Anything wrong with grounding metal conduit to a cold water pipe in a 2-wire house?

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During a kitchen remodel in my mom's circa 1948 house (post WWII made out o f reinforced concrete!) with 2-wire electrical and metal conduit, I mention ed to my brother and nephew that, since it was exposed, it probably wouldn' t be a bad idea to ground the wiring conduit to a cold water pipe, thereby grounding the entire conduit run and at the very least making grounded outl ets work properly.
They reacted in horror saying it could cause a fire or even worse. I said t hat at least you'd know if you had a short circuit because the breaker woul d trip and touching something metal wouldn't kill you.
Ok, who's right here?
BTW, he's my older brother so I just let it go.
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On 2/6/2014 12:51 PM, snipped-for-privacy@gmail.com wrote:

Best to leave things as they are. We once owned a 1948 house. Part of the wiring was done backwards so the white was hot and black was common. Yours could be the same way.
Paul
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On 2/6/2014 4:02 PM, Paul Drahn wrote:

I'd want to find out.
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On Thursday, February 6, 2014 3:51:11 PM UTC-5, snipped-for-privacy@gmail.com wrote:

of reinforced concrete!) with 2-wire electrical and metal conduit, I menti oned to my brother and nephew that, since it was exposed, it probably would n't be a bad idea to ground the wiring conduit to a cold water pipe, thereb y grounding the entire conduit run and at the very least making grounded ou tlets work properly.

I would think that if metal conduit is being used, it's already grounded back at the panel, no?
As to making the grounded outlets work properly, it;s clearly a major code violation to install grounded outlets if they are not grounded properly to begin with. New outlets cannot be put in during a renovation without conforming to the grounding requiremets. And since it's a kitchen, GFCI as well.

that at least you'd know if you had a short circuit because the breaker wo uld trip and touching something metal wouldn't kill you.

You seem to be more on track then your brother. There is no fire risk from properly grounding the conduit. Did you ask him how the new outlets are grounded? If they were put in without a ground, no GFCI, etc, then that is a real shock hazard? Who's doint this work? Permits pulled?
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On Thu, 6 Feb 2014 13:07:39 -0800 (PST), " snipped-for-privacy@optonline.net"

I agree. You can test this pretty easy with an ohm meter. The resistance between the conduit and the water pipe should be very near 0 ohms.

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On Thursday, February 6, 2014 3:51:11 PM UTC-5, snipped-for-privacy@gmail.com wrote:

of reinforced concrete!) with 2-wire electrical and metal conduit, I menti oned to my brother and nephew that, since it was exposed, it probably would n't be a bad idea to ground the wiring conduit to a cold water pipe, thereb y grounding the entire conduit run and at the very least making grounded ou tlets work properly.

that at least you'd know if you had a short circuit because the breaker wo uld trip and touching something metal wouldn't kill you.

If it's conduit all the way to the panel then it is likely grounded at the panel.
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On 02/06/2014 02:51 PM, snipped-for-privacy@gmail.com wrote:

The conduit goes back to your breaker box (or fuse box if the system has not been upgraded) and the breaker box itself is ground...OR SHOULD BE. The proper way to ground the outlets, it you are using a standard three wire plug is to have the ground terminal connected to a ground wire which would normally be inside the conduit. If there is no ground wire inside you will need to run one to do things properly.
Other wise, I'd leave it alone.
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A ground wire is not necessary. You can use a bond jumper screwed into the box. Which I surprisingly can't find a google image of.
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On 02/06/2014 05:12 PM, Metspitzer wrote:

Yes, that will work . I do not know if it would be "code" or not.
The problem I see would be the case of a bad coupling junction. I think a ground wire would be the safer way to go.
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On Thursday, February 6, 2014 4:11:58 PM UTC-5, philo  wrote:

ut of reinforced concrete!) with 2-wire electrical and metal conduit, I men tioned to my brother and nephew that, since it was exposed, it probably wou ldn't be a bad idea to ground the wiring conduit to a cold water pipe, ther eby grounding the entire conduit run and at the very least making grounded outlets work properly.

id that at least you'd know if you had a short circuit because the breaker would trip and touching something metal wouldn't kill you.




