The 780 Series hot surface ignition modules are designed for use on gas fired heating systems. The system acts on a demand for heat by a switch or thermostat to supply power to the ignition control. On non-prepurge models, the ignitor will be energized immediately and remain on for either of two optional selected ignitor heat up times (approximately 17 or 34 seconds). For models with the prepurge option, there is a time delay equal to the heat up time selected before the ignitor is energized. At the end of the ignitor heat up time the gas valve is opened supplying gas to the main burner. After several seconds, the ignitor is turned off and the sensor is energized.
The 780 Series provides lockout and complete gas shutoff if ignition is not proven after the trial for ignition sequences has been completed.