 degrees above the programmed
temperature the microprocessor opens the relay, which
removes power from the bake circuit and closes the
safety valve. When power is removed from the bake
circuit the oven temperature begins to lower. As the
oven temperature lowers the resistance of the oven
sensor decreases. When the oven drops to about 10
degrees below the programmed temperature the
resistance of the sensor tells the microprocessor to
close the relay contacts, and provide power to the bake
circuit. After the first cycle the preheat indicator light on
the control goes out indicating the oven is preheated.
Note:
Full power is on the oven igniter as long as
the control calls for heat.
Note:
Oven controls may have a spread of more
or less than 20 degrees. The important
thing is the average temperature in the
oven.
The average temperature in the
center of the oven should be within 10
degrees of the programmed temperature.
BROIL
When the broil pad is touched, and high or low is set with
the up or down arrows, the broil relay on the board
closes, applying line to neutral voltage across the broil
circuit and oven indicator lights on the control will
illuminate. The broil circuit is a series circuit made up of
the electronic oven control, a silicon carbide igniter that
reduces in resistance as it heats up, and a current
sensitive oven safety valve that needs a minimum of 3.2
amps of current to open. When electrical power is first
applied to the circuit, the resistance of the igniter is high
enough that the current flow in the circuit is below the
amount needed to open the safety valve. As electrical
current flows through the igniter it causes the silicon
carbide material to heat reducing the resistance of the
igniter and increasing the current flow in the circuit.
When the temperature of the igniter reaches around
1800 degrees F the current flow in the circuit exceeds 3.2
amps. The oven safety valve opens allowing gas to flow
into the broil burner. The gas is then ignited by the heat
of the broil igniter and the oven begins to heat up. In the
tip of the oven sensor is a positive coefficient thermistor
that increases in resistance as the oven temperature
increases. The microprocessor reads the resistance of
the oven sensor and compares it with a programmed
temperature set into the control for HI or LO and will cycle
the burner when the temperature is reached.
CLEAN
When the clean pad is touched and a clean time is set,
(if the oven door is closed closing the contacts COM to
NO of the door switch), the door lock relay on the
electronic oven control closes providing line to neutral
voltage (120 VAC) to the lock motor. “Cln” appears in the
display and the door lock indicator light blinks. The lock
motor starts to rotate closing the contacts of the door
lock switch. When the motor rotates one half turn the
contacts of the door lock switch reopen sending a
signal to the control telling it that the door is locked, and
to open the contacts of the lock relay. The door lock
indicator light glows steady and the control closes the
bake relay providing power to the bake circuit. The
clean temperature is preset into the control at around
860 degrees. It takes about 45 minutes for the oven to
reach 860 degrees. When the temperature is reached
the control cycles the bake burner off and on to maintain
the temperature until the clean time is completed. When
the clean time is completed, the control removes power
from the bake circuit and the oven cools down. When the
temperature in the oven goes below 500 degrees the
control closes the contacts of the lock relay. The lock
motor turns 180 degrees closing and reopening the
contacts of the lock switch and unlocking the door and
turning off the door lock indicator light. The open
contacts of the lock switch tell the control that the door
is unlocked and to open the contacts of the lock relay.
CALIBRATION
To check oven calibration:
1. Place a thermometer or thermocouple in the center
of the oven.
2. Program the oven temperature for 350 degrees.
Allow the oven to cycle three times.
3. Average the highest and lowest reading. The average
should be within 10 degrees of 350.
To change the calibration:
1. Touch the bake pad on the control, and using the up
arrow set the oven temperature to maximum 550
degrees.
2. Within 3 seconds touch and hold the bake pad
(usually about 5 seconds) until “00” appear in the
display.
Note:
If any numbers other than “00” appear in
the display, the control has been calibrated
in the field before.
Page 47
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Table of Contents
Troubleshooting
