Siemens 3VA1140-4EF42-0AA0 — 40 A 4-Pole MCCB, TM240 Release, Active Production
Breaking capacity is the headline number here: 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and it still holds 11.9 kA out to 690 V. That means this breaker clears high-fault currents without welding its contacts or venting arc gas into the panel — important when you're protecting a transformer secondary or a bus feeding multiple motor starters. The 4-pole version lets you switch the neutral, which is required on some IT or corner-grounded delta systems.
The 40 A rating holds flat from 40 °C to 50 °C ambient, then drops to 39 A at 55–60 °C and 38 A at 65 °C, hitting 37 A at 70 °C. The maximum power loss is 10.8 W, so heat dissipation inside the enclosure is manageable even with several breakers ganged. That's a standard SENTRON 4-pole footprint — it clips onto the DIN rail and leaves room for auxiliary contacts or a motor drive on the side.
Sourcing and lifecycle — active, quoted to order
Current-production Siemens SENTRON part. The TM240 release is a fixed thermal-magnetic unit; if you later need adjustable electronic trip or ground-fault, you'd look at a different 3VA variant with a different trip block.