Molded case circuit breaker, 40 A, 187 kA SCCR at 240 V
The Siemens 3VA1140-5EF32-0AF0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in three-phase distribution. It carries a rated continuous current Iu of 40 A and a rated insulation voltage Ui of 800 V, with a TM240 thermal-magnetic overcurrent release. The interrupting ratings are 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V — figures that govern the available fault current the breaker can safely clear without upstream coordination failure.
Thermal derating and ambient conditions
The 40 A rating holds at ambient temperatures up to 50 °C. Above that, the continuous current derates per the datasheet curve: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The front face carries IP40 protection — adequate for enclosed panel mounting, not for washdown environments.
Auxiliary contacts and mechanical endurance
This MCCB includes one auxiliary switch and one trip alarm switch (HQ version) for remote status indication. Mechanical endurance is rated at 15 000 cycles. There is no undervoltage release, no ground-fault monitoring, no communication function, and no phase-failure detection — it is a straightforward thermal-magnetic breaker for basic overcurrent and short-circuit protection.