What is the minimum size of grounds used for distribution?

• A. #1
• B. 4/0
• C. #2
• D. 2/0

Answer: (C)

Grounding conductors are sized so they can carry fault current back to the source long enough for the protective devices to trip without overheating or failing. The size is chosen based on the rating of the overcurrent device protecting the circuit, ensuring a low enough impedance path to clear a fault safely.

For distribution circuits, #2 copper is commonly the smallest practical size used for the equipment grounding conductor. It provides a sufficient path for typical fault currents while avoiding unnecessary material cost and stiffness that larger conductors would add. Using a conductor smaller than this could allow the fault current to heat the wire too much before the breaker trips, while many larger sizes aren’t required for standard distribution setups. So, in this context, #2 is the minimum grounding conductor size used for distribution.