Sodium lamp – internal or external ignitor?

Sodium lamps are split into two categories, those requiring an external ignitor in the circuit and those that already have an internal ignitor within the lamp construction.

Sodium Lamps with an ignitor
The way to tell if it has an internal ignitor is to look at the small triangle which should be etched onto the lamp itself. It will have the letter “I” in it if it has an internal ignitor. If there is no lamp in the luminaire currently, look at the gear tray and see if there is an ignitor wired into the circuit. In traditional lighting magnetic ballast circuits, you should have a ballast, capacitor and ignitor. If no ignitor is present in your circuit, you need a lamp with an internal ignitor.

Sodium Lamps without an ignitor
The way to tell if it has no internal ignitor (i.e. the ignitor is external) is to look at the small triangle which should be etched onto the lamp itself. It will have the letter “E” in it if it has no internal ignitor. If there is no lamp in the luminaire currently, look at the gear tray and see if there is an ignitor wired into the circuit. In traditional lighting magnetic ballast circuits, you should have a ballast, capacitor and ignitor. If an ignitor is present in your circuit, you need a lamp without an internal ignitor.

Of course, if you are replacing your sodium lamps, you can replace with metal halide for a “whiter light” or, even better, use an LED alternative for longer life and energy saving.