NEC 430: Motors, Motor Circuits, and Controllers
What This Article Covers
NEC Article 430 covers motors, motor circuits, controllers, and motor disconnects. Motor circuit sizing uses different rules than general branch circuits because of the high starting current motors draw.
Key Requirements
- Motor branch-circuit conductors sized at 125% of motor full-load current (430.22)
- Motor branch-circuit short-circuit and ground-fault protection sized per Table 430.52
- Motor overload protection sized at 115% to 125% of motor nameplate full-load current
- Motor disconnect required within sight of the motor and controller
- Use FLA from Table 430.250 (motors), not nameplate, for conductor sizing
Common Field Applications
- Sizing wire and breaker for a 5 HP 230V single-phase motor
- Selecting a motor starter for a three-phase 480V motor
- Installing a horsepower-rated disconnect at the motor
Common Mistakes & Inspection Failures
- Sizing motor conductors at 100% instead of 125%
- Using a standard 20A breaker when the motor needs higher SCPD
- Missing the within-sight disconnect
Related NEC Articles
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What does NEC 430 cover?
NEC Article 430 covers motors, motor circuits, controllers, and motor disconnects. Motor circuit sizing uses different rules than general branch circuits because of the high starting current motors draw.
What are the key requirements of NEC 430?
Key requirements include: Motor branch-circuit conductors sized at 125% of motor full-load current (430.22); Motor branch-circuit short-circuit and ground-fault protection sized per Table 430.52; Motor overload protection sized at 115% to 125% of motor nameplate full-load current. See the full requirements list on this page.
What are common mistakes with NEC 430?
Sizing motor conductors at 100% instead of 125% Using a standard 20A breaker when the motor needs higher SCPD Missing the within-sight disconnect
Related Resources
Michael B.
IBEW Local 134 Journeyman Electrician · Licensed Electrical Contractor
Michael is a licensed electrical contractor and IBEW Local 134 journeyman with years of field experience. He built Sparky AI after ChatGPT gave him wrong NEC code information on a job — costing him $800 in callbacks. Every answer in Sparky AI is verified against the actual NEC.