The Siemens SENTRON 3VA1120-6EF36-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated 20 A continuously at up to 55 °C ambient, derating to 19 A at 60–70 °C — so in a warm panel you lose 1 A of headroom above 55 °C. The TM240 overcurrent release provides fixed thermal-magnetic protection for line (cable/feeder) duty, not motor or generator protection. Breaking capacity is the standout: 220 kA at 240 VAC, 154 kA at 415 VAC, 121 kA at 440 VAC, and still 17 kA at 500/690 VAC. Power loss is 12 W maximum, which matters for thermal budgeting in a sealed enclosure — a panel with several breakers at full load needs to account for that heat. The auxiliary switch configuration (1 auxiliary + 1 trip alarm, HQ design) allows remote status feedback for the breaker's position and trip condition without an external relay.
Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall — a 3-pole MCCB that fits standard panel-mount cutouts. The 76.2 mm (3 in) width per pole is typical for SENTRON 3VA frames; verify the existing bus-bar spacing if replacing another brand.