From: "Chantecleer"


Have a question on Electrical outlet grounding. Hope you guys can help me
out.

I'm pretty new to Home repairs but learning fast. I had ran into a small
item that I cannot seem to accept. Namely, grounding an outlet.

I had replaced an old two prong outlet with a 3 prong in the garage. The
original was not grounded, obviously. I was told by the "Guy" at Home Depot
that the only thing I had needed to do to ground the outlet was to connect
the GREEN screw to the metal casing I had got to install the plug in. The
old casing was thrown away. I got one of them industrial metal casings and
screwed it to the Drywall in the garage.

For the life of me, I don't see how the outlet is grounded. The "Guy" says,
as long as it is to 'metal' I'm grounded.

True only if that metal box is grounded. What kind of method is used to bring
power to this new industrial box? If it's romex (NM cable) it should have a
ground wire. If it's BX (metal armored cable) the armor *used* to be considered
a sufficient ground, and if it's pipe or EMT (Electrical metallic tubing) it
should be grounded by a continuious metallic raceway system all the way back to
the panel.

The House is grounded with an 8
foot copper bar to the Main breaker box. But the metal box, is just to the
drywall.

That's great but grounding the service won't ground each individual box or
device.


Also am worried about arcing.
The Hot lead and the Neutral are in
this box, and both screws are about 1/4 inch away from the casing. Is this a
cause for alarm? Should it be insulated away somehow?

Well if the box isn't grounded, no cause for alarm, electricity doesn't have a
reason to arc to a non grounded box! Otherwise, we usually wrap a couple wraps
of electrical tape around the body of the outlet, covering the terminal screws.
Not really to protect from arcing though - more to prevent the spackler's knife
from shorting out the outlet when he passes it over the edge of the plaster
ring.


On the outlet, I had connected a #8 piece of copper wire to the metal
casing, and the green screw.

Am I grounded on this outlet?

Many thanks,

Chantecleer

If the box isn't connected to ground, it's not grounded. Why did you use a #8?