The Siemens SENTRON 3VA1225-6EF42-0AD0 is a 4-pole molded case circuit breaker rated for line protection, carrying 250 A continuously at 40 °C without derating. That full-load current holds through 50 °C — at 55 °C it steps down to 243 A, 237 A at 60 °C, and 230 A at 65 °C. The TM240 thermal-magnetic overcurrent release is factory-set for this frame. Breaking capacity is substantial: 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. Insulation voltage is rated 800 V. If you're protecting a feeder or a large motor branch on a high-fault panel, this breaker handles the interrupt without cascading upstream.
Mounting and fit
The 3VA1225-6EF42-0AD0 occupies 140 mm width, 158 mm height, and 70 mm depth — a 4-pole frame that fits standard SENTRON panel cutouts. At 57 W maximum power loss, factor the heat into your enclosure ventilation calculation, especially if the breaker is grouped with other high-current devices. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.