What the ratings mean for your panel
The Siemens SENTRON 3VA2225-5HN42-0BA0 is a 4-pole molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C, with the full 250 A holding through 50 °C before it starts to derate — at 55 °C it's still good for 241 A, and at 70 °C it carries 213 A. That steady thermal curve means you don't lose headroom in a warm enclosure unless the ambient pushes past 50 °C. The interrupting ratings tell the real story for fault coordination: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 4.5 kA at 690 V. That 187 kA at 240 V is the headline number — this breaker will sit comfortably upstream of a transformer or a high-fault bus without needing a current-limiting fuse ahead of it. At 690 V the 4.5 kA figure is modest, so if your line side is 690 V with high available fault current, you'll want to check the coordination study. The ETU350 electronic trip unit gives you adjustable long-time, short-time, and instantaneous protection bands — this isn't a fixed-thermal breaker. You set the curves to match your load, which is the difference between protecting a feeder and nuisance-tripping on a motor inrush.
Sourcing and lifecycle — still in current production
The 3VA2225-5HN42-0BA0 is the line-protection variant with an undervoltage release and no auxiliary contacts. If your panel callout requires auxiliary signaling or a different trip-unit firmware, the 3VA2225-5HN42-0BB0 is the closest sibling — same frame, same 250 A rating, same ETU350, but with auxiliary contact provision. The footprint and wiring are identical; the swap is a terminal-level decision, not a panel rework. Rated insulation voltage is 800 V, and front protection is IP40 — standard for a panel-mounted MCCB with the cover closed. The 50.5 W maximum power loss at full load matters for enclosure thermal calculations; that's the heat you need to vent.
Mounting and integration — fits the standard footprint
Dimensions are 181 mm high, 140 mm wide, 86 mm deep. That 86 mm depth is the critical dimension for shallow enclosures — it's the same as the 3VA2 family standard, so it drops into a panel drilled for a 3VA2225-5HN42-0BB0 without any rework. Four-pole, so it needs the full 140 mm width on the DIN-rail or mounting plate. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. That covers most indoor panel environments and unheated warehouses. The undervoltage release is fitted as standard — if your control scheme doesn't use it, you'll need to wire it continuously energized or order the variant without it.