Dan has been a licensed journey-level electrician for 17 years. He has extensive experience in most areas of the electrical trade.
What Is a Half-Hot Outlet?
Most of the outlets in your home are of the duplex variety—that is, you can plug two devices into them at one time. A half-hot (or switched) outlet is a duplex outlet that has one half permanently "on," or ready to provide electricity, while the other half can be turned off and on via an ordinary wall switch.
While the entire duplex outlet could be turned on via a wall switch, only one of the two plug-ins is usually switched; this leaves the other half permanently powered for other uses.
This kind of outlet is quite common in modern construction. If you plug a lamp into the switched side, you can turn the light off and on via the wall switch. Half-hot outlets are most frequently found in living rooms, but they can be put into any location.
Learning how to wire a switched outlet is not difficult. It is similar to wiring a regular light fixture. Find out how below.
Note: If you are installing a new outlet or pulling additional wire to an existing one, please check this article about adding an outlet; it contains tips and suggestions for pulling wire to both new and existing outlets.
A half-hot (or switched) outlet is a double outlet that has one half permanently on (ready to provide electricity) while the other half can be turned on and off via an ordinary wall switch.
Preparing the Switched Outlet for Wiring
- If you are modifying an existing outlet, it is almost certain that the old outlet won't need to be replaced, although if it is more than a few years old, it should probably be replaced anyway.
- Either the square, Decora-style switch, or the more common semi-round type may be used as a half-hot outlet. You may not, however, use a GFI outlet (it is not possible to modify one so that only half of it is switched), but the entire outlet could be switched.
- If you are purchasing a new outlet, make sure 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 should have a 20 amp outlet.
- After you've taken off the faceplate, on the side of the outlet there is a small tab connecting the two brass screw-plates together. This tab allows one wire to be used to power both halves. This tab has a slot in it so a small screwdriver can be inserted to break it off. To modify the outlet for use as half-hot, use a screwdriver or a pair of needle-nose pliers to twist and break that small connecting tab. Break only the tab on the side with the brass-colored screws; the one connecting the two silver screws needs to remain intact. See photos for details.
- With the tab broken, the outlet is ready for use.
Breaking the Tab for a Half-Hot Outlet
What Kind of Wiring Do You Need for a Switched Outlet?
- The National Electric Code requires 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 terminates on the outlet. Whether or not a half-hot outlet is for lighting is debatable, but you must still have a neutral in the switch box.
- There are two possibilities for the location of the incoming power: either in the outlet box or in the switch box. Either way, you will need what is called a "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 connect the two boxes.
- Check the breaker that turns the circuit off. If it is a 20 amp breaker or fuse, you will need 12-3 wire (12 gauge, 3-wire, plus ground). If it is a 15 amp breaker, you will need either that same 12-3 or 14-3 wire (14 gauge, 3-wire, plus ground). You will find that the 14 gauge wire is cheaper and a little easier to handle.
- The Romex (NMC) wire you will be using is generally available in 25', 50', 100', and 250' rolls.
- Make sure you purchase enough wire, as the job will usually require more than you think. To be safe, add about 20% to your best estimate.