DC link choke for 40 A / 750 V DC bus
The Siemens SIDAC 4EM5317-5CB00 is a single-phase smoothing choke (Glaettungsdrossel) designed to sit in the DC link of a drive or converter system, filtering current ripple and limiting fault current rise rates. It is rated for a continuous DC current of 40 A with a rated value of 36 A at an operating voltage of 750 V DC. The 3 mH inductance defines the smoothing performance and the energy content of 2.4 Ws indicates the stored energy available during a switching event. Total power loss is 48.2 W, split between the coil (47.1 W) and the iron core (1.1 W), which must be dissipated in the enclosure. The thermal class B rating per IEC 60085 means the insulation system withstands a continuous hot-spot temperature of 130 °C, a standard class for dry-type inductors in industrial power converters.
The choke measures 151 mm wide by 151 mm high by 129 mm deep — roughly a 6-inch cube. Connections are via screw-type terminals, which accept standard power wiring without special tools. At 40 °C ambient the choke delivers its full 40 A DC rating. Derating applies above that temperature per the thermal curve; the 48.2 W total loss heats the surrounding air, so forced ventilation or adequate cabinet volume is recommended for continuous duty.