THREE OR FOUR POLE LOW-VOLTAGE POWER SWITCH PROVIDED WITH ROGOWSKI COILS OPERATING AS CURRENT SENSORS

摘要

The inventive three or four pole low-voltage power switches are partly provided with a device for detecting ground faults. For this purpose, the current vectorial sum must be produced in the three or four conductors of a monitored network. For the switches of this type, output signals received from Rogowcki coils (1) are commonly directed via resistances (4, 5) to an integration capacitor (6) whose voltage forms an input signal of another measuring amplifier (7) representing the current sum of a monitored network. The output signal of said measuring amplifier (7) is, afterwards processed in a known manner in the microprocessor of an excess-current trip.