What this MCCB is and what it protects
The Siemens 3VA1140-6EF36-0KH0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. Its 40 A rating at 40 °C and 3-pole construction suit it for protecting feeder circuits in commercial and industrial switchboards. The 220 kA breaking capacity at 240 V means it can safely interrupt very high fault currents — typical for large transformer-fed installations where the available short-circuit current is substantial. At 415 V it still handles 154 kA, and at 690 V it holds 17 kA. Rated insulation voltage is 800 V, giving headroom for 480 V and 600 V class systems. The breaker includes a shunt trip release (STL) for remote tripping, plus two auxiliary switches and one trip alarm switch — useful for status feedback to a PLC or annunciator panel.
Physical fit and panel integration
Dimensions are 70 mm deep, 76.2 mm wide, 130 mm high. The 76.2 mm width (3 inches) is the standard 3-pole MCCB footprint for Siemens SENTRON 3VA frames — it mounts via screw terminals to a backplate or DIN rail adapter. Verify the existing panel's bus bar spacing and mounting hole pattern against these dimensions before committing the BOM line.
Thermal derating and operating range
The breaker holds its full 40 A rating from 40 °C through 50 °C. At 55 °C it derates to 39 A, holding there through 60 °C. At 65 °C it drops to 38 A, and at 70 °C to 37 A. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss is 10.8 W.