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NEC 250 — Grounding and Bonding

Updated May 22, 2026
Governs grounding electrode system, equipment grounding conductor sizing, and bonding requirements at the service. Required for every panel schedule.

Tom-the-MEP cited grounding as a frequent panel-schedule line item that LLMs get wrong. The panel-schedule UI flags grounding as a follow-up — engineer of record must size GEC + EGC per 250.66 / 250.122 against the service rating and the breaker, respectively.

TAGS
NEC250groundingbondingGECEGCservice-grounding
DETAILS
book
NEC 2023
section
250
mep calc workflow
q-panel-schedule
SOURCES
🔗https://codes.iccsafe.org/content/NFPA702023/article-250
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