On Friday, February 7, 2014 6:44:51 AM UTC-5, wrote:
On Thursday, February 6, 2014 4:11:58 PM UTC-5, philo* wrote:

On 02/06/2014 02:51 PM, wrote:



During a kitchen remodel in my mom's circa 1948 house (post WWII made 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 grounded outlets work properly.







They reacted in horror saying it could cause a fire or even worse. I said 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.







Ok, who's right here?







BTW, he's my older brother so I just let it go.



















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.



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.

True. However if the house was built in '48, the insulation on the conductors 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 Edison circuit below - with a dedicated ground conductor - not required, but belt and suspenders.

Read up on your code (NEC aka NFPA 70) ... a kitchen remodel requires a minimum of two dedicated 20A (12AWG) circuits with GFCIs for counter receptacles. 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 method, 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 with current box fill requirements. You definitely will if you are using 12AWG.

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 (not a bad thing to worry about) more bang for your buck and code legal is making 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 upgrading, a surge protector at the panel can be helpful if you're in a storm prone area.

good luck

nate