What is the gauge size commonly used for ground wire?

The commonly used gauge size for ground wire is 12 gauge. This size is favored for its balance between conductivity and protection, providing an adequate amount of current-carrying capacity while also being robust enough to handle safety requirements. In electrical installations, grounding is crucial for safety as it helps to prevent electric shock and protects equipment from electrical faults. The 12-gauge wire is thick enough to carry the necessary fault current without overheating, which is vital in case of a short circuit situation.

While other sizes like 10, 14, and 16 gauge might be found in specific applications or less demanding environments, they do not provide the same level of reliability and safety for grounding in typical residential and commercial settings. Thus, the preference for 12 gauge wire as the standard for ground wiring reflects its suitability for the necessary electrical safety standards.