What it is and what it does
This is a Siemens SIRIUS motor protection circuit breaker, order code 3RV1011-0EA25, designed specifically for protecting small motor loads. It's rated at 0.4 A continuous current and Trip Class 10, meaning it will trip within 10 seconds at 7.2× rated current — standard for most general-purpose motor starts without nuisance tripping on inrush. Phase failure detection is built in, so if you lose a phase upstream, this breaker drops the motor before single-phasing cooks the winding.
Breaking capacity and mounting
The interrupting rating is 100 kA at 240 V, 400 V, 500 V, and 690 V AC — that's a consistent high-fault capability across the board, so you don't have to derate the breaker if your supply voltage changes within that range. It mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, and the 45 mm width means it takes up one standard module slot in the panel. Spring-loaded terminals on both main and auxiliary circuits accept 2x (0.25 to 2.5 mm²) solid or stranded wire — no screwdriver needed for the power connections, which speeds up wiring on a build.
Environmental and compliance
The front face carries IP20 protection — finger-safe, but not sealed against moisture or dust, so it belongs inside a panel, not out in the washdown zone. Storage and transport range is -50 to +80 °C; operating range is -20 to +60 °C. RoHS compliance date is marked January 1, 2013, so it meets the EU directive. Surge voltage resistance is rated at 6,000 V, which covers typical industrial transient environments.