On Monday, November 25, 2013 2:43:01 PM UTC-5, nestork wrote:
bud--;3155057 Wrote:



The earth does not complete the circuit. Wires complete the circuit.





Bud, until recently I would have agreed with you. But, whomever wrote

this web page obviously knows something about electric power generation

and distribution and seems to disagree:



http://tinyurl.com/y4syno6



Look at the bottom paragraph in the section entitled "The Power Plant:

Three Phase Power" where it says:





And what about this "ground," as mentioned above? The power company

essentially uses the earth as one of the wires in the power system. The

earth is a pretty good conductor and it is huge, so it makes a good

return path for electrons. (Car manufacturers do something similar; they

use the metal body of the car as one of the wires in the car's

electrical system and attach the negative pole of the battery to the

car's body.) "Ground" in the power distribution grid is literally "the

ground" that's all around you when you are walking outside. It is the

dirt, rocks, groundwater, etc., of the earth.





I don't think he could have said it any clearer.




And just before that, the author, said:

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

That sentence alone shows that he doesn't know what he's talking
about. A netural or ground wire are not the same thing. And even if they
were, if the earth were used as the return path, then why would you
need the 4th wire? The 4th wire carries the unbalanced current. The
current is flowing in the 3 phase wires and neutral, not the ground.