What is the purpose of a main bonding jumper?

The purpose of a main bonding jumper is to connect grounding and neutral conductors. This connection is crucial for ensuring the safety and proper functioning of an electrical system. By bonding these conductors together at the main service panel, it provides a low-resistance path for fault currents to return to the source, which helps facilitate the operation of overcurrent protection devices, such as circuit breakers. This connection also helps to maintain a consistent reference point for voltage levels in an electrical system, reducing the risk of shock hazards and electrical fires.

It's important to recognize that enhancing electrical flow, isolating electrical circuits, or increasing circuit capacity are not the primary functions of the main bonding jumper. Enhancing electrical flow pertains to improving conductivity and reducing resistance, which is a different concept. Isolating circuits involves separating them to prevent interference or interruptions, while increasing circuit capacity relates to allowing more electrical load to flow, which is managed through proper sizing of conductors, circuit breakers, and load management, not through bonding.