Overvoltage characteristics of atmospheric origin
From Electrical Installation Guide
Lightning strokes in a few figures: Lightning flashes produce an extremely large quantity of pulsed electrical energy (see Figure J4)
Between 2000 and 5000 storms are constantly undergoing formation throughout the world. These storms are accompanied by lightning strokes which represent a serious hazard for persons and equipment. Lightning flashes hit the ground at an average of 30 to 100 strokes per second, i.e. 3 billion lightning strokes each year.
The table in Figure J3 shows some lightning strike values with their related probability. As can be seen, 50% of lightning strokes have a current exceeding 35 kA and 5% a current exceeding 100 kA. The energy conveyed by the lightning stroke is therefore very high.
|Cumulative probability (%)||Peak current (kA)|
Fig. J3: Examples of lightning discharge values given by the IEC 62305-1 standard (2010 - Table A.3)
Lightning also causes a large number of fires, mostly in agricultural areas (destroying houses or making them unfit for use). High-rise buildings are especially prone to lightning strokes.