On Sun, 09 May 2004 18:45:24 GMT, zeno wrote:
Theoretically, if "neutrals" (eg. the center taps of the step down
transformer's secondary) were not grounded anywhere on the Earth, would the
Earth still act as the return path?

Hi Bill,

"Theoretically" if the neutral has no ground anywhere on the Earth,
then the Hot lead has no potential to anywhere on the Earth. This
theory (being perfect) must of necessity invoke no linkage nor leakage
too.

If you hold a metal cylinder flashlight, how much of the battery
potential is draining through your hand to ground? On OR off? Earth
and the battery still have this vast reservoir of electrons, does that
matter in this case?

My intuition says yes simply because of the mass of the Earth. If you have a
static charge, for example, it discharges to the ground (or any body of mass)
it comes in contact with.

The premise of the static charge presumes that the charge was applied
there by reference to another charge (electrons moved from one site to
another). This violates the premise of "not grounded to Earth" as
there must be a complete circuit to perform this act and Earth does,
and always had acted as the reference/reservoir.

Hence your example is mixing two conditions to one argument (the
violation of the original premise).

So if I had a static charge I can get that current to
flow to the Earth or any body of a lower potential. So the "return path" of the
Earth, in the strictest theoretical sense does not depend on the "neutrals"
being grounded

It never did, the "return path" of the hot lead is always the neutral
lead in whatever form suitable to the current demand. It is a
convention to ground the neutral lead so that the path resistance does
not present one standing at ground potential with a lethal voltage
drop. Earth, in whatever form, is a miserable conductor even if it
presents only one Ohm resistance. That same one Ohm to a 100A service
yields 100V potential at the outlet(s). Ground is ground, and this
guarantees "some" current will seek a path through you if you happen
to hold this blighted, neutral lead. If your path resistance to
ground (much less efficient) offers 10K Ohms (mostly confined to the
dermal layer of dead skin cells, roughly a tenth to a hundredth of
this resistance that beneath this 100µM barrier); then Ohms law will
guarantee a lethal current. But wait! There is an special added
bonus!

That same barrier supports a network of ducts for perspiration. Those
ducts, under the excitement of an AC current find muscles contracting
and relaxing at a 60HZ rate causing them to secrete fluid which in
turn lowers the dermal resistance. This is called a positive
coefficient wherein more current demands more current. Well, you are
already dead, this only serves to cook and baste you.

73's
Richard Clark, KB7QHC