Single high voltage line

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danickstr

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Down by the south end of lake Washington here in Seattle there is a single green high voltage wire running atop the poco poles, and I did not know why there would be just one line. But I figured someone here would know.
 
There is a rarely used utility distribution system call Single Wire Earth Return in which earth is the intentional return path for normal currents.
 
If your refering to a SWER system single wire earth return. This is an excerpt from an article concerning its use in the US.

Many national electrical regulations (notably the U.S.) require a metallic return line from the load to the generator. In these jurisdictions, each SWER line must be approved by exception.
 
jim dungar said:
There is a rarely used utility distribution system call Single Wire Earth Return in which earth is the intentional return path for normal currents.
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I see this wire all over the place on Oahu and also wondered about it myself. Now that I find out that it is an intentional earth return I am really wondering. :-?
 
I googled Single wire earth return, and got a big pile of info. Very common in Australia. Saves money for the poco and is considered safe. I bet those that consider it safe have financial ties to the power providers. I had heard talk of this type of transmission way back but considered it and dismissed it as a possible myth. Not so....... No wonder Nellie the cow is mad. :cool:
 
It really does depend upon what you are identifying as a 'single' wire.

A single wire up high, over the regular 3 phase primary, is what Luke has called a 'static' line...I don't know its proper name, but when I see them I can often see bonding wires going to grounding electrodes.

You might also have a single high voltage primary, where the 'return' is the 'multi-earth-neutral' conductor sitting lower down on the poles with the low voltage wiring. The MEN is often both a conductor and a physical support for the low voltage wiring.

You could have real 'single wire Earth return' if there is only a single HV wire on the pole, and nothing else.

Finally, are you sure that this is an electrical wire; is it sitting on insulators? Maybe it is part of some CIA communications antenna :) or possibly you are looking at an Eruv http://en.wikipedia.org/wiki/Eruv#Eruv_for_carrying

-Jon
 
It is on a stack of about 4 bushing type insulators. The standard black and grey HV insulator. Thanks BTW for all the responses. If I see a Poco rtruck in the area I will ask them about it, but I would wager it is lightning protection since the area is a bit flat.
 
static wire

static wire

I believe it is called a counterpoise wire and there is usually one also running underground between poles. And connected from top to bottom.
 
danickstr said:
Down by the south end of lake Washington here in Seattle there is a single green high voltage wire running atop the poco poles, and I did not know why there would be just one line. But I figured someone here would know.
Click to expand...
We used to call them "skeleton" services ... and I have seen them in Australia as someone else noted.
 
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