Siemens SENTRON 3VA1140-3EF36-0AF0 — 40 A MCCB for Line Protection
The Siemens SENTRON 3VA1140-3EF36-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated 40 A at 40 °C, designed for line protection in distribution panels. Its TM240 thermal-magnetic overcurrent release handles overload and short-circuit faults without an undervoltage or shunt trip module — the listing confirms no undervoltage release and no voltage trigger. The 75.6 kA breaking capacity at 240 V AC means it can safely interrupt a fault current up to that level on a 240 V line, which is the figure that governs SCCR compliance in North American panels. At 415 V the interrupting rating drops to 52.5 kA, and at 690 V to 11.9 kA — still adequate for most industrial motor branch circuits.
What the Ratings Mean for Your Panel
Rated current holds at 40 A from 40 °C through 50 °C, then derates to 39 A at 55–60 °C and 38 A at 65 °C, 37 A at 70 °C — a gentle slope that keeps the breaker usable in warm enclosures without oversizing. The 800 V rated insulation voltage (Ui) sets the maximum voltage the internal insulation withstands; the breaker itself is rated for use on systems up to 690 V AC. Power loss is 10.8 W maximum — relevant for thermal management in a tightly packed panel. The trip indicator gives a visual flag when the breaker has tripped, saving troubleshooting time on a line-down call.
Panel Fit and Mounting
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 3-pole footprint fits standard Siemens SENTRON mounting bases and busbar systems. The auxiliary switch configuration is 1 auxiliary + 1 trip alarm switch (HQ) — verify the wiring diagram for your alarm circuit. No communication module is fitted, so this is a standalone breaker; if you need remote monitoring, order the communication-capable variant separately.