250.68(C)(3) Grounding Electrode Connections.
Code Change Summary: A new subsection was added to make it clear that ½ in. or larger footing rebar, used as a concrete encased electrode, can be turned up out of the footing and connected to a grounding electrode conductor above grade.
One of the requirements of a concrete encased electrode is that it is fully encased in concrete. Often, ½ in. or larger rebar, used to reinforce the footing, is also used as a grounding electrode but it only qualifies as a grounding electrode when completely encased in concrete.
Once the rebar is turned up with a 90° bend in order to get it out of the footing and above slab, it is no longer concrete encased. The portion of rebar above slab without concrete encasement no longer qualifies as an actual electrode but according to the 2014 code language, this is ok. A grounding electrode conductor can then be run from the electric service and connected to the rebar stub up in an accessible location.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).
2014 Code Language:
250.68(C) Grounding Electrode Connections. Grounding electrode conductors and bonding jumpers shall be permitted to be connected at the following locations and used to extend the connection to an electrode(s):
(3) A concrete-encased electrode of either the conductor type, reinforcing rod or bar installed in accordance with 250.52(A)(3) extended from its location within the concrete to an accessible location above the concrete shall be permitted.