What it is and what it does
The Siemens SENTRON 3VA2140-5MN32-0AG0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C, designed specifically for motor protection. It includes phase failure detection and comes with one auxiliary switch plus one trip alarm switch. The 187 kA breaking capacity at 240 V means it can safely interrupt very high fault currents without upstream damage — critical for installations where the available fault current is high, like near a large transformer or generator.
Key ratings and what they mean for your panel
Rated current holds flat at 40 A across the full 40 °C to 70 °C ambient range — no derating needed for warm enclosures. Breaking capacity steps down with voltage: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V. At 690 V the 3.7 kA figure is the limiting case; if your system runs 690 V with fault currents above that, this breaker is not the right choice. The 86 mm depth, 105 mm width, and 181 mm height fit standard MCCB panel cutouts.