MCCB with shunt trip for line protection
The Siemens 3VA1140-3EF36-0KA0 is a SENTRON 3VA1 molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 40 A rated current at 40 °C across three poles, with a TM240 thermal-magnetic overcurrent release that handles both overload and short-circuit conditions without external trip indication. A shunt trip release (STL) is integrated, allowing remote tripping via a control voltage — essential for emergency-stop circuits or interlocking schemes where the breaker must open on a signal rather than overcurrent alone. Breaking capacity reaches 75.6 kA at 240 V, 52.5 kA at 415 V, and 11.9 kA at 690 V, so it can interrupt high fault currents across common industrial voltage levels without cascading upstream.
Thermal derating and panel fit
Rated current holds at 40 A from 40 °C through 50 °C, then derates to 39 A at 55–60 °C and 37 A at 70 °C. For a panel running warm near the top of a switchboard, the 70 °C figure is the one that governs continuous load capacity. Dimensions are 130 mm height, 76.2 mm width, and 70 mm depth — a 3-pole footprint that fits standard MCCB mounting slots in SENTRON distribution boards or generic DIN-rail adapters. Rated insulation voltage is 800 V, matching typical 690 V system requirements. Maximum power loss is 10.8 W at rated load, which factors into enclosure thermal calculations when grouping multiple breakers in a sealed panel.
Active lifecycle, no obsolescence concern
The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C — wide enough for unheated warehouses and most industrial enclosures.