Types of Electrical Sockets

There are various types of electrical sockets designed to match the requirements of your appliances, power tools and electronics. The most important factor, however, in choosing the right outlet is the wiring requirements. Most homes in the U.S. are wired with a combination of 15-amp and 20-amp, 120-volt circuits.

• 15-amp receptacles can be used with 20-amp circuits. As such, most of these electrical outlet types are the ones found in American homes. They have two slots and a U-shaped grounding hole. A 15-amp circuit is usually served by 14-gauge wire. It is protected by a 15-amp circuit breaker or fuse.
• 20-amp receptacles have a horizontal slot branching off one of the vertical slots. Appliances, such as microwaves, often have 20-amp plugs and must be plugged into a 20-amp outlet. Electrical plugs designated as 20-amp will not fit into 15-amp outlets. A 20-amp circuit, protected by a 20-amp breaker or fuse, must be served by 12-gauge or 10-gauge wire.

The easiest way to determine whether a circuit is 15 or 20 amps is to look at the corresponding breaker or fuse in the breaker panel. Dedicated circuits are electrical lines that carry an electrical current to one single outlet. For an ample and consistent stream of power for safe operation, 20-amp receptacles are recommended for major appliances.

A 15-amp duplex receptacle outlet is a standard type of electrical socket that's used in most residential homes. Each of the two outlets has a long (neutral) slot, a shorter (hot) slot and a half-round grounding hole.

Combination outlets make it convenient to combine two uses in one outlet. They often provide two features, such as a light or a switch, in one device. Combination electric outlets are ideal for simultaneously powering multiple electronic devices, such as televisions, radios and computers. Or use them when you need to power different types of plugs at once.

One of the most common types of electrical sockets in the home are GFCI outlets (Ground Fault Circuit Interrupter). This type of electrical outlet protects against shocks. It continually monitors the flow of electricity and automatically shuts off power when necessary. Electrical code requires that GFCI receptacles be installed in bathrooms, wet areas of kitchens, basements and outdoors.

When an electrical current jumps between wires or connections it can create a spark. This is called an arc fault. To prevent this, you should use AFCI outlets. Arc Fault Circuit Interrupter outlets are a special type of electrical socket that protects your home from electrical fires. The National Electrical Code recommends AFCI outlets in areas such as bedrooms and living rooms.

Tamper-resistant receptacles are tamper-proof or childproof outlets. These types of outlets have built-in blocks that prevent electrical injury in children when they insert objects into the outlet slots. Tamper-resistant outlets can be used in place of conventional 15-amp and 20-amp outlets. Tamper-resistant outlets are permanent once installed.

Tip: For a removable childproof option, try plastic outlet caps.

Weather-resistant receptacles have a special cover that protects the outlet from moisture. They prevent electrical shock or damage in outdoor conditions, such as rain, ice and snow. The National Electrical Code requires they be used in damp or wet locations, like patios, decks and pool areas. Available in 15- and 20-amp sizes, weather-resistant outlets are made of UV-stabilized thermoplastic, which is corrosion-resistant. Weather-resistant receptacles come in combined weather/tamper-resistant outlets. They're also available as weather-resistant GFCIs, with or without tamper resistance.

A rotating outlet has a plug that can rotate 360 degrees. These types of outlets are especially useful in tight spaces or when you want to accommodate more than one large plug. Rotating outlets reduce the need for power strips. They're also ideal for appliances, such as cell phone chargers, hairdryers and night lights.

Many appliances, tools and electronics require specialty electrical sockets to operate safely and at peak efficiency. These types of electrical outlets are designed to perform specific functions. For example, instead of a surge-protector power strip, you can use a surge-suppression outlet to protect sensitive electronic equipment from power spikes.

Just like there are a variety of electrical sockets, there are different types of plugs. When shopping for major appliances, decide whether you need a 3-prong versus a 4-prong cord.

• 3-prong plugs are used for homes built before the year 2000.
• 4-prong plugs are used for homes built after the year 2000.

Tip: When you purchase a new appliance, a 4-prong cord is usually included with the appliance by default. If your home is equipped with a 3-prong outlet, you will need to get a 3-prong cord or connector adapter separately.

A split circuit receptacle is good for managing power usage and preventing overloading of one circuit. It has two outlets, each wired on a different circuit. Or it can have one outlet live and the other switched or connected to a wall switch in your home.

A 30-amp or 50-amp 125V/250V receptacle is required by some heavy-duty appliances. They provide the right amount of power to dryers, cooking ranges or power tools. A 30-amp receptacle can handle up to 3,600 watts of electricity, while a 50-amp receptacle can handle up to 7,200 watts of electricity. This type of outlet has a special prong configuration.

When buying outlets, it’s important to know whether you will need them to be grounded or ungrounded.

• Grounded outlets generally feature two vertical slots for hot and neutral wires, along with a third prong, or even a combination. This third prong, or ground wire, provides a safe path for electricity to travel away from people and property if a short circuit or power surge occurs.
• Ungrounded outlets accommodate the two-prong electrical plugs. However, they're missing the U-shaped third grounding hole. As a result, they can cause electrical shocks or overload plugged-in devices. Electricity may also flow through any nearby conductive material (or person).
• Most homes built before the mid-1960s had ungrounded and unpolarized outlets. Since then, all structures have required grounded and polarized outlets.
• Modern outlets are also designed to take polarized plugs, in which one prong is wider, to reduce shock risks.

Tip: If your home or business has ungrounded or unpolarized outlets, you may want to install safer grounded and polarized types, or even GFCI outlets. Some older structures may have outlets with circular ground holes, but no connected ground wire. If outlets appear to be grounded but aren't, some electrical devices’ built-in safety features can fail.

Universal Serial Bus (USB) outlets are a type of combination electrical socket. They contain both a standard two-prong plug and a USB charging port for electronic devices. These types of electrical outlets allow you to simply add and remove devices. They save space and are available in USB and USB Type-C port options.

A smart outlet uses WiFi or Bluetooth technology to connect to a home network. It can be controlled remotely through a smartphone or voice assistant app. Smart outlets let you turn off lighting, set schedules for appliances and monitor energy usage.