The Siemens 3VA1450-7EF32-0AA0 is a SENTRON molded case circuit breaker rated 500 A continuous at 40 °C through 50 °C, with a TM240 thermal-magnetic overcurrent release. Three poles, 248 mm tall by 138 mm wide by 110 mm deep. That 138 mm width is about 8 standard DIN modules — plan your gland-plate knockouts and busbar drop accordingly. At full load it dissipates 122.7 W, so in a packed enclosure you'll want a thermal model or at least a vent slot above it.
What the interrupting ratings mean for fault duty
This breaker clears 440 kA at 240 V, 242 kA at 415 V and 440 V, 154 kA at 500 V, and 17 kA at 690 V. Those are the maximum prospective fault currents it can interrupt without welding or rupturing — the 440 kA figure at 240 V covers high-fault industrial services; the 17 kA at 690 V still handles most 690 V distribution. The SCCR of the panel is limited by the lowest-rated device downstream, so this breaker is rarely the weak link.
Thermal derating — where the 500 A holds and where it tapers
At 55 °C it derates to 488 A, at 60 °C to 476 A, at 65 °C to 464 A, and at 70 °C to 452 A.