What it is and what it does
The Siemens SENTRON 3VA1110-4EF36-0KH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, with a continuous current of 100 A at 40 °C and a breaking capacity that reaches 121 kA at 240 V, dropping to 75.6 kA at 415 V and 11.9 kA at 690 V. It carries a rated insulation voltage of 800 V, so it's sized for 400 V class panels with headroom.
Breaking capacity — the real-world fit
The 121 kA at 240 V is the headline number, but the 75.6 kA at 415 V is what matters for most European and Asian 400 V distribution boards. At 690 V it still holds 11.9 kA — enough for most motor control center (MCC) infeeds. The part is designed for line protection, meaning it's the main breaker, not a feeder or motor-circuit protector.
Thermal derating — don't ignore the curve
Rated 100 A from 40 °C to 50 °C, then it starts to taper: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, 91 A at 70 °C. If your enclosure runs hot — say, a non-ventilated panel with multiple breakers — you need to calculate the actual load at the ambient temperature. The part itself operates from -25 °C to 70 °C and stores from -40 °C to 80 °C.
Integrated auxiliaries and release
Comes factory-fitted with 2 auxiliary switches plus a trip alarm switch (HQ), and a shunt trip (STL) release. That means you can signal breaker status back to a PLC and remotely trip the breaker without adding separate modules. No undervoltage release, no ground-fault monitoring — this is a basic line-protection build.