What it is and what it does
The Siemens SENTRON 3VA2225-6KP32-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 250 A, with an ETU850 electronic trip unit handling line protection. Breaking capacity hits 242 kA at 240 V, 187 kA at 415 V, and 121 kA at 500 V — numbers that matter when you're clearing a high-fault panel without cascading upstream. Rated insulation voltage is 800 V, so it's comfortable on 690 V systems (where it still breaks 6 kA). The front carries IP40 protection, meaning it's splash-safe in a closed panel but not washdown-rated.
Ratings and derating — what the numbers mean for your panel
At 40 °C, 45 °C, and 50 °C the breaker holds its full 250 A rating — no derating needed in a typical warm enclosure. At 55 °C it drops to 238 A, at 60 °C to 225 A, at 65 °C to 213 A, and at 70 °C to 200 A. If your panel runs hot, size the load accordingly. The ETU850 trip unit gives you adjustable protection curves and a communication function — useful for remote monitoring or selective coordination studies. Power loss maxes at 48 W, so factor that into enclosure thermal calculations.
Panel integration and dimensions
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep — standard 3-pole MCCB footprint for a 250 A frame. Mounts on a DIN rail or directly to a backplate; the IP40 front means it's fine behind a panel door but not in a washdown zone. The supplied basic switch is order code 3VA2225-6KP32-0AA0 — that's the internal switching mechanism, not a separate accessory.