For many years, ground fault circuit interrupters (GFCIs) have served an important function in the electrical power distribution system of private homes, businesses, and other structures in preventing users from experiencing an electrical shock under many circumstances. Typically, a GFCI is implemented within an electrical power receptacle and performs its function by disconnecting power at a receptacle connection pair of the receptacle in response to detecting small differences in current at the receptacle carried over a live or “hot” current path and a neutral current path that may be indicative of a “ground fault,” in which at least some current is inadvertently being directed to ground from the live or neutral current path. Typically, such detection is performed using a current transformer through which the live and neutral paths are routed within the GFCI. In addition, the GFCI may also provide power to one or more additional receptacles on the same electrical power circuit.
To perform its function properly, a GFCI receptacle typically provides a line connection pair for live and neutral wires received from a circuit breaker of an electrical panel, and also provides a load connection pair for live and neutral wires for one or more additional receptacles of the same electrical power circuit, in addition to the receptacle connection pair, so that the GFCI may disconnect both the receptacle connection pair and the load connection pair from the line connection pair.
Generally speaking, miswiring of the GFCI, in which the live and neutral wires from the circuit breaker panel are mistakenly coupled to the live and neutral lines of the load connection pair, and the live and neutral wires connected to the other power receptacles are connected to the line connection pair, is an all-too-common occurrence. In cases of such miswiring, most GFCIs are unable to detect a ground fault at the GFCI receptacle connection pair since the current transformer is not positioned between the load connection pair and the receptacle connection pair, and thus cannot detect the resulting difference in current in the live and neutral current paths at that point.
In addition, other electrical safety devices, such as, for example, arc fault circuit interrupters (AFCIs), may also be susceptible to a similar miswiring problem.