What connects the equipment grounding conductors to the grounded (neutral) conductors?

The main bonding jumper serves a crucial role in electrical systems by creating a direct connection between the equipment grounding conductors and the grounded (neutral) conductors. This connection is vital for establishing a reference point for voltage and ensuring proper fault currents can return safely to the ground, mitigating the risks of electrical shock and enhancing system reliability.

In addition, the main bonding jumper is specifically designed to bond the electrical system's grounding and neutral conductors at the service equipment, which is typically where the electric utility's system connects with the building's electrical system. It ensures that the neutral conductor is effectively grounded, providing a safe path for fault currents to return to the source.

The grounding electrode conductor, on the other hand, connects the grounding system to one or more grounding electrodes, such as ground rods or plates, and is primarily responsible for providing a path to ground for transient voltages and lightning. This conductor does not connect the grounded conductor to the equipment grounding conductor.

Thus, while both components are essential for a safe and effective grounding system, it is the main bonding jumper that directly connects the equipment grounding conductors to the grounded conductors, making it the appropriate answer to the question.