What you're looking at
At 415 V and 440 V it still holds 121 kA, and even at 690 V it breaks 9 kA. That's a lot of headroom for a 630 A frame.
Thermal derating — the real usable current
If your panel runs hotter — and most do — you lose about 18 A per 5 °C rise: 612 A at 45 °C, 593 A at 50 °C, 575 A at 55 °C, 557 A at 60 °C, 538 A at 65 °C, and 520 A at 70 °C. That last figure is also the maximum operating temperature for the breaker itself. So if you're stuffing this into a tight enclosure with other heat sources, size the load side accordingly.
That's a 3-pole MCCB footprint — standard bolt-on or plug-in mounting for SENTRON switchgear.