SENTRON 3VA1150-3GF42-0AA0 — 50 A 4-Pole MCCB, TM240 Release
The Siemens 3VA1150-3GF42-0AA0 is a SENTRON-series molded case circuit breaker (MCCB) with four poles, rated 50 A continuous at 40 °C and carrying a TM240 thermal-magnetic trip unit. The interrupting rating hits 75.6 kA at 240 V AC and 52.5 kA at 415 V AC — enough for high-fault panelboard or distribution applications where a standard MCB would not hold. Rated insulation voltage is 800 V, and the maximum operating voltage is 690 V AC. The 100% N-conductor protection design means the neutral pole is fully rated, not switched or reduced — important for four-wire systems where the neutral carries load current. Dimensions are 130 mm high, 101.6 mm wide, and 70 mm deep. The front face carries IP40 protection — fine for enclosed panel mounting, not for washdown exposure. Power dissipation maxes at 14.6 W, so factor that into enclosure thermal calculations if you are packing several units side by side.
Interrupting Capacity and Thermal Derating
The 75.6 kA at 240 V is the headline number, but the real-world fault current at your system voltage matters more. At 415 V it still breaks 52.5 kA; at 440 V it drops to 32 kA; at 500 V and 690 V it holds at 11.9 kA. That is a steep derating curve — verify your available fault current at the installed voltage before committing the BOM line. Thermal rating holds a flat 50 A from 40 °C through 50 °C, then begins a gentle roll-off: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If your panel ambient runs above 50 °C, you lose about 1 A per 5 °C rise. The TM240 release is a fixed thermal-magnetic type — no electronic adjustment, no communication function, no undervoltage or shunt trip fitted on this variant.