Abstract: An indicator light for a switch to show when a remote load is energized is provided for installations where no neutral wire is available at the switch box. A circuit including a gas discharge indicator lamp, a diode-resistor charging circuit and a capacitor across the lamp is connected between the load side of the switch and the grounding conductor in the switch housing. Current through the circuit is sufficiently small to create no hazard.

Abstract: Circuitry is utilized to interconnect loads to the power distribution system and only conducts current when voltage conditions from the system are appropriate. Therefore, the load is deenergized whenever reversed connections are made to the power distribution system, or whenever an open circuit exists in any line thereof. Latching means can be included in the circuitry to continually energize the load when an open circuit develops in either nongrounded or hot line of the power distribution system after the load has been initially energized therefrom. Furthermore, the effect of the latching means is externally controlled through a switching means so that remote circuit conditions can be synchronized therewith. When an indicating means is incorporated as the load, the circuitry functions as a detector and when the circuitry is utilized with a circuit breaker to deenergize the load, ground fault protection can be incorporated therewith.

Abstract: A ground fault interrupter (GFI) provided with a reversed line polarity lamp indicator to indicate proper installation of the GFI. The reversed line polarity lamp indicator includes a push button and a lamp connected in series between the line conductor of the GFI and ground. In a wiring system having a ground conductor, the series connection is between the line and the ground conductor in which case the reversed line polarity lamp indicator may also be used to check for open circuits in the ground conductor.