What this breaker does for your panel
The Siemens 3VA2340-6HL42-0AJ0 is a 4-pole IEC molded-case circuit breaker on the 3VA2 frame, rated 400 A continuous and delivering 85 kA breaking capacity at 415 V (class H). The ETU320 trip unit provides LI protection (long-time and instantaneous) with adjustable overload pickup from 160 A to 400 A and instantaneous pickup from 1.5 to 10 times In, so you can tune coordination with downstream breakers without swapping trip units.
The adjustable N-conductor protection (OFF, 50%, 100% of phase pickup) lets you protect the neutral on a 4-wire system or leave it unprotected on a 3-wire delta — a detail that matters when the panel feeds mixed loads. The two auxiliary switches and one trip-alarm switch are wired in, so you get remote status and alarm feedback without adding external relays.