What this MCCB is and what it does
The Siemens 3VA1180-4EF36-0KA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection — meaning it sits at the incoming feeder or a major subfeed, not on a motor branch. It's a 3-pole unit rated 80 A at 40 °C, with a TM240 thermal-magnetic overcurrent release that handles both overload and short-circuit interruption. The shunt trip (STL) release lets you remotely trip the breaker from a control signal or emergency-stop circuit, which is the main reason you'd pick this variant over a plain thermal-magnetic MCCB. Breaking capacity is the headline number that decides whether this breaker holds under fault. At 240 V it's rated 121 kA — that's a very high interrupt rating for an 80 A frame, so it's meant for installations with high available fault current, like a transformer secondary close to the service entrance. At 415 V it's still 75.6 kA, and it drops to 52.5 kA at 440 V, then 11.9 kA at 500 V and 690 V. That steep drop above 500 V tells you this frame is optimized for 240–480 V systems; if you're on a 600 V or 690 V line, the 11.9 kA rating will limit where you can place it in the coordination study.
Current rating and thermal behavior
The 80 A rating holds from 40 °C through 50 °C — no derating in that band. At 55 °C it drops to 78 A, then 77 A at 60 °C, 75 A at 65 °C, and 74 A at 70 °C. If your panel ambient runs hot (say, 55 °C inside the enclosure), you're still getting 78 A continuous, which is close enough that you don't need to upsize the frame for a 75 A load. The maximum power loss is 19.2 W, which is modest for an 80 A MCCB with a shunt trip — helps keep the enclosure heat rise manageable. Rated insulation voltage is 800 V. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.
Physical fit and mounting
Dimensions are 130 mm tall, 76.2 mm wide, 70 mm deep. The 76.2 mm width is standard for a 3-pole MCCB in this frame size.