Dear Mr. Electrician: How do I wire a switched outlet? I need the wiring diagram for a switched electrical receptacle outlet in my basement. I want to be able to control half of the outlets with wall switches.
Answer: 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. Another option is 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 below that depict split outlet wiring. NOTE: Text links below go to applicable products on Ebay and Amazon.
Switched Outlet Diagrams
The wiring diagram at the top of this page 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 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. It has been my experience when working on older homes that the hot white wire has almost never had its color changed. Consequently it is not unusual to find that the white wire in a switch box is a LINE and not a neutral conductor.
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 the switch box to another duplex receptacle outlet that is also live at all times.
Half Switched Outlet Wiring Diagrams
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.
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 diagrams simple. However each outlet and switch is required to have its green screw connected to a grounding conductor.
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.