What it is and what it does
The Siemens 3RV1011-0KA10 is a SIRIUS motor protection circuit breaker designed for motor protection. It's a Class 10 trip device, meaning it disconnects within 10 seconds at 7.2× the thermal setting — fast enough to protect a standard induction motor during a locked-rotor event. Rated for 0.2 kW at 230 V, it's sized for small motor loads like fractional-horsepower pumps, fans, or conveyor drives. The breaker carries a 100 kA breaking capacity at 240 V, which means it can safely interrupt a fault current up to 100,000 amps without welding its contacts or venting arc plasma into the panel. That's a serious short-circuit rating for a compact 45 mm wide device — it handles the kind of fault a large transformer or stiff utility feed can throw at it. Mounting is straightforward: screw and snap-on onto 35 mm DIN rail per DIN EN 60715. The 45 mm width and 75 mm depth fit standard panel layouts. Screw-type terminals on the main circuit accept 2× (0.5 to 1.5 mm²) solid or stranded, or 2× (0.75 to 2.5 mm²) — common for control wiring.
Where it goes in the panel
This breaker lives on a DIN rail inside a motor control center or distribution panel. It feeds a contactor downstream and protects the motor branch circuit. The any-position mounting means you can orient it vertically, horizontally, or even upside-down — handy when you're packing components tight on the rail. Phase failure detection is built in, so if one leg drops out, the breaker trips and keeps the motor from single-phasing. No ground fault detection here — that's a separate device if your circuit needs it.