What it is and what it does
The Siemens SENTRON 3VA1080-4ED42-0KA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying an 80 A continuous current at 40 °C and a TM210 thermal-magnetic overcurrent release. The shunt trip (STL) auxiliary release lets you remotely trip the breaker via a control voltage — useful for emergency-stop circuits or supervisory shutdowns. Breaking capacity is the headline: 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That means it can safely interrupt fault currents up to those levels without welding contacts or cascading failure upstream — critical for high-fault panels near large transformers or motor banks. Rated insulation voltage is 800 V, so the breaker's internal clearance and creepage are designed for 690 V line-to-line systems with margin. Power loss at rated current is 19.2 W maximum — a figure to include in your enclosure thermal budget if you're packing several breakers in a confined DIN-rail panel.
Thermal derating — what the curve tells you
The 80 A rating holds flat from 40 °C through 50 °C ambient. At 55 °C it derates to 78 A, at 60 °C to 77 A, at 65 °C to 75 A, and at 70 °C to 74 A. If your panel ambient runs above 50 °C — say, a sealed enclosure near a drying oven or in a Middle East summer — you need to account for that 6 A drop at the top end. The breaker itself is rated for operation from -25 °C to 70 °C ambient.
Physical fit and panel integration
Dimensions: 130 mm height, 101.6 mm width, 70 mm depth. That's a 4-pole MCCB footprint — wider than a 3-pole unit by roughly one pole pitch. Mounts on DIN rail or via the rear panel-mounting plate (Siemens accessory). The 70 mm depth is shallow enough for most 200 mm-deep enclosures, but check gland-plate clearance if you're running cables behind the breaker.
What the TM210 release means for coordination
The TM210 is a thermal-magnetic release with fixed trip settings — no interchangeable rating plugs. Thermal pickup follows the 80 A frame rating; magnetic short-circuit pickup is fixed at 10× In (800 A). That's a standard motor-circuit or distribution-feeder characteristic. For selective coordination downstream, the magnetic threshold at 800 A means it will trip instantaneously on a bolted fault, so you need upstream devices with intentional delay or higher magnetic pickup to achieve full selectivity.