AFAIK, there is nothing in code that says metal conduit can't be used as the grounding conductor, ie that you don't have to pull a separate wire.
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On Friday, February 7, 2014 6:44:51 AM UTC-5, snipped-for-privacy@optonline.net wrote:

out of reinforced concrete!) with 2-wire electrical and metal conduit, I m entioned to my brother and nephew that, since it was exposed, it probably w ouldn't be a bad idea to ground the wiring conduit to a cold water pipe, th ereby grounding the entire conduit run and at the very least making grounde d outlets work properly.

said that at least you'd know if you had a short circuit because the breake r would trip and touching something metal wouldn't kill you.

s




True. However if the house was built in '48, the insulation on the conduct ors in the conduit is possibly cloth covered rubber, in which case I'd give serious thought to repulling the home run. If the conduit is big enough I would go ahead and pull 12AWG conductors as the old ones are likely 14AWG - and maybe two hots, see comment re: Edison circuit below - with a dedicat ed ground conductor - not required, but belt and suspenders.
Read up on your code (NEC aka NFPA 70) ... a kitchen remodel requires a min imum of two dedicated 20A (12AWG) circuits with GFCIs for counter receptacl es. I'm not sure if a single Edison circuit for the home run would be code compliant now or if you're required to have an AFCI breaker in the kitchen as well.
Using a water pipe as a ground in a situation where you're replacing a two wire receptacle with a grounding type receptacle *used* to be an accepted m ethod, but is no longer code compliant. That would have only applied when there was no ground present however, and a continuous run of metal conduit back to the panel counts as a ground.
You will probably need new (deeper) boxes in the wall as well to comply wit h current box fill requirements. You definitely will if you are using 12AW G.
Finally, check your *local* codes for what you have to do for any new work; sometimes they are more restrictive than the NEC.
One thing that you may want to do, if you are concerned about grounding (no t a bad thing to worry about) more bang for your buck and code legal is mak ing sure that your water service is bonded to the ground/neutral bus at the panel, and if you don't have ground rods or a Ufer ground (I doubt it in a house that old) consider driving some ground rods. Also since you're upgr ading, a surge protector at the panel can be helpful if you're in a storm p rone area.
good luck
nate
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On Friday, February 7, 2014 8:30:34 AM UTC-5, N8N wrote:

de out of reinforced concrete!) with 2-wire electrical and metal conduit, I mentioned to my brother and nephew that, since it was exposed, it probably wouldn't be a bad idea to ground the wiring conduit to a cold water pipe, thereby grounding the entire conduit run and at the very least making groun ded outlets work properly.

I said that at least you'd know if you had a short circuit because the brea ker would trip and touching something metal wouldn't kill you.

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ctors in the conduit is possibly cloth covered rubber, in which case I'd gi ve serious thought to repulling the home run. If the conduit is big enough I would go ahead and pull 12AWG conductors as the old ones are likely 14AW G - and maybe two hots, see comment re: Edison circuit below - with a dedic ated ground conductor - not required, but belt and suspenders.

inimum of two dedicated 20A (12AWG) circuits with GFCIs for counter recepta cles. I'm not sure if a single Edison circuit for the home run would be co de compliant now or if you're required to have an AFCI breaker in the kitch en as well.

You started out replying to my post with a "true" and then segued into the above, about reading code, which I think you meant for the OP. I agree with your observations. How much, if any of that applies, depends on what he means by "kitchen renovation". So far all he's said about anything to do with the electrical was the one very limited question. If they are adding outlets, etc, which is certainly typical of many kitchen renovation, particularly in that age houe, I agree there are a whole lot of issues beyond the question asked. And it also sounds like they are beyond the skill level of those involved. If they are redoing the electrical, it's kind of scary that they would be asking that question. If that's the case, probably time to call a pro. Better to do it right now while the kitchen work is being done, then have to deal with a mess later.

o wire receptacle with a grounding type receptacle *used* to be an accepted method, but is no longer code compliant. That would have only applied whe n there was no ground present however, and a continuous run of metal condui t back to the panel counts as a ground.

ith current box fill requirements. You definitely will if you are using 12 AWG.

k; sometimes they are more restrictive than the NEC.

not a bad thing to worry about) more bang for your buck and code legal is m aking sure that your water service is bonded to the ground/neutral bus at t he panel, and if you don't have ground rods or a Ufer ground (I doubt it in a house that old) consider driving some ground rods. Also since you're up grading, a surge protector at the panel can be helpful if you're in a storm prone area.

