Grounding electrode for pre-fab house

[jaylectricity]

A customer is having the foundation poured for his pre-fab house. After the footings were poured the wire inspector drove by and stopped and told him he needs to embed at least 20' #4 copper in the foundation. There is no rebar to be placed in this foundation.

Looking at 250.52(A)(3), I see that is an acceptable method for the grounding electrode system/conductor, but wondered if it was in lieu of a ground rod, or in addition to one. I asked the inspector and he said that I would not have to drive a ground rod.

I'm fine with all of this, definitely much easier than the ground rod method, but I'm wondering if he can force me to do it this way. What if I wanted to drive a ground rod instead? The materials would be cheaper, and since I'd be the one doing the labor I wouldn't actually be spending money on labor.

What say you, forum?

 

[ptonsparky]

Well I look at 250.50 and think that if it ain't there, it ain't gonna get connected. That said, the local code may require the #4 and in that case, the guy pouring the concrete goofed up.

NEC 05

 

[infinity]

A customer is having the foundation poured for his pre-fab house. After the footings were poured the wire inspector drove by and stopped and told him he needs to embed at least 20' #4 copper in the foundation. There is no rebar to be placed in this foundation.

Is there 20' or more of 1/2" or larger rebar in the footing? There is no NEC requirement to use a CEE if there is no rebar in the footing. Two ground rods is what I would use at this point since the footing is already poured.

Looking at 250.52(A)(3), I see that is an acceptable method for the grounding electrode system/conductor, but wondered if it was in lieu of a ground rod, or in addition to one. I asked the inspector and he said that I would not have to drive a ground rod.

If you did use a CEE in the footing there is no requirement to supplement the CEE with a ground rod.

 

[Dennis Alwon]

I agree with Trevor but it will be a much better system than 2 ground rods. It's also a lot easier and cheaper except for the extra trip.

I have had the builder install it for me since they are out there all the time. I make sure they know what to do otherwise I do it. I have one to do Monday and I don't trust the builder so I will do it.

As long as you know where the service is going to go I would go for it.

 

[jaylectricity]

Is there 20' or more of 1/2" or larger rebar in the footing? There is no NEC requirement to use a CEE if there is no rebar in the footing.

That's what I thought, and no, there's no rebar and he knows that. Anyway, he is still requiring me to put one into the foundation so that 20 feet of it get encased in the floor and wall of the basement and leave enough to terminate in the panel. We have a rough idea of where the panel is going to be.

 

[rich9112]

Heads up!

Heads up!

I don't have my code books available, but you should be aware that several of the newer building codes (2006 IRC, etc) require a CEE for new construction. They even specify that any CEE present (not just available) be used. This last part changed after some EC's were cutting off the CEE so it was no longer 'available'. I have (somewhat reluctantly) had contractors open up the footings to tie into the rebar when the CEE was 'accidently' cut off. There are also min. coverages specified for concrete coverage of a CEE if you are putting it in the slab. As mentioned elsewhere in this forum, the CEE may be ineffective if a vapor barrier is installed below the slab. Good luck!

 

[Dennis Alwon]

So are you saying that a concrete footer without the rebar is a CEE?

 

[electricmanscott]

That's what I thought, and no, there's no rebar and he knows that. Anyway, he is still requiring me to put one into the foundation so that 20 feet of it get encased in the floor and wall of the basement and leave enough to terminate in the panel. We have a rough idea of where the panel is going to be.

There is absolutely nothing to back this inspector up. Period.

IN fact what he is asking you to do does not even meet the requirements for a CEE.

Don't be bullied.

PM me what town.

 

[electricmanscott]

I don't have my code books available, but you should be aware that several of the newer building codes (2006 IRC, etc) require a CEE for new construction. They even specify that any CEE present (not just available) be used. This last part changed after some EC's were cutting off the CEE so it was no longer 'available'. I have (somewhat reluctantly) had contractors open up the footings to tie into the rebar when the CEE was 'accidently' cut off. There are also min. coverages specified for concrete coverage of a CEE if you are putting it in the slab. As mentioned elsewhere in this forum, the CEE may be ineffective if a vapor barrier is installed below the slab. Good luck!

We are talking about the NEC.

 

[raider1]

I don't have my code books available, but you should be aware that several of the newer building codes (2006 IRC, etc) require a CEE for new construction. They even specify that any CEE present (not just available) be used. This last part changed after some EC's were cutting off the CEE so it was no longer 'available'. I have (somewhat reluctantly) had contractors open up the footings to tie into the rebar when the CEE was 'accidently' cut off. There are also min. coverages specified for concrete coverage of a CEE if you are putting it in the slab. As mentioned elsewhere in this forum, the CEE may be ineffective if a vapor barrier is installed below the slab. Good luck!

The 2006 or 2009 IRC does not require a CEE to be installed. It does say that if a CEE is present that it must be used. The original poster mention that there was no re-bar in the foundation therefore no CEE was present unless the electrician choose to place 20' of #4 copper in the footing.

Again if there is no re-bar that qualifies as a CEE present in the footing it is not up to the inspector to require that 20' of #4 copper be installed, it is instead a choose that is up to the owner.

Chris

 

[Article 90.1]

I agree with Trevor but it will be a much better system than 2 ground rods. It's also a lot easier and cheaper except for the extra trip.

I have had the builder install it for me since they are out there all the time. I make sure they know what to do otherwise I do it. I have one to do Monday and I don't trust the builder so I will do it.

As long as you know where the service is going to go I would go for it.

I don't trust the builders either. "Did you run my number 4"? "Yes, there it is sticking out of the foundation... And the other 20' that I cut off is in the back of my truck"!

 

[Dennis Alwon]

I don't trust the builders either. "Did you run my number 4"? "Yes, there it is sticking out of the foundation... And the other 20' that I cut off is in the back of my truck"!

That is not very likely with my builders. I would worry about how much slack they would leave me-- I would rather have too much..

 

[Article 90.1]

I didn't think so.

I just know that in my experience, if there is any shiny metal, or even insulated wire sticking out of concrete, or in a pool bond, etc. there have been times that it was not there upon my return the next day...