Device and method for detecting a neutral wire break

摘要

The invention relates to a device for detecting a neutral conductor break in the supply line to a device (100) operated on a three-phase system (1) with phase conductors (L1, L2, L3) and a neutral conductor (N), characterized in that a virtual 2) is formed by interconnecting the phase conductors (L1, L2, L3) and the neutral conductor (N) via voltage dividers (3, 4, 5, 6, 7, 8, 9, 10), that the device comprises a measuring device (12 ) with a measuring input has for detecting at least the measuring signal curve of the neutral conductor (N) at the center tap of the neutral conductor (N) associated voltage divider (9, 10) that the device has a resistive and rectifying properties having imaging circuit (11) in the device between the three phases (L1, L2, L3) and the neutral conductor (N) is connected, whereby in case of interruption of the neutral conductor (N), the measuring signal of the neutral conductor with respect to the virtual star point with a DC component is applied.