Concrete Encased Electrode

[DonaldKMorgan]

250.52(A)(3)describes what a CEE is and the requirements for it, but I am concerned about the effects of the concrete on the bare copper. We have always been told to protect the bare copper from concrete to allow the copper to remain intact. Exhibit 250.22 shows a sleeve as the copper emerges from the slab but the connection is still in the concrete. One answer was to turn the rebar up into an interior wall and make the connection there, however our inspector insists that the connection be accessible. 250.68 (A) Exception No. 1 could apply but, I think the writers were referring to the connection that is actually encased. Finally my interpertation to the requirement for CEE was to enhance the current grounding requirements not to replace them, am I incorrect in this thnking?

 

[JohnE]

Re: Concrete Encased Electrode

I don't believe that there are any adverse effects of bare copper in contact with concrete. I believe the figure shows copper conductor sleeved to protect from damage where it emerges from pour.

 

[bphgravity]

Re: Concrete Encased Electrode

Yes, I agree with your interpretation on the code change. The CEE was always intended to be used.

There are no problems with copper and concrete. Just be certain that if a clamp is used, it needs to be listed for direct burial or encasement in concrete. If you are attaching to rebar, make sure the clamp is listed for use with rebar.

If the only concern is accessibilty to the connection where the rebar is turned up into a wall, just add a mud-ring and blank plate so the connection can be inspected or accessed at any time in the future.

 

[bphgravity]

Re: Concrete Encased Electrode

Here is a statement from www.copper.org

Concrete is often thought to cause corrosion of copper, but this is a misconception. Copper is unaffected by Portland cements which provide an alkaline environment. However, non-alkaline cements containing sulphurous ash or other inorganic acids should be avoided, as should foamed concretes which employ ammonia-containing foaming agents