For a panel builder, the fixed rating eliminates field-adjustment errors: what you order is what protects the feeder. At 240 V it interrupts 121 kA; at 415 V it holds 75.6 kA; at 690 V it still clears 11.9 kA. Thermal derating is published across the full operating range: full 630 A capability up to 50 °C, then a gentle slope to 583 A at 70 °C. That means in a crowded, warm enclosure — say a MCC bucket with other breakers — you don't lose headroom until the ambient passes 50 °C. The 192.9 W maximum power loss matters for ventilation planning in sealed cabinets.
Dimensions are 248 mm high, 184 mm wide, 110 mm deep — a standard 4-pole MCCB footprint for 630 A frame. The 184 mm width means it occupies roughly 7.24 inches of DIN-rail or mounting-plate space. IP40 on the front face is typical for switchboard installation; no washdown rating, so keep this inside a dry enclosure.