What this 3VA2 carries
The Siemens SENTRON 3VA2340-5JQ32-0HL0 is a 3-pole molded case circuit breaker rated for 400 A continuous current (Iu) with an ETU560 electronic trip unit. It's configured for line protection — meaning it sits at the main feeder or a large branch, not on a motor circuit. The 187 kA breaking capacity at 240 V tells you it can interrupt a massive fault without upstream fuses; at 690 V that drops to 17 kA, so verify the available fault current at your service voltage. The 138 mm width and 248 mm height match the standard 3VA2 footprint, so it swaps into existing SENTRON panels without re-drilling the mounting plate.
Thermal derating and endurance
This breaker holds 400 A from 40 °C up to 50 °C ambient. At 55 °C it derates to 375 A, and at 70 °C it's down to 300 A. If your panel runs hot — say inside a non-climate-controlled enclosure in a foundry or compressor house — size the upstream conductor for the derated value, not the nameplate 400 A. Mechanical endurance is 15,000 operations, which is typical for a fixed-mounted MCCB at this frame size; it's not a switching device for frequent motor starts.
Trip unit and auxiliaries
The ETU560 overcurrent release is a microprocessor-based unit with LSI protection curves. The part ships with a shunt trip (STL) for remote opening, plus a full auxiliary contact block: 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch.