What this MCCB delivers
The Siemens 3VA1140-4EF32-0BH0 is a 3-pole SENTRON molded case circuit breaker rated for line protection. It carries 40 A continuously at 40 °C and derates to 37 A at 70 °C, so the thermal trip curve is predictable across the panel ambient range. Breaking capacity hits 121 kA at 240 V AC and 75.6 kA at 415 V AC — enough headroom for high-fault utility feeds or transformer secondaries without cascading upstream breakers. At 690 V it still interrupts 11.9 kA, covering most industrial motor circuits. Rated insulation voltage is 800 V, so the breaker is suitable for 690 V line-to-line systems with margin. The undervoltage release (UVR) trips the breaker when line voltage drops below a set threshold — common on safety circuits or emergency-stop chains where loss of control power must open the main disconnect. Auxiliary contacts include two auxiliary switches plus one trip-alarm switch (HQ), giving the panel builder feedback on breaker position and fault state without adding external relays. Trip indicator confirms the breaker opened on overload or short circuit, not manual operation.
Panel fit and integration
Dimensions: 130 mm high, 76.2 mm wide, 70 mm deep. That 70 mm depth is the body only — allow clearance for the undervoltage release and auxiliary switch wiring behind the DIN-rail or screw-mount panel. The 76.2 mm width (3 inches) matches the standard 3-pole MCCB footprint; no surprise for a retrofit into an existing SENTRON or comparable cutout. Power loss at full load is 13.3 W maximum — negligible for a single breaker, but when ganging multiple units in a closed panel, account for the cumulative heat rise. The derating table above 55 °C (39 A at 55 °C, 38 A at 65 °C) is the real-world limit; don't size the breaker at 40 A if the panel ambient exceeds 50 °C.