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andybuildz
Grounding old oulets

I was doing a job for someone in a 1950's cape. My electrician installed three outlets and some other things for me.
My customer asked about grounding all the outlets in the house. Approx 24 of em'. Small house.
My sparky told me he pushes a 10' copper grounding rod into the ground outside ..just on the other side of the main panelbox in the basement...
he connects the grounding rod and panel box...that I get...what I don't get is how he turns all the two wire feeds (there's no third wire in the protective fabric) in the house into two wire with a ground. He adds new outlets replacing the two prong old ones then adds a grounding wire from the new recepticle to the old metal boxes...he mentioned something about the old (in good shape) casings/insulation/protective fabric which he says is made from asbestos?? That he can get a grounding off of that????
Sounds too weird to me...can anyone explain what they think he means before I go back and ask him myself.
thanks
andy

canuk
Re: Grounding old oulets

Nope ... don't buy it.
Asbestos is not a conductor and the insulating jacket that surrounds the cable is not conductive either.
The only way I can see him doing this is if the wiring is BX. Then he would be relying on the metal jacket of the BX being the ground conductor back to the panel. That would be assuming the BX is secured to each box properly with metal strains.

Quote:

...he mentioned something about the old (in good shape) casings/insulation/protective fabric which he says is made from asbestos?? That he can get a grounding off of that????

That's a pretty big assumption the jacket is in good shape ... maybe he has X-Ray vision.;)

Re: Grounding old oulets
canuk wrote:

Nope ... don't buy it.
Asbestos is not a conductor and the insulating jacket that surrounds the cable is not conductive either.
The only way I can see him doing this is if the wiring is BX. Then he would be relying on the metal jacket of the BX being the ground conductor back to the panel. That would be assuming the BX is secured to each box properly with metal strains.

That's a pretty big assumption the jacket is in good shape ... maybe he has X-Ray vision.;)

Well thats why I posted this question. Made no sense to me either.
I'm wondering if I'm missing something is all.
Wondering if there is a way to ground two wire or do you have to rewire the entire house which would be a big drag.
And yeh...I know BX might work but thats not the case here.

djohns
Re: Grounding old oulets

Canuck is correct . Your " Electrician " is full of it . No telling what he has done to other clients . He should be reported .

JLMCDANIEL
Re: Grounding old oulets

The only way I know to do it without a complete rewire is to run a new ground wire from the panel box to each outlet.
Jack

Re: Grounding old oulets
JLMCDANIEL wrote:

The only way I know to do it without a complete rewire is to run a new ground wire from the panel box to each outlet.
Jack

Jack...thanks...good idea!

kentvw
Re: Grounding old oulets

There are a couple of ways to wire the existing for use with three prong, grounding type receptacles. Using the cable jacket, regardless of type is not one of them unless it is listed for use, which, it won't be. (see 05 NEC 250.130 (C) and 250.118.

Perhaps the easiest way is to leave the wiring and follow 406.3 (D) and use GFCI type receptacles. If a feed through GFCI type receptacle is used ahead of the other receptacles on the circuit and the load side GFCI is protecting the wiring a three prong recept can be used with nothing connected to the ground on the receptacle. Then mark the receptacles with "No equipment ground" and "GFCI Protected."

JLMCDANIEL
Re: Grounding old oulets

Kent,
That may be allowed but I think it's better to do it right and run ground to the outlets especially now that so many things are electronic and electronic equipment require ground for filtering.
Jack

kentvw
Re: Grounding old oulets
JLMCDANIEL wrote:

Kent,
..................... especially now that so many things are electronic and electronic equipment require ground for filtering.
Jack

Well, I'm all for learning new things, Jack, can you elaborate on electronic equipment that is using the ground for filtering?

Also, Andy did not elaborate on the connections in the panel but if a grounding system is installed then the neutral MUST be bonded to the grounding system for this to function correctly. "Ground" in this situation should really be thought of as an alternate path back to the neutral.

The thought that you clear branch circuit faults to ground and the ground rod is a myth.

JLMCDANIEL
Re: Grounding old oulets

Kent,
Andy stated that a ground rod was installed a a ground wire was run to the panel.

Electronic equipment use filters to ground to remove electrical noise, surges, EMI, and RFI . It may be as simple as an RC network tied to ground to some fairly complicated circuitry. Even those surge suppressor power strips used to protect computers from surges require a ground to work. In doing surveys before the installation of electronic equipment, a proper ground was one of the first things we checked for and required. GFCI protection only protects you from a difference in current between hot and neutral.
Jack

kentvw
Re: Grounding old oulets
JLMCDANIEL wrote:

Kent,
Andy stated that a ground rod was installed a a ground wire was run to the panel.

Even those surge suppressor power strips used to protect computers from surges require a ground to work.
Jack

Andy did state that the wire was brought to the panel but did not elaborate on whether the neutral was then bonded to the grounding system at that point. Point being
that if any "hot to ground" fault occurs the breaker will not see enough of the fault and will not trip unless that bond is made. This is more of a life safety hazard than having no ground at all.

I had not thought about it at the time but you are 100% correct on the power strips with regard to surges and electronic protection being cleared back to the grounding conductor.

I usually try and answer electrical questions per NEC and like the NEC with life safety taking priority over all.

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