Originally Posted By: jpeck
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That abandoned galvanized water supply pipe would not qualify as a rod or pipe electrode because: It is not driven in 8 ft below grade or at an angle not to exceed 45 degrees, or unless it is buried in a trench 30" deep. I doubt the water line is is at least 30" deep (unless you were in a frost area of 30" depth or more, then it might. It also will likely not meet the requirements of rod or ground electrodes because it is probably black iron pipe (see second code reference).
G) Rod and Pipe Electrodes. The electrode shall be installed such that at least 2.44 m (8 ft) of length is in contact with the soil. It shall be driven to a depth of not less than 2.44 m (8 ft) except that, where rock bottom is encountered, the electrode shall be driven at an oblique angle not to exceed 45 degrees from the vertical or, where rock bottom is encountered at an angle up to 45 degrees, the electrode shall be permitted to be buried in a trench that is at least 750 mm (30 in.) deep. The upper end of the electrode shall be flush with or below ground level unless the aboveground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10.
Cast iron sewer pipe does not meet the requirements for pipe electrodes.
(5) Rod and Pipe Electrodes. Rod and pipe electrodes shall not be less than 2.5 m (8 ft) in length and shall consist of the following materials.
(a) Electrodes of pipe or conduit shall not be smaller than metric designator 21 (trade size ?) and, where of iron or steel, shall have the outer surface galvanized or otherwise metal-coated for corrosion protection.
(b) Electrodes of rods of iron or steel shall be at least 15.87 mm ( in.) in diameter. Stainless steel rods less than 16 mm ( in.) in diameter, nonferrous rods, or their equivalent shall be listed and shall not be less than 13 mm (? in.) in diameter.