G—Gas Combustion Combination Controls and Systems—G961DAJ Integrated Function Ignition Control 5
If the main burner flame is established and then lost, the gas valve is
de-energized and the inducer runs through an interpurge. Once the
interpurge period expires, the control initiates another trial for ignition.
The blower will be energized and/or remain energized for the duration of
the interpurge and the ignition retry. After the fifth flameout, the control
proceeds to a 60 minute soft lockout period (during which all outputs are
de-energized) before resetting itself.
Certain models of furnace include an auxiliary limit switch in-line with the
gas valve. The switch responds to an overtemperature condition in the
blower compartment. If the limit switch opens, the power to the gas valve
will be interrupted, causing the control to react to a flameout.
The G961DAJ offers the following responses to the three possible
interrupted thermostat situations.
1.
If the call for heat is removed before the gas valve is energized, the
G961DAJ will de-energize all outputs and reset.
2.
If the call for heat is removed after the gas valve is energized, but
before flame has been sensed, the gas valve and spark igniter are
de-energized, and the inducer motor will run through a postpurge.
3.
If the call for heat is removed after flame has been sensed, but before
the blower comes on, the gas valve is de-energized, the inducer will
run through a 5 second purge, and the blower will run through a
180 second blower-off delay.
The high limit switch is monitored constantly. Any time the switch opens,
the gas valve and igniter will be de-energized, and the inducer and blower
(heat speed) will run continuously. When the switch is reset, the inducer
and the blower will run for 180 seconds before the control returns to
normal operation.
The twinning function allows for simultaneous safe operation of
two furnaces equipped with the same furnace controls (e.g., G961DAJ).
The two controls are connected and operate simultaneously from a single
thermostat. The twinning connection forces the blowers of each furnace to
operate synchronously into a common duct system.
Upon receiving a call for heat (or cool), the controls simultaneously
perform the normal operating sequences detailed previously.
Flameout
Overtemperature
Condition
Interrupted
Thermostat
High Limit Switch
Twinning
Operation
Normal Operation
