Code Change Summary: The definition of an attachment fitting has been revised.

In the 2017 NEC^®, the term “attachment fitting” was used in Section 314.27(E), and Article 422 but a definition for the term did not exist.

In the 2020 NEC^®, a definition was added to Article 100 for the term “attachment fitting”. All 2020 NEC^® applications for the term “attachment fittings” correlate to a male mating device that connects to a locking support and mounting receptacle.

During the 2020 NEC^® first draft meetings, several code making panels struggled with the term “attachment fitting”, which as noted above was already being used in several sections of the 2017 NEC^®. An attachment fitting is comparable to an “attachment plug” which was already defined in Article 100, but the attachment fitting differs to the extent that a separate definition was needed.

In the 2023 NEC^®, the definition of an attachment fitting has been changed to “Weight-Supporting Attachment Fitting” (WSAF). In addition, a new definition of a Weight-Supporting Ceiling Receptacle (WSCR) now appears in Article 100.

These changes were made to differentiate between weight supporting ceiling receptacles (including their associated weight supporting attachment fittings) and general-purpose receptacles with related attachment plugs. 

This should reduce misapplying Code requirements to this specific type of receptacle when they do not apply.

A WSAF makes a connection between the conductors of the attached utilization equipment and the branch-circuit conductors connected to the WSCR (see image).  The WSCR and locking support, combined with the WSAF, will be listed as an assembly and will have electrical ratings, and mechanical weight ratings.

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.