250 A continuous, 242 kA breaking — the SCCR anchor for a distribution backbone
The Siemens SENTRON 3VA2225-6HN32-0HL0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C, holding that same 250 A rating all the way up to 50 °C before it starts to thermally derate — 241 A at 55 °C, 232 A at 60 °C, down to 213 A at 70 °C. That thermal headroom means this breaker doesn't force a upsized frame just because the panel runs warm in a packed enclosure. Breaking capacity is the headline here: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 6 kA at 690 V. For a 250 A frame those are extreme interrupting ratings — this is the breaker you spec when fault current on the secondary side of a large transformer is in the 200 kA range and you need the SCCR to hold without cascading upstream. The ETU350 electronic trip unit handles the protection logic — line protection version, so it's configured for overcurrent and short-circuit on distribution feeders, not motor or generator protection. An undervoltage release is not fitted; instead it carries a shunt trip (STL) for remote tripping, plus the auxiliary contact configuration: 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ). That's enough status feedback for a PLC to map the breaker position, trip event, and electrical alarm separately.
Integration — panel fit and wiring considerations
Dimensions: 105 mm wide, 181 mm high, 86 mm deep — a standard 3-pole MCCB footprint for the 250 A frame class. The 86 mm depth matters when the breaker mounts in a distribution panel with a shallow gland-plate clearance or a rear-connected bus system; verify the panel's internal depth against that figure before committing the layout. Rated insulation voltage Ui is 800 V. Maximum power loss is 48 W. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The 70 °C operating ceiling matches the top end of the thermal derating curve, so if the panel ambient hits 70 °C the breaker is still within its rated operating range at 213 A.