It carries a 440 kA interrupting rating at 240 V AC, stepping down to 330 kA at 415 V and 52.5 kA at 690 V — high enough for most main or feeder breaker positions in industrial switchgear where fault currents are substantial.
Interrupting capacity and what it means for your panel
At 415 V (common industrial three-phase) it still holds 330 kA, and at 690 V it drops to 52.5 kA. For a 63 A frame, those numbers are well above typical available fault currents in most distribution panels — meaning you have headroom for selectivity coordination downstream without worrying about the breaker failing open on a bolted fault. The ETU850 is an electronic trip unit with communication capability, so it can report trip events, current draw, and status over a network — useful for a maintenance team that wants to know why a feeder tripped without walking the panel.