The Siemens SENTRON 3VA1040-3ED36-0JA0 is a 3-pole molded case circuit breaker rated 40 A continuous at 40 °C, with a TM210 thermal-magnetic overcurrent release and an integrated shunt trip (STL) auxiliary release for remote tripping. It's designed for line protection in distribution panels, sized to fit a standard 76.2 mm wide DIN-rail footprint — the same width as most 3-pole MCCBs in this class, so it swaps into an existing panel without drilling new mounting holes. Rated interrupting capacity hits 75.6 kA at 240 V and 52.5 kA at 415 V — enough headroom for most industrial service-entrance or feeder applications where fault current runs high. At 690 V it's still rated 7.5 kA, so it handles line-to-line faults on 480 V systems without issue. The 800 V rated insulation voltage confirms it's built for 690 V class networks.
Current derating and thermal limits
The 40 A rating holds steady up to 50 °C ambient — no derating needed until you cross that threshold. At 55 °C it derates to 38.4 A, at 60 °C to 37.6 A, and at 70 °C to 36 A. That's a shallow curve; you lose only 4 A over a 20 °C rise, so it's forgiving in a warm panel next to transformers or drives. Max operating temp is 70 °C, storage range -40 to 80 °C. Power loss tops out at 10.8 W — that's the heat it dumps into the enclosure. For a 40 A MCCB that's modest; you won't need forced ventilation in a typical 600 x 800 mm panel unless you pack a dozen of them side by side.
Mounting and integration
The 76.2 mm width and 70 mm depth fit standard DIN-rail or panel-mount layouts — no oddball footprint. Three poles, line-side lugs top and bottom; the shunt trip (STL) is built in, so you don't need an external trip module. No undervoltage release, no ground-fault monitoring, no communication function on this variant — it's a straight line-protection breaker with remote trip capability.