What the ratings mean for fit
The 3VA2325-6HN42-0KF0 is a SENTRON molded case circuit breaker (MCCB) in the 3VA2 platform, sized for line protection in distribution panels. Its 250 A rated continuous current (Iu) holds flat from 40 °C to 50 °C — no derating needed in a typical 40 °C panel ambient — then steps down to 242.5 A at 55 °C and 220 A at 70 °C (–). That temperature profile means you can run it at full nameplate in most ventilated enclosures without recalculating the bus bar ampacity. Breaking capacity is the headline: 242 kA at 240 V, 187 kA at 415 V, 85 kA at 440 V, 55 kA at 500 V, and 7.5 kA at 690 V (–). At 415 V, that 187 kA SCCR covers nearly any industrial fault scenario upstream of a step-down transformer — the breaker clears a bolted fault at that level without venting or cascading. At 690 V the rating drops to 7.5 kA, which still handles a secondary-side fault on a 690 V drive bus but won't substitute for a high-interrupting fuse at that voltage. The electronic trip unit is an ETU350, adjustable for long-time delay (tr from 0.5 to 17 seconds, –) and short-time delay (tsd up to 0.4 s,). That adjustability lets you coordinate downstream breakers without swapping trip packs — set the long-time pickup to ride through motor inrush and the short-time delay to let a feeder breaker clear a bolted fault first.
Integration and mounting
Four-pole frame, 184 mm wide (7.2 in), 248 mm tall (9.8 in), 110 mm deep (–, –). That width is standard for a 4-pole 250 A MCCB in the 3VA2 family — it fits the same cutout as the 3VA2225 peer, so a panel laid out for the 3VA2225-5HN42-0BB0 accepts this unit without drilling new mounting holes or reworking the bus bars. Front IP40 is typical for a panel-mounted breaker; no additional gasketing needed inside a closed enclosure. N-conductor protection is adjustable: OFF, 50%, or 100% of the phase current. That covers both solidly-grounded and impedance-grounded systems — set to 50% for a high-resistance ground scheme, 100% for a solidly-grounded 4-wire distribution. Power loss maxes at 37.5 W, so factor that into the enclosure thermal budget if you're stacking several breakers in a sealed cabinet.