NEC Article 250 outlines the specific wires and jumpers needed for a safe system: Connects the ground rod to the grounding bus bar in the main panel. Sized according to NEC Table 250. 66, based on service-entrance conductor size. This guide covers the essential principles and procedures for grounding an electrical panel per the National Electrical Code (NEC) Article 250. While often confused, grounding and bonding serve two separate safety functions: Built for electricians, apprentices, and electrical engineers who want. An electrical ground bus bar is a conductive bar made from materials like copper or aluminum, and it serves as the central point for connecting multiple grounding conductors in an electrical system. Grounding is one of the most crucial safety measures in electrical installations, and the bus bar. California's 2025 electrical code sets clear grounding and bonding rules for service equipment, solar systems, pools, and more.