Which NEC article focuses on Grounding and bonding to establish a safe path to earth and equalize potential?

• A. Article 240: Overcurrent protection: sizing and protecting conductors and devices to prevent overheating.
• B. Article 250: Grounding and bonding to establish a safe path to earth and equalize potential.
• C. Article 300: General wiring methods and the installation of conductors, cables, raceways, and enclosures.
• D. Article 310: Conductors for general use: ampacity, insulation, and temperature ratings.

Answer: (B)

Grounding and bonding is about creating a safe reference to earth and making all noncurrent-carrying metal parts have the same potential so fault currents have a reliable path back to the source. The article that addresses this topic defines how a grounding electrode system is connected to the electrical system, what constitutes an equipment grounding conductor, and how bonding is to be done to ensure metal enclosures and parts are tied together. By establishing a low-impedance path to earth and by tying all exposed metallic parts together, this approach helps ensure that a fault current will trip the overcurrent protective device quickly and reduces shock hazards during normal operation and fault conditions. This is distinct from overcurrent protection, which is about sizing conductors and devices to prevent overheating; general wiring methods, which cover how conductors and enclosures are installed; and conductors for general use, which deals with ampacity, insulation, and temperature ratings.