The indicator light is a panel-mounted lamp assembly consisting of the indicator housing, an internal lamp, terminals, and a lens. The light source of indicator light is a high brightness pure color LED or incandescent bulb. As the name implies, indicator lights reveal the status (ON or OFF) of an electrical apparatus in switchboards. In more sophisticated systems, the indicating lights may annunciate the cause of the current interruption, such as line-to-ground fault, overload, and overcurrent condition.

