Most homes are wired with both 15-amp and 20-amp receptacles. 15-amp outlets have a u-shaped grounding hole and two slots. 20-amp receptacles have a horizontal slot that branches off from the vertical slots. 20-amp outlets work with appliances, such as microwaves, and must operate on a 20-amp circuit.
Some duplex outlets allow for back wiring instead of side wiring because it is generally a much simpler process. However, back wiring is not as secure as a side wiring connection. We recommend installing a duplex receptacle with both type of connectors.
The Americans with Disabilities Act (ADA) mandates that unobscured outlets must measure between 15 inches and 48 inches from the floor.
A duplex outlet, also referred to as a duplex receptacle, is a standard wall outlet that has two spaces to plug in devices. Duplex receptacles are some of the most common outlets found in homes and businesses. Browse HomElectrical’s selection to see the many kinds of electrical outlets we offer!
Generally, you should have no more than 10 duplex receptacles on a 20-amp circuit. Technically, you can run however many outlets you want on any kind of circuit, but the National Electric Code (NEC) advises against this. Overloaded circuits can be hazardous; excess wires and electricity run risks of electrical fires. Instead, the NEC suggests using 80% or less of your circuit’s power to be safe. In other words, 1 receptacle per 1.5 amps, which for a 20-amp would be 10 outlets.
According to the National Electric Code’s 80% rule (1 receptacle per 1.5 amps), the safest amount of outlets to use on a 15-amp circuit is 8.
The rule of thumb to determine how much power your outlet can handle is by multiplying the receptacle’s amps by the voltage of your circuit. Typical households run on a 120-volt circuit, so that means that a 15-amp receptacle can handle 1800 watts, and a 20-amp receptacle can handle 2400 watts. But just because your outlets can handle it, does not mean you should regularly max out wattage. Most duplex outlets are rated at 15A, meaning they can safely and comfortably accommodate up to 1500 watts, so sticking to that maximum per receptacle is good practice to prevent going over capacity.
Yes, you can split a duplex outlet. Most duplex receptacles are made to be able to operate separately. If you have two separate circuits, splitting a receptacle between them allows you to draw twice as much power, and can be a much safer way to plug two high-power appliances into the same outlet without exceeding watt maximums.
You can put a 15-amp outlet on a 20-amp circuit, but not the other way around. Your receptacle’s power should never exceed that of the circuit it is drawing from. If possible, it is best to keep your outlets, circuits, and breakers all the same amperage to minimize any electrical surges or hazards.