The Siemens SIDAC 4EP3900-3US00 is a 3-phase output reactor rated for 460 V AC, carrying a maximum continuous current of 17.5 A (120 Hz output) and a rated operational current of 15.8 A at 3 kHz switching frequency. Inductance is 0.48 mH with a voltage drop (UK) of 2.4%. This is the choke that sits between a variable-frequency drive and the motor cable — it limits the dv/dt stress on the motor windings and reduces bearing currents on long cable runs. The IP00 open-frame construction means it mounts inside a panel or enclosure; screw-type and tab terminals keep wiring straightforward without special crimp tooling.
Thermal class and power loss
Rated for 40 °C ambient and insulation class B per IEC 60085 (130 °C hot-spot). At full load the coil dissipates 60 W and the iron core another 33.8 W — total 93.8 W of heat that must be vented from the enclosure. That much loss in a sealed box will raise internal temperature noticeably; plan for forced airflow or derate if ambient runs above 40 °C.
Designed to EN 61558-2-20 (safety of transformers, reactors, and power supply units) and recognized under UL/CSA. That UL/CSA mark is the key gate for panel builders shipping into North American sites — it avoids a separate component-level evaluation.