What this reversing starter does
The Siemens 3RA6250-0BB30 is a SIRIUS compact reversing starter — a single device combining two contactors and a motor-protective function in one 90 mm wide package, designed for forward/reverse control of three-phase motors up to 370 W at 400 V. It carries a 24 V AC/DC coil, so it pulls straight from a standard 24 V control supply without needing a separate rectifier or AC tap — one less part on the BOM. The adjustable trip class (CLASS 10 and 20) lets you match the overload curve to the motor start profile: Class 10 for quick-starting pumps and fans, Class 20 for high-inertia loads like conveyors or centrifuges that need a longer acceleration ramp without nuisance tripping.
Breaking capacity and fault protection
Continuous operation per IEC 60947-6-2 — this is the standard for semiconductor switching devices for motor loads, not a general-purpose contactor rating. It's built for sustained duty in automated lines, not intermittent jogging.
Shock resistance of 60 m/s² (6 g) for 10 ms across all axes and vibration resistance to 20 m/s² at 5.8–500 Hz make it suitable for mounting on machinery with moderate vibration — conveyor drives, pump skids, compressor packages.