On Sat, 12 Mar 2011 13:52:58 -0800, David Nebenzahl
wrote:

Just a li'l anecdote for those who've always wondered what happens if
you wire a GFCI to protect "downstream" outlets wrong (all 2 of
you)--that is, if you mix up the "line" and "load" wires.

The answer? Nothing.

Installed a GFCI in a client's kitchen, thinking I'd need two, one for
each outlet on a sink counter. It became clear, though, that they were
in a chain, so I could protect both with just one GFCI. So I wired in
the GFCI, wiring the downstream outlet on the "load" side, ass-u-ming
that the position of the cables in the box indicated the upstream and
downstream wiring respectively.

Wrong.

When I turned on the power, the GFCI's LED lit, but I couldn't reset the
outlet, and both outlets were dead.

Strange, when I made the same mistake the outlets worked normally but wouldn't
trip on a "downstream" fault. The differential current sensing was on the
wrong side of the device, so didn't detect the fault. I can't see how they'd
fail the way you suggest.

Whoops.

So I swapped the two sets of wires, repowered it, reset the GFCI and
bingo! everything worked fine.

The moral of the story is, you won't damage a GFCI by making this
mistake (but you'd better correct it if you want the devices to work
correctly).