Q. When sizing an equipment grounding conductor for a solar photovoltaic system, which also has ground-fault protection for equipment, what is the minimum size equipment grounding conductor required for a circuit that is protected by a circuit breaker rated at 30A?
A) The ground-fault protection equipment is all that is required. An equipment grounding conductor is not required.
B) The minimum size of the equipment grounding conductor shall be based on 125% of the photovoltaic-originated short-circuit currents in that circuit.
C) A 10 AWG conductor, as noted in Table 250.122.
D) An 8 AWG conductor, as noted in Table 250.66.

Answer: C
Because ground-fault protection of equipment is provided, you must size the equipment grounding conductor based on Table 250.122. As noted in Table 250.122, a 10 AWG conductor is required for a circuit protected by a 30A overcurrent device.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.