What this MCCB delivers — and what it doesn't
The Siemens SENTRON 3VA1140-4EF36-0JH0 is a 3-pole molded case circuit breaker rated for 40 A continuous current, with a TM240 thermal-magnetic release for line protection. Its breaking capacity hits 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — numbers that put it in the high-interrupting class for industrial distribution panels. No communication module, no phase-failure detection, no ground-fault monitoring: this is a straight line-protection breaker with a shunt trip release (STL) and an integrated auxiliary trip (order code 3VA9688-0BL32). It carries 2 auxiliary switches plus 1 trip alarm switch (HQ configuration).
Thermal derating — the real current you get
The 40 A rating holds flat from 40 °C up to 50 °C. Above that, it derates: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, 36 A at 70 °C. If your panel ambient runs hot, size the breaker for the derated figure, not the nameplate 40 A. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Panel fit — dimensions and mounting
Width 76.2 mm, height 130 mm, depth 70 mm. Standard 3-pole MCCB footprint for DIN-rail or screw-mount panel integration. The IP40 front rating means the breaker face is protected against solid objects >1 mm, but the body expects enclosure protection for the terminals.