Description
ESE Lightning Protection System in Bangladesh
The effects of lightning are those of a high-strength impulse current that propagates initially in a gaseous environment (the atmosphere), and then in a solid, more or less conductive medium (the ground):
– visual effects (flash): caused by the Townsend avalanche mechanism
– acoustic effects: caused by the propagation of a shock wave (rise in pressure) originating in the discharge path; this effect is perceptible up to a range of around 10 km
– thermal effect: heat generated by the Joule effect in the ionized channel
– electrodynamic effects: these are the mechanical forces applied to the conductors placed in a magnetic field created by the high voltage circulation. They may result in deformations
– electrochemical effects: these relatively minor effects are conveyed in the form of electrolytic decomposition through the application of Faraday’s law
– induction effects: in a variable electromagnetic field, every conductor harnesses induced current
– effects on a living being (human or animal): the passage of a transient current of a certain r.m.s value is sufficient to incur risks of electrocution by heart attack or respiratory failure, together with the risk of burns.
Lightning causes two major types of accidents:
– accidents caused by a direct stroke when lightning strikes a building or a specific zone. This can cause considerable damage, usually by fire. Protection against this danger is provided by lightning air terminal systems
– accidents are caused indirectly, as when the lightning strikes or causes power surges in power cables or transmission links. Hence the need to protect with SPD the equipment at risk against the surge voltage and indirect currents generated.
