What it is and what it does
The Siemens SENTRON 3VA2225-6KP32-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C, with a maximum breaking capacity of 242 kA at 240 V AC. That 242 kA rating means it can safely interrupt a fault current up to that level — critical for high-fault installations like transformer secondaries or large motor control centers where upstream coordination demands a high-interrupt device. The breaker is designed for line protection, meaning it's the primary overcurrent protection for a feeder or main, not a downstream branch device. The 250 A continuous rating holds flat from 40 °C through 50 °C, then derates linearly to 200 A at 70 °C. If your panel ambient runs above 50 °C, plan on the lower figure — the breaker doesn't lose capacity until 55 °C, but above that the thermal curve is real. For a 250 A feeder in a 60 °C enclosure, you're effectively working with a 225 A device.
Breaking capacity across voltages
Breaking capacity drops with system voltage: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 4.5 kA at 690 V. The 4.5 kA at 690 V is the weak point — if your 690 V fault current exceeds that, this breaker isn't the right choice. For typical 480 V北美 panels, 121 kA is ample for most transformer ratings up to 2500 kVA.
Built-in auxiliaries and releases
This variant ships with an undervoltage release (UVR) and two auxiliary switches plus one trip alarm switch (HQ configuration). The UVR means the breaker trips when control voltage drops below a threshold — standard for safety circuits where loss of control power must open the main. The communication function suggests it's ready for integration into a higher-level monitoring system, though the protocol isn't specified in the base listing. A trip indicator gives local visual status.
Physical fit and environment
Dimensions: 181 mm high, 105 mm wide, 86 mm deep. That 105 mm width is standard for a 3-pole 250 A frame — it'll fit a typical MCC bucket or panel mount without surprises. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The 50.5 W maximum power loss matters for thermal management in sealed enclosures — at full load, that's heat that needs to be vented or dissipated.