What this 250 A MCCB carries
The Siemens 3VA1225-6GF42-0CC0 is a SENTRON molded case circuit breaker, 4-pole, fixed at 250 A — no adjustment range, so the BOM line is locked to that rating. Interrupting capacity hits 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. That's a lot of fault-clearing headroom for a 250 A frame; it's sized for high-available-fault-current panels where a standard 65 kA MCCB wouldn't hold coordination. Thermal derating is published per degree: holds 250 A flat through 50 °C, then drops 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 above 50 °C, the continuous load needs to be trimmed — or you oversize the frame. Max power loss is 59.5 W, which matters for enclosure thermal rise calculations.
Line protection build and auxiliary content
This variant is designated line protection, meaning it's set up for feeder or main breaker duty, not motor branch circuit. It ships with an undervoltage release (UVR) fitted — that's the '6GF42' code's tell. The UVR drops the breaker on loss of control voltage, which is typical for emergency-stop or undervoltage protection schemes. Two auxiliary switches HQ are included for status feedback to a PLC or panel lamp. Rated insulation voltage is 800 V, so it's comfortable on 480/277 V or 600 V systems with margin. Operating temperature range is -25 to 70 °C, storage -40 to 80 °C. Dimensions: 158 mm high, 140 mm wide, 70 mm deep — standard 4-pole MCCB footprint for Siemens SENTRON 3VA1 panelboards.