What this 3-phase output reactor does
The Siemens SIDAC 4EP3911-0AS01 is a 3-phase output reactor rated for a maximum AC current of 26 A and a rated frequency of 4000 Hz, with an operating range from 0 to 8000 Hz. It's designed to sit between a variable-frequency drive and the motor, smoothing the voltage spikes and limiting the rate of rise of voltage (dV/dt) that long cable runs can reflect back into the drive output stage. The 0.0007 H inductance and 7.9% impedance (UK) at rated conditions give it enough core to handle moderate motor cable lengths — think 50 to 150 meters depending on cable type and drive switching frequency. Rated operational current is 23.4 A AC, with a 26 A maximum thermal current (Ithmax) at 200 Hz fundamental. The thermal class F insulation (IEC 60085) means it can handle a 155°C hot-spot temperature without degrading the winding varnish — important when the reactor is mounted inside a crowded panel with limited airflow. Power loss splits into 53.1 W in the coil and 23.4 W in the iron core, totaling about 76.5 W of heat to evacuate.
IP00 protection class means no enclosure — this is a panel-mount component intended for a clean, dry electrical cabinet. Dimensions are 0.21 m wide, 0.17 m tall, and 0.12 m deep, so it occupies roughly the footprint of a small contactor or a 7.5 kW drive. Screw-type terminals accept standard ring or fork lugs; no special crimp tooling needed. Ambient temperature rating is 40°C; above that, derate the current per the thermal curve in the manufacturer's documentation.