What this MCCB is and what it carries
The Siemens 3VA2450-5MN32-0HH0 is a SENTRON molded case circuit breaker (MCCB) designed specifically for motor protection — that means it includes phase failure detection and a thermal-magnetic trip curve shaped to handle motor inrush without nuisance tripping on start-up. Rated 500 A continuously at 40 °C ambient, it derates predictably: still 500 A at 50 °C, then 495 A at 55 °C, 490 A at 60 °C, 485 A at 65 °C, and 480 A at 70 °C. That derating curve is what you use for panel internal temperature rise calculations — the breaker doesn't lose much headroom until you push past 55 °C. Breaking capacity is 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 9 kA at 690 V. At 415 V — common for European industrial mains — that 121 kA gives you substantial SCCR headroom for most distribution panels without needing a current-limiting upstream device.
Trip characteristics and auxiliary fit
The short-time delay band is adjustable between 4 s minimum and 13 s maximum — that's the intentional delay for selectivity with downstream breakers. For motor starting, you'd set it long enough to ride through the start current without cascading upstream. Comes factory-fitted with a shunt trip (STL) auxiliary release and a 2-auxiliary-switch + 1 trip alarm switch HQ configuration. That means you have remote tripping capability and two separate signal contacts plus a dedicated alarm contact for the trip event — enough for a standard motor control center (MCC) bucket without adding external relays. Power loss at full rated current is 99 W maximum — a figure to include in your panel thermal budget, especially if multiple breakers are ganged in a small enclosure.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage limit is the handling limit — the breaker can sit in a cold warehouse or hot container without damage, but the operating ambient governs in-panel performance.