DIFFERENTIAL TEST CIRCUIT TEST AND SELF-DIRECTED OPENING REMOTE CONTROL

摘要

P A differential trip unit 11 includes a summer transformer 30 associated with a trip relay 36, a test circuit 38 having a test button switch 50 52, and an opening remote control circuit 60, 58 connected to terminals 54, 56 accessible from the outside. The core 32 of the transformer 30 is provided with two auxiliary windings 66, 68 connected in series in the test circuit 38 so as to magnetize the core 32 in the event of an insulation fault of the remote control circuit with respect to the earth. The isolation protection threshold of the remote control circuit 60, 58 is at least equal to the sensitivity of the device 10. / P P Application: Differential circuit breakers or circuit breakers. / P