555.5 Maximum voltage
What changed in 555.5
Pier power distribution is now capped at 250 volts phase to phase, down from 600, unless qualified people service it under engineering supervision.
Point by point
- Pier power distribution can't go over 250 volts phase to phase.
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This section across NEC® editions
2020 NEC®RevisedYou're here
Pier power distribution is now capped at 250 volts phase to phase, down from 600, unless qualified people service it under engineering supervision.
2023 NEC®No change
This section did not change from 2020 to 2023.
2026 NEC®Revised
The voltage cap for pier power distribution went back up, from 250 volts to 600 volts phase-to-phase.
Open the 2026 page →More 2020 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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