The Siemens 3RA6250-1BB32 is a SIRIUS compact reversing starter — a single device combining a contactor and overload relay in a reversing configuration, sized for a 3-phase motor load up to 370 W at 400 V. Rated for continuous operation per IEC 60947-6-2, it handles motor reversing without external interlocking, with a short-circuit breaking capacity of 53 kA at 400 V — enough for high-fault-current panels where a standard 10 kA starter would need upstream fusing. The overload relay offers adjustable Trip Class 10 and 20, letting you tune the thermal trip curve to the motor's start profile: Class 10 for fast-starting pumps and fans, Class 20 for high-inertia loads like conveyors or crushers.
At 90 mm wide, it occupies three 18 mm module spaces in the enclosure. Main power circuit uses screw-type terminals accepting solid conductors from 0.5 to 4 mm², or two conductors 0.5 to 2.5 mm² each — useful for daisy-chaining supply to multiple starters in a motor control center. Control voltage is 24 V AC/DC, with a rated coil power of 2.8 W AC and 2.9 W DC — low enough to be driven by a standard 24 VDC PLC output or a 24 VAC control transformer without derating the power supply.
Depth of 165 mm and height of 170 mm mean it fits most standard 200 mm deep enclosures with clearance for wiring. The three LED indicators show status at a glance — useful for commissioning and troubleshooting without a meter.
The 53 kA SCCR and adjustable trip class make it a drop-in replacement for older reversing starters in panels where fault current has been upgraded.