Research — Auto Demo · Illustrative (draft, unvalidated)
Conduit fill demo — auto
No controls here. 350 kcmil aluminum EPR 15 kV cables are added one at a time to a 4 in PVC Schedule 40 conduit. The fill ring climbs toward the limit, the verdict flips when a cable pushes it over, and the walkthrough steps up to the next trade size and keeps adding. Built for walking a client through why cable count and conduit size trade off.
Cables added
First cablefirst cable over the limitLast step
Reading —
Cross-section · conduit bore with cables, true scale
NEC Chapter 9 fill status
Fill
Limit
Margin to limit
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. Every step is computed by the same TypeScript port as the interactive page, which is compared with cases exported from the real Python. The order of steps is staged: add a cable, and step up one size at the first failure. Maturity, quoted from the domain page: starting inventory, not a completed review. The calculation services were inherited as live code that predates the review process and have had no expert sign-off; ingestion of the NEC standards text has not started.Real function this maps to:
calculate_conduit_fill.Not modeled: anything beyond conduit fill. No pulling tension, sidewall pressure, ampacity or derating, vault sizing, or duct-bank thermal behavior, and no check that a larger conduit is available or affordable on the route. Cable positions in the drawing are an illustrative packing.See also:Conduit fill, interactive