Grounding Conductors Replace By Steel Poles 1

[nonsinusoidal]

It is my understanding that Steel Poles can be utilized as "Grounding Electrodes" as per NESC 094. However, it is not clear to me if a steel pole can be utilized as the Grounding Conductor for an electric distribution overhead system. Please advice.........

 

[jghrist]

How could a steel pole replace a conductor that goes from pole to pole?

 

[waross]

Can you describe your situation in a little more detail please?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[nonsinusoidal]

We are looking into the possibility of utilizing the electric distribution steel poles' structure as the grounding conductor for surge arrestors or any other equipment installed on the steel poles. Currently, a down ground conductor is attached to the wooded poles (currently we only purchase wooden poles) and then connected to a grounding electrode. However, we are in the process of determining if a steel pole itself can be utilized as the grounding conductor and the grounding electrode. Thank you

 

[cranky108]

Actually I have heard of using steel poles in place of ground rods. And it can work, however, an evaluation of the surface area with the ground should be looked at.

I would not use it in utility applications, because there may be corrosion factor that will shorten the life.

 

[jghrist]

I assume you are talking about direct embedment instead of concrete foundations. If the steel pole has a coating below the groundline, then it will not make a good grounding electrode. Sometimes a coating is used only near the groundline and the pole is uncoated below 3 feet. If this is the case, then the they are adequate if they meet the requirements of NESC Rule 94.B.7 for directly embedded metal poles.

My opinion is that you can use the pole as a grounding conductor (sorry for my first post - I was thinking grounded neutral). NESC Rule 93.A says that the metal frame of a structure may serve as a part of a grounding conductor. The pole is at least as good as a separate #6 copper wire for carrying fault current and would be superior to a separate wire for lightning surge current where big diameters mean low inductance. Even if you can't use the pole as an electrode because of coatings, you could use the pole as a conductor and have a ground pad at the base to connect to a ground rod.

If you use the pole as the only grounding electrode, it would seem rather silly to run a #6 copper wire from the top of the pole to a ground pad at the bottom.