Motor FLA Lookup (NEC 430)
Local motor full-load amp rows with conductor and protection sizing context, source warnings, and AHJ review boundaries
Look up motor full-load amps by horsepower, voltage, and phase, then see preliminary overload, conductor ampacity, and protection percentage estimates. The FLA rows follow NEC Tables 430.248 and 430.250, and the 75°C ampacity rows follow Table 310.16 - still verify them against the adopted NEC edition, local amendments, equipment listing, manufacturer instructions, and AHJ requirements before design use. It does not create a permit drawing, conductor schedule, OCPD selection, coordination study, inspection approval, or safe-work authorization.
Calculate ideal voltage, current, and power before electrical review
Ohm's Law / Power Wheel Calculator →Estimate locked-rotor current from nameplate code letters
Motor Starting Current / Code Letter Calculator →Review cable tray fill assumptions for motor feeder cables
Cable Tray Fill Calculator (NEC 392) →How It Works
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Select Motor Parameters
Choose horsepower, nominal voltage, and single-phase or three-phase mode. The app returns the table FLA value per NEC Tables 430.248/430.250; verify against the adopted code edition before design use.
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Review Full-Load Amperage
Use the displayed FLA as a planning row to compare against the selected source material, motor nameplate, and project requirements.
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Review Protection and Wire Estimates
Review the simple percentage and 75°C ampacity estimates, then verify terminal temperature, derating, standard device size, coordination, equipment listing, manufacturer instructions, and AHJ rules before design use.
Assumptions
- Local FLA rows are selected by horsepower, nominal voltage, and phase.
- Conductor estimates use a 75°C ampacity row and do not apply terminal, ambient, fill, or adjustment rules.
- Protection values are unrounded percentage products and do not select a standard device size.
- Selected motor data, equipment listing, adopted code, AHJ, and qualified electrical review remain required.
Limitations
- Local rows are not certified against the adopted NEC edition or local amendments.
- Does not apply terminal-temperature, ambient, conductor-count, raceway-fill, voltage-drop, or manufacturer-instruction checks.
- Does not choose overload relay, fuse, breaker, controller, disconnect, conductor, raceway, grounding, label, or feeder design.
- Does not perform SCCR/AIC, selective coordination, arc-flash, shock, LOTO, inspection, or safe-energization review.
References
- NFPA 70 National Electrical Code source pointer for Article 430 and Table 310.16 context
- NEMA MG 1 source pointer for motor-type and manufacturer-data context
- NFPA 70E and OSHA electrical-safety source pointers for safe-work boundaries
- NIST SP 811 unit context
Frequently Asked Questions
Learn More
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Complete motor circuit design from FLA lookup through wire sizing, overload selection, and branch circuit protection per NEC 430. Worked 25 HP example.
Cable Tray Fill and Installation per NEC 392
Cable tray types, fill rules, single-conductor vs multiconductor differences, ampacity derating, and separation requirements per NEC Article 392.
Motor Starting Methods and Code Letter Interpretation
What motor code letters mean, why starting current matters, and what source data to review before selecting DOL, wye-delta, soft starters, or VFDs.
Fault Current Analysis for Electrical Distribution
Why fault current matters, how transformer impedance affects AFC, and why equipment ratings and arc flash need formal study data.
Torque, Horsepower, and Power Transmission Fundamentals
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