What it is and what it does
The Siemens SIRIUS 3RV2011-0CA20-ZX95 is a motor protection circuit breaker in the size S00 frame, designed to protect three-phase induction motors against overload, short-circuit, and phase failure. Its Class 10 trip characteristic means it will disconnect within 10 seconds at 7.2× the thermal setting — fast enough to protect standard IEC motor windings during a locked-rotor event. The 100 kA breaking capacity at 400 V AC is the figure that governs fault-clearing: it can safely interrupt a bolted short-circuit up to that level without welding contacts or cascading upstream, which is what makes it suitable for high-fault-capacity industrial panels. Phase failure detection is built in, so a lost phase on the line side will trip the breaker rather than letting the motor single-phase and overheat.
Mounting and panel fit
Mounts via screw or snap-on onto 35 mm standard DIN rail per DIN EN 60715. The 45 mm width and 97 mm depth mean it occupies a single 45 mm module on the rail — that's another SKU that fits the same slot as the standard S00 frame breakers. Clearance requirements: 50 mm above and below, 30 mm at the sides, and zero forward or backward clearance needed (–,). Any mounting position is acceptable. Terminals accept 2× 0.5 to 4 mm² solid or stranded wire.