What the ratings mean for fit
The Siemens SENTRON 3VA2340-6KP32-0KL0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with an adjustable thermal-magnetic trip unit covering 600 A to 4000 A. The interrupting capacity is 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V — so at 480 V systems (common in North American industrial panels) you interpolate between the 440 V and 500 V figures, which still puts it well above typical available fault current. The 400 A rating holds flat through 50 °C; above that it derates to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If your enclosure runs hot, that derating curve is the number that governs the real ampacity, not the nameplate 400 A. Maximum power loss is 96 W. The breaker includes a communication function and a shunt trip release (STL) plus 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch HQ.
Panel integration and deployment context
The 3VA2340-6KP32-0KL0 mounts on a DIN rail or can be screw-fixed to a backplate. Dimensions are 248 mm height, 138 mm width, 110 mm depth — the depth is the critical dimension for shallow enclosures or when a rear-mounted bus bar system is present. The 138 mm width for a 3-pole frame is standard for this class; it occupies roughly 5.4 inches of DIN rail. The line protection designation means it is configured for cable and busbar protection rather than motor protection — the adjustable trip range (600-4000 A) is sized for feeder circuits, not individual motor loads.