Patent ID: 6494707
Filing Date: 2002-12-17
Classification: F23N

Abstract:
In a burner control system having a combustion chamber into which fuel may be introduced, a heat sensor for producing a â€œcall for heatâ€  signal when heat is desired, an igniter for igniting fuel in the combustion chamber to produce combustion, a detector to determine when the fuel has been ignited and to determine the loss of combustion, and a primary controller operable upon a â€œcall for heatâ€  signal to move the system to a â€œtrial for ignitionâ€  state where the igniter is energized to attempt to ignite the fuel in the chamber and a) when the flame detector establishes that the fuel has been ignited, the controller moves the system to a â€œrunâ€  state where continued heat is normally produced until the â€œcall for heatâ€  signal is removed, but b) when the flame detector establishes that the fuel has not been ignited, the controller moves the system to a â€œlockoutâ€  stateâ€  which requires nominal human intervention to energize the igniter to attempt to re-establish combustion again, and after the system reaches the â€œlockoutâ€  state a predetermined number of times, the controller operates to place the system in a â€œrestricted lockoutâ€  state which requires special human intervention, to energize the igniter to attempt to re-establish combustion, the system being susceptible when the system is in the â€œrunâ€  state, to a loss of flame after which the controller moves the system to a â€œrecycleâ€  state where further attempts at ignition can be made, the system being subject to multiple recycling from the loss of combustion to re-establishing combustion and back, the improvement comprising:a counter operable to count the number of times that the system recycles; and when the counter reaches a predetermined number to move the system to the â€œlockoutâ€  state.