Ground Fault Circuit Interrupter (GFCI) Wiring Diagrams
by: Dale Cox
By code, the number of conductors allowed in a box are limited depending on box size and wire gauge. Calculate total conductors allowed in a box before adding new wiring, etc. Check local regulations for restrictions and permit requirements before beginning electrical work. The user of this information is responsible for following all applicable regulations and best practices when performing electrical work. If the user is unable to perform electrical work themselves, a qualified electrician should be consulted. How to Read These Diagrams
This page contains wiring diagrams for ground fault circuit interrupter (gfci) receptacles. Included are diagrams for multiple gfci's, a protected standard duplex receptacle, and a protected light fixture. Wiring for a switch and gfci receptacle in the same box is also shown. To wire a gfci circuit breaker see this link and wire a gfci switch combo at this link.
Wiring a GFCI Outlet and a Light Switch
This diagram illustrates wiring a GFCI receptacle and light switch in the same outlet box, a common arrangement in a bathroom with limited space. The hot source is spliced to the LINE terminal on the receptacle and to one terminal on the light switch. The neutral and ground wires are spliced together and run to each device in the circuit. This wiring provides single-location gfci protection. The light and switch are not protected by the gfci receptacle.
Wiring GFCI Receptacles with a Protected Outlet
This gfci wiring provides protection to a duplex receptacle outlet at the end of the series. By connecting the load terminals on the last gfci, the wall outlet at the end is protected and can be used just as if it were one of the gfci receptacles. One ground fault circuit interrupter at the beginning of the circuit can be used in the same way to protect multiple, subsequent wall outlets in a row as illustrated in the diagram below.
GFCI Receptacle in a Series with an Unprotected Outlet
This diagram illustrates the wiring for multiple ground fault circuit interrupter receptacles with an unprotected duplex receptacle at the end of the circuit. The load terminals on the gfci are not used and the last receptacle is wired directly to the circuit source. With this wiring each gfci provides single-location protection and the last outlet in the series is not protected from ground faults.
GFCI Outlet Wiring to Protected a Light
This diagram illustrates the wiring for a circuit with 2 gfci receptacles followed by a light and switch. By connecting the switch to the load terminals on the last gfci, the switch and light are protected against ground faults as well. This gfci wiring method may be found in a bathroom or kitchen where the switch may be near a water source.
GFCI Wiring Method with an Unprotected Light
This diagram illustrates the wiring for a circuit with 2 gfci receptacles followed by an unprotected light and switch. The light switch terminal is connected directly to the source coming from the circuit. Using this wiring method, the light circuit is not protected from ground faults.