The Siemens SENTRON 3VA1225-6EF42-0AH0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 250 A across its 40 °C to 50 °C ambient range — no derating needed up to that point (cites:,). Above 50 °C it derates linearly to 223 A at 70 °C (cites:,). The TM240 thermal-magnetic release provides fixed overload and short-circuit protection curves, with a trip indicator for visual fault confirmation (cites:,). Breaking capacity reaches 220 kA at 240 V AC, stepping down to 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V — sufficient for high-fault utility feeds and transformer secondaries (cites:,).
At 70 mm deep, 140 mm wide, and 158 mm tall, this MCCB occupies a standard SENTRON 3VA footprint — expect a 4-pole unit to span roughly 9 module widths on a DIN rail or direct-mount plate (cites:,). The breaker is designed without undervoltage release, ground-fault monitoring, or communication function, so those features must be added externally if required (cites:,).
Operating Environment and Storage
The thermal derating curve above 50 °C is the binding constraint for continuous load in warm enclosures.