The Siemens SIDAC 4EM5318-4DB00 is a 1-phase smoothing choke rated for 20 A DC maximum, with a continuous rated current of 18 A DC. It operates at 600 V and provides 12 mH of inductance. The part is an open-frame design (IP00) with screw-type and tab terminals for the main circuit connection. Total power loss sums to 50 W — 48 W in the coil and 2 W in the iron core — at a rated ambient temperature of 40 °C. Thermal class B per IEC 60085 means the insulation system withstands a hot-spot temperature of 130 °C, so it handles sustained DC ripple without accelerated aging.
What the ratings mean for fit
The 20 A maximum DC rating sets the absolute ceiling; the 18 A rated value is the continuous design point for a DC bus or DC-link application. At 12 mH, this choke smooths current ripple from a single-phase rectifier or DC supply feeding a drive or converter. The 600 V operating voltage covers 400 V and 480 V DC bus rails with margin. IP00 means no enclosure — it must be mounted inside a panel or cabinet that provides the required ingress protection. The screw/tab terminals accept ring lugs or fork terminals; plan for a 0.129 m depth, 0.151 m width, and 0.151 m height footprint when laying out the panel.
Deployment context
This choke belongs in a DC power circuit — typically the DC link of a variable-frequency drive, a DC motor drive, or a battery charger. The 12 mH inductance and 20 A rating suit single-phase rectifier outputs where ripple reduction is needed to protect downstream capacitors or to meet conducted-emission limits. Because it is IP00, it must be panel-mounted, not exposed to washdown or dust. The screw/tab terminals simplify field wiring with standard crimp lugs.