What it is and what the key ratings mean
The Siemens 3VA2340-5JP32-0JL0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with a 3-pole design for three-phase line protection. Its 187 kA breaking capacity at 240 V AC means it can safely interrupt a fault current of that magnitude without welding contacts or rupturing the case — critical for high-fault installations like transformer secondaries or large motor control centers where upstream coordination demands a high-interrupting device. At 415 V and 440 V it still holds 121 kA, and at 690 V it derates to 7.5 kA, reflecting the arc-extinction challenge at higher voltages. The breaker carries a communication function and a shunt trip release, plus a configurable auxiliary switch block: 2 auxiliary switches + 1 trip alarm switch + 1 electrical alarm switch HQ. That makes it suitable for remote monitoring and automated trip signaling in a SCADA or PLC-controlled distribution panel.
Thermal derating and power loss
The 400 A rating holds flat from 40 °C up to 50 °C (–), then steps down: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C (–). Maximum power loss is 96 W — that's the heat the breaker dumps into the enclosure at full rated current, so factor it into your panel thermal budget, especially if the MCCB is mounted in a sealed cabinet with other heat sources.
Panel fit and dimensions
The breaker measures 138 mm wide, 248 mm high, and 110 mm deep. It mounts on a DIN rail or panel-mount plate in a standard distribution enclosure. The 3-pole footprint matches the SENTRON 3VA family, so if you're swapping a 3VA2116-5JP32-0AE0 (a 160 A frame), the panel cutout and busbar spacing are the same — only the lug kit and trip unit change.