240-Volt Outlets I What's a 240-Volt Outlet?

What’s a 240-Volt Outlet?

One standard electrical outlet contains a 120-volt wire and a neutral wire which deliver power using one phase of your electrical service. 240-volt outlets use two 120-volt wires simultaneously, plus a neutral wire to power a single receptacle.

Older homes and appliances may use three-prong 240-volt outlets. However, modern outlets and appliances use a ground wire too, which means modern 240-volt plugs have four prongs.

Which Appliances Use 240-Volt Outlets?

Many large, motor-driven appliances run more efficiently with a 240-volt power supply. The 240-volt outlets are intended for use specifically with heavier appliances that need more electricity to operate. You may need to have a 240-volt outlet installed if you purchase one of the following items:

Oven, range, or cooktop
Clothes dryer
Water heater
Central air conditioner
Electric car Level 2 charger

Identifying 240-Volt Outlets

Compared to standard 120-volt receptacles, 240-volt outlets are larger, with rounded tops, and three or four holes depending on the age of the outlet. Older three-prong outlets have a hole like a backward “L” on top and two diagonal holes on the sides. Newer four-prong outlets have an “L” on top, two vertical side holes, and a single half-circle hole on the bottom for the ground wire.

Three-Prong vs. Four-Prong 240-Volt Outlets

Recently, 240-volt outlets have switched from three-prong to four-prong. Older three-prong outlets were designed to contain two live wires and one neutral. The additional prong on four-prong outlets adds a ground wire, providing additional safety against electrical shock. Rewiring your appliances with four-wire plugs and installing four-prong 240-volt outlets will solve any safety or compatibility issues.

Rely on Mr. Electric for Installing 240-Volt Outlets

If you would like 240-volt outlets installed in your home, including for your electric car, contact Mr. Electric®. We can also re-wire your older appliances with four-prong plugs so they work perfectly with your new outlets. Schedule an appointment online or call us at (844) 866-1367 today.