MCCB for line protection — 40 A, 3-pole, TM240 release
Siemens SENTRON 3VA1140-4EF32-0AH0 is a 3-pole molded case circuit breaker rated for 40 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. It carries 121 kA interrupting capacity at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — numbers that tell you this breaker handles high-fault utility feeds or transformer secondaries without cascading upstream.
Thermal derating and continuous current
The 40 A rated current holds steady up to 50 °C ambient. Above that, it derates linearly: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C.
Auxiliary contacts and trip alarm
The trip alarm signals a fault condition independently of the main contacts — useful for remote indication on a PLC digital input or a panel lamp.