Protection of Electric Distribution Systems
In overhead electric transmission (high-tension) systems, one or two lighter gauge conductors may be mounted to the top of the pylons, poles, or towers not specifically used to send electricity through the grid. These conductors, often referred to "static", "pilot" or "shield" wires are designed to be the point of lightning termination instead of the high-voltage lines themselves. These conductors are intended to protect the primary power conductors from lightning strikes.
These conductors are bonded to earth either through the metal structure of a pole or tower, or by additional ground electrodes installed at regular intervals along the line. As a general rule, overhead power lines with voltages below 50 kV do not have a "static" conductor, but most lines carrying more than 50 kV do. The ground conductor cable may also support fibre optic cables for data transmission.
In some instances, these conductors are insulated from direct bonding with earth and may be used as low voltage communication lines. If the voltage exceeds a certain threshold, such as during a lightning termination to the conductor, it "jumps" the insulators and passes to earth.
Protection of electrical substations is as varied as lightning rods themselves, and is often proprietary to the electric company.
Read more about this topic: Lightning Rod, Structure Protectors
Famous quotes containing the words systems, distribution, protection and/or electric:
“Not out of those, on whom systems of education have exhausted their culture, comes the helpful giant to destroy the old or to build the new, but out of unhandselled savage nature, out of terrible Druids and Berserkirs, come at last Alfred and Shakespeare.”
—Ralph Waldo Emerson (1803–1882)
“My topic for Army reunions ... this summer: How to prepare for war in time of peace. Not by fortifications, by navies, or by standing armies. But by policies which will add to the happiness and the comfort of all our people and which will tend to the distribution of intelligence [and] wealth equally among all. Our strength is a contented and intelligent community.”
—Rutherford Birchard Hayes (1822–1893)
“The diversity in the faculties of men, from which the rights of property originate, is not less an insuperable obstacle to a uniformity of interests. The protection of these faculties is the first object of government.”
—James Madison (1751–1836)
“The more I see of democracy the more I dislike it. It just brings everything down to the mere vulgar level of wages and prices, electric light and water closets, and nothing else.”
—D.H. (David Herbert)