Motor protection MCCB with ETU350M — what the ratings mean for fit
The Siemens SENTRON 3VA2140-5MN32-0AH0 is a 3-pole molded case circuit breaker (MCCB) rated for motor protection duty, carrying a continuous current Iu of 40 A at 40 °C ambient and an insulation voltage Ui of 800 V. The ETU350M electronic trip unit provides adjustable overload and short-circuit protection curves, plus phase failure detection — so it catches a lost phase before the motor overheats. The 187 kA interrupting rating at 240 V (derating to 121 kA at 415/440 V, 75.6 kA at 500 V, and 17 kA at 690 V) gives selectivity headroom in high-fault panels; the 20 000 mechanical endurance cycles match typical MCCB life for a motor branch circuit. The auxiliary contact configuration — 2 auxiliary switches plus 1 trip alarm switch (HQ) — allows status feedback to a PLC or annunciator without a separate interface module. The front face carries IP40 protection, suitable for a clean indoor panel environment.
Integration and mounting
The MCCB occupies a 105 mm wide by 181 mm high by 86 mm deep footprint — standard for a 3-pole SENTRON 3VA frame. It mounts via screw terminals to a backplate or DIN rail adapter; the 86 mm depth leaves clearance for rear-connected busbars in a typical 400 mm deep enclosure.