The Siemens SENTRON 3VA1120-3EF32-0AB0 is a 3-pole molded case circuit breaker rated 20 A at 40 °C, with a TM240 thermal-magnetic overcurrent release designed for line protection. Its interrupting capacity reaches 75.6 kA at 240 V, stepping down to 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V or 690 V — figures that govern selectivity coordination in a distribution board or motor control center. Rated operational current holds steady at 20 A from 40 °C through 55 °C, then derates to 19 A at 60 °C and above — a curve that matters when the breaker shares a closed panel with other heat sources.
The TM240 release is a fixed thermal-magnetic unit, not electronic, so there is no adjustment dial or communication module; trip characteristics are factory-set. Power loss is 12 W maximum, which factors into enclosure thermal rise calculations when multiple breakers are ganged.