G—Gas Combustion Combination Controls and Systems—G961DAJ Integrated Function Ignition Control 3
The normal system operation for the G961DAJ depends on the demand
from the system thermostat.
Upon receiving a call for heat from the system thermostat, the G961DAJ
follows this normal sequence of operation:
1.
Pressure Switch Detection--The control checks the inducer pressure
switch to ensure that it is open.
2.
Prepurge--The control energizes the inducer motor for the entire
prepurge period.
3.
Pressure Switch Detection--The control checks the pressure switch to
ensure that is has closed.
4.
Trial for Ignition--The control simultaneously energizes the spark
igniter and gas valve in an attempt to light the main burner. During
the trial time, the gas valve is energized for the entire 8 seconds, the
spark igniter is energized for the first 7 seconds, and the control
attempts to sense main burner flame during the last 1 second.
5.
Run--If main burner flame is sensed within the last 1 second of the
trial, the gas valve remains energized, and the heat fan-on delay
begins. Once the heat fan-on delay expires, the blower motor is
energized at heating speed.
6.
Postpurge--Once the thermostat is satisfied, the gas valve is
de-energized, the inducer motor remains energized until the postpurge
period ends, and the heat fan-off delay begins. Once the heat fan off
delay expires, the blower motor is de-energized.
Upon receiving a call for cool from the system thermostat, the G961DAJ
energizes the blower motor at cooling speed. Once the thermostat is
satisfied, the control waits for the cool fan-off delay to expire before
de-energizing the blower motor.
Upon receiving a call for continuous fan-on, the G961DAJ energizes the
indoor blower motor at fan-on speed. The continuous fan-on request is
immediately overridden by a heat or cool demand.
Upon receiving a call for heat and cool simultaneously, the G961DAJ
initiates a normal heating cycle; however, the indoor blower motor
remains energized at cooling speed. The system immediately returns to
normal cooling operation when the auxiliary heat demand is satisfied.
Upon receiving a call for heat at the same time an existing demand for
cooling is interrupted, the G961DAJ initiates a normal heating cycle;
however, the cool fan off delay is preempted.
Normal
Sequence of
Operation
Call for Heat
Call for Cool
Call for Fan-On
Call for Auxiliary
Heat
Call for
Emergency Heat