What this MCCB delivers for a panel line
The Siemens SENTRON 3VA1140-3EF36-0AD0 is a 3-pole molded case circuit breaker rated 40 A continuous current with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity hits 75.6 kA at 240 V and 52.5 kA at 415 V, so it handles high-fault utility feeds without cascading upstream. The 70 mm depth and 76.2 mm width fit standard panel footprints — no rework of the DIN-rail layout needed. Built as a line-protection device (Product version: Line protection), it carries no undervoltage release, no ground-fault monitoring, and no communication module — it is a straight feeder breaker for distribution panels, motor control centers, or branch circuits where selectivity and thermal-magnetic coordination are the only requirements.
Current derating and thermal reality
The 40 A rating holds flat from 40 °C to 50 °C. Above that, derating begins: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. In a sealed panel with poor airflow, that 36 A floor at 70 °C is the number to size against — not the 40 A nameplate. Rated insulation voltage is 800 V, and interrupting capacity at 690 V is still 10.5 kA — enough for 690 V industrial grids with moderate fault levels. Mechanical endurance is 15,000 cycles, typical for a distribution-grade MCCB.
Integration and auxiliary contacts
Three auxiliary switches (HQ type) are built in — enough for remote status feedback or interlocking without an add-on module. The front face carries IP40 protection, so it is suitable for clean indoor panels but not washdown environments. No trip indicator is fitted, so a remote indication relies on the auxiliary contacts.