Concrete encased electrode

[ktoohey]

I am asking for an interpretation of the concrete encased electrode where it states in the 1999 Electric Code that 20 Ft. of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars be located within and near the bottom of a concrete foundation or footing.
We typically see 20 foot rebar tied then pulled up at the rizer about 3 ft now my question is that 3 foot up out of the footing and 17 ft. left satisfy the intent of the code for the 20ft?
Kathy Toohey

 

[bphgravity]

Re: Concrete encased electrode

I feel you must have 20' or more in the concrete. 17' in and 3' out, doesn't exactly meet the section requirement, even though it may be just as effective.

 

[don_resqcapt19]

Re: Concrete encased electrode

The 20' of rebar encased in the concrete does not have to be a single section of rebar. If it is tied to the other rebar in the footing, it will have more than the required 20'.
Don

 

[a.wayne3@verizon.net]

Re: Concrete encased electrode

When a footer is inspected the rebar has to be tyed with wire tight.So 20 ft. is easy to meet,actually there is allot more footage than required.Here a footer has plastic barrier except where the ufer is exposed to earth contact.As long as building inspector signs it off it`s all good.Our building AHJ signs off our uffer.The electrical inspector never sees it :roll:

 

[gndrod]

Re: Concrete encased electrode

Kathy,

The Ufer can also be a 20'x #4 Cu AWG (min size)in addition to contiuous conductor stub-out of the stemwall long enough to reach into the Service panel ground bus. The 20' at NEC 250.52(A)(3)"..encased by at least 2" of concrete located within footing bottom..that is in direct contact with the earth.

rbj, Seattle