What this MCCB is and where it fits
The Siemens SENTRON 3VM1180-5GE42-0AA0 is a 4-pole molded case circuit breaker (MCCB) designed for line protection — meaning it guards the feeder, not a specific motor or load branch. It carries a TM220 thermal-magnetic overcurrent release, so the thermal element handles overloads and the magnetic element handles short circuits, no electronics to program or fail. Rated 80 A at 40 °C ambient, it's the frame size for a main feeder or a large subfeed in a 400 V industrial panel.
Breaking capacity — what the numbers mean for your fault duty
This breaker's interrupting capacity drops as system voltage rises: 187 kA at 240 V, 121 kA at 415 V, 76 kA at 440 V, and 17 kA at 500 V. At 415 V — common for European industrial distribution — the 121 kA rating means it can clear a bolted fault at that level without rupturing. That's well above typical 50-65 kA panelboard ratings, so it works as a main breaker feeding downstream branch protection without coordination concerns at the service entrance.
Thermal derating — don't ignore the ambient curve
Rated 80 A from 40 °C through 50 °C. At 55 °C it's 78 A, at 60 °C it's 77 A, at 65 °C it's 75 A, and at 70 °C it's 74 A. That's a 7.5% drop from 40 °C to 70 °C — tighter than many MCCBs, which can lose 15-20%. The 3VM series uses a compensated bimetal; you don't need to oversize the frame for a warm enclosure. The rated insulation voltage is 800 V, so the internal clearances handle 690 V systems with margin.
Panel fit and environment
Mounts on a DIN rail or panel-mount plate — the 101.6 mm width (4 inches) and 130 mm height fit standard SENTRON 3VM cutouts. IP40 on the front means it's protected against tools and wires >1 mm, but not against dust ingress; install in a closed cabinet, not an open washdown zone. The -25 °C to 70 °C operating range covers unheated electrical rooms and most process areas. Storage range extends to -40 °C to 80 °C for warehousing.