Thanks Chris. Haywired is right! I'll just tap into the lighting circuit
to get power now, then I'll run more wire/conduit in the spring.

Thanks for your help.

MT

"Chris Lewis" wrote in message
...
According to :
Hey gang,

I have two circuits serving the "south 40"

"A" is a security lighting circuit currently switched from three
locations
with a 3-way switch at the final common work box. Power is GFCI
protected
at the panel

"B" is an unswitched dedicated 20A circuit with a GFCI outlet at the
final
common work box.

I decided after the fact (after conduit was covered) that I needed to
have
GFCI protected unswitched power at the light pole A. Since I had
already
run 12/3 WG to the light pole, and had an "extra" unused red wire, I
thought
that I could get a GFCI protected hot lead by connecting my "extra" red
wire
to the load side of my B circuit GFCI, then wired the common and ground
back
through the lighting circuit A.

I did it but as soon as I apply a load I throw the breaker or the GFCI (I
can't remember which)

Is there a way to rewire to make this work without more wire/conduit?

No.

GFCI's work by comparing the current on the hot and neutral wire, and
tripping if the current differs by more than about 3ma.

You're pairing the neutral on "A" with the downstream GFCI'd hot from "B"
to produce your outlet on pole "A". As soon as you pull 3ma or more from
that outlet, _both_ GFCI's will see the exact same imbalance between their
respective neutrals and hots. It's a matter of luck as to which one will
trip first - might even both trip.

Secondly, since these two circuits share the same neutral, it's a no-no.

If the circuits are off the same main leg of the panel, you
could fry the neutral without tripping either breaker (assuming you
got around the GFCI issue).

If the circuits are off opposing legs, you won't overload the neutral,
but code will not permit "haywire routing" like this (usually expressed
in terms of "all conductors for a circuit need to be in the same cable").
This has to do with a notion that circuits should have "predictable
behaviour" (vis-a-vis subsequent rework) without having to know what
wierd way it was wired.

If you originally pulled individual wires, you _might_ get away with it
code-wise, but I really don't like it - requires some additional care
in connections (pigtailing) etc. But you still have the GFCI's not liking
it.

While you _could_ get this to operate by converting "A" to a regular
breaker
(perhaps putting a outlet-less GFCI in pole "A" right on the lamp), and
taking your B "hot" from the line side of the outlet (and using a GFCI
outlet
for "A"), you still have to contend with the shared neutral issue above,
and you're not GFCI'ing anywhere near as much of the circuits as you
originally
were.

Your other suggestions give me a headache, so I'll let someone else answer
;-)
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.