This is a Vigi add-on module for ComPact NSX 400/630 that provides an earth-leakage protection. It is used for 4 poles circuit breakers. The operational rated voltage is between 440 and 550 VAC 50/60 Hz. The earth-leakage sensitivity is adjustable from 30 mA to 30 A. It is installed directly on the device terminals and directly actuates the trip unit in case of earth-leakage default. This Vigi add-on module is self-powered internally by the distribution-system voltage, even is supplied by only 2 phases. It is compliant with IEC 60947-2 standard, annex B.