A PROCESS AND A DEVICE FOR SAFEGUARDING AN ALTERNATING CURRENT CIRCUIT HAVING AN ELECTRICAL LOAD ASSOCIATED THEREWITH

A device runs a precheck of an inductive load for an overload prior to swhing on to supply mains. For this purpose, following switching-on for a load precheck, initially a phase limited voltage signal is applied to the load, whereby the voltage signal duration gradually increases. With the start of each application of voltage, the active current is measured in a narrow time window. If it does not exceed a predetermined active current limit at an application of a specific effective voltage, the load is switched to the mains. Otherwise, the switch-on process is cut off. This switching-on process avoids a high taxing of the mains in the event of a short circuit or an overload. The active current window begins with the application of voltage to the load. At a different time than this time window, a further measurement window is provided for the reactive current, whereby this measurement window begins with the zero crossing of the alternating voltage. The measurement of the reactive current serves to determine a defined state of magnetization of an inductive load in order then to be able to switch the load to the mains in phase and without any switch-on current surge.