SENTRON 3VA1120-6EF32-0AH0 — 20 A MCCB for Line Protection
The Siemens 3VA1120-6EF32-0AH0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for line protection duty, carrying a continuous current Iu of 20 A that holds flat from 40 °C up to 50 °C before a gradual derating curve begins — at 55 °C it's still 19.2 A, and at the 70 °C operating maximum it delivers 18 A. That thermal stability means you can size this breaker for a 20 A feeder in a warm panel without oversizing the frame. The interrupting ratings are the headline here: 220 kA at 240 V, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. Those numbers put this squarely in the high-fault-current category — think transformer secondaries, large motor control centers, or main feeders where the available fault current is well above what a standard MCB can handle. The TM240 thermal-magnetic release gives fixed thermal and magnetic trip settings, no adjustment needed for straightforward line protection. The auxiliary contact block is built in: 2 auxiliary switches plus 1 trip alarm switch (HQ type), so you get remote status and a dedicated alarm contact without adding a separate module. Rated insulation voltage Ui is 800 V, and the front face carries IP40 protection — fine for a closed panel, but not for washdown areas.
Panel Fit — Dimensions and Mounting
The 3VA1120-6EF32-0AH0 measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits SENTRON distribution blocks and most DIN-rail or screw-mount panel layouts. The 70 mm depth leaves clearance for rear-connected busbars or cable ducts in a 200 mm deep enclosure.