Effects of surge voltages
More often than not, surge voltages which couple into a circuit cause considerable damage to equipment and devices. Devices that are in constant use are at particularly high risk.
This damage can result in extremely high costs, as on top of the costs for replacement or repairs further costs may arise as a result of prolonged system failure or even due to the loss of software or data.
Incidence of loss
According to statistics from German insurers for 2008, 57.9% of claims for building fire insurance related to damage caused by surge voltages. Damage caused by lightning represented 10.5%, while 31.6% was attributed to other damage (source: GDV - German Insurance Association).
The extent of the damage depends largely on the dielectric strength of the components used and the energy that can be converted in the affected circuit.
Effective protection according to the protective circuit principle
The protective circuit principle describes a concept for complete protection against surge voltages. An imaginary circle should be drawn around the item to be protected. Surge protective devices should be installed at all points where cables intersect this circle. The nominal data of the relevant circuit should be taken into consideration when selecting the protective devices. The area within the protective circuit is thus protected in such a way that conducted surge voltage couplings are prevented.
The protective circuit concept can be broken down into the following areas:
- Power supply
- Measurement and control technology
- Information technology
- Transceiver technology