What this MCCB delivers for a motor branch
The Siemens 3VA2140-5MN32-0JC0 is a 3-pole SENTRON molded case circuit breaker rated for 40 A continuous current at 40 °C, purpose-built for motor protection with the ETU350M electronic trip unit. That 40 A holds flat through 50 °C — only above 55 °C does it begin to derate, reaching 36 A at 70 °C, so in a warm panel you still get nearly full rating. The ETU350M includes phase failure detection, which is the main reason you reach for a motor-protection MCCB over a standard thermal-magnetic: it catches a lost phase before the motor overheats. Breaking capacity is the other headline: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. That 187 kA at 240 V is exceptionally high — it means this breaker can interrupt a fault at the full available current of a large transformer secondary without needing a current-limiting fuse upstream. For a 480 V panel, the 121 kA at 440 V (the nearest standard voltage) gives you ample SCCR headroom for most industrial services.
Footprint and panel fit
At 105 mm wide, 181 mm tall, and 86 mm deep, this MCCB fits the standard SENTRON 3VA2 frame footprint. The 86 mm depth is the dimension that matters for enclosure depth — it leaves room behind a 200 mm deep panel for wiring and the shunt trip (STL) accessory. Two HQ auxiliary switches are built in, so you get status feedback without an add-on module.