When Grounding Bushings Are Required

According to NEC 250.92, grounding bushings are required for: Service-entrance conductors routed underground to a meter or other enclosure (except a meter socket) located outside or attached to a building. Service-entrance conductors routed underground to one or more buildings from a common service. Service-entrance conductors routed underground to a building or structure from a detached structure.

How Grounding Bushings Are Used

Grounding bushings are installed at the point where the underground service-entrance conductors emerge from the ground. They provide a means to connect the metal raceway or enclosure to the grounding electrode system.

Why Grounding Bushings Are Important

Grounding bushings help ensure that the service-entrance conductors are properly grounded. This is crucial for safety, as it helps prevent electrical shock and fire hazards.

Exceptions to the Requirement

There are a few exceptions to the requirement for grounding bushings: Where the service-entrance conductors are routed through a nonmetallic raceway. Where the service-entrance conductors are installed in a nonmetallic underground enclosure. Where the service-entrance conductors are routed directly to service equipment located indoors without passing through any enclosures.

Variations in Requirements

It's important to note that local electrical codes and utility companies may have their own specific requirements for grounding bushings. Always check with the local authority and the serving utility company for specific guidance.

Inspector Discretion

While the NEC provides clear requirements for grounding bushings, inspectors may have some discretion in enforcing these requirements. It's always advisable to discuss any concerns with the inspector to ensure that the installation meets both the code and the inspector's expectations. Flag for review