Foundation earthing not installed

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dkidd said:
No.

"Metallic components shall be encased by at least 50 mm
(2 in.) of concrete and shall be located horizontally within that
portion of a concrete foundation or footing that is in direct
contact with the earth or within vertical foundations or structural
components or members that are in direct contact with
the earth. If multiple concrete-encased electrodes are present
at a building or structure, it shall be permissible to bond only
one into the grounding electrode system."

I have known of AHJs that make the contractor dig down and cut into the foundation to make the connection. Saying "I forgot" doesn't cut it.
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Keep in mind the OP is in Turkey.

Since it is impossible to determine if the construction meets the requirements for a CEE, I'd say skip it and drive a couple ground rods and be done with it. Assuming that they are actually using NFPA 70 as their standard and the OP isn't just looking for opinions on what might be considered simply good practice.
 
gadfly56 said:
Keep in mind the OP is in Turkey.

Since it is impossible to determine if the construction meets the requirements for a CEE, I'd say skip it and drive a couple ground rods and be done with it. Assuming that they are actually using NFPA 70 as their standard and the OP isn't just looking for opinions on what might be considered simply good practice.
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I see that OP is in Turkey, and they are quoting NEC as requirements.
 
gadfly56 said:
Keep in mind the OP is in Turkey.

Since it is impossible to determine if the construction meets the requirements for a CEE, I'd say skip it and drive a couple ground rods and be done with it.
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There is another perspective on this topic.

If there is no official inspection of the construction of the footing you sort of can't verify whether there is a qualifying electrode within it, or if building steel is a qualifying electrode either.
 
mwm1752 said:
Why have a path if it is so insignificant to you?
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Seems like that kind of was his point.

I don't have a problem with having a path regardless of how good or bad that path is, but don't see it being as critical as some think it is. Bonding of non current carrying components is much more important then grounding. You can't expect the earth to reliably carry current for under 1000 volts applications.

Now enter the lightning strike with extremely high voltage and high frequency components, that electrode that only has 100 ohms impedance still looks like a low impedance, and you may not have much difference in damages even if that electrode were 10 ohms.
 
kwired said:
If you can only get 100 ohms with two rods chances are you aren't getting down to only one ohm with the CEE, unless it is a really large CEE. But I also agree that it really doesn't matter. Inspectors get fixed on the importance of a GES, when in reality unless you are not connected to a utility system with many grounding electrodes connected to it, one missing electrode at one service isn't as big of a deal as they want it to be.

Areas with a high level of lightning incidents maybe it becomes somewhat higher importance though.
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it only takes one lighting strike to cause damage -- I've seen it
 
kwired said:
Seems like that kind of was his point.

I don't have a problem with having a path regardless of how good or bad that path is, but don't see it being as critical as some think it is. Bonding of non current carrying components is much more important then grounding. You can't expect the earth to reliably carry current for under 1000 volts applications.

Now enter the lightning strike with extremely high voltage and high frequency components, that electrode that only has 100 ohms impedance still looks like a low impedance, and you may not have much difference in damages even if that electrode were 10 ohms.
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did you opine or is that your scientific study -- the military whom designed the UFER may disagree.
 
dkidd said:
I see that OP is in Turkey, and they are quoting NEC as requirements.
Click to expand...

Interestingly, I searched for a national electrical code for Turkey and couldn't find anything. There was some reference to the use of ad hoc standards based on the project specifications. So, my question remains: is this actually a requirement or is the engineer just trying to do his best without having the benefit of an actual local standard?
 
mwm1752 said:
did you opine or is that your scientific study -- the military whom designed the UFER may disagree.
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The UFER is proven to be less resistance in nearly all instances then a ground rod. Or two, or three, or maybe even a hundred.

That has nothing to do with whether presence of a grounding electrode of any resistance actually benefits the building or structure.

