The Siemens SENTRON 3VA2340-7KQ32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated 400 A continuous at 40 °C, configured for line protection with an ETU860 electronic trip unit. Interrupting capacity hits 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V — figures that confirm it for high-fault infrastructure, not just branch panels. The 800 V rated insulation voltage (Ui) and IP40 front protection suit it for enclosed switchgear where personnel access is restricted to the front face.
Thermal derating and panel fit
The 400 A rating holds through 50 °C ambient; above that the frame derates linearly — 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, 300 A at 70 °C. If this breaker lives in a non-ventilated enclosure near other heat sources, size the bus and lugs for the derated value, not the nameplate. Dimensions are 248 mm high × 138 mm wide × 110 mm deep — a standard 3-pole SENTRON 3VA footprint that drops into existing Siemens switchboard mounting plates without re-drilling. The 96 W maximum power loss at full load needs to be factored into enclosure thermal calculations.
Communication and optional accessories
The breaker supports communication functions — the ETU860 can interface with Siemens communication modules for power monitoring and remote trip indication. An optional motor drive (Product Extension / Optional / Motor Drive = Yes) enables remote open/close for automated load shedding or generator sequencing. The ground-fault monitoring version uses summation current formation on the L-conductor, which means it sums the phase currents internally to detect residual current without an external core-balance transformer.