The 4-pole configuration covers three-phase plus neutral, with the N-conductor protection adjustable OFF, 50%, or 100% of the phase rating. The interrupting curve drops to 187 kA at 415 V, 85 kA at 440 V, 55 kA at 500 V, and 7.5 kA at 690 V. For a 400 A feeder on a 480 V system, you've got roughly 85 kA of SCCR headroom — enough for most industrial switchboards. The ETU350 release gives you adjustable long-time pickup (Ir), short-time pickup and delay (Isd, tsd), and instantaneous (Ii) settings, plus a ground-fault option if you add the module. The thermal derating curve is flat to 50 °C, then drops to 385 A at 55 °C and 340 A at 70 °C — so if the panel runs hot, you lose about 15% of the ampacity at the top end.
The 3VA2340-6HN42-0KF0 measures 248 mm tall, 184 mm wide, and 110 mm deep. That 184 mm width (7.2 inches) is a standard 4-pole MCCB footprint — it'll drop into the same DIN-rail or panel-mount cutout as other SENTRON 3VA 4-pole frames. The IP40 front protection means it's rated for indoor panel use where no washdown or dust ingress is expected.