The military did not design the UFER. Herbert G. Ufer was a consultant working for the U.S. Army, and they wanted him to find a better method to protect bomb storage vaults from lightning strikes then ground rods provided - particularly in the southwest desert.

This original intent had little to do with electrical systems and a lot to do with lightning protection.
 
mwm1752 said:
it only takes one lighting strike to cause damage -- I've seen it
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So have I, with structures that have grounding electrodes as well as those that don't.

Grounding electrode on the electrical system is not the same thing as a lightning protection system.
 
kwired said:
The UFER is proven to be less resistance in nearly all instances then a ground rod. Or two, or three, or maybe even a hundred.

That has nothing to do with whether presence of a grounding electrode of any resistance actually benefits the building or structure.

The military did not design the UFER. Herbert G. Ufer was a consultant working for the U.S. Army, and they wanted him to find a better method to protect bomb storage vaults from lightning strikes then ground rods provided - particularly in the southwest desert.

This original intent had little to do with electrical systems and a lot to do with lightning protection.
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"The UFER is proven to be less resistance in nearly all instances then a ground rod. Or two, or three, or maybe even a hundred." comparing to 100 rods seems significant.

"military did not design the UFER. Herbert G. Ufer was a consultant working for the U.S. Army," ???( the army is not military ?)

"This original intent ( electronic malfunction protection) had little to do with electrical systems ??? and a lot to do with lightning protection" ( again the grounding electrode system primary objective is to protect electrical system damage from high voltages induced from lighting strikes by aiding its path to earth to be absorbed -- have seen the results of a home burned down with the conclusion of faulty install of electrode system, the copper staple to the exterior absorbed so much energy it ignited the wood siding on fire. quite a bit of the insulation on NM was compromised and had to be replaced.

We certainly do have different values for the electrode system and its importance. You seem to be on a scale of 1 to my 9.
 
kwired said:
So have I, with structures that have grounding electrodes as well as those that don't.

Grounding electrode on the electrical system is not the same thing as a lightning protection system.
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a
true but the purpose follows the same path -- is lighting protection a better path to earth?????
 
And of course depending on the magnitude and duration of the strike determines how well any grounding electrode system will work. I have seen sites with massive grounding systems driven 10' rods around the complete site and a Ufer 27' into the ground 15' across. Took a lighting hit on the tower fried everything in the site, all the electronics in an adjacent 7-11, house and Cable company facility, blew the TVSS/SPD off the wall and damaged the concrete for the tower.

In the OP's case electric jack hammer, expose some rebar, I'd Cad Weld on your GEC (we almost always Cad Weld) and be done with it.
 
mwm1752 said:
a
true but the purpose follows the same path -- is lighting protection a better path to earth?????
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The idea that a "better" ground will have any effect whatsoever on lightning damage is just a myth.

It probably will help with a properly constructed LPS to have a lower impedance path to earth, but the normal earthing required by the code does little or maybe even nothing to protect a typical structure from lightning damage.
 
gadfly56 said:
Interestingly, I searched for a national electrical code for Turkey and couldn't find anything. There was some reference to the use of ad hoc standards based on the project specifications. So, my question remains: is this actually a requirement or is the engineer just trying to do his best without having the benefit of an actual local standard?
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The site is located in middle east and the designers in turkey. however, the project does have a requirement to meet the NEC. and turkey does have local standards similar to the European ones:"TS/EN"
 
mwm1752 said:
"The UFER is proven to be less resistance in nearly all instances then a ground rod. Or two, or three, or maybe even a hundred." comparing to 100 rods seems significant.

"military did not design the UFER. Herbert G. Ufer was a consultant working for the U.S. Army," ???( the army is not military ?)

"This original intent ( electronic malfunction protection) had little to do with electrical systems ??? and a lot to do with lightning protection" ( again the grounding electrode system primary objective is to protect electrical system damage from high voltages induced from lighting strikes by aiding its path to earth to be absorbed -- have seen the results of a home burned down with the conclusion of faulty install of electrode system, the copper staple to the exterior absorbed so much energy it ignited the wood siding on fire. quite a bit of the insulation on NM was compromised and had to be replaced.

