250.52 (a)(3)

[surf more]

so this method would replace 2 ground rods???guess you would just termiate #4 at service??????

 

[KevinVost]

If you have a CEE (UFER) complying with 250.52 A 3, then you would not need to install ground rods, its not about replacing rods, its about what electrode is available. Check 250.50, it says any electrode present, must be used. If the CEE is not available (or any other electrode) you would be required to install a electrode complying with 250.52 A4 - A7.

 

[surf more]

that is what i was getting at ,by complying to article 250.52(a)(3) you would not need two ground rods...thanks

 

[infinity]

that is what i was getting at ,by complying to article 250.52(a)(3) you would not need two ground rods...thanks

Yes, that is correct. The use of a CEE eliminates the need to use ground rods. If the CEE is made of 20' of #4 or larger rebar your GEC is sized based on 250.66 and is not required to be larger than #4.

 

[tom baker]

Ground rods were required to be installed to supplement a metal underground water pipe(metal today, plastic tommorrow), and in the 1970s we saw less and less metal underground water pipes, so we ended up just using ground rods as the GE. A CEE could always be used, but the 05 NEC made it mandatory. There is no need to supplement a CEE with a ground rod.
It used to be drive two and go home, now its pour one and go home.

 

[bphgravity]

I understand the context of the question but think Tom hits on an important point. One type of electrode doesn't replace another one. Try not to look at it that way. The code makes it clear that ALL electrodes that are present be bonded together to form the GES. When certain electrodes are not present, the code provides other methods of "creating" an electrode.

 

[vinster888]

so conveniently enough, no one went and stuck some rods in there for you, so you dont need to install them. but if someone had snuck them in when you werent looking, then you would need to connect to them.

 

[cpal]

I understand the context of the question but think Tom hits on an important point. One type of electrode doesn't replace another one. Try not to look at it that way. The code makes it clear that ALL electrodes that are present be bonded together to form the GES. When certain electrodes are not present, the code provides other methods of "creating" an electrode.

Bryan thats the best explanation I've heard in a long time.