What this MCCB is and what it protects
The Siemens 3VA2225-5KQ32-0AA0 is a SENTRON molded case circuit breaker (MCCB) for line protection. It is a 3-pole unit rated 250 A continuous at 40 °C, with a full-scale adjustable trip range from 375 A up to 2 500 A. The insulation voltage is rated 800 V.
Breaking capacity — what the numbers mean for your fault duty
This breaker carries a rated ultimate short-circuit breaking capacity (Icu) that varies sharply with system voltage: 187 kA at 240 V, 121 kA at both 415 V and 440 V, 75.6 kA at 500 V, and 4.5 kA at 690 V. At typical North American 480Y/277 V or 600 V industrial services, the 75.6 kA and 4.5 kA figures respectively tell you where this breaker can safely interrupt a fault without welding contacts or venting arc gas. The 4.5 kA at 690 V is low — if your 690 V bus has more available fault current, you need a higher-rated frame or a current-limiting upstream device.
Thermal derating — don't size by the 40 °C sticker alone
The 250 A rating holds flat from 40 °C through 50 °C. Above that, it derates linearly: 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. If your panel ambient hits 60 °C — common in a non-conditioned enclosure near a furnace line — you only get 225 A continuous out of this frame. The maximum operating temperature is 70 °C, with storage from -40 °C to 80 °C. Maximum power loss is 48 W, which matters for enclosure heat-rise calculations.
Built-in communication and ground-fault monitoring
This variant includes a communication function for remote trip indication, current metering, and parameter readback via the SENTRON communication bus or a gateway module. It also carries a ground-fault monitoring version configured for summation current formation on the L-conductor.
Dimensions and panel fit
The 3VA2225-5KQ32-0AA0 measures 181 mm high, 105 mm wide, and 86 mm deep. That's a 4.13-inch wide footprint — standard for a 250 A frame MCCB — so it fits a typical 3-pole breaker slot in a Siemens panelboard or a separate enclosure. No trip indicator window on the front face, so you'll rely on the communication output or a handheld ammeter for status.