Jamie wrote:
D Yuniskis wrote:

Also, note that there is no way a (typical) GFCI can "test
itself" to determine that it is (likely) operational. So, a
failure in the sense electronics can cripple the protection
feature in a way that is not obvious to the user (i.e., the
circuit still supplies "unprotected power").

Btw. there are Self testing GFCI's..

Really? I stand corrected (I will have to chase down the link
to see how they work). Presumably, they test the sense
electronics *while* disabling the "trip" function? (I
can't see how else they could operate as you surely wouldn't
want the circuit to open each time it tested itself : )
In which case, I guess they hope that the circuitry that
inhibits the trip never fails! :

http://www.hubbell-wiring.com/Press/PDFS/H5185.pdf

We use these extensively. Coast more, but what the hell.

What sort of cost premium? Are they required for use in
certain applications (medical, etc.)? Or, is it just
"a nice feature to have"?

And those that get a little confused with the AGFCI units
which are mostly in the modern GCFI receptacle, just not
stated. Most don't know the difference.

Those that don't have U-ground corded devices get confused when they
still see their GFCI trip just from sliding in the
plug. This only happens with the newer GFCI's that include the arc fault
detection along with the ground fault current sense.

Ah, OK. So, I assume most modern electronic loads (i.e.,
things with line switchers in them like PC's) trip these
often?

I just love it when high powered R.F. disturbances trip those lovely
AGFCI and AFB units

RF as in *radiated* (not *conducted*)? Like someone keying
a transceiver nearby? How close do they have to be (i.e. does
this cause grief in actual *practice*)?

I also like it when the installer removes what looks like excess
neutral wire that's in a coil. by by RF choke. I haven't looked in a
code book lately how ever, Since it's not designed to teach those about
electricity, but just follow some guide lines for safety, I don't think
there is an assert about the coil being present. This is done via the
manufacturer for noise amuity. Not all may suggest to do this how ever,
if you see it packaged in a coil, bets are, you should keep it that way
or as much as possible. We have some Square-D line that will false
trigger if you remove that coil form, in the plant.

Is it an air core or ferrite? In either case, it is fairly obvious (?)
that this is something that is *meant* to be part of the assembly?
(contrast that with a pigtail that just "happens" to be coiled
up nicely for packaging)