The National Electrical Code (NEC) does not limit the number of outlets per circuit. The NEC only states that a circuit cannot supply more than 80% of the circuit breakers limits. This is so the circuit breaker does not constantly trip during regular use.
Living areas require wall receptacles no farther than 12 feet apart. Any section of a wall wider than 2 feet requires a receptacle. Dining rooms usually require a separate 20-amp circuit for an outlet that can be used for microwaves, window air conditioners or other appliances.
Watch out: do not install a pair of interior and exterior electrical receptacle boxes in the same stud bay back-to back. The result of such an installation can violate the fire resistance of the wall. Instead, as you will read below, the boxes need to be offset from one another.
The NEC (National Electrical Code) and ADA (Americans with Disabilities Act) guidelines dictate outlets' required height. Outlets must be installed between 15 and 48 inches above the finished floor, with the center of the outlet being no more than 12 inches from either side of the room.
The General Rule of Thumb for Outlet Spacing
Receptacles are needed in every room of a home such that no point on a wall is over 6′ from an outlet. This means that you need an outlet within 6′ of a doorway or fireplace. A long wall, however, may have up to 12′ between outlets.
Ideally, you should spread as many outlets around your home as possible and assign them to a single circuit. Just keep in mind the maximum load for a single circuit. A good rule of thumb is to assume that there will be a maximum power draw of 1.5 amps for each outlet, allowing 10 outlets for a single 20-amp circuit.
You may have heard horror stories about knob and tube wiring or Federal Pacific Electrical panels. But don't worry. According to the National Electric Code, two-prong outlets are allowed if they are properly working.
Do not piggyback or plug a power strip of any type into another. Do not overload electrical sockets. Never use an extension cord with an appliance — plug them directly into wall sockets. Never place anything that can burn over a lamp.
The maximum spacing between receptacles, according to the National Electric Code (NEC), has been set at 12-feet since 1956--with no point along a wall being more than 6-feet from a receptacle. There is no minimum.
All receptacles must be AFCI and GFCI-protected, either by circuit breakers or individual receptacles that offer AFCI and GFCI protection. Light fixtures and wall switches must be on a separate circuit.
Accessibility for Non-hazardous Locations: NEC 314.29
Junction boxes must be securely supported to prevent them from coming loose or moving. In addition, they have to be supported by framing, clamps or other similar supports. Box covers must be securely fastened to prevent accidental contact with live conductors.
You can mix and match 15A and 20A. But your garbage disposal should be on a dedicated, circuit. No GFCI required for that circuit. In general practice, 20 amp receptacles are only used on a dedicated 20 amp circuit.
In general, a 20A circuit should have no more than 10 outlets. The National Electrical Code (NEC) stipulates that the total load on a 20-amp circuit should not exceed 1250 watts. It includes all the outlets, lights, and appliances on the circuit.
On a regular basis, most people will almost exclusively use 15 amp outlets. However, there are situations where 20 amp outlets are necessary. This is because 20 amp outlets are designed to handle devices that need more power. This usually means powerful kitchen equipment like refrigerators or electric stoves.
Wiring an Outlet From Another Outlet
In fact, if there's an existing outlet on the opposite side of the wall from where you'd like to add one, the job can be pretty simple. In this situation, you can usually cut a new opening, install an electrical box, and add a new outlet without having to snake wires through studs.
In reality, there is no code requirement that says an outlet receptacle should be installed one way or the other. 1 In fact, at one time some manufacturers actually recommended the orientation that many of us view as upside down—with the round grounding slot at the top.
Two prong outlets are inherently unsafe and can be extremely dangerous. They are a well-known cause of residential home fires worldwide. According to the U.S. Fire Administration, 12 percent of residential homes fires in the United States involve outlet receptacles.
According to the National Electric Code, you can sell a house with existing two-prong outlets as long as they're working correctly. Even if you choose to replace two-prong outlets, they do not have to be rewired and upgraded.
If your home was built before 1974, which was the year the National Electric Code (NEC) was updated to require the installation of only grounded outlets in all newly built homes, you may have ungrounded, two-prong outlets in your house.
If the switches are part of the outlets, then you just count them as outlets. If the switches are rated for 15A or more, then you can use them. You don't otherwise count them, but excess wiring length, presents loss of available voltage.
Same is the case for IEC where the safety factor of 80% of the total rating of the breaker is applicable for general lighting circuits. As a general rule of thumb, a total of 8-10 numbers of light bulbs can be installed on a single pole, single phase 15A, 120V circuit breaker.