New York State Master Electrician Practice Exam

The requirement for a green finish for a screw main bonding jumper stems from the National Electrical Code (NEC) and industry standards that specify the use of color coding to enhance safety and improve identification of electrical components. The color green is universally recognized for its association with ground conductors, which is crucial for ensuring that individuals working on or around electrical systems can easily identify which conductors are related to bonding and grounding.

By using a green finish, the screw main bonding jumper is clearly marked, helping electricians and inspectors quickly ascertain its purpose. This color coding helps prevent errors during installation and maintenance, thereby promoting safety in electrical systems.

In contrast, the other colors mentioned (blue, red, and yellow) do not have the same standard recognition for grounding and bonding applications, which is why they would not be suitable for this particular identification requirement.