What this 250 A MCCB is and where it lands
The Siemens SENTRON 3VA1225-6GF42-0BH0 is a 4-pole molded case circuit breaker (MCCB) rated 250 A continuous, designed for line protection in distribution panels and industrial switchboards. It carries a 220 kA interrupting capacity at 240 V AC, stepping down to 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V — giving you the SCCR headroom to coordinate downstream feeders without cascading upstream. The 250 A rating holds flat from 40 °C through 50 °C ambient; above that it derates to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. If your panel ambient runs hot, that curve tells you exactly where you lose margin. It ships with an undervoltage release (UVR) and a 2-auxiliary-switch plus 1-trip-alarm-switch HQ configuration, so it's ready for remote status and shunt-trip integration out of the box. The basic switch core is order code 3VA12256GF420AA0.
Panel fit and integration
Dimensions: 158 mm height, 140 mm width, 70 mm depth. The 70 mm depth (2.76 in) is shallow enough to clear most standard gland plates and backpanel wiring troughs without a spacer. Mounts on a DIN rail or direct-panel footprint common to SENTRON 3VA frames. Power loss at rated load is 59.5 W maximum — factor that into your enclosure thermal rise calculation, especially in a sealed or low-ventilation panel. Operating temperature range -25 °C to 70 °C; storage range -40 °C to 80 °C. The storage limit governs handling and warehousing, not running duty.
Key ratings at a glance
Insulation voltage rated 800 V. No communication function onboard. No ground-fault monitoring version. Trip indicator present; undervoltage release fitted. No voltage-trigger function.