What this MCCB carries and where it fits
The Siemens SENTRON 3VA2225-5HN42-0AG0 is a 4-pole molded case circuit breaker rated for 250 A continuous current (Iu) with an ETU350 electronic trip unit configured for line protection. Its 187 kA interrupting capacity at 240 V means it can clear a fault at that level without the arc flashing over to adjacent gear — critical for high-fault panels close to the transformer secondary. At 415/440 V it still holds 121 kA, dropping to 79 kA at 500 V and 5.1 kA at 690 V, so the SCCR coordination study needs to check the voltage at the fault point, not just the system nominal. The breaker carries a 1 auxiliary switch plus 1 trip alarm switch (HP version) as standard, so you get both a position signal and a separate fault-indication contact without adding a module. No undervoltage release, no shunt trip, no communication module — this is a straight line-protection MCCB with the trip unit doing the selectivity work.
Thermal derating and panel fit
The breaker holds its full 250 A rating up to 50 °C ambient. Above that it derates linearly: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, 213 A at 70 °C. If the panel internal ambient runs hot — say next to a drive bank or transformer — size the upstream conductor for the derated value, not the nameplate 250 A. Maximum power loss is 48 W, so ventilation or spacing in the enclosure matters when ganging multiple breakers. Dimensions are 140 mm wide, 181 mm high, 86 mm deep. The 140 mm width is the standard 4-pole frame width for this SENTRON 3VA2 platform — it occupies the same footprint as the equivalent fixed-thermal-magnetic version, so a panel laid out for a 3VA2 frame accepts this breaker without re-drilling the mounting plate.