Output Reactor for VFD Motor Protection
The Siemens SIDAC 4EU2752-0EE00-4BA0 is a 3-phase output reactor (choke) rated for 60 A maximum continuous current and a switching frequency of 3.2 kHz. It is designed to sit between a variable-frequency drive and the motor, limiting the rate of voltage rise (dV/dt) and reducing peak voltages that can stress motor winding insulation. The 0.45 mH inductance per phase provides enough impedance to smooth the PWM waveform on longer cable runs — typically over 50 meters — without excessive voltage drop at the motor terminals. Per the datasheet, the reactor is rated for a 420 V AC line voltage and a fundamental frequency range of 0 to 550 Hz, which covers standard induction motors and most servo or spindle drives.
Thermal and Connection Details
Total power loss is 303 W (176 W in the coil plus 127 W in the iron core) at the rated 40 °C ambient. That heat must be managed — the reactor measures 0.27 m wide by 0.24 m tall by 0.18 m deep, so it occupies a moderate footprint on the panel backplate. The thermal class is H (180 °C) per IEC 60085, meaning the winding insulation can withstand a 180 °C hot-spot temperature, which gives a generous safety margin above the 40 °C ambient. Main circuit connections are flat-type terminals, which accept busbar or crimp-on lugs; no screw-clamp or spring-cage option is listed. The reactor complies with EN 61558-2-20 for chokes, so it meets the safety isolation and thermal endurance requirements of that standard.