The Siemens 3VA2040-5HN32-0AJ0 is a 3-pole IEC frame 100 molded case circuit breaker with a 55 kA breaking capacity at 415 V (class M). The ETU350 electronic trip unit gives you LSI protection: long-time (Ir adjustable 16 A to 40 A), short-time (Isd 1.5 to 10 x Ir), and instantaneous (Ii fixed at 12 x In). That adjustable short-time band lets you achieve selective coordination downstream, so a branch fault clears without dropping the main feeder. That saves panel-build labor versus field-fitting accessory packs.
The factory-fitted auxiliary switches and alarm contact reduce wiring points inside the enclosure — fewer terminal blocks, less chance of a loose connection during commissioning.