What the ratings mean for your panel
The 3VA1225-5EF32-0AJ0 is a 3-pole SENTRON molded case circuit breaker rated for a continuous current Iu of 250 A, with a TM240 thermal-magnetic release. The headline breaking capacity — 187 kA at 240 V and 121 kA at 415 V — means it can safely interrupt fault currents up to those levels without welding contacts or cascading failure upstream. At 690 V it still holds 17 kA, which covers most industrial distribution secondaries. The 250 A rating holds flat from 40 °C to 50 °C; above that it derates to 223 A at 70 °C, so factor in enclosure ambient if the panel runs hot. This is a line-protection version — no undervoltage release, no ground-fault module, no communication. The auxiliary contact block ships as 2 auxiliary switches plus 1 trip-alarm switch (HP type), enough to signal the breaker state back to a PLC or annunciator. The adjustable response time tr max is 1 s, which gives some coordination flexibility on the time-current curve.