What it is and what it does
The Siemens SIDAC 4EP3705-7DS00 is a 3-phase output reactor (choke) rated for 18 A maximum current and a switching frequency of 8 kHz, with 0.5 mH inductance per phase. It is designed for AC motor drive output circuits to limit the rate of voltage rise (dV/dt) and reduce reflected-wave overvoltage on long cable runs — a common cause of premature motor insulation failure in variable-frequency drive installations. Thermal class B with rated ambient 40°C, dissipating 44 W in the coil and 22 W in the iron core at full load.
Key ratings and what they mean for fit
18 A maximum current is the continuous thermal rating at 40°C ambient, carrying load without exceeding class B temperature rise. 8 kHz switching frequency matches the carrier frequency of many IGBT-based drives. IP00 means the reactor has no enclosure protection — it must be mounted inside a panel or cabinet that provides the required ingress protection for the environment. The screw-type terminals accept standard ring or fork lugs for the main circuit connections. Dimensions are 0.17 m wide by 0.15 m tall by 0.1 m deep — a compact footprint for a 3-phase 18 A reactor, but verify panel clearance for the magnetic field and heat dissipation around the core.
Panel integration notes
Mount on a flat metal panel inside the enclosure — IP00 requires the panel to provide the environmental seal. Screw terminals accept conductors sized for 18 A continuous.