If the grounding electrode conductor connection for a PV DC system is a sole connection to a rod, pipe, or plate electrode, the largest grounding electrode conductor required is which size?

• A. 6 AWG copper
• B. 4 AWG copper
• C. 8 AWG copper
• D. 10 AWG copper

Answer: (A)

When sizing the grounding electrode conductor for a PV DC system that connects to a single earth electrode (rod, pipe, or plate), the code specifies a minimum size based on 250.66. For copper, the minimum GEC size in this case is 6 AWG. This provides a reliable, low-impedance path to earth for fault currents without being unnecessarily large. Therefore, the required size is 6 AWG copper; smaller gauges would be undersized, while a larger gauge (like 4 AWG) would also meet the requirement but isn’t required by the stated condition.