Leakage current detector for leakage currents of any type - has at least one total current transformer and accepts AC normal DC or pulsed DC

摘要

The current transformer primary winding consists of mains cables, and has at least one magnetic bias winding and at least one secondary winding. The secondary winding output is connected to a trip, possibly through an amplifier and an evaluation circuit. The trip operates a latch operating contacts in the mains cables. Magnetic bias winding (9,10) generates a magnetisation with a d.c. and an a.c. component, so that in a state free from leakages magnetic flux varies between saturation and a value below remanence induction. The windings (9,10) are connected with a generator whose windings are coupled to the other circuit links and to the trip circuit.