Code Change Summary: A clarification was brought to the existing language on multiwire branch circuits.
Article 100 defines a Multiwire Branch Circuit as “a branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a neutral conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral conductor of the system”.
In the 2023 NEC®, the language on multiwire branch circuits in Section 210.4 was clarified to ensure that multiwire branch circuits always originate from the same equipment where the overcurrent device is located, except as permitted in 300.3(B)(4) which applies to column-width panelboard installations.
The previous language allowed a multiwire branch circuit to originate from the same panelboard or similar “distribution equipment” which is not defined in the NEC®.
By deleting the words “or similar distribution equipment”, it is now crystal clear where a multiwire branch circuit must originate.
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:
210.4(A) General. All conductors of a multiwire branch circuit shall originate from the same panelboard or similar distribution equipment.
2023 Code Language:
210.4(A) General. Except as permitted in 300.3(B)(4), all conductors of a multiwire branch circuit shall originate from the equipment containing the branch-circuit overcurrent protective device or protective devices.
Based on the 2023 NEC, which of the following is true?
Please register or sign in for electrical continuing education courses. If you were already signed in, your session probably expired, please sign back in. |