What this MCCB is and what it does
The Siemens 3VA1140-6EF36-0CH0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C ambient, with a 3-pole configuration and a TM240 thermal-magnetic overcurrent release designed for line protection. It carries an undervoltage release (UVR) as standard, and the auxiliary contact block is configured as 2 auxiliary switches plus 1 trip alarm switch (HQ).
Breaking capacity and selectivity headroom
Breaking capacity is specified at multiple voltage levels: 220 kA at 240 V, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. Those figures give substantial fault-current headroom for most low-voltage distribution panels — the 415 V rating alone covers the majority of industrial 400 V-class installations without needing an upstream current-limiting fuse.
Thermal derating and operating range
The breaker holds its full 40 A rating up to 50 °C ambient. Above that, derating is gradual: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. The front face carries IP40 protection — suitable for enclosed panel mounting where the breaker is not exposed to dust or splash.