Method of operating a residual current circuit breaker and residual current circuit breaker for a frequency converter

摘要

The method involves receiving switching information regarding switching operations in frequency converter (10). A current signal of common mode current in a power management device (50) via which main power signals (In1-In3) are supplied to frequency converter, is detected. A target current signal of common mode current is determined based on the switching information. The fault current (I5) is determined based on the detected current signal and target current signal, so as to interrupt main power signals supplied to frequency converter. An independent claim is included for fault current circuit breaker.