Section 406.4(D)(4) of the 2020 National Electrical Code (NEC) is a prime example of why understanding the definitions in Art. 100 is of the utmost importance when it comes to deciphering and applying the rules of the Code.
The definition of “receptacle outlet” in Art. 100 is “an outlet where one or more receptacles are installed.” A good example of this would be a duplex receptacle in an outlet box. In contrast, the Art. 100 definition of “receptacle” states in part that a receptacle is “a contact device installed at the outlet for the connection of an attachment plug, or for the direct connection of electrical utilization equipment designed to mate with the corresponding contact device.” Understanding the difference between a receptacle and a receptacle outlet is needed to help understand the AFCI protection requirements specified in Sec. 406.4(D)(4). This Section has undergone several changes over the past few Code revision cycles, and I expect more changes will be coming soon.
Presently, the literal wording in Sec. 406.4(D)(4) triggers AFCI protection requirements when a receptacle outlet located in any area specified for dwelling units [Sec. 210.12(A)], dormitory units [Sec. 210.12(B)], or guest rooms, guest suites, and patient sleeping rooms in nursing homes and limited-care facilities in [Sec. 210.12(C)] is replaced but does not trigger AFCI protection requirements where only the receptacle itself is replaced. Do you think that is the intent of this rule?
Based on the previous wording of Sec. 406.4(D)(4) in the 2017 Code and the revisions made in the First Draft Report based on Public Input that was submitted for the 2023 edition, I believe the intent of the present wording in Sec. 406.4(D)(4) was to trigger the AFCI protection requirements even when performing a simple receptacle replacement. However, the literal wording does not quite get there, since it only applies where a receptacle outlet is replaced. While receptacle outlet boxes are sometimes replaced, I think replacing the outlet box is a much less likely occurrence than replacing only the receptacle.
Perhaps the 2023 Code will provide some much-needed clarity on the intent of these rules, but until that time comes, we will need to continue to do our best for keeping our customers safe and to have professional and productive conversations with our AHJ to make sense of these sometimes confusing rules.
