On 11/25/13 6:03 PM, wrote:

So, now one reference to a light-weight, novice level tutorial on power
distribution is the authoritative source? Why don't you look at
all the other sources that say he's wrong? As I already pointed out,
you can start with looking at what the author of that reference
himself said immediately preceeding:

" "There are four wires coming out of every power plant: the three phases plus a neutral or ground common to all three."


If the power company is using the earth, why would there be a 4th wire?
And clearly the author doesn't understand the difference between a
neutral, which is a current carrying conductor, and a ground. Neither did
you until we explained it to you with regard to split-phase service
to a house. But you don't have a clue to how it works on the primary
side. I've told you at least 6 times now, that with a balanced load,
which is what the world looks like to a power plant, there is no
need for any return circuit path other than the 3 phase wires coming out.
Good grief.


There is or was something called SWER, single wire earth return.
A bit he http://preview.tinyurl.com/mccxaq2
The source calls itself Transmission and Distribution World.
I don't remember seeing a single wire anywhere in my travels. It's
admittedly not high on my list of things to observe while traveling.
And I haven't traveled outside of the continental U.S.

SWER evidently isn't efficient according to this bit.

Quote:

Conductor characteristics. Line length varies according to customer
distribution, with an average SWER feeder length of 60 km (37 miles),
although a 400-km (250-mile) SWER system is in operation in one state.
Therefore, circuit losses because of the high resistance of the SWER
conductors, reactive losses in the isolating transformers and resistive
losses in the earthing systems can be up to 100% greater compared to
those of a single-phase (two-wire) system serving similar loads.

End quote.