Dear Mr. Electrician: Where do I find switched outlet wiring diagrams?
Answer: Switched outlet wiring diagrams are below. There are a few methods for wiring switched and half switched outlets. Generally speaking the outlet would get wired the same as if it were a light fixture. NOTE: Some text links below go to applicable products on Amazon. As an Amazon Associate I earn from qualifying purchases.
Alternatively it is possible to have a split outlet where one half of the outlet is switched and the other half is live at all times. There are two switched outlet wiring diagrams further below that depict split outlet wiring.
If your intent is to convert a switched outlet to hot at all times in order to control a ceiling fan or light from the existing switch, then you should click here to read my blog post with photos about doing that.
SWITCHED OUTLET WIRING DIAGRAMS
The wiring diagram above shows how switched outlets are often wired. Although Article 404.2(C) in the National Electrical Code (NFPA 70) requires that a wall switch controlling a light fixture also has a neutral conductor available, switches controlling outlets are exempt from this requirement.
The neutral conductor is required for lights in case the standard wall switch is changed to a smart home device or other type of control such as a timer.
I think it is a good idea to include the neutral for a wall switch controlling an outlet anyway because the regular wall switch could still be changed to a smart home device which usually needs a neutral conductor to function.
It has been a common practice among the uninformed to use the equipment grounding conductor as a neutral whenever a neutral is unavailable. That is an unsafe practice and could be a shock hazard.
When using the white wire as a hot or LINE it is required that the white wire be re-identified with a different color. However, it has been my experience when working on older homes that the white wire has almost never had its color changed when being used as the LINE. Consequently it is not unusual to find that the white wire in a switch box is a LINE and not a neutral conductor. A non-contact voltage detector is good for checking which wires are hot
Any receptacle outlet that could be accessible by children, including kitchen counter top outlets, must be tamper resistant outlets. They prevent things from being inserted into the outlet slots as children are known to do. Article 406.12 gives the details of this code requirement.
In the diagram below the power is shown coming from the circuit breaker panel. The same wiring diagram can be used if the power is instead coming from another outlet and connected to one of the depicted outlets on the end.
In the wiring diagram above a hot and a neutral enter the single pole switch box. From there a 3 conductor cable is installed to a switched electrical receptacle outlet. A two conductor cable is installed from the switched outlet to feed an outlet that is live at all times. A two conductor cable is run from the switch box to another duplex receptacle outlet that is also live at all times.
HOW TO WIRE SPLIT SWITCHED OUTLET
The following two switched outlet wiring diagrams depict how split or half switched outlets can be wired. The first one shows the method with the neutral conductor in the switch box. The bottom drawing shows how it is usually done.
Split outlets are standard duplex outlets that have had their tabs cut to separate the top and bottom. In the drawings below only the tab on the LINE side of the outlet is cut because the top and bottom are using the same neutral.
Outlets are split wired so that the top half of the receptacle is live all of the time and the bottom of the receptacle is controlled by the wall switch. Depicted above is the neutral conductor in the switch box as well as the cut tab location on the receptacle.
The outlet above has a tab cut out on the hot wire side to make it a split receptacle. Now a constant hot wire can be attached to one screw and a switched hot wire can go under the other screw.
No need to cut the tab on the neutral side if the top and bottom of the outlet are on the same circuit. If there will be two separate circuits, then two neutrals may be required and the neutral tab would need to be cut. If using a multi-wire circuit there would be no need to cut the neutral tab.
A multi-wire circuit consists of a three wire cable with two LINES or hot wires and one neutral in addition to an equipment grounding conductor. It gets connected to a two pole circuit breaker.
Depending on the brand of electrical receptacle you can break the tab between the top and bottom sections of the outlet using needle nose pliers to bend the tab forth and back or small diagonal pliers to cut it.
In the wiring diagram below the white wire that goes to the switch is being used as the hot conductor, not as a neutral. When using the white wire as a hot or LINE it must be re-identified with a different color other than white, gray, or green.
The switch leg is controlling the bottom half of each split receptacle outlet. A three conductor cable is used to bring the hot wire, the switch leg, and the neutral conductor to the outlet on the right.
The required grounding conductor is not shown in order to keep the wiring diagrams simple. However, each outlet and switch is required to have its green screw connected to an equipment grounding conductor. Click here to see my post about how to ground an outlet or switch.
Only one grounding wire can go under the green screw. If you have multiple ground wires they must be spliced together with a pigtail added. The pigtail is connected under the green screw.
There are green wire connectors available with a hole in them that allow the use of one long wire to act as the pigtail and the other wires are twisted around it.
Ground wires can be spliced with any approved wire connector, they are not required to be green.
An example of the above split outlet wiring diagram can be seen at the top of this post. Not pictured in the photo is the next outlet along the wall which was not controlled by the wall switch. It was fed by a two conductor cable instead of a three conductor cable. All outlets after the one pictured were hot at all times.
The two neutral conductors were connected through the outlet rather than being spliced and pigtailed. The original installer did it that way to save time.
Here’s a video from “Ask This Old House” showing how a split switched receptacle outlet is wired:
My light switch wiring diagrams may be helpful to you.
For information and wiring diagrams about three-way and 2-way switches click here.
See my post about four way switch wiring diagrams.