What this MCCB delivers on the line
The Siemens SENTRON 3VA2340-5KP32-0AD0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C — the same rating holds through 50 °C, so you don't lose headroom in a warm panel. It's designed for line protection, meaning it sits at the feeder or main distribution point, not downstream on a motor branch. The 187 kA interrupting capacity at 240 V gives serious fault-clearing muscle; at 415 V it still handles 121 kA. That SCCR lets you coordinate downstream breakers without worrying about cascading failure on a high-fault service. Dimensions are 110 mm deep, 138 mm wide, 248 mm tall — a standard SENTRON 3VA footprint that fits existing panel layouts without re-drilling the mounting plate. The unit includes a communication function (likely PROFIBUS or PROFINET via a plug-in module) for remote trip indication and load monitoring, which is useful for a plant engineer tracking breaker status from the SCADA screen rather than walking the panel.
Thermal derating and power loss
The breaker carries a full 400 A up to 50 °C ambient. Above that it derates: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If your panel runs hot — say near a VFD bank or in a non-conditioned enclosure — factor that derating into your load calculation. Maximum power loss is 96 W, which matters for enclosure heat rise; a 400 A frame dumping nearly 100 W needs ventilation or a larger cabinet than a standard 200 A MCCB.