# ufer ground



## newspark80 (Feb 20, 2011)

Can someone direct me to the requirements for a ufer ground connection. I have always just drove ground rods since I rarely do new construction. If I have a ufer ground can I run a #4 cu to the exposed rebar and make my connection and call this good? Code references appreciated!


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## backstay (Feb 3, 2011)

250.52(A)(3)
250.66(B)
Yes


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## Deep Cover (Dec 8, 2012)

The ufer only take the place of the rods in my neck of the woods.



> 250.50 Grounding Electrode System. All grounding electrodes
> as described in 250.52(A)(1) through (A)(7) that are
> present at each building or structure served shall be bonded
> together to form the grounding electrode system. Where
> ...


I should note that if the incoming water is plastic and there isn't any building steel to bond, then the ufer would be good.


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## macmikeman (Jan 23, 2007)

When I read that code section I see that it says rebar at the bottom of the footing. I say that it must be connected to the rebar at the bottom of the footing. Go to your code books and check it out.


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## backstay (Feb 3, 2011)

macmikeman said:


> When I read that code section I see that it says rebar at the bottom of the footing. I say that it must be connected to the rebar at the bottom of the footing. Go to your code books and check it out.


I don't see that. Encased by 2 inches of concrete, located horizontally.


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## 220/221 (Sep 25, 2007)

(3) Concrete-Encased Electrode. An electrode encased
by at least 50 mm (2 in.) of concrete, located horizontally
near the bottom* or vertically, and within that portion of a
concrete foundation or footing that is in direct contact with
the earth,* consisting of at least 6.0 m (20 ft) of one or more
bare or zinc galvanized or other electrically conductive
coated steel reinforcing bars or rods of not less than 13 mm
(1⁄2 in.) in diameter, or consisting of at least 6.0 m (20 ft) of
bare copper conductor not smaller than 4 AWG. Reinforcing
bars shall be permitted to be bonded together by the
usual steel tie wires or other effective means


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## backstay (Feb 3, 2011)

220/221 said:


> (3) Concrete-Encased Electrode. An electrode encased
> by at least 50 mm (2 in.) of concrete, located horizontally
> near the bottom or vertically, and within that portion of a
> concrete foundation or footing that is in direct contact with
> ...


I think you are a cycle behind. We are on the 2011 NEC and 250.52 A(2) & (3) were changed quite a bit.


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## ilikepez (Mar 24, 2011)

I don't know what the inspectors down in Seattle are like but here they want to see the actual connections or a picture of the connections before the concrete is poured.


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## 220/221 (Sep 25, 2007)

backstay said:


> I think you are a cycle behind. We are on the 2011 NEC and 250.52 A(2) & (3) were changed quite a bit.



We are always behind. No TR or AFCI's everywhere yet. Did they change the wording?


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## backstay (Feb 3, 2011)

220/221 said:


> We are always behind. No TR or AFCI's everywhere yet. Did they change the wording?


Yes, no bottom of the foundation is in there. It just talks about how much bar you need and that all of the bar doesn't have to be connected. Also a FPN about what in contact with the earth is.


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## mbednarik (Oct 10, 2011)

#4 you will always be ok, that is the largest you have to run to a UFER.


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## chicken steve (Mar 22, 2011)

macmikeman said:


> When I read that code section I see that it says rebar at the bottom of the footing. I say that it must be connected to the rebar at the bottom of the footing. Go to your code books and check it out.



The hardest part of this code is convincing the 'crete guys we need to do it

~CS~


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## Stranberg (Sep 24, 2011)

Washington State has not adopted the 2011 code and will not due to legislation. From what I understand the 2014 code will be adopted immediately after the release. We always tie 20 feet of bare copper to the bottom bar of the footing which eliminates any issues with connections, bar length, position, etc...


