What is the minimum size of a grounding electrode conductor for a 200-amp service?

The minimum size of a grounding electrode conductor for a 200-amp service is established by the National Electrical Code (NEC), which specifies requirements based on the size of the service entrance conductors. For a 200-amp service, the code dictates that the grounding electrode conductor should be at least #4 AWG copper or #2 AWG aluminum.

This requirement ensures adequate grounding, which is crucial for safety. A properly sized grounding electrode conductor provides the necessary path for fault currents to safely dissipate into the ground, reducing the risk of electrical shock and fire hazards.

Using #4 AWG copper or #2 AWG aluminum achieves the objective of creating a reliable grounding system, as these sizes have been determined to provide sufficient conductivity and strength for the intended application in a 200-amp service scenario. Thus, option C is supported by regulatory standards and the fundamental principles of electrical safety.