What this MCCB carries and where it fits
The Siemens 3VA1140-3EF32-0KA0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection in distribution panels. Its 40 A rated continuous current at 40 °C and 3-pole construction suit it for feeder or branch-circuit duty in commercial and light industrial switchboards. The TM240 thermal-magnetic overcurrent release handles both overload and short-circuit protection without an external relay — a common choice where adjustable electronic trip is not required. Interrupting capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V. These figures govern SCCR coordination downstream: at 415 V, for example, the breaker clears a 52.5 kA fault without upstream reinforcement, which simplifies panel design in 400 V distribution. A shunt trip release (STL) is integrated, allowing remote tripping via a control signal — useful for emergency-stop or interlock circuits. The auxiliary release order code is 3VA9688-0BL33. No auxiliary contacts, undervoltage release, or communication function are fitted, so add-on blocks are needed if those features are required.
Thermal derating and panel fit
The breaker holds its 40 A rating through 50 °C ambient (–). Above that, current must be derated: 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, uncooled enclosure near other heat sources, use the 55 °C column for continuous load sizing. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth. The 76.2 mm width is a standard 3-pole MCCB footprint — it occupies three 25.4 mm (1-inch) module positions on a DIN rail or panel-mount base. Front IP40 protection means it resists tools and wires larger than 1 mm, but not water ingress; keep it inside a rated enclosure.