What this MCCB carries
The Siemens SENTRON 3VA1225-6EF32-0KC0 is a 3-pole molded case circuit breaker rated 250 A at 40 °C, with a breaking capacity of 220 kA at 240 V AC. That 220 kA figure at 240 V means it can safely interrupt fault currents up to that level on a 240 V line — critical for high-fault-capacity panels where upstream coordination and SCCR headroom matter. At 415 V it still breaks 154 kA, and at 690 V it holds 17 kA, so it's sized for industrial distribution rather than light commercial. This variant is configured for line protection with a shunt trip release and two auxiliary switches HQ built in. The shunt trip lets you remotely trip the breaker from a safety circuit or emergency-stop chain — useful in a panel where you need to kill power without walking to the MCC. No undervoltage release or ground-fault monitoring on this order code, so if those are required, this isn't the variant.
Thermal derating and panel fit
The 250 A rating holds flat from 40 °C up to 50 °C, then derates to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. If the panel ambient runs hot — say a packed enclosure near a furnace line — the 70 °C derated figure (223 A) is the one to size against, not the nameplate 250 A. Maximum power loss is 57 W, which factors into enclosure thermal calculations. Dimensions are 158 mm high, 105 mm wide, 70 mm deep. The 70 mm depth is shallow enough that it won't force a deeper enclosure than the standard 200 mm backpan. It mounts on a DIN rail or direct panel; the 105 mm width means it occupies three 35 mm module spaces if you're counting busbar takeoff points.