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The electrodes for electrical grounding are often called ground rods and are often made from steel with a copper clad surface – typically 1 to 2 m long and 20 millimetres (0.79 in) in diameter. These are driven vertically into the ground and bonded together with bare copper wire. [1]
An example implementation given consists of copper rods buried 0.3-0.5m below ground, and spaced 3-7m apart. In situations where space is at a premium, or other difficulties prevent the construction of a proper grounding grid, ground rods may be driven in deeper, and a wire mat may also be used.
According to the IEEE standards, grounding rods are made from material such as copper and steel. For choosing a grounding rod there are several selection criteria such as: corrosion resistance, diameter depending on the fault current, conductivity and others. [30]
Long-distance electromagnetic telegraph systems from 1820 onwards [a] used two or more wires to carry the signal and return currents. It was discovered by German scientist C.A. von Steinheil in 1836–1837, that the ground could be used as the return path to complete the circuit, making the return wire unnecessary. [2]
IG does not break ground loops, which can damage equipment like computers, printers, etc.. Interconnected computer equipment often benefits from single-point grounding. IG is only used with special equipment that requires it. The IG is typically insulated and separate all the way back to the point of earth grounding rod outside of the building.
The extremely dry soil conditions would have required hundreds of feet of rods to be driven into the earth to create a low impedance ground to protect the buildings from lightning strikes. In 1942, Herbert G. Ufer was a consultant working for the U.S. Army. Ufer was given the task of finding a lower cost and more practical alternative to ...
At each grounding point is an array of buried conductive rods that form an electrode, marking the actual transition into the earth for the current. Within the electrodes for Path 27 are sixty rods [s] arranged in a circular rim about 3,000 feet (910 metres) in diameter [55] and spaced evenly for the best result.
This type of cable is the least expensive for a given size and is appropriate for dry indoor applications. The designation NM XX-Y indicates, respectively, the type of sheathing (in this case, non-metallic), the size of the main conductors, and the total number of circuit conductors (exclusive of the grounding conductor). For example, NM 14-2 ...