Switch i.e. low voltage circuit breaker, has power source including current transformer with iron core having winding formed from diamagnetic materials so that large short-circuit current flows through electrical resistor of winding

摘要

The switch has a current sensor to detect current through a conductor. An electronic trip unit triggers an opening of the switch when the detected current exceeds a threshold value. The trip unit is supplied with operating current from a power source comprising a current transformer with an iron core having a winding, where the power source is connected with the trip unit over lead lines. The winding and/or lead lines are formed from diamagnetic materials so that magnetic field of the conductor is arranged to flow a large short-circuit current through an electrical resistor of the winding.