High voltage power lines and metal parking lot poles

[Lee Graves]

I received the following response from an engineer and was curious if anyone had any further insite or experience on this situation. We were asked to VE a project and my first suggestion was to convert to a direct burrial concrete pole. Here is his response:

"The use of metal poles on this project is due to the close proximity of the high voltage overhead utility transmission lines. By using the metal poles (which require the concrete foundations) we can dissipate the induced voltage from the transmission lines. Using concrete or fiberglass direct buried poles could cause a static charge buildup on the poles. The metal pole characteristics also make it is less likely that the high voltage would be induced onto the lighting wiring in the pole causing problems with the lights"

 

[drbond24]

The statement is plausible.

'Dissipating the induced voltage' means nothing more than 'connecting it to ground'. I wouldn't think it would be difficult to ground the metal reinforcing structure within a concrete pole to achieve the same end.

 

[kingpb]

Does not make sense. A metal pole around transmission lines would be the last choice, as wood or concretre would be better due to less chance of surface static charge build-up. Grounding of all three types is necessary. Wood ground conductor would have to be on the outside, but a ground wire is provided internal in the construction of the concrete pole. Metal (aluminum) poles are lighter weight, but concrete is cheaper, and wood is cheaper yet.

 

[boater bill]

The engineer sounds like a theory guy, not practical.
Ask him to do a short circuit calculation of the induced voltage of the poles from the overhead transmission lines.
If he won't, then substitute the concrete poles. Which BTW have steel rebar running the entire length that will be grounded after you install them.

Good Luck.

 

[buck33k]

This reminds me of a photo Tom Baker posted some time ago of a Home Depot parking lot in close proximity to high voltage lines. A grid of cables was suspended from poles above the parking lot. The photo came from the forum archives.

http://i42.photobucket.com/albums/e334/TomBakerPhotos/OHPandParkingLot.jpg

 

[rr]

1) Are these metal poles within the POCO's transmission line easement?
2) What is the opinion of the POCO if this is the case?
3) I have seen Concrete and Fiberglass poles used for smaller transmission lines.

 

[tshea]

I'll post a picture tomorrow of a unique way of gaining clearance from the utility's lines.:roll:

 

[tshea]