MCCB for high-fault panels
The Siemens SENTRON 3VA2225-5HN32-0AJ0 is a 3-pole molded case circuit breaker rated for 250 A continuous current, with an ETU350 electronic trip unit for line protection. Its interrupting capacity hits 187 kA at 240 V — that's the number that governs fault clearing in high-available-fault panels like main switchboards or large distribution boards where the upstream transformer can dump serious energy into a short. The ETU350 is a fixed electronic trip; no voltage trigger, no communication module, no phase-failure detection — it's a straightforward thermal-magnetic replacement for standard line protection. The auxiliary contact package comes as 2 auxiliary switches plus 1 trip alarm switch (HP version), which is enough to signal the breaker state to a PLC or annunciator panel without adding a separate aux block.
Interrupting capacity across voltages
The interrupting curve drops as voltage rises: 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V. That 5.1 kA at 690 V is the weak point — if your panel feeds a 690 V motor drive, confirm the available fault current stays under that figure, or step up to a higher-rated frame.
Thermal derating and panel fit
Rated 250 A from 40 °C through 50 °C ambient; above that it derates linearly to 213 A at 70 °C. In a sealed enclosure with other heat sources, use the 60 °C column (232 A) as your real-world limit. The breaker measures 105 mm wide, 181 mm tall, 86 mm deep — fits standard 3-pole MCCB panel cutouts. Front protection is IP40, so keep it inside a cabinet, not in a washdown zone.