What it is and what it does
The Siemens 3VA2140-5MN32-0KH0 is a SENTRON molded case circuit breaker (MCCB) designed specifically for motor protection, with built-in phase failure detection and a shunt trip release (STL) for remote tripping. It carries 2 auxiliary switches plus 1 trip alarm switch, giving the panel builder feedback on breaker status without extra wiring. Rated at 40 A continuously across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling — and breaking capacity hits 187 kA at 240 V AC, 121 kA at 415/440 V, and 75.6 kA at 500 V. At 690 V it still clears 3.7 kA. That covers most industrial distribution panels and motor branch circuits.
Panel fit and integration
Three-pole, 105 mm wide, 181 mm tall, 86 mm deep — standard panel-mount footprint for a 40 A frame MCCB. The shunt trip (STL) allows remote opening from a PLC or emergency-stop circuit; the auxiliary switches and trip alarm feed status back to the control system without add-on contact blocks.
What the ratings mean for your BOM
The 187 kA interrupting rating at 240 V means this breaker can safely clear a fault up to that level without upstream fuses or a current-limiting reactor — important for high-fault panels near large transformers. The motor-protection design includes phase failure detection, so it trips on loss of a phase, preventing single-phasing damage to a motor load.