What this MCCB is and what the ratings mean for your panel
The Siemens 3VA2225-6HN32-0AG0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It's a 3-pole unit rated for a continuous current of 250 A at 40 °C, and it holds that same 250 A rating all the way up to 50 °C — so you don't have to derate for a warm enclosure unless you're pushing past that. At 55 °C it's still at 241 A, at 60 °C it's 232 A, and at 70 °C it's 213 A, which gives you a clear thermal curve to size against. The interrupting ratings are what make this breaker stand out: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 4.5 kA at 690 V. Those numbers mean it can handle high-fault-current scenarios without needing an upstream current-limiting fuse — useful when you're feeding a transformer or a busway where the available fault current is high. The 690 V rating is lower, so if you're on a 690 V system, you'll want to verify that 4.5 kA covers your SCCR requirement. It ships with a built-in auxiliary switch and trip alarm switch (1 each, HP type), so you get remote status indication for both the breaker position and whether it tripped on fault. No undervoltage release, no ground-fault monitoring, no communication module — this is a straight line-protection breaker with basic signaling. The power loss at full load is 48 W maximum, which matters for heat buildup in a compact panel.
Physical fit and mounting
The 3VA2225-6HN32-0AG0 measures 105 mm wide, 181 mm high, and 86 mm deep. That depth includes the arc chamber and terminals — make sure your enclosure depth clears it with room for cable bending. It's a DIN-rail-mount MCCB in the SENTRON 3VA2 family, so it clips onto standard 35 mm DIN rail and integrates into a panel alongside other SENTRON components.