20 A MCCB with TM240 release — line protection for distribution panels
The Siemens SENTRON 3VA1120-5EF36-0AE0 is a 3-pole molded case circuit breaker rated for 20 A continuous current (Iu) at 40 °C, holding that rating up through 50 °C before it starts to derate — 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. That flat thermal curve through 50 °C means you don't lose headroom in a warm panel unless ambient pushes past that threshold. Breaking capacity is voltage-dependent: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. The 187 kA figure at 240 V puts it in the high-interrupting class for low-voltage distribution — useful where available fault current is high, like near a large transformer. The TM240 overcurrent release is a thermal-magnetic type — thermal element handles overloads, magnetic element handles short-circuits. No electronic trip unit here, so no adjustable curves or communication; it's a straight line-protection breaker for fixed-threshold applications.
Panel fit and auxiliary configuration
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that mounts into SENTRON distribution panels or standalone enclosures. IP40 on the front means it's protected against tools and solid objects over 1 mm, but not sealed against moisture; keep it inside a cabinet for washdown areas. Comes with 4 auxiliary switches HQ (high-rupturing-capacity type) for status feedback to a PLC or indication lamp. No undervoltage release, no shunt trip, no ground-fault monitoring — this variant is the bare-bones line-protection build with auxiliary contacts only. Rated insulation voltage Ui is 800 V, so it's suitable for 690 V systems with margin. Mechanical endurance is 15,000 operations — fine for distribution duty where it cycles rarely; not a motor-switching breaker.