What it is and where it lands
The Siemens 3VA2225-5HN32-0BA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, carrying a continuous 250 A through three poles. It's built around the ETU350 electronic trip unit, which gives you adjustable overload and short-circuit protection curves — not a fixed thermal-magnetic, so you can dial it in to the load rather than swap the breaker when the motor FLA changes. That 250 A holds steady from 40 °C all the way up to 50 °C, then starts a gentle slope: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your panel runs hot — and most MCC buckets do — that derating curve is what you need for the BOM, not the nameplate number.
Interrupting duty — what those kA numbers mean
This MCCB punches a 187 kA interrupting rating at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V. That 187 kA figure at 240 V tells you it's built for high-fault-capacity industrial feeds — transformer secondaries, main distribution panels, or any point where the available fault current is north of 100 kA. The sharp drop to 5.1 kA at 690 V is normal for a 250 A frame; at that voltage the arc extinction physics changes, so you coordinate downstream breakers accordingly.
What's on the side — auxiliary releases and dimensions
The 3VA2225-5HN32-0BA0 ships with an undervoltage release (UVR) built in — part number 3VA9608-0BB11 for the integrated auxiliary trip — and no auxiliary contact block. If your safety circuit needs a shunt trip or a signal contact, you'll add those externally. The base switch module is 3VA2225-5HN32-0AA0, which is the same frame without the UVR. Footprint: 105 mm wide, 181 mm tall, 86 mm deep. That 105 mm width is the standard 3VA2 frame size for 250 A — it drops into the same panel cutout as other SENTRON 3VA2 breakers, so a swap from a different trip unit doesn't mean re-drilling the backplate.
Environmental limits and power loss
Operating temperature spans -25 °C to 70 °C; storage range is wider at -40 °C to 80 °C. Maximum power dissipation is 50.5 W at rated current — that's the heat you need to vent from the enclosure. If you're packing several of these in a row, the cumulative heat load matters for the panel cooling calc.