Line protection MCCB with high interrupting capacity
The Siemens 3VA1140-6EF32-0KH0 is a 3-pole SENTRON molded case circuit breaker rated for 40 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. It carries a 220 kA breaking capacity at 240 V AC, dropping to 154 kA at 415 V and 121 kA at 440 V — meaning it can safely interrupt very high fault currents on the secondary side of a distribution transformer or at a main service entrance without cascading upstream. At 690 V the rating is 17 kA, so verify coordination if the breaker lands on a 690 V bus. The thermal-magnetic release holds full 40 A up to 50 °C ambient, then derates to 38.4 A at 55 °C and 36 A at 70 °C. That flat 40 A plateau through 50 °C is useful in a warm panel — you don't lose headroom until the ambient climbs above 50 °C. The breaker is rated for operation down to -25 °C and storage down to -40 °C, which covers unheated enclosures in cold climates.
Auxiliary contacts and shunt trip
This version ships with 2 auxiliary switches plus 1 trip alarm switch (HQ configuration) and a shunt trip release (STL) for remote tripping. The integrated auxiliary trip is order code 3VA9688-0BL33. There is no undervoltage release, no phase failure detection, and no communication module — this is a straightforward line-protection MCCB with remote trip capability, not a smart breaker. The front face carries IP40 protection, so it's suited for a clean indoor panel; not for washdown zones.