🚀 go-pugleaf

In article <29646@cci632.UUCP>, rdi@cci632.UUCP (Rick Inzero) writes:
> A curious thing (before I discovered this ungrounded wire) is that when I 
> replaced the existing ordinary outlet with a new ground fault interrupt 
> outlet, it thought that there was a valid ground!!  It functioned correctly 
> for about a year and a half (using the "test" button) ALTHOUGH NO ACTUAL, 
> TRUE GROUND WAS PRESENT!!

Actually, a GFCI does not require any ground connection to operate. It
works by comparing the current flow through the hot line with that through
the nutral. If one is passing more current than the other, the button
pops. The ground line is not involved at all other than you assume that
the extra current must be flowing to ground somewhere.

I assume that the test button works by connecting a resistor between hot
after the GFCI circuit and nutral before the circuit.

Finally, be aware that in houses where there is no ground run to the
outlets (i.e. built before the National Electrical Code (or whatever
the name actually is) reqired 3 prong outlets), the Code allows you to
replace two prong outlets with GFCI three prong outlets with the ground
lug unconnected! I originally read this fact in Popular Science
magazine and it was confirmed by a code inspector for the city of San
Jose. Because the GFCI will detect current flowing from the hot line to
a ground (including through your body), this provides the same kind of
protection as a conventional, properly wired 3 prong outlet.

-- 
Ted Marshall          ...!uunet!blia!ted   <or>   ted@blia.bli.com
ShareBase Corp., 14600 Winchester Blvd, Los Gatos, Ca 95030     (408)378-7000
The opinions expressed above are those of the poster and not his employer.