What it is and what it does
The Siemens 3VA2140-5MN32-0BL0 is a SENTRON molded case circuit breaker (MCCB) designed specifically for motor protection. It carries a full rated current of 40 A across its entire operating temperature range from -25 °C to 70 °C, so there's no derating to calculate when the panel gets warm. That's a solid spec for a motor branch circuit that sees seasonal ambient swings. Three-pole construction with an undervoltage release (UVR) and phase failure detection built in. The UVR drops the breaker if supply voltage falls below a set threshold, which keeps a motor from trying to start under brownout conditions. Phase failure detection catches a lost leg before single-phasing cooks the winding.
Interrupting capacity — what those numbers mean for your fault current
This MCCB is rated to interrupt 187 kA at 240 V, dropping to 121 kA at 415 V and 440 V, then 75.6 kA at 500 V, and 3.7 kA at 690 V. The 187 kA figure at 240 V means it can safely clear a bolted fault on a high-capacity 240 V transformer secondary — common in industrial step-downs. At 415 V, the 121 kA rating still covers most distribution panels. The sharp drop to 3.7 kA at 690 V tells you this breaker is not intended for 690 V motor circuits with high available fault current; it's sized for the 240–500 V range where the interrupting capacity stays well above typical panel SCCR requirements.
Panel fit and auxiliary configuration
Dimensions are 181 mm high, 105 mm wide, 86 mm deep. That's a standard SENTRON 3VA2 footprint — it bolts into the same mounting pattern as other 3VA2 frames in the family. The 86 mm depth leaves room in a 200 mm deep enclosure for wiring and finger-duct clearance behind the breaker. Comes pre-configured with two auxiliary switches, one trip alarm switch, and one electrical alarm switch (HQ type). That's enough status feedback for a remote PLC to know whether the breaker is on, tripped on fault, or switched off manually — no need to add separate aux blocks for basic monitoring.