The Siemens 4EP3801-5DS00 is a 3-phase commutating choke (line reactor) for converter applications, rated at 400 V AC, 50 Hz, with a maximum continuous current of 35.5 A and a rated current of 31.95 A. It's the inductive element that limits current rise and harmonics on the AC side of a variable-speed drive or rectifier — without it, the converter's switching noise reflects back into the line and the DC link sees higher ripple.
The 35.5 A maximum and 31.95 A rated current define the thermal envelope. The 35.5 A figure is the absolute limit at 40 °C ambient; the 31.95 A is the continuous rating at that same ambient. If your drive's input current exceeds 31.95 A RMS, you'll need to either derate or step up to a larger choke. The 43.5 A DC rating applies if you're using it in a DC-link circuit — that's the current it can carry on the DC side, which is typically higher because DC has no skin-effect heating. Power loss breaks into 59 W in the coil and 19.7 W in the iron core, totaling about 79 W at rated load. The thermal class B means the insulation system is rated for a 130 °C hot-spot temperature, which is standard for industrial chokes and gives reasonable overload headroom. IP00 means no ingress protection — the choke is an open-frame component. The screw-type terminals accept standard ring or fork lugs; no special tooling needed.
The choke measures 0.178 m wide, 0.153 m high, and 0.12 m deep. That's a 178 mm width — about 7 inches — so it needs a clear footprint on the mounting plate. No DIN-rail clip; it's a bolt-down component. Plan for adequate clearance around the screw terminals for cable bending radius and tool access.