What this MCCB does on the line
The Siemens 3VA1120-6EE36-0AA0 is a SENTRON molded case circuit breaker—line protection version—rated for 20 A continuous current in a 3-pole package. Breaking capacity hits 220 kA at 240 V and 154 kA at 415 V, so it handles high-fault utility or transformer-fed panels without cascading upstream. The TM220 overcurrent release gives you a fixed thermal-magnetic curve—no electronic adjustment, simple and reliable for motor branch circuits or distribution. IP40 on the front means it keeps out tools and fingers in a closed panel; the body itself isn't rated for washdown, so mount it inside a suitable enclosure.
What you need for panel fit
Dimensions: 130 mm tall, 76.2 mm wide, 70 mm deep—standard 3-pole MCCB footprint for DIN-rail or screw-mount panels. Rated insulation voltage 800 V, max operational voltage 500 V DC. Power loss max 12 W—factor that into your thermal budget if you're stacking breakers in a sealed enclosure.
Temperature derating — stays flat to 55 °C
Rated 20 A from 40 °C through 55 °C ambient, then 19 A at 60–70 °C—useful headroom for hot panels or outdoor cabinets.