I have a home that was built in the '50's and want to replace some of
the 2-prong electrical outlets with 3 prong outlets (the third prong
being the ground). Following all the normal safety precautions can I
simply install a 3 prong outlet in its place, leaving the ground
unconnected? I know this will defeat the whole purpose of a ground,
I'm just looking to have to stop using adaptors anytime I want to plug
in a three pronged device (which also defeats the purpose of the
ground). Aside from losing out on the safety aspect, are there any
other risks to doing this?
Otherwise, what's involved in running a ground? Is it complicated for
a DIY'er? (maybe if I have to ask, I shuldn't try it). Or would
installing GFCI outlets be an alternative? Thanks!!
SAFETY is and should always be the #1 reason to follow the rules. You are a
even consider such an installation. Other complications certainly include
when someone either in the near or distant future gets hurt because of hooking
up this way.
I agree that YOU shouldn't try it. If you would even consider running without a
proper ground, you are probably the kind that would take a lot of shortcuts, and
wouldn't make sure the system was properly inspected and SAFE when you are done.
I'm not looking to take shortcuts and put safety at risk, Currently
half of the outlets are the older 2 prong variety (all in
kitchen/bath/livingroom are updated). We just have a few outlets in
hall ways and bedrooms that are older 2 prong still. the only devices
that get plugged into these are 2 prong devices likes vacuum, and the
laptops which are three prong (using an adaptor). We're repainting the
hallways and I was going to upgrade these outlets more for looks now
(to white outlets) and when money is less tight have them grounded.
I'm just wondering if there is risk (ie fire, etc) due to hooking 3
prong outlets to ungrounded box.
We plan on grounding eventually. How big a job is this for experienced
electrician? The outlets are all on 1st floor of a ranch and the
finished basement below has suspended ceilings (ie access to flooring
above by moving tiles).
NEC does allow 2 prong receptacles to be replaced with 3 prong
receptacles _IF_ they are GFCI protected.
What you need to do is find in first outlet in each circuit, then
install a GFCI receptacle at that location, feeding the downstream
receptacles through that GFCI receptacle. All the downstream
receptacles can then be replaced with reguler 3 prong receptacles to
meet NEC requirements. If line and load are not available at the
first outlet, another soltion is to use GFCI breakers.
In addition, you should check and see whether you do in fact have a
ground wire that may just be connected to the metal junction boxes.
You probably have just 2-wire cable connecting all your outlets, but
there was a period where an undersized ground wire was included in the
cable and was simply twisted to the other ground wires and tied to the
box. Another variation was that the undersized ground wire was wrapped
around the outside of the cable sheath and the cable was clamped to the
box which would still nake a ground connection to the box. In this
case, it may not be readily apparent that there is in fact a ground
wire connected to anythig.
A quick way to see if there may be a ground would be to take the cover
plate off a duplex outlet, and use a neon light tester between the hot
side of the duplex and the metal box. If the tester lights, then you
probably have a ground wire. If this is the case, then write back here
for more instructions about what to do to actually hook up a ground to
a 3-prong duplex outlet.
But, you probably have no ground wire at all, and will need to either
add GFCI outlets like volts500 said, or else start fishing new cables.
volts500 is on the money. I also beleive (but am not completely sure if
this is actually in the NEC) you are supposed to label all of the
ungrounded-but-gfci 3-prong outlets with a sticker saying "NO GROUND"
or similar. If I remember from last time I did a gfci, the box even
included a half dozen such little stickers. Or maybe that was just the
"GFCI" stickers I'm thinking of... hmmm.
Is there a ground to the outlets that got replaced already? Or are maybe the
boxes grounded, either through armored cable or actual ground wire romex?
Only way for sure is to disable a circuit, pull an outlet out, and see if
there is any bare copper in there. For the outlets that have already been
switched, one of those ten-buck testers will do it. In this 1960 house, half
the outlets were grounded, and half 2-hole. Lucky for me, there was grounded
romex to all the boxes, so all I had to do was switch 14 outlets.
The outlets that got replaced already seem to have new wire runs as
well. These outlets are connected to beige flat cables (I think this
is called Romex). The older/original wiring is going to metal boxes.
This cable looks to be a rubbery substance covering some kind of mesh.
The cable says Citex NON METALIC COVERING. I have pulled one of the
older outlets, its in a metal box with four wires coming in (two
: >I have a home that was built in the '50's and want to replace
: > the 2-prong electrical outlets with 3 prong outlets (the
: > being the ground). Following all the normal safety
precautions can I
: > simply install a 3 prong outlet in its place, leaving the
: > unconnected? I know this will defeat the whole purpose of a
: > I'm just looking to have to stop using adaptors anytime I
want to plug
: > in a three pronged device (which also defeats the purpose of
: > ground). Aside from losing out on the safety aspect, are
: > other risks to doing this?
: SAFETY is and should always be the #1 reason to follow the
rules. You are a fool to
: even consider such an installation. Other complications
certainly include liability
: when someone either in the near or distant future gets hurt
because of hooking things
: up this way.
uMMM, no, you're a blithering idiot yourself to be calling
someone doing honest research and asking intelligent questions
about something he's not familiar with, a fool.
