555.9 Engineered pier design
What changed in 555.9
New 555.9 lets the AHJ ask for documentation of an engineered design for pier power distribution, except at one- or two-family dwellings served single-phase at 240 volts or lower.
Point by point
- New section covers engineered designs for pier power distribution systems.
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- 3 more points on exactly what changed
- The 2023 rule next to the 2026 rule, side by side
- Why it changed
- What to do and check on the job
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This section across NEC® editions
2020 NEC®No change
This section did not change from 2017 to 2020.
2023 NEC®No change
This section did not change from 2020 to 2023.
2026 NEC®NewYou're here
New 555.9 lets the AHJ ask for documentation of an engineered design for pier power distribution, except at one- or two-family dwellings served single-phase at 240 volts or lower.
More 2026 changes in Article 555
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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