The 3RB1253-0FM01: The 50-205 A current range covers medium to large motor loads — think 30-100 kW induction motors at 400 V. The Class 5-30 F adjustment lets you match the tripping characteristic to the motor's thermal withstand curve: Class 5 for short acceleration times, Class 30 for high-inertia loads like centrifuges or crushers. The AC 220-240 V control supply is standard for European panel voltages; verify your control transformer matches before wiring.
Integration Notes
Size S6 means this relay mounts on Siemens S6 contactors or individually on a panel. The busbar main circuit connection handles high current without cable lugs — plan busbar routing in the enclosure. Auxiliary screw terminals accept 0.5-2.5 mm² wire; strip length 8 mm. The bistable outputs hold state on power loss, which is useful for fault memory in unattended installations. Ground fault signaling requires a separate core-balance transformer; check the wiring diagram for the specific GF terminal assignment.