What should be used when a tap is made from a common grounding electrode conductor?

When tapping into a common grounding electrode conductor, using a copper busbar is correct because it provides a reliable and effective means of distributing the grounding connection. A copper busbar serves as a solid point of connection where multiple grounding conductors can be attached, ensuring that the grounding system maintains its integrity and effectiveness.

Copper is chosen for its excellent conductivity and resistance to corrosion, which are critical properties for grounding applications. The busbar allows for multiple taps without compromising the grounding system’s performance, making it a practical choice in electrical installations.

Other methods such as using a grounding clamp, soldered joint, or insulated wire may not provide the same level of reliability or may complicate the grounding system. A grounding clamp can be effective as well, but a copper busbar ensures uniform distribution and connection stability. Soldered joints can introduce potential failure points, and insulated wire would not be appropriate since it should not be used for direct grounding connections.