Siemens SIDAC 4EU2731-3UA00-0A — Output Reactor
The Siemens SIDAC 4EU2731-3UA00-0A is a 3-phase output reactor — a line reactor placed between a variable-frequency drive and the motor to limit voltage spikes, reduce capacitive charging currents, and smooth the motor current waveform. The 3 kHz switching frequency matches the typical carrier frequency of modern IGBT drives.
The 260 A maximum current rating (at 120 Hz) and 234 A rated operational current define the motor full-load ampacity this reactor can carry continuously. If your motor draws more than 234 A at the drive's switching frequency, this reactor is undersized — no exceptions. The 0.016 mH inductance is low; it's sized for the dv/dt and common-mode filtering role, not for significant impedance-based current limiting. A higher-inductance reactor would be needed if you're trying to limit harmonic distortion or reduce fault current. The IP00 protection class means the reactor has no enclosure — it's an open-core, open-coil assembly. Thermal class H per IEC 60085 means the insulation system is rated for a 180 °C hot-spot temperature. At the rated 161 W coil loss and 130 W iron loss, expect significant heat dissipation inside the enclosure. The 40 °C ambient rating is the baseline; derate for higher ambient temperatures or restricted airflow inside a sealed cabinet.
The UL and CSA recognition noted in the description means the reactor carries third-party listing to North American safety standards. The EN 61558-2-20 reference covers the European safety standard for reactors.
The 4EU2731-3UA00-0A measures 0.27 m wide, 0.24 m tall, and 0.18 m deep. It is a panel-mount reactor that bolts directly to the backplate or mounting chassis.