What it is and what the ratings mean for fit
The Siemens SIRIUS 3RV2011-0CA25-ZW96 is a motor protection circuit breaker in the size S00 frame, designed to protect small motors drawing 0.25 A full-load current — think fractional-horsepower fans, small pumps, or control-transformer primaries. The CLASS 10 trip curve means it must clear a stalled-rotor condition within 10 seconds at 7.2× rated current, which matches the thermal withstand of most standard IEC induction motors. That 0.25 A operational current rating is the continuous current the breaker carries without tripping; the instantaneous short-circuit trip fires at 3.3 A, so it catches a hard phase-to-phase fault before the overload element sees the rise. The 100 kA breaking capacity holds across the full voltage range from 240 V to 690 V AC (–), which gives you full-rated SCCR without needing an upstream current-limiting fuse — a real advantage when you are trying to keep a 100 kA SCCR on a 480 V panel bus without adding a fuse block.
Where it goes and how it mounts
This breaker snaps onto a 35 mm DIN rail per EN 60715, same footprint as every other S00-frame SIRIUS device. The spring-type terminals accept solid or ferruled stranded wire up to 2.5 mm² — no screw torque to verify, no loosening under vibration. The transverse auxiliary switch pack (1 NO + 1 NC) rides on the side, so you can wire a remote trip indication or a PLC digital input without a separate auxiliary contact block. Panel builders will appreciate that the S00 frame leaves 9 mm side clearance to the next device, keeping the DIN-rail density high.