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If they are adding outlets, etc, which

No outlets are being added. You couldn't add them if you wanted to--all of the electrical is buried in concrete (the house is solid reinforced concrete) . The new kitchen is merely taking the place of the old kitchen. Same footprint.
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On 2/7/2014 3:08 PM, snipped-for-privacy@gmail.com wrote:

New outlets may be added, but that is a different discussion.
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On 02/07/2014 03:08 PM, snipped-for-privacy@gmail.com wrote:

Since the kitchen is going to be all new, I just don't see the point of even trying to re-use 65 year old wire, I'd pull all new through the conduit. It should be an easy job.
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On Friday, February 7, 2014 4:47:51 PM UTC-5, philo  wrote:

of the electrical is buried in concrete (the house is solid reinforced con crete) . The new kitchen is merely taking the place of the old kitchen. Sam e footprint.


It certainly is unusual. A new kitchen is a lot of money and work. And you want more outlets, higher amps, GFCI, more circuits, etc. I think it's rather odd to put money into a lot of other stuff and then wind up with a 75 year old electrical system. Both from a functionality standpoint and safety.
Around here, NJ, you couldm't even pull the permits for the other work that required, eg plumbing, without also pulling electrical permits and bringing it all up to code. It's kind of like rebuilding a room and I think once you open up the can of worms that the kitchen is being renovated, then everything that applies in the code has to be done. Other places, requirements may be different.
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On 02/07/2014 04:23 PM, snipped-for-privacy@optonline.net wrote:

When I remodeled the kitchen over 20 years ago , since all the walls and ceiling were out, I found it easy to put in all new wiring everywhere /except/ one outlet that was hard to get at.
Guess which one just failed recently?
I just disconnected it and put in a whole new outlet and a separate feed.
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On Friday, February 7, 2014 4:08:10 PM UTC-5, snipped-for-privacy@gmail.com wrote:

It's still unclear what exactly that means, but if the wiring in question isn't being modified, added onto, etc, then the answer to your question is probably to verify that the conduit is grounded back at the panel, in which case it can serve as the grounding conductor.
As others have pointed out or assumed, etc, it's a bit unusual for a kitchen renovation of a house from the 40's to not include electrical work, eg more outlets, GFCI, lights, more circuits, 20 amp vs 15, wiring for appliances, etc., even if it's just the same footprint, which it typically is. And if you get into that, then you clearly have to bring the kitchen electrical up to code. And even if you're ripping out some of the wiring and re-doing it, ie still trying to have the same outlets on the same circuits when you;re done, you can't do that either. It has to be brought up to code.
Even if that conduit is buried in the concrete, if it was installed correctly there should be endpoints, access points, etc where it's possible to pull new conductors. Something to keep in mind perhaps.
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On 02/06/2014 12:51 PM, snipped-for-privacy@gmail.com wrote:

The main caveat is that you have absolute certainty that the water pipe is metal all the way to the water meter, and doesn't transition into PVC. You also have to make a solid connection to the pipe that will not be compromised due to corrosion if the pipe is steel.
If you can accomplish these two issues, it would technically work, but I'm guessssing it's probably not going to be code compliant (should the incoming pipe be replaced by PVC in the future, the ground would end up being non functional).
Jon
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On Thursday, February 6, 2014 4:14:36 PM UTC-5, Jon Danniken wrote:

That about sums it up. It would work, but it's not code compliant. Nor should it be necessary because the conduit should be grounded back at the panel.
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