What is the Correct Way to Install Electrical Outlets: Ground Up or Down?

Ask an electrician which way a receptacle, aka outlet, should be installed: “Ground up or down?” Typically, the answer is “both are fine,” though most of us have a preference. The National Electrical Code (NEC) doesn’t require a particular orientation, so you can install them any way you want, even sideways or on the floor.

So why do we think one way is “right-side up” and another is “upside down”? In the United States, the majority of three-prong, grounding-type receptacles (as opposed to non-grounding ones with two slots) are oriented with the circular opening on the bottom. It looks like a face, right? We’ve been conditioned to think this is the right way.

If we tend to think one way is “right,” why are they sometimes installed with the grounding connection up? Is one better than the other? What should you do in your home? Let’s dig in below.

Why Are Receptacles Installed Ground Up?

Proponents of installing ground-up receptacles cite the potential for short circuits if something metal falls on the exposed blades of a partially plugged-in cord. Plugging the cord in with the grounding pin on top could offer some protection by deflecting the falling object. Ground-up receptacles are common in hospitals, where electrical arcs from a short circuit would be particularly disruptive.

Sometimes, electricians install switched receptacles ground up to differentiate between regular ones. (Switched receptacles are controlled by a wall switch and often have a lamp plugged in.) Dryers and other appliances with large, bulky plugs are often more easily accommodated by “upside-down” receptacles.

There’s also just plain preference or habit. Many people were taught a specific way to install a receptacle, and since either direction is valid, they continue the practice they first learned. Local codes or specific client requirements could dictate which way they go, too. Early patents for grounding-type receptacles show the grounding prong on top, so there’s that, too.

Why Are Receptacles Installed Ground Down?

Mostly, it’s familiarity and custom. Once we start doing something, we tend to stick with it. Seeing a ground-down receptacle “face” is reassuring because it’s what we’ve always known. That’s why ground-up receptacles stand out—they’re not as common.

Manufacturing and design evolution could also play a role. When you reach for and grab a cord, the natural way to hold the plug is with the flat side on top, under your thumb. Inserting the plug into a ground-down receptacle doesn’t require flipping the plug around in your hand, suggesting manufacturers anticipate a ground-down orientation.

Is One Way Better Than the Other?

Not according to the NEC. Both methods are safe and valid as long as they are wired correctly. Grounding-type, three-prong receptacles must be connected to the green or bare equipment grounding conductor (EGC). In the event of a short circuit or other fault, the EGC carries the abnormal current back to the electrical panel so the breaker can trip. The EGC works no matter how a receptacle is oriented.

Older homes wired with knob-and-tube won’t have an EGC. You can tell because the receptacles only have two slots, hot and neutral. If you have these (I did for years), it’s a good idea to replace them with a GFCI.

Why Not Change the Code?

Why doesn’t the NEC come down one way or the other? Changing the electrical code is a rigorous process that requires evidence that one way is far superior and safer. John Williamson, a retired chief electrical inspector for the Minnesota Department of Labor and Industry, says it’s likely that NEC code-making panels (made up of industry experts) would reject proposals to add a requirement for lack of substantiation.

Of course, the NEC is not the only code that counts. Your local electrical and building codes may dictate how you should orient receptacles. Contact your locality or a licensed electrician in your jurisdiction if you have any questions.

Sources

• Labre, Philip F. (1927). US1672067A, United States: “Grounding receptacle and plug.”
• Williamson, John. Chief Electrical Inspector, Minnesota Department of Labor and Industry (Retired).