The Siemens SIRIUS 3RV2411-1BA20-0DA0 is a circuit breaker explicitly designed for transformer protection — not a general-purpose motor-protective breaker, but one tuned to the inrush and overload profile of a transformer primary.
Breaking capacity is the headline number here: 100 kA at 240 V AC and 400 V AC, 100 kA at 500 V AC, then 10 kA at 690 V AC. The gG fuse-links it coordinates with are 25 A at 400 V and 500 V, dropping to 20 A at 690 V, so the selectivity curve is baked into the design. Trip class is CLASS 10, clearing an overload within 10 seconds. Rated operating voltage spans 20 to 690 V.
The spring-loaded terminals on the main current circuit accept 2× (0.5 to 4 mm²) solid or stranded wire; a 3 mm screwdriver shaft is specified for the terminal screws. Clearance requirements are 50 mm upwards and downwards, 30 mm to the side, and zero forwards and backwards — so it can be mounted flush against the back panel, which saves depth in shallow enclosures.