Risk-based vs Rule-based Electromagnetic Compatibility in Large Installations

Many engineers (still) think that if the equipment fulfils the applicable standard, that a large installation will work first-time-right. This rule-based approach, i.e. following electromagnetic interference standards, is the basic methodology for small apparatus. But for complex and large installations we need a smarter approach, based on assessing and controlling the electromagnetic risks. This trend is also visible in the newest European Directives where a risk-based approach is even mandatory; This shall result in electromagnetic compatible systems operating properly in their intended environment. This risk-based approach is described, the process and methodology is detailed, and some examples are given in this paper.