Motor FLA NEC 430 Calculator

NEC motor full-load amps calculator for electricians, apprentices, and electrical engineers. Look up motor FLA from NEC Tables 430.248 and 430.250, then get conductor sizing, overload protection, short-circuit protection device (SCPD), and disconnect ratings all per NEC Article 430. This electrical motor circuit calculator works 100% offline on the job site.

Whether you're sizing a motor branch circuit for a 10 HP three-phase motor, selecting the correct breaker for a 5 HP single-phase motor, or verifying overload protection settings, this motor FLA calculator gives you accurate NEC-compliant results in seconds. Use it as your motor circuit reference from full-load current lookup to complete branch circuit sizing.

MOTOR FLA CALCULATOR FEATURES:
• Full-load amps lookup from NEC Table 430.248 (single-phase) and 430.250 (three-phase, induction and synchronous unity-PF sections)
• Single-phase motors: 1/6 HP through 10 HP
• Three-phase motors: 1/2 HP through 500 HP
• 6 voltage presets: 115V, 200V, 208V, 230V, 460V, 575V
• Conductor sizing per NEC 430.22 (125% of FLC)
• Overload protection per NEC 430.32 (service factor adjustment)
• SCPD sizing per NEC Table 430.52 with 4 motor types and 3 device types
• Disconnect rating per NEC 430.110
• Copper and aluminum conductor support
• Wire size recommendation from NEC Table 310.16 (75°C column)
• Standard breaker and fuse size selection per NEC 240.6, including fuse-only ratings 1, 3, 6, 10, 601

NEC ARTICLE 430 REFERENCES:
• NEC Table 430.248 - Single-phase motor full-load current
• NEC Table 430.250 - Three-phase motor full-load current
• NEC Table 430.52 - SCPD maximum rating percentages
• NEC 430.22 - Motor branch circuit conductor sizing
• NEC 430.32 - Overload protection sizing
• NEC 430.110 - Disconnect rating requirements
• NEC Table 310.16 - Conductor ampacity for wire sizing

SCPD SIZING (NEC TABLE 430.52):
• Non-time-delay fuse sizing
• Dual element (time-delay) fuse sizing
• Inverse time circuit breaker sizing
• 4 motor design types: squirrel cage, Design B energy-efficient, wound rotor, synchronous

PRO FEATURES (one-time purchase):
• No ads - clean interface for professionals
• Save motor calculation history
• Export calculations as PDF reports for permits and records
• Dark theme support

HOW THE MOTOR FLA CALCULATOR WORKS:
1. Select motor type (single-phase or three-phase)
2. Choose horsepower rating
3. Select voltage
4. Set motor design type and SCPD type
5. Choose conductor material (copper or aluminum)
6. Toggle service factor setting
7. Get complete motor branch circuit sizing instantly

The motor FLA calculator automatically provides:
• Full-load amps from official NEC tables
• Minimum conductor size with ampacity reference
• Maximum overload protection rating
• SCPD (breaker/fuse) size rounded to standard sizes
• Minimum disconnect ampere rating

BUILT FOR ELECTRICIANS ON THE JOB SITE:
This motor FLA calculator is designed by electricians, for electricians. Select your motor parameters, get the complete branch circuit sizing instantly - no complicated menus or unnecessary features. One-hand operation, instant results.

PERFECT FOR:
• Licensed electricians sizing motor circuits daily
• Electrical apprentices studying for journeyman exams
• Electrical engineers and designers
• Electrical contractors bidding jobs
• NEC code exam preparation
• Journeyman and master electrician exam study

OFFLINE & PRIVACY:
• Works 100% offline - no internet needed on the job site
• No account required
• No data collection - your motor calculations stay on your device

Simplify your motor circuit sizing on the job site.

Recent changes:
Added a link to TradeTools — the one-app version of this calculator and 61 more, for HVAC, electrical, plumbing, fire protection, solar and carpentry. Nothing else changed.