The Siemens SIDAC 4EM5004-4CB00 is a single-phase smoothing choke rated for 23.5 A DC continuous with a 690 V DC operating voltage. Its 2.9 mH inductance (0.0029 H) filters ripple from DC bus or drive output circuits, keeping downstream electronics clean. Total power loss runs 25.5 W (25 W in the coil, 0.5 W in the iron core) at the rated 21.15 A DC and 40 °C ambient — factor that into your enclosure ventilation.
Mounting is open-frame (IP00), so it needs a clean, dry enclosure — no washdown, no dust. The main circuit connects via screw-type or tab terminals. Dimensions are 0.115 m deep, 0.097 m wide, 0.111 m high — plan for a footprint roughly 100 × 115 mm on the panel floor or DIN-rail bracket. Thermal class B per IEC 60085 means the insulation system handles a 130 °C hot-spot limit; derate if your ambient pushes above 40 °C.