What identification must be visible on a main bonding jumper that uses a screw?

The main bonding jumper is a critical component in ensuring that the grounding system of an electrical installation operates safely and effectively. The identification for the main bonding jumper is specifically designated to indicate its purpose, which is to connect the grounding system to the service equipment or the ground.

A green finish is required to be visible on a main bonding jumper that uses a screw. This color coding is aligned with the National Electrical Code (NEC) requirements, which specify that green is universally recognized for grounding conductors, including bonding jumpers. The green finish helps electricians and inspectors quickly identify the bonding jumper as related to grounding, ensuring compliance with safety regulations and codes.

In contrast, other colors such as red, yellow, or blue may represent different functions within an electrical system, such as phases, feed conductors, or circuit identification, and are not suitable for identifying grounding components. The use of a consistent color code helps maintain safety and clarity within electrical installations.