What this breaker brings to the panel
The Siemens 3VA2340-5HL42-0KB0 is a 4-pole IEC frame 400 molded case circuit breaker with a 55 kA interrupting capacity at 415 V AC — class M breaking capacity, meaning it clears high fault currents typical in industrial distribution without cascading upstream. The ETU320 LI trip unit gives you adjustable overload protection (Ir from 160 A to 400 A) and short-circuit pickup (Ii from 1.5 to 10 x In), so you dial in the protection curve to match the feeder or motor load, not the other way around. The neutral conductor protection is adjustable — OFF, 50%, or 100% of the phase rating — handy for 4-wire systems where you need to coordinate ground-fault or harmonic currents without nuisance trips.
The ETU320 is a Li (long-time and instantaneous) electronic trip unit — no short-time delay. For selectivity with downstream breakers, use an ETU350 or ETU550.
The shunt trip occupies the left accessory slot; the two auxiliary switches fit the right side. Wire the shunt trip coil to a normally open emergency-stop circuit — it's a trip-to-open function, so loss of control power opens the breaker. The nut keeper kit (included per the order code suffix) prevents the busbar connection nuts from backing off under vibration — a small detail that saves a callout on a motor control center with frequent starts.