What it is and what it does
The Siemens SENTRON 3VA2225-6JQ32-0KA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 250 A at 40 °C and is built to interrupt fault currents up to 242 kA at 240 V, dropping to 187 kA at 415 V and 4.5 kA at 690 V — so it handles high available fault current on the low-voltage side of a transformer but needs coordination attention at higher line voltages.
Thermal derating and trip adjustment
The breaker holds its full 250 A rating from 40 °C up to 50 °C, then derates linearly to 200 A at 70 °C. That means a panel running warm — say 55 °C inside the enclosure — you lose 12 A off the headline number. The adjustable thermal-magnetic trip is set from a minimum of 375 A to a maximum of 2 500 A, with the full-scale value at 250 A. Initial trip setting is 50 A, so this unit ships set low and needs field adjustment to match the load.
Panel fit and integration
Footprint is 105 mm wide by 181 mm tall by 86 mm deep — a standard 3-pole MCCB form factor that drops into most SENTRON panelboards and distribution blocks without re-drilling. The unit includes a shunt trip release (STL) for remote tripping and a communication function for integration with building management or PLC-based monitoring. No auxiliary switch is fitted from the factory, so if you need status feedback, plan for an add-on module.