The Siemens 3VA1140-5EF42-0AA0 is a SENTRON 4-pole molded case circuit breaker (MCCB) rated for line protection. It carries a continuous current of 40 A at 40 °C, with a TM240 thermal-magnetic release that handles overloads and short-circuits without an external trip unit. The interrupting capacity hits 187 kA at 240 V AC, which gives you serious fault-current headroom for high-available-current service entrances or distribution panels.
Breaking capacity and selectivity
The 187 kA at 240 V is the headline number, but the real-world selectivity picture depends on the voltage your system runs. At 415 V it still breaks 121 kA, at 440 V it's 75.6 kA, and at 500 V or 690 V it holds at 17 kA. That means on a 480 V panel you've got 75.6 kA of interrupting capacity — enough to coordinate with most downstream breakers without cascading. The 800 V rated insulation voltage (Ui) confirms it's built for 690 V industrial networks.
Thermal derating and power loss
The 40 A rating holds steady from 40 °C up to 50 °C — no derating needed in a warm enclosure. At 55 °C it drops to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. Maximum power loss is 10.8 W, so heat buildup inside a compact panel is manageable. The IP40 front protection means it's fine for clean indoor switchgear but not washdown areas.
Physical fit and mounting
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep. That 4-inch width is standard for a 4-pole MCCB in the SENTRON 3VA platform — it fits the same mounting footprint as other 3VA frame sizes. No undervoltage release, no trip indicator, no communication module on this variant; it's a straight thermal-magnetic line-protection device.