An Electrical expert Explains How to Wire a Switched (Half-Hot) Outlet

What Is a Half-Hot Outlet?
Most of the outlets in your home are of the duplex variety– that is, you can plug 2 devices into them at one time. A half-hot (or switched) outlet is a duplex outlet that has one half completely “on” or ready to supply electricity while the other half can be shut off and on through an ordinary wall switch.

While the whole duplex outlet could be turned on through a wall switch, only one of the two plug-ins is usually changed; this leaves the other half completely powered for other usages.

This sort of outlet is quite typical in modern-day construction. If you plug a light into the changed side, you can turn the light off and on through the wall switch. Half-hot outlets are most often discovered in living spaces, however can be taken into any location.

Knowing how to wire a changed outlet is easy. It is similar to wiring a regular light fixture. Learn how below.

Keep in mind: If you are installing a new outlet or pulling extra wire to an existing one, please examine this article about adding an outlet; it consists of ideas and recommendations for pulling wire to both brand-new and existing outlets.

A half-hot (or switched) outlet is a double outlet that has one half permanently on (all set to provide electricity) while the other half can be switched on and off via a common wall switch.

Preparing the Switched Outlet for Circuitry
If you are customizing an existing outlet, it is practically certain that the old outlet won’t need to be changed, although if it is more than a couple of years old it need to probably be changed anyhow.
Either the square, Decora-style switch or the more common semi-round type might be used as a half-hot outlet. You might not, nevertheless, utilize a GFI outlet (it is not possible to modify one so that just half of it is changed), but the entire outlet could be switched.
If you are acquiring a new outlet, ensure that you match the outlet’s ampacity (amps) to that provided by the circuit breaker for that circuit; a 15 amp breaker requires a 15 amp outlet and a 20 amp breaker ought to have a 20 amp outlet.
After you have actually taken off the faceplate, on the side of the outlet, there is a little tab connecting the 2 brass screw-plates together. This tab permits one wire to be used to power both halves. To modify the outlet for usage as half-hot, utilize a screwdriver or a pair of needle-nose pliers to twist and break that little linking tab.
With the tab broken, the outlet is ready for usage.
Breaking the Tab for a Half-Hot Outlet

What Type of Wiring Do You Need for a Switched Outlet?
The National Electric Code needs that all lighting switch boxes contain a “neutral”, which is an electrical term for a grounded conductor (not to be confused with a ground wire). In your outlet, it is the white wire that ends on the outlet. Whether a half-hot outlet is for lighting is arguable, however you must still have a neutral in the switch box.
There are 2 possibilities for the area of the inbound power: either in the outlet box or in the switch box. In either case, you will require what is called “3-wire cable” (black, red, white, and green OR metal all sheathed together: yes I know that makes 4 wires, but that’s what it’s called!) to link the two boxes.
Examine the breaker that turns the circuit off; if it is a 20 amp breaker or fuse, you will require 12-3 wire (12 gauge, 3-wire, plus ground). If it is a 15 amp breaker, you will require either that very same 12-3 or 14-3 wire (14 gauge, 3-wire, plus ground). You will discover that the 14 gauge wire is cheaper and a little easier to deal with.
The Romex (NMC) wire you will be using is typically offered in 25′, 50′, 100′, and 250′ rolls.
Make sure you purchase enough wire, as the job will typically need more than you think. To be safe, add about 20% to your finest price quote.
There Are 4 Wires in a Romex 3-Wire Cable Television! What Do the Colors of the Wires Indicate?
White: the neutral. See warning below!
Green or bare copper without insulation: the ground wire.
Red: hot.
Black: hot.
These will all be cabled together in a sheath. Romex wire is generally used in houses.

The White Wire: A Word of Care
Switch boxes in older houses typically used the white wire as a power wire, not a neutral. When the white wires in a switch box are entwined together, any that go to a switch should be overlooked and left right where they are.

Do not splice those white wires already on a switch to any other white wires, and particularly not to the new white wire that is a part of your brand-new 3-wire cable.

It wasn’t till 2011 that the National Electric Code ruled that a white wire being utilized as a neutral was needed in the switch box. Prior to that, it was acceptable to use the white as the switched “hot” wire, although a conscientious electrician would color it to something else (using magic marker, black tape, and so on).

So if you are changing an older, existing switched outlet, and if it has 2-wire cable in between the outlet and the switch, then the white wire is being utilized as either a permanent hot or as the changed power and IS NOT neutral. Care needs to be required to keep it separate from other white wires.

How to Wire a Half-Hot Switched Outlet
A non-contact voltage detector can be vital here for identifying power through the insulation of the wire. Make sure that the power is off.

As noted above, there are 2 possibilities for the inbound power: either in the switch box or in the outlet box. These will be treated separately below.
How to Wire a Changed Half-Hot Outlet That Gets Its Power From the Outlet Box
This is the favored approach of circuitry a half-hot switched outlet, due to the fact that if the power is coming from the switch, it is most likely a lighting circuit that is intended to operate lights, not outlets. Yes, you will most likely have a lamp plugged in, however the other half of the outlet could run anything. It is finest if this outlet is on a circuit meant for outlets. If there is an option, utilize the power already in the outlet box.

In order for the outlet box to work, it must already consist of one or more cables comprised of black, white, and green/bare ground wires all cabled together. In order to add the switch, you will be including a Romex 3-wire cable to the box.
This provides you four various colored wires to splice in with the matching wires in the box. Strip off the last 1/2 inch of colored plastic finish on each end of each wire.
You ought to pull them into a cool package with the removed ends all together, twist them into one, put a plastic twist-on wire nut over them, and screw it down securely as if it were a bolt head. Hold the wire nut in one hand and tug securely on each specific wire to make sure it doesn’t come loose.
Do the same with all the black wires (and the additional 6″ piece of black wire you cut in step 2).
Entwine all the white wires together, once again with the 6″ additional white piece.
The loose end of the 6″ ground wire will terminate on the green ground screw of the outlet. The black 6″ wire will terminate on among the brass-colored screws, the red one on the other brass screw, and the white one on the silver-colored screw. It is most typical to put the red wire on the bottom screw, because that will make the leading plug-in “hot” at all times and will be a little simpler to plug things into it.
To end (attach or link) the wires, flex a hook in the wire, loop it around the screw in a clockwise direction, and tighten the screw strongly. If the wire tends to come out from under the screw while tightening up, you have looped it the wrong instructions. Alternatively, lots of house grade outlets have small holes in the rear of the outlet where the wires can be just pushed in instead of wrapping around the screw.
At the switch, put a wire nut on the white wire, topping it off, and tuck it into the back of the box. Entwine all ground wires in the box together (if multiple switches or other wires are in the box), once again with an extra 6″ green/bare piece to go to the switch.
End the black wire from your new 3-wire cable on among the screws on the side of the switch, and the red on the other. It doesn’t matter which one goes where.