Questions Like This Concern Me
Mike, Would it be wise to do away with ground rods at the metal poles and just run a equipment grounding conductor with the other conductors and what about the thousands of metal poles installed with just a ground rod for grounding without an equipment grounding conductor?
Mike Holts Response: Again, my concern is not to prevent a ground rod at a metal pole (but why waste the customers money) but to ensure that the metal pole is properly bonded to a low impedance path (equipment grounding conductor) in accordance with the NEC 250.4(A)(5). This is required so that we stop killing people by removing dangerous touch/step voltage!
The only ANSI (American National Standard Association) standard I know of that covers outside light fixtures (luminaires) is published by National Electrical Contractors Association which was jointly developed with the Illumination Engineers Society of North America [NECA/IESNA 501-2000 Recommended Practice for Installing Exterior Lighting Systems]. This project is managed by Brooke Stauffer, the NECA Executive Director of Standards and Safety. To order this standard at $25, call 1-301-215-4504 or visit www.neca-neis.org.
Its interesting to note there is no reference that a ground rod be installed at outside metal poles supporting luminaires.
I have been very busy lately so I do not have time to organize all of the reasons people have commented on why they think a ground rod at a light pole is useful (I did individually). As soon as I can I will put together an item-by-item discussion and send this out to you, but it might be a month or so.
Mike Holts Comment: If you have any comments or feedback, please let me know, Mike@MikeHolt.com
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