Line protection MCCB, 40 A, 3-pole — what the ratings mean for fit
The Siemens SENTRON 3VA1040-3ED36-0AE0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 40 A, sized for line protection in distribution panels. Its TM210 thermal-magnetic overcurrent release handles the overload and short-circuit trip curve without needing an external trip unit — a fixed-release design that simplifies specification and reduces wiring in standard 40 A feeder circuits. Breaking capacity is the headline selector: 75.6 kA at 240 V AC, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 690 V. That 52.5 kA at 415 V is the figure that governs most European 400 V industrial panels — it tells you this MCCB can safely interrupt a bolted fault up to that level without welding contacts or venting arc gas into the enclosure. The 690 V rating (7.5 kA) confirms it is usable on 690 V line-to-line systems, though with reduced fault-clearing margin. Current derating across temperature is published: full 40 A up to 50 °C, then 38.4 A at 55 °C, stepping down to 36 A at 70 °C. If the breaker sits in a warm cabinet — say 55 °C ambient — you must load it at 38.4 A max, not 40. The rated insulation voltage Ui is 800 V, which covers all standard low-voltage networks up to 690 V phase-to-phase.
Panel fit and auxiliary switching
Dimensions: 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint. The 76.2 mm width matches the common 3-pole cutout. Four auxiliary switches (HQ type) are built in — two normally-open and two normally-closed contacts rated for signaling the breaker status to a PLC or indicating lamp. No separate auxiliary block to buy and snap on; it ships ready for remote status monitoring. The front face carries IP40 protection — suitable for a closed panel interior, but not for washdown or outdoor exposure. Latching endurance is rated at 15 000 cycles — the mechanical life of the switching mechanism under load. For a line-protection breaker that may see only a few operations per year, this is effectively unlimited; for a breaker used as a manual disconnect cycled daily, it sets the replacement interval.