Just found an answer to big question in the Theory forum.
There is a good white paper from APC about the neutral.
It's not quite a loop-- but the electrons travel back and forth through hot conductor, the actual load itself, and the 'neutral' whether it be L-N or L-L.
What kept screwing me up was thinking that there had to be some potential difference eg. 120v to zero at the ground, for electrons to move. I have thoroughly purged that from my head. Where did that come from? Whoa!
Bob's poetic statement about neutral not needing to be grounded now makes sense. One point the APC article doesn't make is with the alternating +/- on the 'neutral' in the case of L-N loads-- where does the current on the noodle terminate. At the panel it goes to building ground. But couldn't it also go through the meter up to the transformer?
By the way, if you feel like I'm not making progress here, please tell me to go to "H-E-double-two-sticks". I'll understand. :-)
