What it is and what it does
The Siemens 3RV2011-1AA20 is a SIRIUS motor-protective circuit breaker rated for motor protection with a CLASS 10 trip characteristic. It breaks fault currents up to 100 kA at 400 V AC, which means it can handle a hard short on a motor branch without needing an upstream fuse for that fault level — the breaker itself clears it. Phase failure detection is built in, so if a phase drops on a three-phase motor, the breaker trips before the motor cooks. Mounts on a standard 35 mm DIN rail per DIN EN 60715, either snapped on or screwed down for vibration-heavy spots. Dimensions are 97 mm deep, 45 mm wide, 106 mm tall — fits a standard motor-starter footprint. Clearance: 50 mm above and below, 30 mm to the side, nothing in front or back. Spring-loaded terminals on the main current circuit accept 2x 0.5 to 4 mm² solid or stranded. Operating temperature range is -20 to +60 °C; storage and transport hold -50 to +80 °C.
What the ratings mean for fit
The 100 kA breaking capacity at 400 V AC (and at 240 V, 500 V, 690 V) means this breaker can be used on high-fault-capacity panels without cascading coordination issues upstream. The CLASS 10 trip class is the standard for general-purpose motor starting — it lets the motor draw starting current for about 10 seconds before the thermal element trips, which covers most pump, fan, and conveyor starts. If you're protecting a high-inertia load that needs a longer start, you'd want a CLASS 20 or CLASS 30 trip instead. Compared to the 3RV1011-0GA10 (a similar SIRIUS motor-protective breaker), the 3RV2011-1AA20 shares the same DIN-rail footprint and CLASS 10 trip, but the 3RV1011-0GA10 has a lower breaking capacity. If your panel's available fault current is under 100 kA, either works; if it's above, the 3RV2011-1AA20 is the one you need. No rewiring required for a swap — same terminal layout and mounting.