DC smoothing choke for 38 A bus rails
The Siemens SIDAC 4EM5203-4CB00 is a single-phase smoothing choke rated for 38 A DC maximum, with a continuous rated current of 34.2 A. Its 2 mH inductance at 600 V insulation class (IEC 60085 thermal class B) filters ripple from DC bus lines in drives, power supplies, and converter sections. The 30.2 W coil losses and 0.7 W iron-core losses add up to about 31 W total dissipation at rated load — factor that into your enclosure ventilation budget.
What the ratings mean for fit
The 38 A maximum is the DC current the choke can carry without saturating the core — exceed it and inductance drops off fast, losing the smoothing effect. The 34.2 A rated value is the continuous current at 40 °C ambient; above that ambient, derate per the thermal class B curve. At 0 Hz operating frequency, this choke is designed for pure DC — not for AC line filtering or PWM output stages. The 1.44 W energy content is the stored energy at rated current, useful for sizing discharge resistors if the bus is interrupted.
Mounting and wiring
IP00 means no enclosure — mount this inside a panel or cabinet where it's protected from dust and contact. Screw-type terminals accept lugged or ferruled conductors; no spring-cage or push-in here. Dimensions: 0.128 m deep, 0.121 m wide, 0.131 m tall (–). That's roughly a 5-inch cube — allow breathing space around it for the 31 W heat dissipation. No parallel windings option, so it's one path only.