Roof Fan Grounding

[richanton]

I just walked our building roof and noticed tat some fans have external grounds and some don't. Just wondering what common practice is. NEC doesn't address it except in 430.12 where it implies that it may sometimes be required. I would think it's safer just to do it as I have a ground loop around the perimeter of the building.

 

[BWerm]

Are these grounds possibly for lightning protection?

 

[richanton]

Yes, I found out they were added for lightning protection due to the presence of pyrophoric gas storage in the vicinity.