Whirlpool 4322452 Service Manual page 57

Self-Clean ovens use a dual safety valve that is bimetal-operated. The dual valve has one gas inlet
and two gas outlets; one for the Bake burner and the other for the Broil burner (see Figure 4-23).
It uses two identical electrically-operated devices, one for each outlet, to control thc gas flow. The
devices consist of an electric heater coil wrapped around a bimetal strip. One end of the bimetal
is riveted to the plate of the valve. The other end has a rubber seat attached to it that covers a gas
outlet. At room temperature, the spring force of the bimetal presses the rubber seat against the gas
outlet.
Broil Bimetal
Main Gas Inlet
When current flows through the ignitor, heat is applied to the bimetal strip. The amount of heat
necessary to warp the bimetal enough to open the valve requires 3.0 amps of current flow in the
circuit (see Figure 4-24). The reason the valve is designed not to open below 3.0 amps, is to insure
that the temperature of the oven ignitor is above 1800˚F before the valve opens.
To prevent miswiring, the Bake terminals and Broil terminals are sized differently.
The electrical circuit is initiated by relays on the electronic control board. The electrical circuit is
similiar to the circuit used with the Glo-Bar Ignition System (see Figure 4-25).
L1 OVEN CONTROL
BROIL RELAY
BK
P3-1
Terminals
Dual
Safety Valve
Bake
Gas Valve
Bimetal
Coil
Broil Terminals
BAKE IGNITOR
R
P3-4
Broil Burner
Gas Outlet
Bake Bimetal
Bake Burner
Gas Outlet
Gas Outlet
To Bake Burner
Bake Terminals
Bimetal
Coil
Broil
Gas Valve
Gas Outlet
To Broil Burner
BAKE VALVE
W
Figure 4-25
Page 4-13
Terminals
Figure 4-23
Figure 4-24
OVEN CONTROL
BAKE RELAY
P2-1
P2-4
N
W