What is the minimum size of bare copper conductor required for a ground ring encircling a building?

The minimum size of a bare copper conductor required for a ground ring encircling a building is 2 AWG. This specification is outlined in the National Electrical Code (NEC), which provides guidelines for safe electrical installations, including grounding methods.

A ground ring is utilized to provide a continuous conductive path for ground fault currents and to help stabilize the voltage to ground during electrical disturbances. The larger conductor size ensures that the ground ring can effectively handle potential fault currents without overheating, providing necessary protection for the electrical system and enhancing safety.

Using a conductor size of 2 AWG or larger makes it capable of handling the capacities determined by NEC requirements, ensuring reliability and performance in grounding applications. It also aids in minimizing resistance and increasing the overall effectiveness of the grounding system, which is particularly important in areas with high soil resistivity or in installations with significant grounding needs.

In contrast, the other sizes (10 AWG, 6 AWG, and 4 AWG) do not meet the minimum requirements set forth by the NEC for this application, which is why they are not considered acceptable in this context.