What this 630 A MCCB is and where it lands
The Siemens 3VA2463-5JQ32-0JH0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels and motor control centers. Rated 630 A at 40 °C, it handles the main feeder or large downstream loads in industrial and commercial switchboards. Three-pole construction, so it switches three-phase circuits. The electronic trip unit is adjustable — minimum setting 945 A, maximum 5670 A — which gives you selectivity headroom against downstream branch breakers without oversizing the frame. Breaking capacity sits at 187 kA at 240 V, dropping to 121 kA at 415 V and 440 V, then 75.6 kA at 500 V, and 9 kA at 690 V. That 187 kA figure at 240 V covers high-fault utility feeds; the 121 kA at 415 V handles most European industrial networks. At 690 V the 9 kA rating limits it to lower-fault systems or transformer-secondary applications. Auxiliary switch complement is two auxiliary switches plus one trip alarm switch (HQ configuration), and a shunt trip (STL) is built in for remote tripping. Communication function is present.
Thermal derating and power dissipation
Current rating is temperature-dependent: 630 A at 40 °C, 600 A at 45 °C, 570 A at 50 °C, 540 A at 55 °C, 510 A at 60 °C, 480 A at 65 °C, and 450 A at 70 °C. If your panel ambient runs hot, size the breaker for the actual enclosure temperature, not the 40 °C nameplate. Maximum power loss is 162 W. That's the heat the breaker dumps into the enclosure at full rated current — factor it into your panel thermal calculation, especially in a sealed or high-density cabinet. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage minimum is the handling limit, not the running limit.
Physical fit and panel integration
Dimensions: 248 mm height, 138 mm width, 110 mm depth. That depth (110 mm) is the body only — add clearance for wiring, arc chute exhaust, and the rotary handle if used. The 138 mm width is the standard 3-pole MCCB footprint for this frame size; it replaces an older 3VA2 or 3VF breaker in the same cutout. Mounts on a DIN rail or directly to a backplate via the breaker's integral mounting feet. The SENTRON 3VA series uses the same drilling pattern as the previous 3VL series, so retrofitting into an existing panel usually requires no new holes.