Motor Branch-Circuit from Nameplate
Compute full-load current from HP / V / eta / PF; flag the design value as the larger of computed vs nameplate; 125% branch-conductor + overload sizing.
Formula and source
Single-phase: I = HP * 746 / (V * eta * PF). Three-phase: I = HP * 746 / (sqrt(3) * V * eta * PF). Branch-circuit conductor at 125% per NEC §430.22; overload max at 115% or 125% per NEC §430.32 (SF >= 1.15 -> 125%).
NEC 2023 (NFPA 70). §430.6(A)(1) (reference-FLA tables), §430.22 (branch conductor 125% rule), §430.32 (overload sizing).
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