Verfahren und Vorrichtung zur Fehlerstromueberwachung in einem elektrischen Wechselstromnetz

WO2004017483 A UPAB: 20040326 NOVELTY - A process for monitoring fault currents in AC mains of given frequency comprises determining (12), digitizing (14) and summing (16) current values, forming sum blocks (18) and splitting these into spectral components (24) and monitoring (36) against a threshold spectral value to evaluate the danger of the fault current. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a device for operating the above process. USE - As a method and device for monitoring fault currents in an AC mains (claimed) in order to evaluate the danger for people and material. ADVANTAGE - Frequently unnecessary disconnections on safety grounds are avoided and a safer and more reliable of the danger potential is achieved