518.4 Assembly occupancy wiring
What changed in 518.4
Cables in assembly occupancies no longer have to contain an insulated equipment grounding conductor when the wiring method itself qualifies as one.
Point by point
- Fixed wiring still has to be metal raceway, nonmetallic raceway encased in 2 inches or more of concrete, or Type MI, MC or AC cable.
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- 4 more points on exactly what changed
- The 2017 rule next to the 2020 rule, side by side
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This section across NEC® editions
2020 NEC®RevisedYou're here
Cables in assembly occupancies no longer have to contain an insulated equipment grounding conductor when the wiring method itself qualifies as one.
2023 NEC®No change
This section did not change from 2020 to 2023.
2026 NEC®Revised
Found at 518.6 in the 2026 NEC®.
Assembly occupancy wiring methods moved from 518.4 to 518.6, and the conditions for using Type AC cable there got much tighter.
Open the 2026 page →More 2020 changes in Article 518
This is a plain-English summary, not the NEC®'s exact wording. Always check the full section in the NEC® edition your area has adopted, plus any local amendments.
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