What it is and what it does
The Siemens SENTRON 3VA2140-8HN36-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 40 A across the full ambient temperature range from 40 °C to 70 °C — no derating needed up to the enclosure's thermal limit. The 480 A frame size means the breaker's physical bus and contacts are rated for that maximum, but the ETU350 electronic trip unit is set for 40 A. That electronic trip gives you adjustable overload and short-circuit protection curves, not just a fixed thermal-magnetic response.
Breaking capacity — what the ratings mean for fit
Breaking capacity is the real differentiator here. At 240 V AC this breaker interrupts 440 kA — that's utility-grade fault current, typical for large transformer secondaries or industrial service entrances. At 415 V and 440 V it still handles 330 kA, and at 500 V it's 220 kA. Even at 690 V it manages 52.5 kA. Those numbers mean you can place this MCCB on a high-fault bus without worrying about cascading failure upstream. The 800 V rated insulation voltage confirms it's built for 690 V line-to-line systems.
Panel fit and environment
Dimensions: 86 mm deep, 105 mm wide, 181 mm tall. That's a standard SENTRON 3VA footprint — it bolts into the same mounting pattern as other 3VA frame breakers. IP40 on the front means it's protected against tools and wires larger than 1 mm, but it's not sealed against water; keep it in a dry enclosure or add a cover. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. Power loss is only 1.2 W at rated load, so heat buildup in a dense panel is minimal.