Selective electronic tripping element

摘要

The instantaneous tripping threshold of the selective tripping device is a decreasing function of a quantity representative of the time necessary for the current to reach the peak value. The variation curve is disposed between first and second curves, obtained experimentally, representative of envelopes of the peak current values. The first curve is obtained when the circuit breaker associated to the selective tripping device is alone and the second curve when it is connected in series with another circuit breaker connected down-line.