Research — Illustrative (draft, unvalidated)

Substation fence clearance

Choose the station voltage and BIL, then drag the measured distance from the inside of the fence to the nearest exposed live part. The required zone comes from NESC Rule 110A2 / Table 110-1 and is never interpolated: an unlisted BIL rounds up.

Plan view · fence line and nearest live part (fixed illustrative drawing)

Nominal voltage

Typical BIL · rows tabulated for this class

Measured clearance

Fence has openings (chain-link / mesh) Internal fence inside the perimeter fence Clearance not measured yet

Fence clearance status

Actual

Required

Margin

How the check read it

Client-side port:the logic and table in this page are a TypeScript port of the harness function, checked against values exported from the Python tests. Not a live API call. Domain maturity, quoted from the research page: “Draft. No substation design engineer has reviewed it yet; AI-assisted review is a QA pass, not a sign-off. The audit trail records real bugs found and fixed, including a 500 kV case that would have wrongly passed.” The table was confirmed against the 2007 edition of the standard; the 2023 edition has not been compared.Real function this maps to:check_substation_fence_clearance.Not modeled: only fence clearance to live parts, not the other 20 checks. Also not modeled: the real Exception 1 condition (live parts below the line projected from the top of the fence), jurisdiction or utility overrides, and any geometry beyond the one measured distance. The plan view is a fixed illustrative drawing, not site data.See also:Fence clearance, auto sweep