Earthing guide for surge protection
A lightning flash is caused by an electrical current flowing in the
atmosphere. Moist air currents interacting with ice particles within a cloud lead to the formation of concentrations of electric charges at different heights. Very large voltage differences, of the order of many millions of volts, develop between the charge concentrations and the base of the cloud and the surface of the earth. When this voltage difference becomes sufficient to overcome atmospheric resistance, a lightning stroke occurs. Most lightning strokes take place cloud-to-cloud but some are cloud-to-ground. As a result of cloud to ground lightening, installations which are prone to attract lightening and get damaged due to high current need to be well protected.
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