What the ratings mean for fit
The Siemens 3VA1140-3EF36-0AB0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current (Iu) with a 3-pole configuration. Its TM240 thermal-magnetic trip unit provides fixed thermal and magnetic protection for line-feeder or downstream panelboard applications. The 75.6 kA interrupting rating at 240 V drops to 52.5 kA at 415 V and 32 kA at 440 V — the 415 V figure is the one that governs most European 400 V distribution panels, and at 690 V it still holds 10.5 kA, which covers most motor-circuit fault scenarios upstream of a VFD. Thermal derating is flat from 40 °C to 50 °C (40 A), then drops to 38.4 A at 55 °C and 36 A at 70 °C. In a sealed, uncooled enclosure the 55 °C figure is the realistic continuous rating — size the load at 38 A if the panel ambient runs warm. The auxiliary contact version ships with two HP auxiliary switches, which is enough for a remote trip-indication and a status feedback to a PLC without adding an external aux block. No undervoltage release, no shunt trip, no ground-fault module — this is a bare line-protection breaker; add those externally if the application requires it. Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. The 76.2 mm width is a standard 3-pole MCCB footprint for DIN-rail or screw-mount panels — verify the bus-bar pitch against an existing panel layout, but it matches the common 25 mm per-pole spacing.
Panel integration notes
Front IP40 rating means the breaker face is protected against tools and small wires, but the enclosure itself must provide the overall panel IP rating — this is standard for switchgear cubicles. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. The 800 V rated insulation voltage (Ui) covers 480 V and 600 V class systems with headroom. The adjustable thermal time delay tr max. is 1 second — this is the long-time delay band at maximum setting, used to coordinate with downstream branch breakers. No communication function, no phase-failure detection, no voltage trigger — this is a pure overcurrent protector, not a smart breaker.