Siemens SENTRON 3VA2340-5HN42-0AB0 — 400 A MCCB with ETU350 Trip Unit
The Siemens 3VA2340-5HN42-0AB0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C through 50 °C, with a 4-pole configuration and an ETU350 electronic overcurrent release. The interrupting ratings are substantial: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V.
Interrupting Capacity and SCCR Planning
For a site electrical engineer doing a selective coordination study, those numbers give headroom to avoid nuisance upstream tripping.
The breaker carries 400 A continuously up to 50 °C ambient, then derates to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. In a sealed panel with limited airflow, that derating curve is the real selection parameter — not the 400 A nameplate. The enclosure dimensions (248 mm height, 184 mm width, 110 mm depth) fit standard SENTRON 3VA mounting footprints; check the panel cutout against the existing 3VA backplate or DIN-rail adapter.
Trip Unit and Auxiliary Contacts
It ships without undervoltage release, voltage trigger, phase failure detection, or communication function — this is a straightforward line-protection breaker, not a smart breaker. Two auxiliary switches (HP type) are integrated for status feedback to the PLC or SCADA system. The basic switch variant is 3VA2340-5HN42-0AA0.
The storage limits govern handling and warehousing, not running conditions. Maximum power loss is 96 W — account for that in the enclosure thermal budget.