Breaking capacity — the number that decides the fault level
At 690 V AC it still holds 10 kA, which covers most 690 V industrial bus faults. The fuse coordination ratings tell you what upstream fuse to pair it with: gL/gG 25 A at 400 V and 500 V, stepping down to gL/gG 20 A at 690 V. That's the fuse size that lets the breaker clear a fault without the fuse blowing first.
The 3RV2311-1BC10 measures 45 mm wide, 97 mm deep, and 97 mm tall — a compact footprint that fits standard 45 mm modular device spacing on DIN rail. Main circuit terminals are M3 screw-type, accepting 2x (0.75 to 2.5 mm²) solid or stranded, or 2x 4 mm². No ground-fault or phase-failure detection built in — that's handled externally if needed.