Grouped Motor Circuit Sizing Calculator — Multiple Motors on One Circuit

NEC 430.24 feeder ampacity and NEC 430.53(C) group OCPD for two or more motors sharing a feeder or branch.

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What This Calculator Sizes

NEC 430.24 feeder conductors: sum of all motor table FLAs + 25% of the highest-rated motor FLA. NEC 430.53(C) group branch OCPD: Table 430.52 allowance for the largest motor plus the FLA of every other motor on the circuit — device rating must not exceed that ceiling. Each motor still needs its own overload (430.32).

Full walkthrough: Grouped Motor Circuit Sizing Guide. Single-motor chart: Motor Circuit Sizing Chart.

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