We certainly do have different values for the electrode system and its importance. You seem to be on a scale of 1 to my 9.
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Some of what you have in quotation marks is what I said and some of it is changed from what I said??

Information I posted is based on what I read in this Wiki article, most of it coming from the very first section titled "history"
Ufer was not in the Army, he was a consultant and the Army was his client.

The article said "The extremely dry soil conditions would have required hundreds of feet of copper rods to be inserted into the ground in order to create a low enough impedance ground to protect the buildings from lightning strikes."

"Electronic malfunction protection" was never mentioned ?


Lightning has little trouble with 25 ohms of resistance on an electrode, and 100 ohms probably makes little difference as well.
You ever look at the conductor used on a real lightning protection system? Quite different then what we use for GEC's to electrical systems. If you get a direct lightning strike to a building that has a GEC with resistance of less then 10 ohms you are still going to have damage, and probably a lot of it.

A 20 foot CEE still has many times more soil contact surface then several hundred ground rods, which is why it will always be a lower impedance, which is basically what Herbert Ufer had discovered.

mwm1752 said:
a
true but the purpose follows the same path -- is lighting protection a better path to earth?????
Click to expand...
 
Gilf said:
The site is located in middle east and the designers in turkey. however, the project does have a requirement to meet the NEC. and turkey does have local standards similar to the European ones:"TS/EN"
Click to expand...

Since apparently we've wandered into lightning protection I'm not too concerned with exacerbating thread drift. Thank you for clarifying that the project has a specific requirement to meet the US NEC. I did see references to the TS/EN standards at a couple of Turkish sites, but nothing that I could pin down as an electrical standard. Out of curiosity, do you have a link to the current Turkish national or local standards for electrical installation similar to the US NEC?

Q1. Regarding foundation earthing. There is no requirement to specifically design a foundation to act as a CEE. If you used fiberglass rod for rebar, or the rebar was plastic-coated, or there was a moisture barrier (ie, plastic sheeting) under the slab, all these things would prevent you from having a CEE or Ufer system. You could look at NFPA 70-2014 250.50(A)(4) as a possible solution (grounding ring) if there is a concern.

Now if, and only if, the foundation reinforcement meets the requirements to be a CEE, you will have to expose the rebar somehow and cadweld a connection to it or use some other approved method.

Q2. You can still use an exothermic weld to make the connection. As others have pointed out, there are other ways to get it done that are acceptable and that may or may not be easier to execute.
 
gadfly56 said:
Since apparently we've wandered into lightning protection I'm not too concerned with exacerbating thread drift. Thank you for clarifying that the project has a specific requirement to meet the US NEC. I did see references to the TS/EN standards at a couple of Turkish sites, but nothing that I could pin down as an electrical standard. Out of curiosity, do you have a link to the current Turkish national or local standards for electrical installation similar to the US NEC?

Q1. Regarding foundation earthing. There is no requirement to specifically design a foundation to act as a CEE. If you used fiberglass rod for rebar, or the rebar was plastic-coated, or there was a moisture barrier (ie, plastic sheeting) under the slab, all these things would prevent you from having a CEE or Ufer system. You could look at NFPA 70-2014 250.50(A)(4) as a possible solution (grounding ring) if there is a concern.

Now if, and only if, the foundation reinforcement meets the requirements to be a CEE, you will have to expose the rebar somehow and cadweld a connection to it or use some other approved method.

Q2. You can still use an exothermic weld to make the connection. As others have pointed out, there are other ways to get it done that are acceptable and that may or may not be easier to execute.
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Thanks a lot,it is a lot more clear now.

The standards are also similar to the EN/IEC in numbers. You can see them in below link.

https://intweb.tse.org.tr/Standard/...121065088069103122116075065074050108056082116
 
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