Installation of over voltage protection in LV systems
Author: Denis Imširović, B.SC.E.E.
From old times the human beings have been fascinated by the lightning phenomenon, but unfortunately they were unable to explain it. Nowadays, in the era of computers and other sensitive devices it has become necessary to expand technical possibilities for successful or complete protection of vitally important services.
1. Introduction
Technology is entering into the future with big steps; therefore the devices are installed into the areas where can not be imagine a while ago. An enormous quantity of information is used
over the world, which must be properly connected, reach faster transfers and use best possible protection. Now days especially in such an economically and technically developed world
there is no possibility to refuse those demands. Over voltage protection must be considered, as hard cuirass which protects devices and people against strong outside influences, as stroke of
lightning and prevent technological and economical damage.
Over voltages are caused because of following:
- Atmospheric discharges resulting in direct strikes to structures or systems, or large induced voltages caused by those direct strikes
- Over-voltage cause by power switching transients
- Faults in power distribution systems such as line-to-ground contacts, or commingling of power and low voltage telecommunication lines
- Power regulation faults as can occur near large industrial consumers of power or near electrified rail systems
The statistic of damages caused on electrical apparatus is demonstrated in below graph (Picture 1). The biggest share damage on electrical apparatus is caused because of over voltages and ranges between 27% and 35%.
