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Monday, October 25, 2021
Question:
Hello,
I am a Dr and not an engineer but reading the NEC guides for installing a ground mount solar array, I would think it is mandatory to place an earth ground at the ground mount but your NEC code says it is optional? If struck by lightening without an earth ground, I could see the strike passing directly into the next earth ground in a residence.
Dr. Smith MPH
A
Answer:
Hello Dr. Smith and thanks for the question. Section 690.47(B) of the 2020 NEC addresses the concerns in your question, relative to the requirement. This section indicates that grounding electrodes shall be permitted to be installed in accordance with 250.52 and 250.54. The grounding electrodes shall be permitted to be connected directly to the PV module frame(s) or structure. The grounding electrode conductor shall be sized according to 250.66. The structure of a ground-mounted PV array shall be permitted to be considered a grounding electrode if it meets the requirements of 250.52. PV arrays mounted to buildings shall be permitted to use the metal structural frame of a building if the requirements of 250.52(A)(2) are met. That said, the NEC process always welcomes participation so substantiated revisions can be incorporated. Visit www.nfpa.org under Codes and Standards for more information about participating in the NEC development process.