a WARNING
To reduce the risk of electric shock, fire, explosion, serious injury or death:
• Disconnect electric power to the dryer before servicing.
• Close gas shut-off valve to gas dryer before servicing.
• Never start the dryer with any guards/panels removed.
• Whenever ground wires are removed during servicing, these ground wires must be
reconnected to ensure that the dryer is properly grounded.
W001
52
RS3200001 (502992R3)
Figure 50
WIRING SCHEMATIC
49.BURNER SYSTEM OPERATION (Figure 50)
Components
This burner has four basic components: A silicon
carbide (glow bar) igniter, burner tube, flame
sensor, and a two-stage gas valve consisting of
a split-coil valve and a secondary coil valve. The
split-coil valve is opened when the dryer
thermostat calls for heat, while the secondary
valve does not open until the igniter has attained
ignition temperature.
Pre-Ignition Circuits
When the dryer thermostat calls for heat, circuits
are completed through the holding coil, flame
sensor, booster coil and igniter. Both coils must
be energized to open split-coil valve. Once
opened, the holding coil can hold the valve open
without assistance from the booster coil. The
current shunted around the secondary coil by the
flame sensor, passes through the igniter causing
it to get hot.
Burner Circuit
In approximately 30 seconds, the igniter attains
ignition temperature and the flame sensor
(located on burner housing beside the igniter)
contacts open. A circuit is then completed
through the secondary valve coil, opening the
valve and allowing gas to flow. Ignition is made
and the heat from the burner flame causes the
flame sensor contacts to open.
IGNITION SYSTEM FEATURES (Figure 50)
MOMENTARY POWER INTERRUPTION: Upon
resumption of power, flame sensor contacts will
still be open, permitting secondary valve to open.
However, with the secondary coil in the circuit,
the booster coil cannot draw enough current to
open the split-coil valve. When flame sensor
contacts do reclose, the secondary valve will
close, and the burner system will be in the
normal pre-ignition circuit.
FLAME FAILURE: In case of flame failure, the
flame sensor contacts will reclose in about 45
seconds. This will close the secondary valve and
the burner system will be in the normal pre-
ignition circuit.
IGNITION FAILURE: If flame is not established
as flame sensor contacts open, secondary valve
will remain open until flame sensor contacts
reclose. Flame sensor will continue to recycle the
igniter and secondary valve (about once per
minute) until ignition is made or dryer is turned
off.
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