DIY Home Improvement Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
I hate two-prong outlets. I have one in a box that is cemented in the wall with no access to the type AC (armored cable) feeding it. (It used to be a fireplace.) Among the thousands of threads I have read it was said that one should not depend on the armor as a ground conductor. However NEC 2011 250.118(8) seems to indicate that it is acceptable. But maybe the cable I have is not up to current standards. Comments?

Let's assume the armor is unacceptable and I can somehow run a ground wire up and into to box. Is it acceptable to run this wire (green insulated 12 gauge) to any other adequately sized (i.e. in this case 15A) ground? Or does that ground wire have to follow the supply circuit back to the subpanel for termination?
 

·
Registered
Joined
·
10,109 Posts
The ground wire from your newly to-be grounded receptacle must go back to the panel more or less following the route of the supply circuit cable. But if the new ground wire should reach the fat ground wire (grounding electrode conductor) between the panel and the entering cold water pipe (or a ground rod) first then the ground wire can stop there.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #4 ·
My municipality has adopted the Uniform Construction Code of PA. I don't know if that has anything to do with wiring.

I was happy to be able to read the NEC online simply by signing up with the NFPA. Allan, just for my edification, can you site the approximate location in the code where it says follow the supply circuit cable? I couldn't find anything about it.

Thanks to all for your replies.
 

·
Registered
Joined
·
10,109 Posts
Allan, just for my edification, can you site the approximate location in the code where it says follow the supply circuit cable? I couldn't find anything about it.
It doesn't have to follow exactly; for example if you don't want to break open the walls and the outlet is on an exterior wall then you could drill a small hole to the outside and run the ground wire under the edge of a clapboard and at an appropriate location, down and into a small hole in a rim joist.

I don't have the code chapter and verse handy but that has been paraphrased more than once on this forum including such things as "to a point on the grounding electrode system".

The grounding electrode system consists of three parts: (1) a ground rod, or an underground metal water pipe entering the building, (2) a continuous (nonstop; home run) copper wire of minimum specified size (#6 for 100 amp or smaller services) and (3) the connection point of #2 to the service neutral including an appurtenant terminal strip or bus bar, in the panel.

Specifically mentioned was the panel (could be a subpanel) where the corresponding circuit cable enters.

Local codes may define additional points, such as water pipes going upstairs, to which something may be connected to and then be considered bonded for grounding purposes.
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
you can connect to any other ground wire of at least the same size.
No you cannot connect to just any ole 'ground wire' of the same size. The NEC is specific about the points where an added egc may terminate. None of which is another ground wire of the same size.

The code articles were given by Saturday Cowboy.
 

·
Registered
Joined
·
18 Posts
No you cannot connect to just any ole 'ground wire' of the same size. The NEC is specific about the points where an added egc may terminate. None of which is another ground wire of the same size.

The code articles were given by Saturday Cowboy.
you are correct, it must be of the same branch circiut, I stand corrected on that but you can connect to any ole ground wire on the same branch circiut.
 

·
" Euro " electrician
Joined
·
5,369 Posts
you are correct, it must be of the same branch circiut, I stand corrected on that but you can connect to any ole ground wire on the same branch circiut.
That part is true however for olé grounding conductour it will depending on how well it is before you can make a judgement call on this one.

Merci.
Marc
 

·
Registered
Joined
·
18 Posts
That part is true however for olé grounding conductour it will depending on how well it is before you can make a judgement call on this one.

Merci.
Marc
AS i said ealier in simple terms, same size wire or lager. NEC says grounding con ductor must be able towithstand the entire circiut load ie 20 amp breaker = ground wire must be sized to handle that much current.. There is no judgement call if it is on the same branch circiut because the overload/short circiut protection will be one in the same as the groungind conductor you tap. And something for all of us to remember is that the NEC is the bare minimum of what we are permitted to do. With that said an unbroken ground from point of use to the grounding bad is always the best but usually not practical.
 

·
" Euro " electrician
Joined
·
5,369 Posts
Jadbad.,

I understand what you are refering to this however did you see old style NM cable with reduced grounding conductor size in there before ??

Few of us in this forum allready see it before. { I have see in both North Americian and European verison so I did see both ways }

Merci.
Marc
 

·
Registered
Joined
·
18 Posts
Jadbad.,

I understand what you are refering to this however did you see old style NM cable with reduced grounding conductor size in there before ??

Few of us in this forum allready see it before. { I have see in both North Americian and European verison so I did see both ways }

Merci.
Marc
Yes I have seen smaller ground conductor which is common and acceptable refer to NEC talble 250.122 and that is also why I said ground conductor needs to be same size or larger than the one being tapped. (assuming original calculations on existing system was correct)
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
you are correct, it must be of the same branch circiut, I stand corrected on that but you can connect to any ole ground wire on the same branch circiut.
HUH?

How can you connect to the equipment ground wire on the same branch circuit when there isn't one? The op is asking if he doesn't have an egc in the branch circuit can he run a seperate ground wire.

To answer the op's question you would refer to the code articles Saturday Cowboy posted. You can run an egc to any of those places any how you want to get there...or you can install a gfci receptacle.
 

·
A "Handy Husband"
Joined
·
14,356 Posts
Not sure of the OP's statement that he hates 2 wire receptacles, is he worried about personnel safety or does he need to plug in a 3 wire plug?

If the ground is not needed for electronic equipment protection, why not install a GFCI? This would give personnel protection and allow the use of 3 wire plugs without an adapter.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top