What does the main bonding jumper connect?

The main bonding jumper is crucial in ensuring the proper functioning of the electrical system by establishing a reliable connection between the grounded circuit conductor (neutral) and the equipment grounding conductor. This connection plays a vital role in grounding systems by providing a low-resistance path to ground for fault current, which helps protect both people and equipment.

When a fault occurs, the main bonding jumper ensures that the grounding system can efficiently clear the fault by allowing the fault current to return to the source, helping activate protective devices such as circuit breakers or fuses. This also helps maintain the neutral point of the transformer or service properly grounded, which is essential for the safety and reliability of the electrical system.

The other options mention connections that do not accurately represent the function of the main bonding jumper. Understanding this specific connection is key for maintaining safety in electrical installations, as improper bonding can lead to dangerous conditions.