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). That Icu rating means it can safely interrupt a fault current up to 85 kA without welding contacts or rupturing the case — critical for high-fault installations like large motor control centers or transformer secondaries where available fault current is high. 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.
What the ratings mean for fit
The 85 kA Icu at 415 V is the short-circuit breaking capacity — the maximum fault current the breaker can clear once without damage. That is the number that decides whether this breaker holds in a high-fault location; if your available fault current exceeds 85 kA, you need a higher-frame or current-limiting breaker upstream. 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.