What it is and what it does
The Siemens SIRIUS 3RV2011-0JA40 is a motor protection circuit breaker designed to protect motors against overloads and short circuits. It's built for a 0.2 kW motor at 230 V AC, and it carries a 100 kA short-circuit breaking capacity at 240 V, 400 V, 500 V, and 690 V — that's high enough to sit upstream of most common distribution faults without needing a separate fuse or upstream breaker to back it up.
What the ratings mean for your panel
Trip Class 10 means it will trip within 10 seconds at 7.2× the thermal setting — standard for protecting standard induction motors during startup. The 100 kA SCCR at 400 V means this breaker can safely interrupt a fault current up to that level without blowing apart or welding contacts, so it's suitable for high-fault installations like large MCCs or transformer-fed panels. It mounts on a 35 mm DIN rail per DIN EN 60715, and you can either snap it on or screw it down. The 45 mm width means it takes up two standard 22.5 mm module spaces — a tight fit for a motor starter combo in a crowded enclosure. Clearance requirements: 50 mm above and below, 30 mm to the sides, and zero clearance forward or backward, so you can butt it against a backplane or adjacent devices. Phase failure detection is built in — if one phase drops out, the breaker trips, which prevents single-phasing a motor. No ground-fault detection on this variant, so if you need that you'd look at a different order code in the same family.