Wiring a Receptacle

This article and detailed wiring diagram explain how to wire the common household receptacle. The 15A, 125V receptacle is the most widely used device in your home.

This is your standard receptacle that powers everything from your toaster to your TV. Whether you are replacing or adding a receptacle, here’s how to connect them.

Always ensure that the power is off before working on any circuit!

Step #1- Make sure that the circuit is properly grounded. When installing or replacing a receptacle, connect the ground wire first. When removing an old receptacle, disconnect the ground wire last. The ground or bonding wire should be connected to the bonding screw in the device box, and either pig-tailed (in the case of more than one conductor), or left long enough to connect to the green grounding / bonding terminal on the receptacle.

Step #2 – Connect the neutral wire (s) next. They connect to the silver terminals that correspond with the longer vertical prong on the face of the receptacle.

Step #3 - Then connect the black (or red) hot wire (s). They connect to the brass terminals that correspond with the shorter vertical prong on the face of the receptacle.

Our sample receptacle has two cables entering the device box, and in this first diagram we are using the device terminals to complete the circuit.

Note that this is a practice that is not accepted by everyone, so check with your local electrical authority.

*Click on images to enlarge.

The second method is to connect the receptacle by the use of “pig-tail” splices so that the receptacle is connected to only one set of conductors.

In your home, most of the receptacles will have at least two cables entering the same box. The second cable is usually feeding another receptacle, however, it could also be coming from a light or switch.

If you have only one cable entering the device box, tighten the unused screws to avoid them coming in contact with the metal box (if using a metal box), or to mitigate the risk of the unused terminals coming in to contact with the bare ground wire when installing the device in place.

There are many other types of receptacles that you may find around the house, like 20A, or 15/20A, 125V Receptacles, GFCI (ground fault circuit interrupter) Receptacles, electric Dryer Receptacles (30A, 125/250V), and electric Range Receptacles (50A, 125/250V), to name a few.

Vince

I have recently painted my living room and started replacing the old beige recepticles with new white one. Most of the recepticles they were originally wired with two cables in a box as advised above, but in some in a way where the one was connected to the top terminal, and the other was connected to the bottom terminal. I ended up installing the new outlets the exact same way they were wired previously. Will this be an issue?
Scmcca

Our house was built in 1949 (zip 94010). Although the kitchen and a few rooms have
been remodeled and a second electrical fuse panel installed for the rewired /remodeled
rooms, some rooms still have two prong outlets and no ground wires in the
duplex receptacles. It would be very
costly to upgrade all this wiring back to the old fuse box. We’d like to replace some of the two prong
outlets on 20 amp circuits with 20 amp GFCI protected receptacles (where they
are not protected by an upstream GFCI).
The GFCIs each have a ground screw to which a ground wire is to be
pigtailed. My question relates to correct
installation of the GFCI, and is not answered in the installation instructions
and home wiring manuals.
Since the two
prong outlet boxes have no incoming ground wire (just one or two cables each with two
wires, the hot and the neutral), and no ground is available at the metal outlet
boxes: (a) Should a ground wire be
connected from the GFCI device with a ground screw to the back of the box (as per
the instructions)? (b) If (a) is unnecessary because a GFCI doesn’t
need a ground to work and/or there is no way to ground the box anyway, would such a
ground wire be merely a waste of effort, or would it actually be hazardous if
such a ground wire were installed? I’d
like to understand the reasoning for the ground wire connection (between device
and box), since apparently plastic boxes are sold that don’t need a ground wire
connection. I’d also like to know if adding the ground wire would increase a risk of fire, since it would not be connected to a ground wire going back to the fuse box.

Wiring a Receptacle

Using a Digital Multi Meter E-Book

The Basics of Household Wiring DVD