On May 26, 7:18*am, "John Gilmer" wrote:
"One way to improve the safety of the installation but at a fraction of
the effort is to install GFI's and label them "no equipment ground";
which was allowable under previous codes but I'm not sure about
current code."

Amen!

ASSuming the GFCI functions, you get more protection against shock with the
GFCI without ground than from a properly grounded outlet.

The "shock" comes from the person being grounded by some other means (e.g..:
by placing a hand on a radiator or sitting in a bath tub) and then touching
a metal object that has been entergized by a cross between "frame" and the
hot wire.

What the proper ground "buys" you is that the GFCI will 'trip' as soon as
you plug in the faulty 3 pin appliance. * Without the ground, the GFCI will
only trip when your soft body makes a connection between frame and "real"
ground.

A proper ground without the GFCI should trip the breaker if there is a fault
in th 3 pin appliance.

Yes, this is the best approach, short of rewiring the house.

Some practical advice: your old outlets may be in very small boxes, or
no boxes at all. Pull one or two (power off at the panel, and tested
with a lamp!) to find out.

If the former, shop around for the smallest-bodied gfi receptacles you
can find; avoid the ones with hardwired pigtails because you won't
have room for the wirenuts. Look for ones which accept the wires into
holes in the back, with screws that clam them down.

If you have no boxes, use "old work" boxes which can be inserted into
the wall and clamp against the back of the wall. These come in a
couple of styles, basically some clamp on the sides and some on the
top and bottom. Some of your outlet locations may allow for only one
of these; for instance, if they're hard against a stud on one side,
you'll need the kind that clamp top and bottom. And you'll need to
enlarge the holes for these, whether the outlets are in the baseboards
(very common in old homes) or plaster walls. This will be the most
annoying part of the job, and to save you another post, no, there is
no secret *good* way to cut lath and plaster, just work away with
whatever saw, knife or chisel you have at hand. Since your old wires
will be frustratingly short, enlarge the hole in the direction from
which the wires come, to give yourself an extra half inch of wires in
the box.

It's true in theory that a gfi can protect downstream outlets, however
(a) you need to understand which outlets are downstream of which
others, and this can be massively confusing in an old home (b) you'll
still want to replace the old outlets with 3-prong ones, so you're not
saving any labour, and (c) any nuisance trip will affect the whole
circuit. I'd err on the side of putting a cfi in each location.

K&T is usually not marked for hot vs neutral, so get a little three-
lamp tester and be prepared to reverse the connections in about half
the ones you've wired. Also invest upfront in a good pair of long-
nosed pliers, a stubby screwdriver appropriate to the screws on the
gfi (probably philips, maybe robertson in Canada), a flashlight, and a
low comfortable stool, unless you're a yoga master.

Chip C
Toronto