Interesting responses. This is a great group.

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?

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. 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 is just the fact that the Earth is this large mass at a
lower potential. That the "neutrals" are grounded is an additional safety
factor. In the era of knob and tube wiring I cannot remember neutrals being
grounded the way they are today. There were just two wires going to the
outlets. Later it was determined that this was not always safe. This is my
simple understanding at the moment, but I am still digesting all the responses
here.


remember those funny little straps we attached under our cars supposedly to
eliminate those "zaps" from sliding over the car seats? hi hi

Bill K6TAJ

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

"Richard Clark" wrote in message
...
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,

...[snip...]
there must be a complete circuit...
the "return path" of the hot lead is always the neutral
lead...

In other words, if the center tap of the pole transformer is not
connectod to a ground rod, connecting one side of a bulb to ground (to
complete the circuit) can't result in any current (given no other "secret"
paths).

Simply think of the pole transformer as a DC battery. Connect a light bulb
between one terminal of the battery and a ground rod. With the other
terminal of the battery not connected to a groung rod there is no complete
circuit. Its just hanging there.
The pole transformer has the center tap grounded for other safety
considerations - not to conduct current.

Take that bulb out in the field (with ONE hot lead back home) and it
will light with a brightness roughly proportional to the length of its
ground rod...unless there are problems in your neighbor's electrical
systems, then all bets are off...or you accidently grab the wire...

Measure the voltage between yours and your neighbor's ground rods.
Should be interesting.

OT:
[snip] Ground is ground,
Reminds me...
I have an old (toung-in-cheek) saying (when it comes to RF):
""A grounds a ground the world around."" Not many get my light-hearted
sarcasm.
--
Steve N, K,9;d, c. i My email has no u's.