How Many Receptacles Are Allowed On A 20 Amp Circuit?
March 22, 2006
Q: According to the National Electrical Code, 10 receptacles are permitted on a 15A branch circuit and 13 are permitted on a 20A branch circuit in commercial buildings. How many receptacles are permitted on a 20A branch circuit in a single family home?
A: There is no limit to the number of receptacles permitted on a 20A branch circuit in a single family home. For other than dwelling units, part (a) of 220.3(B) requires that each single or multiple receptacle on the same yoke be calculated as a load of 180VA, or a receptacle outlet that has four or more receptacles be counted at 90VA for each receptacle. Using this load of 180VA for each single or duplex receptacles allows 10 receptacles on a 15A branch circuit and 13 on a 20A branch circuit.
In residential occupancies receptacles are required to be spaced at fixed intervals; this is not the case for commercial occupancies. In commercial, industrial, institutional, etc. occupancies receptacles are generally located only where required to supply cord-and-plug connected loads. For this reason, unit loads are assigned to receptacles in other than residential occupancies. The Code mandates spacing of receptacles in dwelling units to provide flexibility in the use of table lamps, floor lamps and other appliances and to reduce the use of exterior cords; not because there will be loads plugged into every receptacle.
In all occupancies 210.11 requires an adequate number of branch circuits for the calculated loads. And 210.11(B) require that the calculated load be evenly divided among the branch circuits.
Some inspection authorities have local laws or ordinances that limit the number of receptacle outlets on 15 and 20A branch circuits in residences. I am not in favor of such a regulation, but you should be aware of such a restriction if one exists.
Do you need assistance with your electrical wiring project? Please visit my DIY Electrical Wiring Help from a Master Electrician page. Where I provide electrical wiring tips, expert electrical advice, answers to your electrical questions and electrical consulting & design services over the phone, via instant messenger or via email.