Code Change Summary: Revised code language now addresses deflection of conductors (wire-bending space) in meter socket enclosures.

NEC Article 312 is all about cabinets, cutout boxes and meter socket enclosures and provides specific measurements to ensure conductors can be properly deflected within the enclosures. In the past, for some reason, Section 312.6 required conductors at terminals or conductors entering or leaving cabinets or cutout boxes “and the like” to comply with the deflection rules in 312.6(A) through (C).

“And the like” is a bit confusing, especially when the article is only about three specific types of enclosures: cabinets, cutout boxes and meter socket enclosures.

In the 2020 NEC^®, a public input (code change proposal) was accepted to simply add meter socket enclosures to the list of equipment that requires space for conductor deflection. Knowing the rules and selecting the correct table in Article 312 is important. The notes under the tables are also important since some enclosures have lay-in type lugs which allow for a conductor to easily lay into place rather than resorting to bending the conductor tightly in order to terminate it as required for other than lay-in type lugs (see image). This results in reduced measurements when lay-in lugs are present.

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 2020 NEC^® edition of NFPA 70.