What this MCCB delivers on the line
The Siemens SENTRON 3VA1140-4EF36-0KA0 is a 3-pole molded case circuit breaker rated for 40 A continuous current across the 40 °C to 50 °C ambient band, with a TM240 thermal-magnetic overcurrent release. At 415 V it interrupts 75.6 kA — enough to handle high-fault utility feeds without cascading upstream. The shunt trip (STL) release lets a safety PLC or E-stop circuit kill the breaker remotely, which is the typical integration point in a machine control panel. This is the line-protection variant — no ground-fault monitoring, no communication module, no auxiliary contacts. It is a straight thermal-magnetic breaker with a voltage-trigger shunt trip, sized for feeder or large branch-circuit protection where remote trip is required but data feedback is not.
Breaking capacity — the real fault-handling story
The 75.6 kA at 415 V is the rating that matters for most European and Asian industrial panels running 400 V class supplies. At 240 V it jumps to 121 kA, and at 690 V it holds 11.9 kA. That spread tells you the breaker is designed for high-fault applications on the 400 V tier — not a general-purpose 690 V device. For a 40 A frame, 75.6 kA at 415 V gives substantial SCCR headroom against typical transformer-fed fault currents in the 25–50 kA range, which keeps selectivity coordination simpler downstream.
Thermal derating and panel fit
The breaker holds full 40 A from 40 °C through 50 °C. At 55 °C it derates to 38.4 A, and at 70 °C it drops to 36 A. In a sealed, uncooled enclosure those upper ambient points matter — if the panel runs hot alongside drives or transformers, expect to downrate the branch load accordingly. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth. The 76.2 mm width is a standard 3-pole MCCB footprint — fits most DIN-rail or panel-mount backplates without re-drilling. Front IP40 means it is protected against tools and wires >1 mm but not against water ingress; keep it behind a panel door or in a clean enclosure.