Siemens 3VA1150-5EF32-0HA0 — 50 A MCCB with TM240 Release and Shunt Trip
The Siemens 3VA1150-5EF32-0HA0 is a 3-pole molded case circuit breaker from the SENTRON series, designed for line protection in distribution panels. It carries a continuous current rating of 50 A at 40 °C, with minimal thermal derating up to 70 °C (45 A at 70 °C). The TM240 thermal-magnetic release provides fixed overload and short-circuit protection curves, while the integrated shunt trip (STL) allows remote tripping for emergency-off or supervisory control circuits. Breaking capacity is the headline number here: 187 kA at 240 V AC, stepping down to 121 kA at 415 V and 75.6 kA at 440 V. At 500 V and 690 V it still holds 17 kA. That SCCR headroom means this breaker can sit upstream of a high-fault panel without cascading — useful for industrial switchboards where the transformer rating drives available fault current above 100 kA. Dimensions are 70 mm deep, 76.2 mm wide, and 130 mm high. Insulation voltage is rated 800 V.
Integration and Mounting
Panel integration is straightforward: the 70 mm depth and 76.2 mm width match the standard 3-pole MCCB cutout in SENTRON panelboards and most third-party enclosures. The shunt trip (STL) auxiliary release requires a separate control voltage — verify polarity and free-wheel diode on the coil before energizing. Maximum power loss is 14.6 W, so ventilation in a sealed enclosure is advisable if multiple breakers are ganged. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.