The Siemens 4EU4351-8UC08 is a 3-phase line reactor (choke) rated for 400 V AC, 50 Hz, carrying a continuous rated current of 819 A with a maximum overload capacity of 910 A. Its 32 µH inductance smooths current ripple and limits harmonic distortion on the line side of a drive or power converter. Built to thermal class H per IEC 60085, it handles a 40 °C ambient without derating — the insulation system is rated for 180 °C hot-spot, which gives headroom in a crowded cabinet.
Footprint is 0.46 m wide by 0.435 m tall by 0.265 m deep — that's a substantial block. Plan for a dedicated mounting plate; it won't clip onto a DIN rail. The main circuit connects via flat-type terminals, so budget for busbar or crimp lugs, not ring terminals. At 819 A continuous, the flat terminals need a torque spec from the nameplate — verify before terminating. Leave at least 100 mm clearance around the IP23 vents for natural convection.