What it is and what it does
The Siemens SENTRON 3VA1140-5EF32-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current of 40 A, making it the line-protection backbone for a feeder or a large motor branch in a 400 V class panel. It carries a TM240 thermal-magnetic overcurrent release — the thermal element handles overloads, the magnetic element clears short circuits — and is built for the SENTRON 3VA platform, which is Siemens' current-generation MCCB family for commercial and light industrial distribution. Rated insulation voltage is 800 V. The front face carries IP40 protection.
Breaking capacity — the real number
This breaker's interrupting rating is what you spec around. At 240 V it clears 187 kA; at 415 V it's 121 kA; at 440 V it drops to 75.6 kA; at 690 V it's 17 kA. For a 400 V class panel with a transformer feeding a high-fault bus, the 121 kA at 415 V tells you it can sit downstream of a large transformer without needing a current-limiting fuse upstream. The 690 V figure is low enough that you'd check the available fault current if the breaker lands in a 690 V wind or industrial application.
Thermal derating and panel fit
Rated continuous current holds at 40 A from 40 °C through 50 °C ambient. At 55 °C it derates to 38.4 A; at 60 °C to 37.6 A; at 65 °C to 36.8 A; at 70 °C to 36 A. If the panel ambient runs hot — say a packed enclosure with drives — you lose roughly 4 A by the time you hit 70 °C. Plan the branch load accordingly. Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep.
Integrated shunt trip and auxiliary options
This version ships with a shunt trip (STL) release designed in — order code 3VA9688-0BL30 for the integrated auxiliary trip module. That means remote tripping via a control signal is built in without external add-on hardware. No undervoltage release, no auxiliary contact, no ground-fault monitoring, no communication function. If you need those, this is not the variant; you'd look at a 3VA1 with the appropriate suffix. Mechanical endurance is rated at 15,000 operations.