I've never understood the blatherskites that seem to so enjoy
calling another person, who is only ignorant (and that is NOT an
insult; check your dictionary), a fool, and wishes to learn
something. Responses like yours are a real wart on the ass of
When you hav e nothing to say, that's what you should say:
After doing more research online it seems there's a chance of there
being a ground even though there's still a 2 prong outlet (I guess this
was sometimes the case in the 50's). I'm going to buy a tester and
determine if this is in fact the case. If this is not the case, I
think I'll trade off and install a GFCI outlet on the first outlet in
the circuit then change the others (in said circuit) with three prong
outlets. Still none would be grounded, but it would still be to code
(or that's the impression I get). Being a first time home buyer, I'm
trying to save where I can and learn as I go. For things like
electrical, before trying to "experiment" I like to get an idea of
what's involved and determine from there.
This was the case in my 1959 house. Two prong receptacles. I took one
out and there was the ground wire (smaller guage, as mentioned above).
So the house has 3 wire cable. So I just replaced with three prong
outlets and connected the ground.
Get a home wiring book from your library. You will learn quite a bit
No one who knows what they are talking about will tell you that what I'm
about to suggest is required by code but I'm going to suggest that you
use isolated ground receptacles for your replacement receptacles that
will be supplied from the Ground Fault Circuit Interrupters. The reason
that I suggest this is that with metal boxes and especially with older
armored cable that does not have a bonding strip a fault on any plugged
in load can energize the other three wire loads that are plugged in or
metallic fixtures supplied by that circuit.
Isolated ground receptacles assure that any fault is isolated to the
defective cord and plug connected load rather than having stray voltage
present on the rest of the ineffectively grounded or ungrounded circuit.
You still label the receptacles as having no equipment ground. The
code already requires that no equipment ground connection be made to
receptacles that are installed from an ungrounded GFCI protected supply
but the connection between the receptacle grounding terminal of a
regular receptacle and it's yoke make that instruction ineffective at
isolating the receptacles from each other.
Once again this is not a requirement of any code I am aware of but it
will reduce the chance of electric shock. The reason for being so
careful is that GFCIs will only protect older children and adults in
good health. Smaller children and adults who are old enough or sick
enough to already have an irregular heart beat can still be killed by
electric shock. Even healthy adults can be injured and even killed by
the physical reaction to the momentary electric shock that occurs before
the GFCI opens the circuit. Electric shock causes muscle contractions
that can result in falls or other dangerous involuntary motions.
If it was built in the 50's there is a good chance it has BX, which is
a metal spiral around the wires. Since they didnot have plastic boxes
back then, I assume you have metal boxes, Therefore you have a
ground. TEST THEM ALL TO BE SURE.
You need to run a green pigtail wire from the box to the outlet.
Those older metal boxes did not always have a hole for a ground screw.
Get a ling enough drill bit to drill holes in the rear of the boxes.
In the electrical dept, they sell an alectricians multi-sized tap.
But one to thread the holes, OR get self tapping screws with a hex
head and use a nutdriver. I believe the green ground screws are a
10-32 thread (I may be wrong). Be sure you dont chop up the wires
with the drill chuck.
Here's a tip. Shove then in a piece of small sized hose and bend them
upward. That's my own "invention". I always keep a few pieces of 6"
gas line hoses in my electrical toolbox. just for that purpose, and
they have come in handy a few times when I opened a box and found bad
wires, but needed to keep the wires live to test to find the source.
Just slip them over the wires during the tests. (not premanently -
replace all bad wires). I also used them a few times when working on
a live circuit with lots of wires. Helps keep hands away from the
ones you are not testing at the time, without having to bend that old
insulation so much. Just slip the hose over the wire ends.
There are two types of Armored cable. One is BX that was built in
General Electrics Bronx plant; hence the designation BX; which has no
bonding strip inside the armor. The other is a product of later
manufacture that has a bonding strip in the armor and is more properly
referred to by it's electrical code designation of AC. BX is not
suitable for use an Equipment Grounding (Bonding) Conductor. The
corrosion between the turns of the armor makes the impedance of the
return pathway too high. Before you try to use the armor of the cable
in your walls as an EGC you will need to check for the presence of a
bonding strip. If there is no bonding strip then you will need to
protect the circuit with a Ground Fault Circuit Interrupter. When
unbonded BX cable carries fault currents the result is often a fire due
to the heating of the armor.
Well we aren\'t no thin blue heroes and yet we aren\'t no blackguards to.
On Sun, 05 Feb 2006 19:51:36 GMT, "Thomas D. Horne, FF EMT"
You are correct, but I believe in the 50's they all had the bonding
strip. and BX was always the trade name even though you are correct
about the AC which was always a confusing term considering the power
is AC, thus is probably whey they kept the BX terminology.
Just curious, does anyone know what both BX and AC stand for?
A note to the OP. If you have a dedicated outlet for a computer or
other device that requires a good ground, if you dont want to replace
the cable, you can always run a green wire alongside the armored
cable. Whether this ia acceptable to code is questionable, but it
will get you a good ground (if taken all the way back to the main
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