To the unobservant eye, all electrical outlets are identical. Rectangular shape, screw in the center, two faces with uneven eyes and a downturned mouth. Sound familiar? But if you take a look around, you’ll notice slight variations. There are several types of electrical outlets commonly seen in the United States. Some are outdated, some have special purposes, and some have been adapted to include safety features. While you probably have been using electrical outlets safely all along, there’s no harm in learning a little more about the various types of electrical outlets.
Types of Electrical Outlets
Standard Outlets
Chances are, these are the outlets you see scattered about your home and office. You can plug in just about any small appliance to them (TV, computer, hair dryer, toaster) because they supply a basic 120 volts of electricity. Although it’s possible to see them in two- or three-pin varieties, these days (since the 1960s, to be exact) three-pin receptacles are far more common. They have a third, thicker pin on the bottom that is grounded. If the neutral wire in the outlet fails, the grounded wire carries the electricity safely into the ground. If you have grounded appliances (like computer cords and power tools), you must plug them into a grounded outlet. However, ungrounded appliances (toaster, curling iron) can be plugged into a grounded outlet without any problems. If there are ungrounded outlets in your home, you need to have an electrician update them.
Non-Polarized Outlets
If your home is very old, you might have outlets that are not only ungrounded but non-polarized as well. You can tell that they’re non-polarized because the pins are the same size and the receptacle is symmetrical. It’s very uncommon to see non-polarized outlets today because they’re very unsafe. Polarization reduces the risk of electrical shock, so if you have non-polarized outlets, you need to have them replaced right away.
GFCI Outlets
In rooms that sometimes get wet (kitchens, bathrooms, garages), you will usually find GFCI (ground fault circuit interrupter) outlets. GFCI outlets can be identified by two special buttons in the center—one black and one red. They contain a circuit breaker so that if water tampers with the outlet, the receptacle will turn itself off without shutting off electricity in the rest of the house. You can use the black button to test the outlet and the red button to reset it.
Range Outlets and Dryer Outlets
Some appliances in your house require too much power to work with standard outlets. A range receptacle (top photo) provides electricity specifically to your cooking range and is attached to its own circuit breaker. A dryer receptacle (bottom photo) comes with four pins so that it can supply 240 volts of electricity. Some homes have dryer receptacles with three pins, but these are fading out because new homes are required to be built with four-pin dryer receptacles.
Outlets with USB Charging Ports
Finally, you may soon start to see standard outlets fitted with two extra holes—USB charging ports. These allow homeowners to plug in items that are charged using a USB connector, like cell phones and MP3 players. They’re very convenient if you’re not near a computer, but they’re still quite rare.
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Remember that although there are many different types of electrical outlets, you cannot use them interchangeably. If a plug does not match an outlet, do not attempt to plug it in. The prongs of the plug should never have to bend in order to fit into the outlet. If a particular outlet is giving you trouble, call a qualified electrician to assess it.
