This MCCB delivers 242 kA at 240 V, 187 kA at 415 V and at 440 V, 121 kA at 500 V, and 40 kA at 690 V. The 40 kA at 690 V keeps it viable for 690 V industrial grids, though the 400 A continuous rating is the practical limit for that voltage class.
Above that it drops: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If your panel internal ambient runs at 60 °C — common in a packed enclosure with upstream devices — you're looking at 370 A available, not the nameplate 400 A. That derating curve is the one that governs real-world sizing, not the catalog headline.