What this MCCB brings to the panel
The Siemens SENTRON 3VA1120-3EF36-0AH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection — the go-to for feeder and branch circuits in distribution panels where you need a solid interrupting rating without the footprint of a larger frame. Rated 20 A continuous at 40 °C ambient, it holds that same 20 A all the way up to 55 °C, then derates to 19 A at 60–70 °C — useful if the panel sits near a heat source or in a warm enclosure. Breaking capacity hits 75.6 kA at 240 V AC, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V and 690 V — that's a lot of fault-clearing muscle for a 20 A frame, meaning it can handle high available fault currents downstream of a large transformer without needing a current-limiting fuse upstream. The TM240 thermal-magnetic release gives fixed thermal and magnetic trip settings — no field-adjustable dials, so what you see on the nameplate is what you get for coordination studies.