This connection is established by the Main Bonding Jumper (MBJ), which connects the neutral bus bar to the panel enclosure and the ground bus bar. It establishes a reference point for the electrical system and is a vital safety. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical insights into proper grounding techniques, with a special focus on how selecting quality materials from a reliable building material supplier impacts your entire system's safety and longevity. According to NEC Article 250, both the neutral and ground wires must be connected only in the main panel or at the first service disconnect.