The Siemens SENTRON 3VA1120-5EF32-0AB0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 20 A at ambient temperatures up to 50 °C without derating — at 55 °C it still holds 19.2 A, and at 70 °C it delivers 18 A, so a panel running warm near the top of its operating range (-25 °C to 70 °C) still gets full 20 A protection as long as the enclosure stays under 50 °C. The breaking capacity is the headline here: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V — these are the fault currents the breaker can safely interrupt without welding or exploding. The TM240 overcurrent release gives a fixed thermal-magnetic curve with an adjustable short-time delay tr max of 1 second — useful for coordinating with downstream MCBs on a motor control centre feeder.
At 70 mm deep, 76.2 mm wide, and 130 mm tall, this MCCB fits standard 3-pole MCCB cutouts in distribution panels. The IP40 front protection means it's suitable for dry indoor enclosures where tools or fingers won't contact live parts through the front cover.