The Siemens SENTRON 3VA2140-7HN42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 40 A continuous current, built for line protection in distribution panels. It carries the ETU350 electronic trip unit, which gives you adjustable overload and short-circuit protection curves — not a fixed thermal-magnetic, so coordination studies get more flexibility.
Breaking capacity and what it means for your panel
At 240 V this MCCB interrupts up to 330 kA, which is a very high interrupting rating — it handles faults at the main distribution level without needing a current-limiting fuse upstream. At 415 V and 440 V it still holds 242 kA, and at 500 V it's rated 187 kA. The 690 V figure drops to 3.7 kA, so if you're on a 690 V system this breaker is only suitable for low-fault locations downstream of a current-limiting device.
Thermal derating and operating range
The 40 A rating holds flat from 40 °C all the way up to 70 °C ambient — no derating needed in a warm enclosure. Operating temperature floor is -25 °C, storage from -40 °C to 80 °C. That means it's fine for unheated electrical rooms or outdoor enclosures in temperate climates, but if you're in a deep-freeze warehouse verify the -25 °C minimum is sufficient.
Physical fit and panel integration
Dimensions are 181 mm high, 140 mm wide, 86 mm deep. The 140 mm width is standard for a 4-pole MCCB in this frame size — it occupies four 35 mm DIN-rail modules. Front face is IP40 rated, so it's protected against tools and wires but not against water ingress; keep it inside a closed panel.