Motor Circuit Calculator

Motors pull 5 to 7 times their normal current when they first start up, so you cannot size a motor circuit the same way as a regular circuit. NEC Article 430 has its own rules. This tool looks up the motor's full-load amps from the NEC tables, then calculates the minimum wire size and the maximum allowed breaker size.

Tip: Always use the NEC table FLA value, not the motor nameplate FLA, for branch circuit sizing. The nameplate value is used for overload protection only.

Motor Circuit Results

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FLA (A)
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Min Conductor
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Max OCP (A)
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Overload (A)
RequirementValueNEC Ref