What is the minimum length of bare copper conductor in a ground ring?

• A. 20 ft
• B. 10 ft
• C. 30 ft
• D. 40 ft

Answer: (A)

A ground ring uses a bare copper conductor buried around the building to form a continuous loop that connects to the grounding electrode system. The length must be at least 20 feet to ensure the ring encircles the structure and provides an effective, low-impedance path for fault currents and potential equalization around the perimeter. If the ring is shorter, it may not form a complete loop around the building, reducing its effectiveness. So the minimum practical and code-compliant length is 20 feet. Longer lengths aren’t required by the basic rule, though they would still satisfy the requirement.