Conduit Fill

Percent fill by conduit type and conductor count.

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Formula and source

Conductor cross-sectional area sum / interior conduit area, compared to NEC Chapter 9 Table 1 fill limits (53% / 31% / 40% for 1, 2, ≥ 3 conductors).

NEC 2023 (NFPA 70). Chapter 9 Tables 1, 4, 5.

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