"François Yves Le Gal" wrote in
message
On Sun, 19 Mar 2006 12:05:23 -0500, "Robert Morein"
wrote:

Francois, are you perhaps misphrasing this? A GFCI is
effective only if it is connected to a mains circuit
with a 3rd wire ground.

Nope, a GFCI is basically a breaker. Re-read NEC
406.3(D)(2) regarding the installtion of GFCI's in a "No
Equipment Ground" context. It works with or without a
grounding wire.

This is completely true. A GFCI works by tripping whenever the current flow
through the hot and neutral sides of the circuit passing through it are
slightly unbalanced.