High Power Grounding: Changes to state-of-the-art over the past 150 years

Changes to state-of-the-art over the past 150 years This presentation tracks the progress of electrical grounding design in the United States over 150 years, from simple use of electrodes (ground rods) in the 1800s to the modern US ground grid, and the misnomer term "leakage” current from conductors into the soil. Emphasis is placed on intellectual discussions about the transmission of grounding energy into the soil via various shaped conductors, including round cables, flat plates, round rods, and flat strips from about 1936 to 1953, which resulted in a variety of ground grid designs ranging from 1/0 copper to 500 kcmil. A new class of flat composite strip conductors is explored with benefits that challenge the predominance of round 4/0 copper cable by addressing some of the familiar issues, including theft, buried corrosion, and breakage… and driving the transmission of fault current into the soil, instead of “leaking” it there.