Furthermore this is from a Mike Holt Perspective(yeah it's not about service ground rods, but it's about ground rods, and ground rods are ground rods wether is a service or a light pole)
"Question: Mike I had an engineer tell me that there was a Code change in the 1999 NEC requiring metal poles for parking lot lighting with HID fixtures to be grounded to the earth. He said that a ground rod must be driven at each pole. If this is true I can't find it, please help me out because I have a job to set 17 in the next few days.
Thanks, Dush
Mike Holt’s Comment: The previous question continues to bug me that people insist that a ground rod be driven at metal poles that support lighting fixtures. From the mouth of one of my members "A lot of ‘black magic, shaman dancing, urban legends, wild-eyed guesses, and whatever someone taught you years ago’ are repeated as gospel."
Let me make a few statements to try to clarify this issue:
The National Electrical Code does NOT require a ground rod at metal poles.
A ground rod at a pole will NOT clear a line-to-ground fault for systems that operate at less than 600 volts.
A ground rod at a pole will NOT reduces the touch potential from the metal pole to the earth from a line-to-ground fault.
A ground rod is NOT required at a metal light fixture pole by the Lightning Protection Institute
http://www.lightning.org.
A ground rod is NOT required at a metal light fixture pole by the Lightning Protection Standard (NFPA 780)
http://www.nfpa.org.
A ground rod at the metal pole does NOT reduce damage to the fixtures, lamps, and the pole wiring, because the lightning traveled through the equipment on the way to the earth.
A ground rod at a metal pole does NOT protect the concrete foundation that supports a metal pole from lightning damage. If there were true, then electric utilities would never use concrete poles to support overhead wiring.
A ground rod at the metal pole does NOT protect the circuit wiring and equipment in the building from lightning damage (open back door). If you want to protect the circuit wiring in the building, then surge protection should be installed on the circuit conductors that go outside to the metal poles.
If driving a ground rod at a metal pole is such a good idea (some people are very passionate about this), then why are there no papers or standards recommending this practice? Don’t you think that if this was such a good ideas that someone would have proposed it and incorporated it into the NEC, IEEE standard, the Lightning Protection Code, or some other recommended practice?
From: Maddox, Robert
I believe that the grounding of lighting poles is a holdover from old Power Company standards. Wood poles were first used to carry power wires & then higher voltage lines. A lightning protection wire was strung along the tops of the poles to protect the power cables below. That practice continues today. At each pole a ground wire was brought down to a ground rod. Over the years lights were added to these poles, typically wooden poles. As electrical street lighting became more common some poles were used only for lighting, but the practice continued. Also the Power Company ran street lights at 240V-LL & 480V-LL with no neutral or ground, thus as metal poles came into vogue the ground rod & wire were used to ground the metal pole in case the lines came into contact with the metal pole. Once the Power Company started, everyone copied the practice, many times without knowing why. It just seemed like a good idea!
Mike’s Comment:
This is exactly what I believe."
Notice the reason ground rods came into play.
