The Siemens 3VA1120-6EF32-0CA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection. It's a 3-pole unit rated 20 A at 40 °C, with a TM240 thermal-magnetic overcurrent release. The headline number here is the interrupting capacity: 220 kA at 240 V, dropping to 154 kA at 415 V and 121 kA at 440 V — still plenty for most industrial service entrances and distribution panels. At 500 V and 690 V it holds at 17 kA, which covers feeder duty in lower-voltage sections.
What the ratings mean on the van
The 20 A rating holds flat from 40 °C through 55 °C, then derates to 19 A at 60 °C and stays there through 70 °C. So if this lives in a hot panel — say next to a drive or a transformer — you still get 19 A continuous without nuisance tripping. That's a solid thermal curve for a 20 A frame. Rated insulation voltage is 800 V, so it's comfortable on 480 V or 600 V systems with headroom. Power loss maxes out at 14.5 W — negligible for panel heat budget, but worth knowing if you're stacking breakers tight.
Integration and fit
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — fits standard panel-mount cutouts for the 3VA frame family. The undervoltage release (UVR) is factory-installed, so no field wiring of a separate shunt trip module.