320.30(C) Supporting.
Code Change Summary: Revised code language on securing and supporting of armored cable type AC.
There are two basic requirements when trying to ensure that a cable stays put: securing and supporting. Securing an AC cable keeps it from moving while supporting it keeps it from sagging and takes the weight or strain off the cable.
In the 2020 NEC®, a change was made to make it clear that where an AC cable passes horizontally through wood or metal stud holes, the cable is considered secured AND supported without the need to do any additional cable strapping as long as the studs are spaced at no more than 4 ½ foot intervals.
The new language aligns with a similar existing allowance for metal clad type MC cable passing horizontally through framing members spaced no more than 6 feet apart in Section 330.30(C).
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.
2017 Code Language:
320.30(B) Securing. Unless otherwise permitted, Type AC cable shall be secured within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting and at intervals not exceeding 1.4 m (4 ½ ft).
320.30(C) Supporting. Unless otherwise permitted, Type AC cable shall be supported at intervals not exceeding 1.4 m (4 ½ ft). Horizontal runs of Type AC cable installed in wooden or metal framing members or similar supporting means shall be considered supported where such support does not exceed 1.4 m (4 ½ ft) intervals.
2020 Code Language:
320.30(B) Securing. Unless otherwise permitted, Type AC cable shall be secured within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting and at intervals not exceeding 1.4 m (4 ½ ft).
320.30(C) Supporting. Unless otherwise permitted, Type AC cable shall be supported at intervals not exceeding 1.4 m (4 ½ ft).
Horizontal runs of Type AC cable installed in wooden or metal framing members or similar supporting means shall be considered supported and secured where such support does not exceed 1.4 m (4 ½ ft) intervals.