The Siemens 3VA1120-6EF36-0JC0 is a 3-pole SENTRON molded case circuit breaker rated for 20 A continuous at 40 °C, with a TM240 thermal-magnetic overcurrent release and a shunt trip (STL) auxiliary release that triggers on voltage. Its interrupting capacity hits 220 kA at 240 V, 154 kA at 415 V, and 121 kA at 440 V — numbers that tell you it's built for high-fault panels where downstream coordination matters.
The 20 A continuous rating holds flat from 40 °C to 50 °C, then derates to 18 A at 70 °C; if your enclosure runs hot, that derating curve (–) decides the actual ampacity. The shunt trip (STL) means a remote voltage signal can trip the breaker, handy for emergency-stop or fire-alarm integration. The 2 HQ auxiliary switches give status feedback; no undervoltage release is fitted, so a voltage dip won't drop the load automatically.