Multi-Port Ignition System for a Sectional Furnace

Abstract

An ignition system for a gas furnace being controlled by a main controller and having at least one burner is provided. The ignition system may include at least one flame sensor and an interface module. The flame sensor may be disposed in close proximity to the burner and configured to output a flame check signal indicative of a status of a flame at the burner. The interface module may be configured to receive the flame check signal and generate a fault check signal based on the flame check signal.

What is claimed is: 
     
         1 . An ignition system for a gas furnace being controlled by a main controller and having at least one burner, comprising:
 at least one flame sensor disposed in close proximity to the burner, the flame sensor being configured to output a flame check signal indicative of a status of a flame at the burner; and   an interface module configured to receive the flame check signal, the interface module configured to generate a fault check signal based on the flame check signal, the interface module configured to output the fault check signal.   
     
     
         2 . The ignition system of  claim 1 , wherein the interface module is configured to output the fault check signal to the main controller. 
     
     
         3 . The ignition system of  claim 2 , wherein the main controller is in electrical communication with at least one igniter, the main controller being configured to selectively ignite the igniter based on the fault check signal. 
     
     
         4 . The ignition system of  claim 2 , wherein the main controller is configured to selectively turn off gas flow to the burner based on the fault check signal. 
     
     
         5 . The ignition system of  claim 1 , wherein the interface module is in electrical communication with at least one igniter, the interface module being configured to selectively ignite the igniter based on at least one of the fault check and flame check signals. 
     
     
         6 . The ignition system of  claim 2 , wherein the interface module is configured to selectively instruct the main controller to turn off gas flow to the burner based on the fault check signal. 
     
     
         7 . The ignition system of  claim 1  further comprising one or more additional flame sensors, the additional flame sensors configured to output one or more additional flame check signals. 
     
     
         8 . The ignition system of  claim 7 , wherein the interface module comprises a multiplexer configured to receive the flame check signals and generate the fault check signal based on all of the flame check signals, the fault check signal indicating a normal condition only if all flame check signals indicate presence of a flame, the fault check signal indicating an abnormal condition if at least one flame check signal does not indicate presence of a flame. 
     
     
         9 . The ignition system of  claim 1 , wherein the flame sensor is configured to detect presence of a flame using one or more of flame heat and flame light. 
     
     
         10 . The ignition system of  claim 1 , wherein the flame sensor is configured to detect presence of a flame using flame rectification. 
     
     
         11 . An ignition system for a gas furnace being controlled by a main controller and having a plurality of burners, comprising:
 a plurality of flame sensors wherein each flame sensor is disposed in close proximity to its corresponding burner, each flame sensor being configured to output a flame check signal indicative of a status of a flame at its corresponding burner; and   an interface module configured to receive the flame check signals provided by the plurality of flame sensors and output a fault check signal, the interface module comprising a multiplexer configured to generate the fault check signal based on the flame check signals.   
     
     
         12 . The ignition system of  claim 11 , wherein the interface module is in electrical communication with at least one igniter, the interface module being configured to selectively ignite the igniter based on at least one of the flame check signals. 
     
     
         13 . The ignition system of  claim 11 , wherein the main controller is in electrical communication with at least one igniter, the main controller being configured to receive the fault check signal and selectively ignite the igniter based on the fault check signal. 
     
     
         14 . The ignition system of  claim 11 , wherein the fault check signal indicates a normal condition only if all flame check signals indicate presence of a flame, the fault check signal indicating an abnormal condition if at least one flame check signal does not indicate presence of a flame. 
     
     
         15 . The ignition system of  claim 14 , wherein, in the abnormal condition, the interface module is configured to determine the burner that does not have a flame and generate signals to re-ignite that burner. 
     
     
         16 . The ignition system of  claim 14 , wherein the interface module is configured to output the fault check signal to the main controller, the main controller being configured to turn off gas flow to the burners if the fault check signal indicates an abnormal condition. 
     
     
         17 . The ignition system of  claim 11 , wherein the flame sensors are configured to detect presence of a flame using flame rectification. 
     
     
         18 . A method for providing a multi-port ignition system to a gas furnace having a plurality of burners and corresponding igniters, comprising the steps of:
 providing a flame sensor in close proximity to each burner, each flame sensor configured to output a flame check signal indicative of a status of a flame at each burner;   determining if flames are expected in the burners;   monitoring the flame check signals;   indicating a normal condition if flames are expected and if all flame check signals indicate presence of a flame;   indicating a normal condition if flames are not expected and if none of the flame check signals indicate presence of a flame;   indicating an abnormal condition if flames are expected but not all flame check signals indicate presence of a flame; and   indicating an abnormal condition if flames are not expected but at least one flame check signal indicates presence of a flame.   
     
     
         19 . The method of  claim 18  further comprising the steps of:
 continuing furnace operation if a normal condition is indicated; and 
 shutting off gas flow to the burners if an abnormal condition is indicated. 
 
     
     
         20 . The method of  claim 18  further comprising the steps of:
 temporarily disabling the flame sensors if a normal condition is indicated; 
 monitoring the flame check signals; 
 re-enabling the flame sensors and continuing furnace operation if none of the flame check signals indicate presence of a flame; and 
 turning off gas flow to the burners if at least one flame check signal indicates presence of a flame.