What this 3VA2 breaker carries
The Siemens 3VA2510-5HN42-0BA0 is a 4-pole IEC frame 1000 circuit breaker with a 55 kA breaking capacity at 415 V (class M). It is fitted with an ETU350 LSI trip unit, rated In=1000 A, with overload protection adjustable Ir=400 A...1000 A, short-circuit protection Isd=1.5...10 x Ir, and instantaneous Ii=10 x In. The N-conductor protection is selectable OFF, 50%, or 100%. It also includes an undervoltage release (24 V DC) as an integrated accessory.
The ETU350 LSI trip unit gives selective coordination: you set the long-time pickup (Ir) to match the load, the short-time pickup (Isd) and delay for downstream coordination, and the instantaneous (Ii) for cable protection. The adjustable N protection (OFF/50%/100%) is useful on 4-wire systems where neutral current may be unbalanced or where you want to omit neutral protection to save space. The integrated undervoltage release (24 V DC) allows remote tripping via a safety circuit or emergency-stop chain. It is wired as an accessory for 3VA1 and 3VA20 frames, but on this 3VA2 frame it is factory-fitted.