The 3RB1246-1EG11: The 25-100 A range covers full motor protection for medium-horsepower induction motors — think 15-50 kW at 400 V. Class 5-30 means the trip curve is adjustable from fast (class 5, for short-time overloads like fans) to slow (class 30, for high-inertia loads like centrifuges). The AC 110-120 V control voltage is for the auxiliary circuit only; the main circuit is transformer-isolated, so the relay doesn't pass full motor current through its control side. That transformer isolation also means the relay can be set for a motor FLA without needing a separate current transformer.
Integration Notes
Individual mounting (not DIN-rail) — the relay bolts directly to the panel or onto a size S2/S3 contactor. Screw terminals on the auxiliary side accept standard ring or fork lugs. Bistable outputs hold their state after a trip, which simplifies fault annunciation in a panel: the overload warning contact stays closed until manually or remotely reset. The manual-automatic-remote reset selector gives the commissioning engineer flexibility — automatic for unmanned stations, manual for local reset after clearing the fault.