BACK TO BASICS: NEMA Connector (“the plug”)

The plug. That’s what everyone calls it. You know, the way that everything gets power? Did you know that its proper name is a “NEMA Connector?” It’s also sometimes called an Edison connector.

The name comes from the National Electrical Manufacturers Association (NEMA), an organization founded in 1926. The connector itself dates back to roughly that time as well. Prior to its use, there were several different ways to connect electrical appliances to a power socket, from bare wires to incompatible plugs.

NEMA connectors are used throughout North America but their use in other parts of the country is limited. Other countries created their own plug standards, which is just as well because other countries also use power setups that could potentially destroy your home appliances if you’re not ready for them.

The basic NEMA connector has to flat prongs spaced exactly .5″ apart. If that’s all it has, that’s a NEMA type 1. If it also has a round prong below the flat prongs, that’s a NEMA type 5, generally referred to as a “grounded plug” since the third prong is used for grounding.

Some plugs are polarized, meaning it matters which prong goes in which hole, and some aren’t. If a device requires a polarized plug, one prong will be slightly longer than the other so that the plug cannot go in the wrong way.

There are quite a few specifications for NEMA connectors but the type 1 and type 5 are the most common. Washing machines and other appliances will use other NEMA connectors as well.

No matter what though, if you have a NEMA 5-15 outlet, which is the standard here in the US, you’ll find that you can plug anything in that you want. It’s nice to know that some standards don’t change. Imagine having to buy a new plug for every device you have!

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 5,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.