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Tuesday, October 13, 2020
Question:
Good Morning CQD,
I am constructing a shop building at the foundation stage, and there is a requirement for a ufer electrode. NEC 250.52(A)(3) states the electrode is to be coated in electrically conductive material. What do you consider an electrically conductive material?
Edward Iskra
A
Answer:
Hello Edward,
Thanks for the question. In Section 250.52(A)(3)(1) indicates that the concrete-encased electrode can consist of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm (1∕2 in.) in diameter, installed in one continuous 6.0 m (20 ft) length, or if in multiple pieces connected by the usual steel tie wires, exothermic welding, welding, or other effective means to create a 6.0 m (20 ft) or greater length. It can also be a bare copper conductor not smaller than 4 AWG. The idea is that there is a conducting connection to the concrete, which could be accomplished using an open reinforcing bar. Coated reinforcing bars would not be accepted as the steel would be insulated from the concrete. I hope this is helpful.