Electrolux NEXT GEN, Service Manual

Page: 53 / 88

53
Convection roast:
Convection roast operates the same as convection bake
except the control does not operate above the set
temperature and the temperature differential is larger.
Broil:
When the broil pad is touched, and a temperature is
entered with the numbers between 400° F and 550° F.
(usually 550° F) the broil relay on the board closes, and
connects one side of the line to the broil element. In the
tip of the oven sensor is a positive thermistor that
increases in resistance as the oven temperature
increases. The EOC microprocessor reads the resistance
of the oven sensor, and compares it with the programmed
temperature set into the control. Usually you do not want
the broil element to cycle so the oven door is opened to
the broil stop position. If the door is not opened the broil
element will cycle when the set temperature is reached.
Clean:
With the oven door closed, contacts COM to NO of the
oven door switch close. Then when the clean pad is
touched and a clean time is set the door lock relay on the
electronic oven control closes providing line to neutral
voltage (120 VAC) to the lock motor. 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 EOC that the door is locked, and to open the
contacts of the lock relay. The lock indicator light then
glows steady and the EOC closes the bake relay
providing power to the bake element. The clean
temperature is preset into the EOC at around 860° F. It
takes about 45 minutes for the oven to reach 860° F.
When the temperature is reached the control cycles the
bake element off and on to maintain the temperature until
the clean time is completed. When the clean time is
completed the EOC removes power from the bake
element and the oven cools down. When the temperature
in the oven goes below 500° F the control closes the
contacts of the lock relay. The lock motor then turns 180
degrees closing and reopening the contacts of the lock
switch and unlocking the door. The open contacts of the
lock switch tells the control that the door is unlocked and
to open the contacts of the lock relay and turn the lock
indicator light off.
Calibration:
To check oven calibration:
1. Place a thermometer or thermocouple in the
center of the oven.
2. Program the oven for bake and the temperature to
350° F. Allow the oven to cycle three times.
3. Average the highest and lowest reading. The
average should be within 10° F of 350° F.
To change the calibration:
To adjust the oven temperature higher:
1. Press the Bake pad for 6 seconds. “ 0 ” will appear
in the display.
NOTE: If any numbers other than “0” appear in the
display, the control has been previously calibrated
in the field.
2. To increase the temperature, use the number pads
to enter the desired change. The temperature may
be increased up to 35° F.
3. Press Start to accept the temperature change and
the display will return to the time of day. Press Clear
Off to reject the change if necessary.
To adjust the oven temperature lower:
1. Press the Bake pad for 6 seconds. “ 0 ” will appear
in the display.
2. To decrease the temperature, use the number pads
to enter the desired change and then press
Clean .
The temperature may be decreased up to 35° F.
(NOTE: Pressing
CLEAN allows the entry of negative
degree change.)
3. Press Start to accept the temperature change and
the display will return to the time of day. Press Clear
Off to reject the change if necessary.
Troubleshooting:
The ES 400 has some self diagnostics built into the
microprocessor to help in troubleshooting the system.
When a failure occurs one of three codes will appear in
the display window: F1, F3, or F9.
F1 code:
An F1 indicates a malfunction in the EOC itself, and the
control should be replaced.
F3 code:
An F3 indicates a defective sensor, electronic oven
control or the wiring in between.
To determine which part is defective: