Line protection MCCB with TM240 release
The Siemens SENTRON 3VA1140-3EF36-0BC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection duty, carrying a continuous current Iu of 40 A at ambient temperatures up to 50 °C before derating begins. Above 50 °C the rating steps down in 0.8 A increments per 5 °C, reaching 36 A at 70 °C — useful to know when the breaker sits in a densely packed panel where internal heat rise is a factor. The TM240 thermal-magnetic release handles overload and short-circuit protection with a fixed magnetic trip threshold. Breaking capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V — the 415 V figure is the one most often checked for 400 V-class distribution panels in IEC markets. This MCCB includes an undervoltage release (UVR) and 2 auxiliary switches (HQ design) for status feedback to a PLC or indication circuit. The auxiliary trip module is order code 3VA9608-0BB11. No voltage trigger, no communication function, no ground fault monitoring — it is a straight thermal-magnetic breaker with UVR and aux contacts.
Panel fit and operating conditions
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint for DIN-rail or screw-mount panel integration. IP40 on the front face keeps dust out of the mechanism; the rear and sides are open to the enclosure interior, so overall panel IP rating governs the rest. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. The rated insulation voltage Ui is 800 V, and the mechanical endurance is 15,000 operations. These numbers matter when the breaker is in a non-climate-controlled cabinet near a furnace line or outdoor substation.