What this 250 A MCCB delivers in the panel
The Siemens SENTRON 3VA2225-5HN42-0CH0 is a 4-pole molded case circuit breaker rated for 250 A continuous current at 40 °C ambient, with a line protection design that handles fault currents up to 187 kA at 240 V and 121 kA at 415 V or 440 V. At 500 V the interrupting rating drops to 75.6 kA, and at 690 V it holds 4.5 kA — so the SCCR you need at your system voltage is the one that governs the fit, not the headline 187 kA figure. The basic switch variant is 3VA2225-5HN42-0AA0, which means the UVR and aux-switch package are factory-integrated — no field retrofit required.
Thermal derating — the real continuous current in a warm cabinet
Above that, the breaker derates: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your panel ambient sits at 55 °C, you lose 9 A — small, but enough to trip a fully loaded feeder on a hot day.