What the 187 kA interrupting rating means for your panel
The Siemens 3VA2463-5KQ42-0AA0 is a SENTRON 3VA2 molded case circuit breaker (MCCB) rated for line protection, carrying a 630 A continuous current at 40 °C and a 4-pole configuration. Its interrupting capacity hits 187 kA at 240 V AC and 121 kA at 415 V and 440 V AC — numbers that tell you this breaker is built for high-fault utility or industrial service entrances where available fault current is substantial. The 9 kA at 690 V AC is the ceiling for the operating voltage range, so if your system runs at 690 V, that's the SCCR you coordinate to. The ETU860 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves, plus communication capability for remote monitoring. Ground-fault monitoring uses summation current formation on L + N conductors, and the N-conductor protection is adjustable from OFF to 100% in 20% steps. That level of configurability is what you need for selective coordination downstream of a transformer or generator main.
Thermal derating — don't spec the 630 A number cold
The 630 A rating is at 40 °C ambient inside the enclosure. At 50 °C it's 570 A; at 60 °C it's 510 A; at 70 °C it's 450 A. If your panel runs hot — and most do, especially with other breakers and buswork sharing the air — you need to apply the derating curve from the spec table. The 162 W maximum power loss also means ventilation or larger enclosure volume matters; stuffing this into a tight, sealed box without airflow will push internal temperature up and reduce the usable current. Dimensions are 248 mm high, 184 mm wide, 110 mm deep — a 4-pole frame that fits standard SENTRON 3VA2 mounting patterns. IP40 on the front face means it's protected against tools and wires >1 mm, but not against water ingress; keep it inside a panel with at least an IP54 enclosure if there's washdown nearby.