What it is and what the ratings mean
The Siemens 3VA1140-4ED46-0AA0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection in distribution panels. Four poles, rated 40 A continuous at 40 °C, with a TM210 thermal-magnetic release — that means a fixed thermal trip curve and a magnetic short-circuit pickup at 10x In, so it handles motor inrush without nuisance trips but clears hard faults fast. The interrupting capacity hits 121 kA at 240 V AC, 75.6 kA at 415 V, and 52.5 kA at 440 V — numbers that tell you this breaker is built for high-fault service entrances or sub-distribution where the available fault current is substantial. At 690 V it still holds 11.9 kA, which covers most industrial 600 V class systems.
Where it fits in the panel
Mounts on a DIN rail or panel-mount base. The 101.6 mm width (4 in) and 70 mm depth (2.76 in) mean it occupies a standard MCCB footprint — no surprises when you slot it into an existing SENTRON or third-party distribution board. IP40 on the front keeps dust out of the enclosure; the rest of the breaker is rated for inside a dead-front panel, not washdown areas.
Thermal derating and operating limits
The 40 A rating holds from 40 °C up to 50 °C. At 55 °C it steps to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. That's a gentle slope — you don't lose a full breaker size until you're well above typical panel ambient. Rated insulation voltage is 800 V, operating voltage 690 V AC. Maximum power loss is 10.8 W, which matters for thermal coordination in a sealed enclosure. Storage range is -40 °C to 80 °C; operating range -25 °C to 70 °C.