VERFAHREN UND ZUGEHOERIGE MESSANORDNUNG ZUR BEWERTUNG DES LICHTBOGENS AN GLEITKONTAKTEN VON ELEKTRISCHEN MASCHINEN

摘要

In motors or the like, for example, the arc, especially commutator sparking, and/or a replacement criterion is detected at the connecting terminals and evaluated with reference to predetermined characteristics. According to the invention, either the motor current is measured and the high-frequency component generated by commutator sparking is evaluated from that or the high-frequency components are decoupled at the connection terminals of the electric motor and capacitatively short-circuited. Alternatively, high-frequency stray currents flowing from the connection terminals to the casing can be detected and capacitatively short-circuited. The individual measuring arrangements therefore essentially comprise an h.f. current transformer (10), the signal from which is taken to an evaluating instrument (12, 22, 32).