Oven Circuit - Electrolux E30GF74GPS Technical & Service Manual

the silicon carbide igniter
Oven and broiler
Griddle
and a current sensitive safety valve.

Oven circuit

When electrical power is applied to the range, power
is applied to one side of the cycling contacts of the
thermostat. When the thermostat dial is set to a tem-
perature, the cycling contacts of the thermostat close
and connect power to terminal C of the selector switch
portion of the thermostat. With the thermostat dial set
to a temperature that contacts between terminal C and
terminal BA close applying power to one side of the
oven burner igniter. The other side of the igniter is con-
nected to one of the terminals of the oven safety valve.
The other side of the oven safety valve is connected to
neutral completing the circuit. The thermostat, igniter
and oven safety valve form a series circuit. The oven
igniter is a silicon carbide igniter that decreases in resis-
tance as it heats up. The oven safety valve is a current
sense of the valve that will open when the current flow
in the circuit reaches 3.2 amps. At room temperature,
the resistance of the oven igniter is above 50 ohms.
When power is applied to the series circuit form by the
thermostat, igniter and oven safety valve, the current
flow in the circuit closes the igniter to heat. As the
temperature of the igniter increases the resistance of
the igniter decreases in the current flow in the circuit
increases. When the temperature of the igniter reaches
about 1800°F the current flow in the circuit increases to
above 3.2 amps, which opens a safety valve allowing
gas to flow into the oven burner. A combustible mixture
of gas and air will ignite at 1100°F., therefore when
the oven safety valve opens the gas and air mixture is
ignited by the 1800° igniter.
When a thermostat dial is turned to broil the contacts
between terminal C. and terminal BR. closed providing
power to the broil igniter and the broil burner safety
valve. The operation of the broil circuit is identical to
the oven burner circuit.
Note: Terminal BR is also connected to the convec-
tion fan relay coil. When power is applied to BR. The
convection fan relay activates opening the contacts
that provide power to the convection fan motor. This
prevents the convection fan from operating. When the
broiler is being used.
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