Fenwal electrodes and sensors are an integral part of the ignition system for gas-fired equipment and ensure reliable ignition, optimal performance and long service life over a wide range of operating conditions. Fenwal uses only high-quality materials such as glazed Alumina ceramics and certified rod materials suitable for up to 2175° F (1190° C). Fenwal electrodes are RoHS compliant and CSA certified. Design, configuration and application are key factors in selecting the proper electrode. Rely on Fenwal’s experience to provide our full range of gas ignition controls and accessories for your gas-fired equipment application.
Spark electrodes typically have a 0.125″ ±.03” gap between the high voltage (HV) rod tip and the ground rod or burner. To facilitate consistent sparking, the gap should be from a sharp edge to a sharp edge. Position this “spark gap” at the optimal location in the burner for reliable lighting of the gas.
IMPORTANT: High efficiency and modulating-condensing appliances may use mesh burners. These often use larger spark gaps and may need special consideration in the system design. Consult FENWAL CONTROLS for guidance and best practices.
Flame sensors are single rods used in the flame rectification circuit of the ignition control to confirm the presence (or absence) of flame. Position this sensor so that it is well exposed to the flame over some length (not just the tip) to reliably complete the flame safeguard circuit.
In Local Sense, or “spark and sense” systems, the HV electrode rod performs both spark and sense functions.
For Remote Sense systems, a separate rod is used to sense the flame, which may be placed remotely from the spark electrode, or integrated with it on the same mounting bracket. Please refer to pages 2-15 for a wide range of designs that are in production and available for sampling.
Please contact your local sales representative or Sales Manager for samples, or detailed dimensions on any electrode of interest. Fenwal can provide custom design electrodes to meet your appliance or burner application for annual volumes ≥ 2000.
Proper location of electrode assembly is important for optimum system performance. The electrode assembly should be located so that the tips are inside the flame envelope and about 1/2-inch (1.2 cm) above the base of the flame as shown below.