The 3RV2011-4AA25 carries a 30 kA rated short-circuit breaking capacity at 400 VAC. At 690 VAC the capacity drops to 2 kA, and at 240 VAC it holds 100 kA. For a 400 V panel with an available fault current under 30 kA, this breaker coordinates cleanly with a downstream contactor — no need for a separate current-limiting fuse upstream unless the SCCR exceeds that ceiling.
Width is 45 mm, depth 97 mm, height 106 mm (–). That is a single 45 mm module on the DIN rail — one standard slot. The screw terminals accept 2 × (0.5 to 2.5 mm²) solid or stranded wire. Clearance requirements: 50 mm above and below, 30 mm to the side.