MCCB for high-fault panels
The Siemens 3VA1450-6MH32-0AA0 is a 3-pole SENTRON molded case circuit breaker rated 500 A continuous at 40 °C, with a TM120M thermal-magnetic release. The li pickup is adjustable between 2500 A and 5000 A, so you can tune the magnetic trip to the inrush of a large motor or transformer without nuisance trips. Breaking capacity hits 220 kA at 240 V AC, dropping to 154 kA at 415 V and 440 V, then 121 kA at 500 V, and 17 kA at 690 V — this breaker is built for high-fault panels where the available short-circuit current is substantial.
Thermal derating and panel fit
At 40 °C, 45 °C, and 50 °C the breaker holds its full 500 A rating. Above 50 °C it derates linearly: 488 A at 55 °C, 476 A at 60 °C, 464 A at 65 °C, and 452 A at 70 °C. If your panel ambient runs hot, use the 55 °C column for sizing. The case dimensions are 248 mm high, 138 mm wide, and 110 mm deep — that depth matters when routing cables behind the breaker in a shallow enclosure. Front protection is IP40, so the breaker face is splash-protected but the terminals need to be inside a sealed cabinet or gland plate.