What the ratings mean for your panel
The 3VA2225-5HL32-0AJ0 is a Siemens SENTRON molded case circuit breaker rated for 250 A continuous current (Iu) with an ETU320 electronic trip unit. The 187 kA breaking capacity at 240 V AC means it can safely interrupt fault currents up to that level without upstream devices needing to clear the fault — critical for high-fault installations like transformer secondaries or large motor control centers. At 415 V and 440 V the interrupting rating holds at 121 kA, dropping to 79 kA at 500 V and 5.1 kA at 690 V, so verify the available fault current at your system voltage before specifying. The thermal derating curve is published: full 250 A through 50 °C ambient, then 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your panel internal ambient runs above 50 °C, size the load or provide ventilation to stay within the rated envelope.
Integration and mounting
The breaker occupies 105 mm width, 181 mm height, and 86 mm depth — fits standard SENTRON 3VA panel cutouts and busbar systems. IP40 on the front means it's protected against tools and small wires entering the enclosure face; the back and sides rely on the panel enclosure for overall IP rating. The auxiliary contact configuration ships with 2 auxiliary switches plus 1 trip alarm switch (HP type), so you get both status and fault indication without adding external relays.