It is the responsibility of the user of this information to know and understand the NEC (National Electrical Code) as it applies to them, as well as any local regulations or laws that may pertain. While many jurisdictions do adopt the standards of the NEC, some may have requirements in addition to, or exemptions from those standards. The information on this page is intended to aid in electrical wiring projects that become necessary when doing DIY home improvements and repairs. We cannot assume responsibility for personal injury or property damage as a result of using the information provided here.
This page contains wiring diagrams for adding a receptacle outlet to an existing circuit. The source for the new outlets here can be taken at a light fixture or a light switch with an always-hot wire.
In the diagrams on this website the brass colored terminals on the devices represent the hot side of the circuit and the silver colored terminals represent the neutral side. Green is used to denote ground wires and terminals. Not all outlet boxes or older devices will have a grounding terminal. When running new wiring the ground wires should be spliced with a short piece of wire to connect to each device that has a grounding terminal, and to any grounding terminals in the outlet boxes. Also be aware that the white wire may be use to carry current in some household circuits, in these cases it should be marked with black electrical tape to indicate it is hot.
These diagrams illustrate 15 amp circuits and 14/2 awg cable, however, existing lighting and receptacles may be on 15, or 20 amps circuits. When working with 20 amp circuits use 12 awg cable and 20 amp switches and receptacles.
This circuit diagram shows the wiring for a new receptacle outlet connected at a light fixture. The source at the fixture is always hot and a switch loop controls the light. New 14/2 cable runs from the fixture box to the new receptacle and the source hot, neutral and ground are splice to it and a short jumper wire to connect back to the light fixture.
This diagram shows the wiring for a new receptacle outlet added from a light switch. The switch must have an always-hot wire for the source and a neutral wire must be present for the return path. The hot source is spliced to a jumper wire back to the switch and to a new 14/2 cable running to the new outlet. The neutral is spliced in the switch box to both, the existing light, and the cable to the new receptacle.
Here a gfci receptacle is used as the source for a new receptacle. This arrangement allows for adding a switched receptacle to the circuit, and it protects both the new devices. The gfci and new switch occupy the same outlet box, making it necessary to install a new, double-gang box at that location.
In this diagram the gfci is used as a source for the new devices, but the switch and outlet are not protected. The gfci can be wired to protect any other receptacles in the circuit by connecting them to the load terminals.