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## Change Order (Apr 11, 2013)

During World War II, the U.S. Army required a grounding system for bomb storage vaults near Tucson and Flagstaff, Arizona. Conventional grounding systems did not work well in this location since the desert terrain had no water table and very little rainfall. 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.
In 1942, Herbert G. Ufer was a consultant working for the U.S. Army. Ufer was given the task of finding a lower cost and more practical alternative to traditional copper rod grounds for these dry locations. Ufer discovered that concrete had better conductivity than most types of soil. Ufer then developed a grounding scheme based on encasing the grounding conductors in concrete. This method proved to be very effective, and was implemented throughout the Arizona test site.
After the war, Ufer continued to test his grounding method, and his results were published in a paper presented at the IEEE Western Appliance Technical Conference in 1963.[1] The use of concrete enclosed grounding conductors was added to the U.S. National Electrical Code (NEC) in 1968. It was not required to be used if a water pipe or other grounding electrode was present. In 1978, the NEC required rebar to be used as a grounding electrode if present. The NEC refers to this type of ground as a "Concrete Encased Electrode" (CEE) instead of using the name Ufer ground.
Over the years, the term "Ufer Ground" has become synonymous with the use of any type of concrete enclosed grounding conductor, whether it conforms to Ufer's original grounding scheme or not.[2]


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## Dennis Alwon (May 9, 2009)

If the rebar is stubbed above grade then it may be used as a point of connection to the ufer (CONCRETE ENCASED ELECTRODE)


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## Dennis Alwon (May 9, 2009)

I install #4 to the rebar at the bottom of the footer but leave 15' or so for connection to the panel. I always bury the extra wire so nobody steals it.


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## BBQ (Nov 16, 2010)

Dennis Alwon said:


> If the rebar is stubbed above grade then it may be used as a point of connection to the ufer (CONCRETE ENCASED ELECTRODE)


In my opinion the NEC does not allow that. The rebar stops being a grounding electrode as soon as it is less than 2" in the concrete.

What section of the NEC allows rebar to act as a GEC?


I do know it is commonly done, I just do not believe the current wording allows it.


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## Dennis Alwon (May 9, 2009)

BBQ said:


> In my opinion the NEC does not allow that. The rebar stops being a grounding electrode as soon as it is less than 2" in the concrete.
> 
> What section of the NEC allows rebar to act as a GEC?
> 
> ...


I understand the argument but 2014 supposedly clarifies it the way I stated it as an extension to the electrode and it will be officially allowed


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## Dennis Alwon (May 9, 2009)

IMO, it is no different then a 10' rod driven into the ground and connecting to the few inches at the top that may be left out of the ground


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## BBQ (Nov 16, 2010)

Dennis Alwon said:


> I understand the argument but 2014 supposedly clarifies it the way I stated it as an extension to the electrode and it will be officially allowed


Cool, I am interested in how it will be worded.

How far can I go on rebar, can I extend it with tie wire and make it reach the panel?


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## BBQ (Nov 16, 2010)

Dennis Alwon said:


> IMO, it is no different then a 10' rod driven into the ground and connecting to the few inches at the top that may be left out of the ground


A ground rod is listed as an electrode, it is an NEC electrode over it's entire length as soon as 8' of it are in the ground.

A rebar is only an electrode while it is inside at least 2" of concrete.

The real difference is due to the NEC definitions of each type of electrode.


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## wendon (Sep 27, 2010)

BBQ said:


> A ground rod is listed as an electrode, it is an NEC electrode over it's entire length as soon as 8' of it are in the ground.
> 
> A rebar is only an electrode while it is inside at least 2" of concrete.
> 
> The real difference is due to the NEC definitions of each type of electrode.


It also has to have 20' of it encased in concrete. This is kind of a dead horse that gets beaten over and over. Our state commercial electrical inspector says to leave the rebar stubbed out and clamp on to that. Easy enough for me. As the code states, you can use rebar ties to tie the rebar together. Normally here they put a 20 piece in the footer and tie on another length to stub out.


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