Electrolux 30" GAS FREESTANDING RANGES, Service Manual

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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 oven circuit.
Note: 120 VAC is at 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 oven relay on the board
closes, applying line to neutral voltage across the oven
circuit. The oven 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 burner. The gas is then ignited by the heat of
the 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 settings and
will cycle the burner when the temperature is reached.
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.
The calibration of the ES100 system cannot be
adjusted:
1. If the oven temperature test off. Check the resistance
of the oven sensor circuit against the chart below. If
the sensor circuit check good replace the control.
TROUBLESHOOTING
The ES 100 has some self diagnostics built into the
microprocessor to help in troubleshooting the system.
When a failure occurs one of two codes will appear in all
the display windows: F1 or F3.
F1 code:
F1 indicates a malfunction in the control itself, and the
control should be replaced.
F3 code:
F3 indicates a defective sensor, electronic oven control
or the wiring in between. To determine which part is
defective:
1. Disconnect the 6 pin plug from the back of the oven
control that connects the sensor to the oven control.
2. With an Ohmmeter measure the resistance between
pins 1 and 2 in the plug (not on the control board) .
If the meter reads around the value of the oven
temperature sensor resistance chart the oven
control is defective. If the meter reads less than 800
Ohms or more than 3000 Ohms, go to step 3.
3. Disconnect the harness from the oven sensor and
measure the resistance of the oven sensor. If the
reading is the same as that in step two the oven
sensor is defective. If the reading is correct with
the chart the harness is defective.
RTD SCALE
Temperature (°F) Resistance (ohms)
32 ± 1.9 1000 ± 4.0
75 ± 2.5 1091 ± 5.3
250 ± 4.4 1453 ± 8.9
350 ± 5.4 1654 ± 10.8
450 ± 6.9 1852 ± 13.5
550 ± 8.2 2047 ± 15.8
650 ± 9.6 2237 ± 18.5
900 ± 13.6 2697 ± 24.4