SENTRON 3VA1120-5EF32-0AF0 — 20 A MCCB with TM240 release
The Siemens SENTRON 3VA1120-5EF32-0AF0 is a 3-pole molded case circuit breaker rated for 20 A continuous current at 40 °C, using a TM240 thermal-magnetic overcurrent release. That TM240 designation means the thermal element is fixed at 20 A (the frame rating), and the magnetic pickup is fixed at 240 A — no field adjustment on the trip curve, which simplifies spec-in for a fixed-load line protection role. Short-circuit breaking capacity runs 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V — numbers that put this squarely in high-rupturing-capacity territory for a 20 A frame. If your panel SCCR requirement sits at 65 kA at 480 V, this breaker clears it with headroom to spare.
Thermal derating and panel fit
The breaker holds full 20 A rating from 40 °C through 50 °C ambient. Above that it derates linearly: 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. If your enclosure runs hot — say a packed panel near a drive — factor that curve into the load calculation. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth. That 70 mm depth is shallow enough to clear most standard backpanel depths without a sub-panel spacer. The front face carries IP40 protection — fine for a dry indoor enclosure, but not for washdown zones.
Auxiliary contacts and compliance
Factory-fitted with one auxiliary switch and one trip alarm switch (HQ configuration) — that covers remote status indication without needing a separate accessory block. No undervoltage release, no ground-fault monitoring, no communication module on this variant. If you need those, the 3VA platform supports them as add-on modules, but this order code ships clean. Rated insulation voltage is 800 V, and the storage temperature range runs from -40 °C to 80 °C. Operating ambient spans -25 °C to 70 °C. The part carries the SENTRON brand and is designed to meet IEC 60947-2 (the MCCB standard) — compliance documentation (declaration of conformity, CE, UKCA) is available from Siemens on request.