What defines a bonding jumper on the supply-side of a service?

A bonding jumper on the supply side of a service is primarily defined as a conductor installed within a service enclosure that ensures electrical conductivity. This conductor is essential for maintaining a low-resistance path between different conductive parts within an electrical system. The main function of the bonding jumper is to establish an effective ground reference, which helps to prevent any potential differences between metal parts that could lead to a dangerous shock or fire hazard.

In the context of electrical installations, especially on the supply side, the bonding jumper plays a crucial role in ensuring that all metal parts of the electrical service are properly interconnected and at the same electrical potential. This is vital for system reliability, safety during fault conditions, and overall system performance.

The other choices do not accurately describe the function or definition of a bonding jumper in this context. For example, while a connection between equipment and the main circuit breaker is important, it doesn't encompass the specific role of a bonding jumper. Similarly, although an additional grounding point can enhance safety, it doesn't reflect the specific function of a bonding jumper as integrated within a service enclosure. Lastly, a device to monitor electrical load is unrelated to the concept of bonding, which deals specifically with electrical continuity and safety, not load measurement.