NEC 430 Motors and Controllers 2 — Flashcards

NEC Article 430 covers requirements for motor circuits, controllers, and protection, primarily focusing on sizing conductors and overcurrent devices (OCPD) to handle high inrush currents, typically requiring branch circuit conductors sized at 125% of the motor full-load current (FLC). Key requirements include separate short-circuit/ground-fault protection (Part IV) and overload protection (Part III). 

Key Components of NEC Article 430:
Motor Conductor Sizing (430.22): Conductors supplying a single motor must have an ampacity not less than 125% of the motor’s full-load current (FLC) rating.
Branch-Circuit Short-Circuit and Ground-Fault Protection (430.52): Protects against, faults; devices must handle startup inrush, typically sized using Table 430.52 (e.g., 175%–250% of FLC for fuses).
Overload Protection (430.32): Protects motor from overheating. Generally, motors with a marked service factor (SF) of 1.15 or higher must have overload protection sized at 125% of the motor nameplate full-load ampere (FLA) rating.
Motor Controller (430.83): Must be rated to make and break the motor's starting current and be capable of interrupting stalled rotor current.
Disconnecting Means (430.102): A disconnecting means must be located in sight from the motor controller location and the motor itself.
Motor Control Centers (MCCs) (430.8): Covered under Part VIII, these are assemblies of motor controllers and protection devices. 

Key Considerations:
FLC vs. FLA: For conductor and branch-circuit protection sizing, use the FLC values from NEC Tables 430.247–430.250, not the motor nameplate FLA, which is only used for overload protection.
Figure 430.1: A crucial reference diagram within the article that outlines the necessary components of a motor circuit. 

Note: This information is based on general NEC standards and may not reflect the most recent code cycle or local amendments. Always refer to the official NFPA 70® National Electrical Code® for compliance.