Solid state tripping device for three-phase main system protection circuit breaker to detect fault patterns

摘要

The static trip device of a circuit breaker for protecting a three- phase network comprises a detection circuit of the fault type comparing the currents (I1, I2, I3,IN) travelling along the conductors of the network to a first threshold (S1) and to a second threshold (S2) greater than the first. It supplies a signal (A) representing a certain type of fault, single-phase or two-pole series, when a first number of currents is less than the first threshold (S1) and a second number of currents greater than the second threshold (S2). …IMAGE…