While power electronics is continuously superseding the traditional “hardware” solutions in electrical engineering, common mechanical contacts still remain important constituents of any electrical power distribution system. A survey of the types of switches, relays and contactors, their properties and areas of application will be given. Further, a detailed overview shall draw a picture of the impact caused by new electronic types of loads upon these conventional mechanical contacts. More in particular, the inrush currents resulting from this situation are far from negligible. This paper highlights the causes, types and effects of inrush currents. It discusses how these problems are dealt with by different suppliers and what information these provide their customers with in order to deal with these impacts.
Application Note Author & Publisher: Leonardo ENERGY