The Siemens 3VA2340-5HN42-0AC0 is a SENTRON molded case circuit breaker (MCCB) for line protection, rated 400 A continuous current across a 4-pole frame. Its interrupting capacity hits 187 kA at 240 V AC, 121 kA at 415/440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — the 690 V figure means it handles fault clearing on 690 V systems but with a lower ceiling, so verify available fault current at that voltage before specifying. Thermal derating is published from 40 °C up to 70 °C: full 400 A up to 50 °C, then 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. That 70 °C limit is the operating ambient maximum; storage range is -40 to 80 °C.
Panel footprint: 184 mm wide, 248 mm tall, 110 mm deep. Four-pole frame means it occupies the full width of a standard 600 mm enclosure's backplate when mounted vertically — plan gland-plate clearance on the line side. No undervoltage release, no ground-fault monitoring, no auxiliary release fitted on this variant; the auxiliary switch pack is two HQ contacts. The basic switch version is order code 3VA2340-5HN42-0AA0, so this -0AC0 suffix carries the added auxiliary switch assembly.