80 A MCCB with 121 kA interrupting capacity at 240 V
The Siemens SENTRON 3VA1180-4EF36-0CA0 is a 3-pole molded case circuit breaker rated for 80 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity reaches 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — figures that cover most industrial distribution panels and motor control center feeder circuits. The 800 V rated insulation voltage (Ui) gives headroom for 690 V line-to-line systems where the interrupting rating drops to 11.9 kA. This is a line-protection version with an integrated undervoltage release — the UVR trips the breaker when control voltage drops below the dropout threshold, a standard requirement for safety circuits that must fail to a safe state on power loss. There is no auxiliary contact block, no communication module, and no phase-failure detection; the part is a straightforward thermal-magnetic MCCB for basic overcurrent and short-circuit protection. The TM240 release is a fixed thermal-magnetic design — no interchangeable trip units, no electronic adjustments. For a panel builder, that means the breaker is set at the factory for 80 A and cannot be field-recalibrated. The 15,000 latching endurance cycles indicate the mechanical life under load-switching conditions; this is a distribution breaker, not a switching device for frequent motor starts.
Thermal derating and panel integration
The 3VA1180-4EF36-0CA0 holds its full 80 A rating from 40 °C through 50 °C ambient. Above that, the TM240 release begins to thermally derate: 76.8 A at 55 °C, 75.2 A at 60 °C, 73.6 A at 65 °C, and 72 A at 70 °C. In a sealed, uncooled enclosure near other heat sources, the effective ampacity may be lower than the nameplate — the derating curve is the one to size against, not the 40 °C number. Dimensions are 130 mm height, 76.2 mm width, and 70 mm depth (–). The 76.2 mm width is a standard 3-pole MCCB footprint — it fits the same DIN-rail or panel-mount cutout as other SENTRON 3VA frames. IP40 on the front means protection against tools and wires >1 mm; the rear and sides are not sealed, so the breaker belongs inside a rated enclosure, not in a washdown zone.