What this MCCB is and what it does
The Siemens 3VA2325-7MN32-0AB0 is a SENTRON molded case circuit breaker (MCCB) in the motor protection variant, carrying 250 A continuously at 40 °C ambient and rated to switch 110 kW motor loads in AC-3 duty at 400 V. It uses the ETU350M electronic trip unit, which gives you adjustable overload and short-circuit protection curves plus phase failure detection — the M suffix means it's tuned for motor starting inrush without nuisance tripping. Three poles, 800 V rated insulation voltage, and a front-side IP40 protection class that keeps dust and tools out of the breaker face in a standard panel enclosure.
Interrupting capacity — what the numbers mean for your fault duty
At 240 V this breaker clears 330 kA — that's the highest short-circuit current it can safely interrupt without welding contacts or rupturing the case. At 415 V and 440 V it still holds 242 kA, dropping to 187 kA at 500 V and 52.5 kA at 690 V. For a 480 V panel in North America, the 187 kA at 500 V rating covers the typical available fault current on most industrial services. If your transformer is oversized or you're close to the substation, verify your SCCR study against the 242 kA at 440 V curve — that's the conservative bound for 480 V systems.
Thermal derating and continuous current
Rated 250 A from 40 °C through 50 °C ambient. At 55 °C it derates to 240 A, at 60 °C to 235 A, at 65 °C to 230 A, and at 70 °C to 225 A. The maximum operating ambient is 70 °C; storage range is -40 °C to 80 °C. Power dissipation at full load is 37.5 W maximum — that's the heat you need to vent from the enclosure. In a sealed stainless panel with multiple breakers ganged, factor this into your thermal budget.
Physical fit and auxiliary contacts
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The width is the critical panel cutout dimension — 138 mm is the standard 3-pole MCCB footprint for this SENTRON frame size. Comes with 2 HP auxiliary switches factory-installed (high-performance type, rated for control-circuit isolation). No undervoltage release, no shunt trip, no ground-fault module on this order code — those are add-on accessories if you need them.
Lifecycle and sourcing reality
The base switch (without auxiliaries) is order code 3VA2325-7MN32-0AA0. This -0AB0 suffix adds the 2 HP auxiliary switches at the factory rather than as a field-installed kit.