How to Wire a Switched Outlet - Half Hot Outlet
Many times people would like to have an outlet controlled by a switch to be able to turn on a lamp or some other device. Sometimes they have a switched outlet, but it is in the wrong location, or they would like to plug in another device that they would like to remain on all the time. A situation like this calls for a half hot outlet where a switch controls the top half of the outlet and the bottom remains hot all of the time.
As always when working on electrical systems turn off the power to the circuit at the breaker panel or remove the fuse for older electrical systems.
If you have an outlet that is switched, you will still need to run a new wire with two hot conductors and one neutral and one ground, 12-3 or 14-3 wire. The “3” stands for 3 conductors, black, red, and white. The red wire is required to keep one half of the outlet hot at all times.
Traditionally the black wire is used for the hot portion of the outlet and the red wire for the switched portion, but it will work either way. The outlet will share the neutral, white wire, in this case.
Half-Hot outlet Wiring Diagram
To run the new wire you will need to either cut a few access holes in the wall board new the studs to run the wire from the switch to the outlet. I you are lucky it will only require two of three small holes to get your hand inside. Cut the holes to straddle the stud, you can use the switch box and outlet box for the beginning and ending holes. If you have access from the basement, you can run the wire straight down, staple it to the floor joist, and then drill a hole up into the stud bay of the outlet. Make sure that you have the location marked accurately.
1. With the power off to the circuit, remove the switch and outlet from the wall boxes.
2. Remove the wire nuts off of the wires. Strip the insulation from the insulated wires according to the strip gauge on the back of the outlet. Use you wire strippers or pliers to make a hook on the end of the ground wire so it can be attached to the ground screw of the outlet.
3. There is a tab that joins the upper and lower sections of the power side of the outlet together. This is a flat brass piece of metal; the hot side of the outlet is the side with brass colored screws. Leave the other side intact.
4. By using a pair of needle nose pliers you can grip the flat tab of metal and with a side to side motion bend it until it breaks off.
5. Connect the red half of the outlet you want controlled by the switch and the black for the half of the outlet which is hot all the time. (Typically the top is the switched part of the outlet) It is best to use the side screw terminals to make the wiring connections. The white wire is connected to the white (aluminum) screw on the other side. The tab remains in place to share the neutral connection. I like to use electrical tape to wrap the outlet and cover the screw terminals for the hot and neutral.
Red and Black wires in place.
6. At the switch, the white wires are connected together with a wire nut.
a. The black wire coming into the switch is normally hot; connect it to the top of the switch with the new black wire going to the hot part of the outlet.
b. Connect the red wire to the bottom terminal of the switch that is connected to the switched portion of the outlet.
c. Connect the bare or green ground wires to the ground terminal screw on the switch.
7. The wiring is folded back into the outlet box being careful that the ground wire is not near the screws of the outlet's hot or neutral side.
8. Use the outlet mounting screws to secure the outlet firmly to the wall adjusting the outlet from side to side as necessary and replace the outlet cover.
9. Turn on the power to the circuit and test the operation by plugging in a lamp and radio into the switched and hot portions of the outlet.
While this job may not add much value to your home, it will offer you great flexibility and convenience for the rooms you choose to make this electrical modification. Check with your local building inspector to determine if you require a permit before you start the work.