MCCB for high-fault panels
The Siemens SENTRON 3VA1120-6EF32-0HH0 is a 3-pole molded case circuit breaker (MCCB) rated for 20 A continuous current at 40 °C through 50 °C, with a thermal-magnetic TM240 overcurrent release. Its interrupting capacity reaches 220 kA at 240 V and 154 kA at 415 V, making it suitable for high-fault-level distribution panels where standard MCBs would weld shut. The breaker carries a shunt trip (STL) auxiliary release and comes with 2 auxiliary switches plus 1 trip alarm switch HQ integrated. Front IP40 protection suits indoor panel mounting.
Breaking capacity across voltage levels
The 3VA1120-6EF32-0HH0 delivers 220 kA at 240 V, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. These figures define the maximum prospective fault current the breaker can safely interrupt at each voltage — critical for selectivity studies and SCCR compliance in industrial switchgear. The 690 V rating drops sharply, so verify the line-to-line voltage at the installation point.
Thermal derating curve
Rated continuous current Iu is 20 A from 40 °C to 50 °C ambient. Above that, derate linearly: 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. The breaker can operate from -25 °C to 70 °C ambient and store from -40 °C to 80 °C. Panel builders should account for the 70 mm depth and 76.2 mm width when laying out DIN-rail or mounting-plate positions.