What the interrupting ratings mean for your coordination study
The Siemens SENTRON 3VA2340-6JQ32-0CA0 is a 3-pole molded case circuit breaker on a 400 A frame, designed for line protection. Its interrupting capacity of 242 kA at 240 V and 187 kA at 415 V means this breaker can safely clear a fault at those levels without rupturing — critical for high-fault locations like a main service entrance or a large motor control center fed by a utility transformer. At 690 V the rating drops to 7.5 kA, so if your system runs at that voltage, the available fault current must be verified against that lower figure; the breaker is not a universal high-interrupting device at every voltage. The continuous current rating holds at 400 A from 40 °C through 50 °C (–), then derates to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If this breaker lives in a non-air-conditioned switchroom that hits 55 °C in summer, the load must be capped at 375 A — the nameplate 400 A is only valid up to 50 °C ambient. That derating curve is the one that governs the real panel loading, not the frame size.
Panel integration and physical fit
The breaker measures 248 mm high by 138 mm wide by 110 mm deep (–). That 110 mm depth (4.33 in) is the dimension that matters for enclosure depth clearance — a standard 200 mm deep enclosure leaves adequate room for the breaker plus rear-mounted bus bars or cable connections. The 138 mm width (5.43 in) for a 3-pole frame is typical for this class; verify the mounting footprint against the existing panel cutout or DIN-rail adapter if retrofitting into an older board.
Built-in undervoltage release and communication
The breaker includes an undervoltage release (UVR) as the auxiliary release. This means if the control voltage feeding the UVR coil drops below its dropout threshold, the breaker trips — standard for applications where a loss of control power must also disconnect the load (e.g., emergency stop circuits or safety-related disconnects). A communication function is present, which allows integration with a higher-level monitoring or SCADA system for trip status and load data. The basic switch variant is listed as 3VA2340-6JQ32-0AA0, confirming this -0CA0 suffix carries the UVR and communication options.