Code Change Summary: New language on identifying feeders where only one voltage is present.

SME commentary: The 2026 National Electrical Code (NEC) introduces new provisions in Section 215.12(C) for AC systems to clarify feeder conductor identification in installations where only one nominal voltage system exists. Prior to this change, Section 215.12(C)(1) addressed conductor identification solely in the context of feeders supplied from more than one nominal voltage system. This created a gap, as there was no explicit requirement in Article 215 for identification practices for feeders where only one voltage system was present. The new language fills that gap and aligns the feeder identification rules with the structural approach already taken for branch circuits in 210.5(C).

New subsection, 215.12(C)(1), specifically addresses single-voltage AC systems. It directs that ungrounded feeder conductors be identified in accordance with 310.6(A)(3). That section requires ungrounded conductors, whether installed as individual conductors or within a multiconductor cable assembly, to be finished in a manner that makes them clearly distinguishable from grounded conductors and equipment grounding conductors. This requirement ensures that even in a single-voltage installation, installers, inspectors, and maintenance personnel can readily differentiate between conductor types, reducing the chance of errors during installation or servicing.

This clarification is significant because many smaller or simpler premises wiring systems, such as those found in residential or light commercial installations, may only be served by one nominal voltage system. Without explicit identification requirements, these systems could otherwise present confusion in conductor recognition, especially in facilities where modifications or expansions occur over time. By referencing the identification provisions in 310.6(A)(3), the NEC^® now ensures that all ungrounded conductors in feeder systems, regardless of the number of voltages present, are properly identified.

In addition to this new subsection, the existing requirements were renumbered. What was previously 215.12(C)(1) in the 2023 NEC^®, covering feeders supplied from more than one nominal voltage system, is now 215.12(C)(2). This section continues to require identification of each ungrounded conductor by phase or line and system at all terminations, connections, and splice points. It also maintains the allowance for identification by color coding, marking tape, tagging, or other approved means, along with the requirement that identification methods be posted at each panelboard or distribution point.

The structural reorganization and the addition of 215.12(C)(1) provide consistency with other NEC^® provisions, especially 210.5(C), which requires identification of branch circuit conductors for both single-voltage and multi-voltage systems. By bringing feeder identification requirements in line with branch circuit practices, the Code eliminates uncertainty and creates a clearer framework for ensuring safe and reliable conductor identification across all premises wiring systems.

The 2026 changes to 215.12(C) close an important gap, improve usability for field installations, and further the NEC’s objective of reducing hazards caused by misidentification of conductors.

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 2026 NEC^® edition of NFPA 70.

2023 Code Language:

215.12(C) Identification of Ungrounded Conductors. Ungrounded conductors shall be identified in accordance with 215.12(C)(1) or (C)(2), as applicable.

(1) Feeders Supplied from More Than One Nominal Voltage System. Where the premises wiring system has feeders supplied from more than one nominal voltage system, each ungrounded conductor of a feeder shall be identified by phase or line and system at all termination, connection, and splice points in compliance with 215.12(C)(1)(a) and (C)(1)(b).

(a) Means of Identification. The means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means.

(b) Posting of Identification Means. The method used for conductors originating from each panelboard or similar distribution equipment shall be documented in a manner that is readily available or be permanently posted at each panelboard or similar distribution equipment.

2026 Code Language:

215.12(C) Identification of Ungrounded Conductors. Ungrounded conductors shall be identified in accordance with 215.12(C)(1) through 215.12(C)(3), as applicable.

N (1) Feeders Supplied from One Nominal Voltage System. Where the premises wiring system has feeders supplied from one nominal voltage system, feeder ungrounded conductors shall be identified in accordance with 310.6(A)(3).

(2) Feeders Supplied from More Than One Nominal Voltage System. Where the premises wiring system has feeders supplied from more than one nominal voltage system, each ungrounded conductor of a feeder shall be identified by phase or line and nominal voltage system at all termination, connection, and splice points in compliance with 215.12(C)(2)(a) and 215.12(C)(2)(b).

(a) Means of Identification. The means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means.

(b) Posting of Identification Means. The method used for conductors originating from each panelboard or similar distribution equipment shall be documented in a manner that is readily available or be permanently posted at each panelboard or similar distribution equipment.