concrete encased electrode

[gadfly56]

After discussing this with a member of CMP 5, I was told that galvanic action is not an issue with copper and steel embedded in concrete.

Chris

Well, OK....I guess. {shuffles off, muttering about "experts" and "the Titanic"}

 

[raider1]

Well, OK....I guess. {shuffles off, muttering about "experts" and "the Titanic"}

I was just stating what I was told when asking this same question.

Chris

 

[infinity]

Is twenty feet of 4 AWG in a concrete footing an electrode?

Is twenty feet of 1/2" re-bar in a concrete footing an electrode?


Now what does 250.50 say?



Just pointing it out ........... :grin:

If you put in 20' of bare copper you don't need to use the rebar. If we call the 1/2" rebar an electrode then last sentence of 250.52(A)(3) says that we do not need to use it.

 

[Dennis Alwon]

If you put in 20' of bare copper you don't need to use the rebar. If we call the 1/2" rebar an electrode then last sentence of 250.52(A)(3) says that we do not need to use it.

Yes but which one---if the rebar is required then that would be the one, IMO. I had not thought of this scenario since I always opt for the rebar but I am beginning to think you must use the rebar if it is present.

 

[infinity]

Yes but which one---if the rebar is required then that would be the one, IMO. I had not thought of this scenario since I always opt for the rebar but I am beginning to think you must use the rebar if it is present.

\


If you have two electrodes, the 20' of copper and the rebar doesn't the last sentence say you do not need to use both?

 

[Dennis Alwon]

\


If you have two electrodes, the 20' of copper and the rebar doesn't the last sentence say you do not need to use both?

Yes it does but if the rebar is there then it is present and must be used. Thus the 20' of copper would be the one that isn't necessary. 250.50 states we must use all electrodes that are present- the key is whether the rebar is an electrode. To me it is so it must be used.

 

[infinity]

Yes it does but if the rebar is there then it is present and must be used. Thus the 20' of copper would be the one that isn't necessary. 250.50 states we must use all electrodes that are present- the key is whether the rebar is an electrode. To me it is so it must be used.

So if a building had two additions one on the south side and one on the north. Both have 20' of 1/2" rebar, do you need to use both or do you need to use a concrete encased electrode which would be either?

 

[throttlebody]

It is still a building or structure if the addition is tied to the main structure, making still yet, a single building or structure.

 

[Dennis Alwon]

So if a building had two additions one on the south side and one on the north. Both have 20' of 1/2" rebar, do you need to use both or do you need to use a concrete encased electrode which would be either?

Good question, I am not certain-- we must use the steel , water pipe and CEE if present then perhaps if 2 CEE's are present we would need to use both- much in the same way we use 2 rods. I see your point but to steal your thunder from another thread-- I still like my way.

 

[infinity]

Good question, I am not certain-- we must use the steel , water pipe and CEE if present then perhaps if 2 CEE's are present we would need to use both- much in the same way we use 2 rods. I see your point but to steal your thunder from another thread-- I still like my way.

Under the 2005 and earlier versions I would say that the wording could be interpreted either Dennis's way or my way. This was changed in the 2008 to state that only one CEE is required even if multiple sections of CEE exist.