Code Change Summary: Additional text in note 4 provides clarity on connectors.

In the 2023 NEC^®, a public input was accepted to clarify the existing language allowing conduit or tubing nipples 24 inches or less to be filled to 60% of their total cross-sectional area and be exempted from the adjustment factors in 310.15(C)(1).

The revised 2023 language makes it clear that the conduit or tubing nipple is to be measured without the connectors. This allowance is for conduit or tubing nipples, not including connectors, with a maximum length not to exceed 24 inches that are installed between boxes, cabinets, and similar enclosures. Such conduit or tubing nipples shall be permitted to be filled to 60% of their total cross-sectional area, and 310.15(C)(1) adjustment factors need not apply.

This change makes it clear that the connectors on the end of conduit or tubing nipples are not included in the 24-inch measurement of a nipple between junction boxes or enclosures when applying the code language in note (4).

A 24-inch conduit or tubing nipple installed between boxes will actually measure a bit longer than 24 inches if the connectors are included and the installation is still code compliant.

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.