Integrator's terse spec recap
The Siemens SENTRON 3VA2225-7HN32-0HC0 is a 3-pole molded case circuit breaker rated for 250 A continuous current at 40 °C, with a maximum interrupting capacity of 330 kA at 240 V AC. It is designed for line protection and includes a shunt trip release (STL) plus two auxiliary switches (HQ). The frame size carries a 2500 A maximum rating, but the thermal-magnetic or electronic trip unit fitted here limits continuous duty to 250 A — so the breaker is sized for a 250 A feeder, not the full frame capability.
Breaking capacity and selectivity
The interrupting ratings drop as voltage rises: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 4.5 kA at 690 V. At 415 V, the 242 kA SCCR gives substantial headroom for most industrial distribution panels — coordination studies typically require 50–100 kA at the main, so this breaker sits well above that threshold. The steep drop at 690 V (4.5 kA) means it is not intended for 690 V line-side fault duty; verify the available fault current at that voltage before specifying.
Thermal derating and panel integration
The breaker holds 250 A continuously up to 50 °C ambient, then derates linearly to 213 A at 70 °C. In a sealed enclosure with multiple devices, the 70 °C derated figure (213 A) is the practical limit — plan for forced ventilation or a larger enclosure if the load approaches 250 A in a hot panel. Dimensions are 181 mm height, 105 mm width, 86 mm depth, fitting standard SENTRON 3VA mounting footprints. Power loss is 48 W maximum at rated current, which contributes to enclosure heat rise.