Lower Oven Bake And Clean Thermal Tco's ( Double Wall Ovens) - GE JS998 Series Technical Service Manual

Lower Oven Bake and Clean Thermal
TCO's (
Double Wall Ovens)
The bake and clean FAD's (Fan Apparency
Device) TCO's are located between the upper
and lower ovens on the floor of the component
compartment in front of the fan motor. They are
monitored by the controls software.
Both lower oven clean and bake FAD's are
ignored by the control when the upper oven is in
self-clean.
Clean
Bake FAD
• Is wired in series with the lower door unlock
motor switch.
• Opens at 185°F and closes when cooled
below 158°F.
• The bake FAD can only be detected by the
control when in non self-clean operations
(unlock switch closed, lock switch open).
Higher Temperature (
• Is wired in series with the common of the lock/
unlock switch.
• Opens at 275°F and closes when cooled
below 205°F.
• The clean FAD is always detected by the
control.
If the thermal switch opens in any mode of
operation, the control will display F9 failure code.
When this condition exists, check for proper fan
operation (look for obstructions), and inspect oven
installation (make sure grille areas are not
blocked), oven insulation and lock/unlock circuit of
lower door lock.
Bake
) FAD
Clean
Left and Right Thermal TCO's (
)
Range
The left and right FAD's (Fan Apparency Device)
TCO's are located at the rear of the component
compartment, in front of the respective cooling
fan.
• Both remove power from the controls when
open.
• Both are normally closed and wired in series
with the magnetron TCO, supplying L1 to the
main power board to power the controls.
• The left FAD opens at 185°F and closes when
cooled below 158°F. The right TCO opens at
194°F and closes when cooled below 167°F.
• If either FAD opens, check for proper fan
operation.
• Each FAD has an internal heater. N is
connected to one side of the heaters, and L2
is connected to the other side through the
convection DLB relay. The heaters are
powered when the DLB relay is energized.
The DLB relays are energized continuously in
in Service Mode and any cooking or clean
mode.
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Slide-In
Left FAD
Right Fan
Right FAD