210.18 Branch Circuit Rating.

LED lighting and other energy efficient systems may benefit from the new allowance to use 10-ampere branch circuits.
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LED lighting and other energy efficient systems may benefit from the new allowance to use 10-ampere branch circuits.

Code Change Summary: Branch circuits can now be 10 amps.

In the 2023 NEC®, the work of a special task group appointed by the Standards Council resulted in the allowance of 10-ampere branch circuits in Section 210.18. It is important to note that this is only for “other than individual branch circuits” and that a 10-amp branch circuit is NOT permitted to supply receptacle outlets.

The task group submitted several other public inputs (PI’s) throughout the NEC® in a coordinated effort to introduce 14 AWG copper-clad aluminum conductors into the NEC® for branch circuit wiring. Some were accepted at the first draft meetings and then deleted during the second draft meetings in the 2023 NEC® development process.

Bringing 14 AWG copper-clad aluminum conductors into the NEC® for branch circuit wiring would involve adding the appropriate language on overcurrent device ratings in Article 240, adding an ampacity to the ampacity tables in Article 310, as well as many other coordinated changes throughout the NEC® and the product safety standards.

During the first draft meetings, Code Making Panel 6 (CMP-6) accepted several proposals for the effort in articles 310, 320, 330, 334, 336, and 340. During the second draft meetings, CMP-6 acted to revert to 2020 code language for the minimum size of conductors in those articles. CMP-6 felt that further time is needed to study 14 AWG copper-clad aluminum and 16 AWG copper as minimum conductor sizes.

The change in Section 210.18 was under the purview of CMP-2 and made it through the 2023 NEC® development process. This change in 210.18 is specific to branch circuit ratings rather than conductor types used to create the wiring portion of the branch circuit.

CMP-2 felt that the Energy Codes and energy efficiency technology in general has brought forward possible applications where 10-ampere branch circuits can be used for loads such as LED lighting and specific dedicated limited loads such as alarm system panels.

New exception 2 in 210.18 prohibits receptacles from being supplied by 10-amp branch circuits because of the various types of utilization equipment that could be plugged into a 15-ampere receptacle. Technically, having this requirement as an exception rather than positive language in the charging text before any exceptions seems strange since exceptions usually provide relief, or an allowance rather than a prohibition.

Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC® edition of NFPA 70.

2020 Code Language:

210.18 Rating. Branch circuits recognized by this article shall be rated in accordance with the maximum permitted ampere rating or setting of the overcurrent device. The rating for other than individual branch circuits shall be 15, 20, 30, 40, and 50 amperes. Where conductors of higher ampacity are used for any reason, the ampere rating or setting of the specified overcurrent device shall determine the circuit rating.

2023 Code Language:

210.18 Rating. Branch circuits recognized by this article shall be rated in accordance with the maximum permitted ampere rating or setting of the overcurrent device. The rating for other than individual branch circuits shall be 10, 15, 20, 30, 40, and 50 amperes. Where conductors of higher ampacity are used for any reason, the ampere rating or setting of the specified overcurrent device shall determine the circuit rating.

Exception No. 2: Branch circuits rated 10 amperes shall not supply receptacle outlets.

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210.18 Branch Circuit Rating.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Based on the 2023 NEC, which of the following is true?

A: A 10-amp branch circuit may supply receptacle outlets.
B: A 10-amp branch circuit is NOT permitted to supply receptacle outlets.
C: A 10-amp branch circuit is NOT permitted in the NEC.
D: A 10-amp branch circuit is NOT permitted in section 210.18.
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