What this MCCB delivers for the panel
The Siemens SENTRON 3VA2340-6HN32-0HC0 is a 3-pole molded case circuit breaker rated for 400 A continuous current, with an ETU350 electronic trip unit and a shunt trip release. It carries a 242 kA interrupting capacity at 240 V, dropping to 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V — so it handles high-fault utility feeds and large motor branch circuits without cascading upstream. The thermal derating curve is flat from 40 °C to 50 °C (full 400 A), then steps down: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. That means in a warm enclosure you lose about 15 % of capacity at the top end — plan your load margin accordingly. The 110 mm depth and 138 mm width fit standard panel-mount cutouts for this frame size. Two HQ auxiliary switches are integrated, plus a shunt trip (STL) for remote opening — no separate undervoltage release fitted, but the shunt trip covers emergency-stop logic.
Integration and compliance notes
Rated insulation voltage Ui is 800 V, so it is suited for 690 V line-to-line systems. Maximum power loss is 96 W — account for that in enclosure thermal calculations. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The basic switch is order code 3VA2340-6HN32-0AA0; the integrated auxiliary trip is 3VA9688-0BL30. These are the replacement subassemblies if a service swap is needed.