Raceway / Cable Support-Spacing Lookup (NEC Chapter 3)
The securing and support intervals for the common wiring methods from their NEC Chapter 3 .30 sections: EMT within 3 ft of a box and every 10 ft, NM within 12 in and every 4.5 ft, MC within 12 in and every 6 ft, AC within 12 in and every 4.5 ft; RMC and PVC intervals vary with trade size. The securing exceptions (fishing, terminations) and the AHJ govern.
Formula and source
by wiring method: EMT secure within 36 in, support every 10 ft (358.30); NM within 12 in, every 4.5 ft (334.30); MC within 12 in, every 6 ft (330.30); AC within 12 in, every 4.5 ft (320.30); RMC/PVC intervals vary with trade size.
Securing and supporting sections of NEC 2023 Chapter 3 (320.30, 330.30, 334.30, 344.30, 352.30, 358.30), by name.
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