Since July 1, 1988, the City of Boise Electrical Division has required a “Concrete-Encased Electrode” on all new construction within Boise City Limits. Concrete-Encased Electrodes are also required for additions to existing buildings where the service is being moved.
Article 250: Concrete-Encased Electrode . An electrode encased by at least 2 inches (50 mm) of concrete, located within and near the bottom of a concrete foundation or footing that is direct contact with the earth, consisting of at least 20 ft (6.0 m) of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 1/2 inch (13 mm) in diameter, or consisting of at least 20 ft (6.0 m) of bare copper conductor not smaller than 4 AWG. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.
4 AWG or larger bare copper conductor or steel reinforcing bar or rod not less than 1/2 inch diameter at least 20 ft . long.
Grounding electrode conductor
Non-metallic protective sleeve
Connection listed for the purpose
Foundation in direct
contact with earth
2 in. min.