Experimental investigations on switching overvoltages induced by current chopping in low voltage contactors

Based on a large number of experiments the effects of current chopping in low voltage contactors are investigated for switching off inductive loads. The experimental set-up consists of a standard three-phase low voltage application. Voltage and current are measured three phase at the contactor and at the load simultaneously. 12 signals are evaluated per experiment. The experimental results are compared with the experiences of medium voltage applications.