250 A MCCB with 242 kA interrupting capacity — what that means for your panel
The Siemens 3VA2225-6HL32-0KF0 is a SENTRON 3-pole molded case circuit breaker rated for 250 A continuous current at 40 °C ambient, with a full-load current rating that holds flat up to 50 °C before beginning a linear derating curve — 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. That means in a warm enclosure near the top of the ambient range you still have about 85% of nameplate capacity, which is better than many older frame designs that drop off sooner. The interrupting rating is the headline here: 242 kA at 240 V AC, 187 kA at 415/440 V, 121 kA at 500 V, and 4.5 kA at 690 V. That 242 kA figure at 240 V is high for a 250 A frame — it means this breaker can interrupt a fault current up to 242,000 amps at that voltage without welding contacts or venting plasma into the panel. For most North American 480Y/277 V distribution, the 187 kA at 415 V is the relevant number, and it covers virtually any service entrance or large subfeed application where the available fault current is high. This is a line-protection design — not a motor-protective breaker with integrated overloads. It's meant for feeder and main breaker duty where you need high short-circuit withstand and selective coordination downstream. The 3-pole construction fits standard 3-phase distribution panels on a 105 mm wide footprint, 86 mm deep, 181 mm tall.
Built-in accessories — shunt trip and auxiliary switch
The breaker ships with a shunt trip release (STL) for remote tripping and one auxiliary switch plus one trip alarm switch (HQ configuration). The shunt trip lets you drop the breaker from a PLC output, emergency-stop circuit, or fire-alarm panel without needing an external contactor. The auxiliary switch provides position feedback — N/O or N/C contacts that tell your control system whether the breaker is open or closed. The trip alarm switch signals only when the breaker has tripped on fault, not when manually opened. No undervoltage release is fitted on this variant, and no communication module — this is a standalone breaker for hardwired distribution, not a power-monitoring node. If you need remote metering or Modbus, you'd step up to the 3VA2 with communication option.
Current lifecycle — active production, no obsolescence concern
Maximum power loss is 48 W at rated current — that's the heat you need to vent from the enclosure. At 250 A, the I²R losses are modest for a 250 A frame, but in a sealed panel with multiple breakers ganged, still factor it into your thermal budget.