What this MCCB delivers — and what the ratings mean for your panel
The Siemens 3VA2325-7MN32-0AE0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current with an ETU350M electronic trip unit. The 330 kA breaking capacity at 240 V tells you this breaker can safely interrupt fault currents up to that level without cascading upstream — critical for high-fault installations like transformer secondaries or large motor control centers. At 690 V the breaking capacity still holds at 52.5 kA, so it covers 480 V and 600 V class panels with headroom. The 3-pole design with phase failure detection means it protects motors against single-phasing, and the four HQ auxiliary switches give you status feedback for PLC or HMI without adding external relays.
Thermal derating and endurance — the numbers that govern real-world fit
The 250 A rating holds flat from 40 °C through 50 °C, then derates to 240 A at 55 °C and 225 A at 70 °C. That means in a warm enclosure — say 55 °C ambient — you have 240 A of usable capacity, not the full nameplate. The 15 000 latching-endurance cycles (mechanical) tell you this breaker is built for switching duty, not just backup protection. Power loss at full load is 37.5 W, so factor that into your enclosure thermal calculation. Operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C.
Panel fit and mounting — what the dimensions tell you
The 138 mm width, 248 mm height, and 110 mm depth fit the standard SENTRON 3VA2 panel footprint. Mounts via four-point screw fixing or optional DIN-rail adapter. The 110 mm depth means it clears most 200 mm deep enclosures with room for wiring gutters. No undervoltage release or ground-fault module fitted on this variant — those are add-on accessories if your application requires them.