On Mon, 12 Nov 2012 03:14:11 -0600, wrote:

On Sun, 11 Nov 2012 20:13:39 -0500, Nate Nagel
wrote:

which is not hard; Klein makes a tap tool with a screwdriver handle for
just this purpose. Have used it quite a few times for just this
application. (trying to use a standard tap with T-handle is difficult
due to the depth of the boxes, but you don't need a whole lot of torque
to thread the steel of a typical electrical box.)

That sounds like a handy tool.

I would, however, splice the ground wires on the cables entering the box
together, along with a long bare pigtail of the proper gauge, with a
wire nut. The pigtail then loops under the box's ground screw and then
is connected to the ground terminal of the device installed in the box.
If both of the ground wires coming from the cables are long enough,
you could loop one under the box's ground screw, the other under the
device's terminal, then splice with wire nut. This way all connections
are good and proper, and you don't have to mess with BS like trying to
shove two short wires under a single screw without a Sta-Kon.


The problem with old wiring is that there is often no bare wires. The
wiring is armoured cable (BX), or metal conduit. The conduit is
normally a good ground, but only the BX with the bare metal insert in
the cable is a decent ground. Aside from ripping the whole house apart,
one can only use what exists as a ground.


Aside: Why don't spec grade "back wire" devices allow two ground wires
to be inserted under a single screw like the hots and neutrals?

I fully agree, actually all devices *could* have more than one ground
screw to make wiring easier. At least two screws, since probably hanf
the outlets and switches feed at least 2 cables. (the source wire and
the wire that goes to the next fixture).

Grounds are not supposed to be daisy-chained (neither are neutrals).

When I wire a box, I normally make one cable longer, than take the bare
and wrap it to the box screw near the entry point (box clamp). Then the
end of that bare wire goes to the outlet or device. If there are two or
more wires, that means more wirenuts. Which of course fills the box
faster and makes wiring harder.