The Siemens SIRIUS 3RV1011-1FA15-0BA0 is a motor protection circuit breaker — a single device that combines a thermal overload relay and a magnetic short-circuit trip in one 45 mm wide package, sized for a 5 A continuous rated current and a 1.5 kW motor at 400 V. The magnetic short-circuit trip (instantaneous) handles fault clearing, with a breaking capacity of 100 kA at 240 V AC and 400 V AC, dropping to 3 kA at 500 V and 2 kA at 690 V — that 100 kA figure means this breaker can interrupt a bolted fault on a high-capacity transformer secondary without upstream fuses needing to clear first, as long as the available fault current at its mounting point stays under that rating.
Main circuit terminals accept 2× (0.5…1.5 mm²) solid or 2× (0.75…2.5 mm²) stranded, or 2× (18…14 AWG) — screw-type terminals, not spring-cage, so factor in the screwdriver time if your panel shop is used to push-in connectors. Auxiliary and control circuit terminals are also screw-type; the auxiliary switch is a transverse design, which means the contact block mounts on the side of the breaker rather than the front, keeping the overall depth unchanged.
Shock rated at 25 g for 11 ms — suitable for mounting on machinery that sees vibration from conveyors or presses.