What is the minimum distance in inches, an electrode for an oil burner, can be to the center of the nozzle.

• A. 1/4 inch
• B. 1/2 inch
• C. 3/4 inch
• D. 1 inch

Answer: (B)

The ignition spark needs to jump in the air between the electrode and the nozzle’s spray, not inside the nozzle itself. Setting the electrode about one-half inch from the nozzle center provides a reliable spark gap right where the atomized fuel and air mix begin to ignite, while protecting the nozzle and electrode from excessive heat and fouling. If the electrode is closer than this, you risk heat damage and flashback into the nozzle; if it’s farther away, the spark may occur outside the fuel-air mix, making ignition unreliable. So, the minimum recommended distance is one-half inch.