What it is and what it does
The Siemens SENTRON 3VA2225-5JQ32-0KC0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current, built around the ETU560 electronic trip unit. It's the line-protection variant — meaning it's set up to protect cables and busbars from overload and short-circuit, not motor or generator circuits. The ETU560 gives you adjustable long-time, short-time, and instantaneous pickup settings plus ground-fault alarm or trip via the integrated summation-current ground-fault module. Breaking capacity is the headline number here: 187 kA at 240 V, 121 kA at 415/440 V, 79 kA at 500 V, and 5.1 kA at 690 V. That 187 kA figure at 240 V means this breaker can safely interrupt a fault current nearly 750 times its continuous rating — it's sized for high-available-fault installations like transformer secondaries or large distribution switchboards where the upstream transformer can dump serious energy into a bolted fault. Thermal derating is published across the operating range: full 250 A up to 50 °C, then 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. If your panel ambient runs hot — say 55 °C inside a non-ventilated enclosure — you're still good for 238 A continuous without tripping. The maximum power loss is 48 W, which matters for ventilation planning in a sealed cabinet.
Panel fit and wiring
Dimensions are 105 mm wide, 181 mm tall, 86 mm deep. That 105 mm width is a standard 3-pole MCCB footprint — it'll drop into the same mounting hole pattern as other 250 A frame SENTRON breakers. The 86 mm depth includes the arc chamber and line/load terminals; allow clearance behind the panel door for the rotary handle or motor operator if you're adding one. Comes with 2 auxiliary switches (HQ type) factory-installed, plus a shunt trip (STL) for remote tripping. Verify polarity on the shunt trip coil before energizing. Operating temperature range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. That storage minimum is worth noting if the breaker sits in an unheated warehouse over winter — it's fine at -40 °C as long as it's not energized until it warms above -25 °C.