Anyone who has ever needed to find an outlet and been unable to locate one that’s right for their device knows the challenges that come with electrical outlet types. If you need to install or upgrade outlets in your house, you have to know what the different types are and what are their uses. In the Twin Cities Metro area, you can expect to find outlets designed around the National Electrical Manufacturers Association standard that’s common throughout North America. Here are the most common NEMA-standard electrical outlets.
The Venerable Two-Prong Outlet
A two-prong outlet is technically a NEMA 1-15, often referred to as a Type A. As the name suggests, it only has two prongs, and one prong will be slightly larger than the other. This standard supports a 120-volt outlet that operates at 15 amps.
Notably, the Type A outlet doesn’t support a connection to your home’s grounding system. The Type A is okay for devices that don’t pull a lot of juice, such as a lamp or a plug-in USB charging adapter. However, you shouldn’t use it for any device that might need to build a charge to operate. For example, Type A outlets aren’t good for power tools. Some people will break off the ground pin from a device to make it work, but this risks damaging the device or even starting a fire.
Many homeowners just avoid using Type A outlets altogether. They offer the least compatibility. Likewise, the savings are negligible, especially in houses that are already wired for grounding. Consequently, you are more likely to see Type A outlets in old houses than new ones.
Three-Prong, 15 Amps
A three-prong outlet is what people commonly think of as a grounded outlet. While there are many other types of ground outlets, the three-prong NEMA 5-15 outlet is the one you see everywhere. Frequently known as the Type B, this outlet is ideal for use with many types of modern appliances. Ideally, the appliance should be relatively low-draw, such as a microwave.
The Type B also supports 120-volt connections up to 15 amps, and it is reverse compatible with Type A devices. For example, you can plug your two-prong toaster into a Type B socket with no problems.
Three-Prong, 20 Amps
Some devices draw enough power to justify adding about five more amps of capacity. This is where the NEMA 5-20 outlet enters the picture. If you’ve ever seen a three-prong outlet with a sideways T-shaped socket on one side, then you’ve seen a NEMA 5-20. The primary use for the NEMA 5-20 outlet is appliances with higher electrical draws, such as refrigerators, freezers and some bigger air conditioners. These devices often pull a lot of electricity at the start of a cooling cycle, and the extra five amps of capacity allow the outlet to sustain that big burst.
As with the NEMA 5-15, this outlet is reverse compatible. Feel free to plug your two- or three-prong devices into these outlets, even if they don’t require the extra capacity.
NEMA 6-15 and 6-20
Another three-prong outlet, the NEMA 6 class supports 240-volt connections. The prongs are oriented differently to prevent people from accidentally connecting devices for the other classes of outlets into these. If you’ve ever seen a washer or dryer with a big plug with a largely round design, then you’ve seen a NEMA 6 outlet. These are best for major appliances and some heavier power tools.
NEMA 14-30 and 14-50
This is the four-prong class of outlets. The NEMA 14 class used to be unusual in home environments, but EV charging stations are starting to change that. These outlets have three vertical slots and one rounded one for the ground. With support for 120- and 240-volt systems, they are great for electric-powered clothes dryers. You may also see them in households that use higher-end shop equipment.
GFCI
The ground fault circuit interrupt is a variant of the common Type B outlet. It has the same features as the Type B, but it adds a built-in system that interrupts the circuit in the event of a possible short or overload. You often see them around bathrooms and kitchens to add safety near water. They are also common on outdoor residential receptacles.
The right outlet can make a huge difference in terms of safety and convenience with your electrical system. If you have questions about installing, repairing an outlet, contact Plugz Electric today.
