I recently bought an older home with a newer addition. The original
portion of the house has 2 conductor wire with no ground. The addition
and recently wired parts of the basement use 3 conductor wire and all
the outlets are grounded and appear to be wired correctly (when tested
with a $5 outlet tester from the hardware store).
I need to plug in some computer equipment to two older outlets in the
original part of the house. I understand that I need a "real" ground
wire back to the panel for surge protectors / computer equipment (no
GFC or ground tied to water pipes etc).
Here is what I want to do - I would like to know if there are any
concerns with this approach:
The new wiring for the basement and the addition are easily accessible
in the basement and each has a junction box located near the older
outlets I want to add ground to. I plan to run a ground wire from the
two older outlets where I need to connect my computer to the juction
boxes with the newer wiring in the basement, and connect them to the
ground wires in the juction boxes.
Assuming that the ground wires in the newer wiring are properly
connected back at the panel, will this present any sort of problem?
Will the two older outlets be properly grounded for use with computer
That green wire should run all the way back to the electrical panel, or to
one of the grounding electrode conductors if that is easier. "Borrowing" a
ground from another nearby circuit isn't Kosher (even though it works,
wink, wink, nudge, nudge)
Thanks Bob. After looking at it some more, running a ground to the
panel isn't that bad. It's only about 30 feet, 2 outlets, and there
are plenty of ground lugs in the panel, so that is what I will do.
You can extend a properly connected equipmemt grounding conductor as
long as it is bog enough. The code says a shared equipment ground
needs to be sized to the largest breaker involved. For example you
could ground a 15a circuit to a 30a circuit with a 10 or 12 ga ground.
Just be carefull around older wiring methods that used a ground
smaller than the circuit coinductors.
Alternately you could "bus" a #12 around the attic/basement and pick
up all the receptacl;es you could fish a wire to. Just use boxes for
the splices and something like smurf tube (the blue tube) to provide
physical protection for anything exposed. This could also carry an
extra circuit or 4
hint hint, wink wink
On 30 Dec 2006 09:09:56 -0800, firstname.lastname@example.org wrote:
Too many words.
First check if you have an existing grounding method. See if the
receptacle boxes are metal and the wiring method is AC (BX). Now if
you aren't a qualified electrician then get one to do the work.
Cheaper than replacing computers, and such.
tom @ www.Consolidated-Loans.info
I agree. I get too wordy sometimes for a simple question ;)
The boxes are metal, but the wiring is not armored. Even if it were, I
would not rely on it as grounding.
When it comes to electrical I do feel that one needs to know what they
are doing, be safe, and be comfortable with the job. I do not feel
every task requires putting hundreds of dollars in someone else's
pocket, however. If I needed to replace my panel, I'd hire an expert.
If I'm just installing a new outlet or running a ground wire, I feel
All things considered if you have the extra capacity in your panel, or if
you have access to the old line feeding the outlet for the computer, I'd
pull a new line, with a ground, to some central point, where you can put a
junction box and feed the computer outlet, including the ground. This can
then be the point to pull grounds for any other outlets that were on that
Mark came closest, but I wouldn't even mess with the existing outlets. Add a
new 2-gang outlet behind the computer desk, tied to any convenient
non-switched grounded circuit in the basement. Modern computers don't draw
much. If OP is comfortable fishing wires, a length of 12-3 or 14-3 (for a
single outlet) would be about as quick to fish as the seperate ground. And
if he has an easy road to the service panel, and an open breaker socket, a
dedicated string wouldn't take much longer to run. If an old-work box and
fishing through the wall is a problem, a baseboard- level surface-mount box
and bushed conduit running through the floor wouldn't look that bad, and
could easily be moved or removed, if needed in the future, with only a tiny
hole to plug with a hardwood dowel. For that matter, they sell raised
floor-mount boxes (aka 'couch outlets') that could go through the floor
under the desk.
Thanks everyone for the replys. This is actually what I'm going to do.
The addition is really just a mud room, and the _only_ thing we use in
that room is two lights - we have never even used the outlets. I'm
just going to fish a short line up to the new outlet I need.
Not to mention when I took the cover off one outlets in the mud room I
was shocked (haha, not literally), at what I saw. Hots with 2" of bare
copper, and not screwed onto the outlet securely, and the whole outlet
wrapped with tape around the outside, almost as if it's to keep the
wires on there. I had to look because in the older part of the house
the guy just put in 3 prong outlets with no ground connection at all
and didn't fill in the ground hole.
Every time I look at a new project in this house I find something like
this, just below the surface.
Don't feel like the lone ranger- I keep finding stupids like that in this
house, too. Miswired outlets, open junction boxes in attic with loose
connections, buried floating butt splices, etc. I'm no pro electrician, but
I can do simple stuff, and what I put back is safer than what I found.
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