What it is and where it goes
The Siemens 4EP3805-4BK00 is a 3-phase commutating choke (line reactor) designed for the DC link or AC input of a converter drive. It limits current rise during commutation, reducing harmonic distortion and protecting the converter's semiconductors from di/dt stress. Rated for 400 V AC, 50 Hz line frequency, it carries a continuous rated current of 55.8 A with a thermal maximum of 62 A — sized for a drive output in that current class, not a motor FLA match. The 0.19 mH inductance and 1.6 % relative voltage drop at rated current are the key numbers for sizing: this choke is meant to work with a specific converter, not as a generic input reactor.
What the ratings mean for fit
The 55.8 A rated current (62 A max) is the continuous thermal rating at 40 °C ambient, thermal class B per IEC 60085 — that's an 80 °C temperature rise limit. If your cabinet ambient runs hotter, you derate. The 0.19 mH inductance at 50 Hz gives a 1.6 % voltage drop at rated current, which is a relatively low impedance; this choke smooths commutation notches without dropping much line voltage under load. The IP00 enclosure means it's an open-frame component — no finger protection, no drip shield. Mount it inside a cabinet, not on the wall. Screw terminals for the main circuit accept standard lug connections.
Physical integration
Footprint: 0.178 m wide × 0.153 m tall × 0.12 m deep. That's about 7 × 6 × 4.7 inches. It's a panel-mount component, not DIN-rail clip-on. Plan for screw-terminal access on the main circuit connections. The IP00 rating means it needs enclosure protection from the panel builder — no exposed live parts allowed in a touch-safe cabinet.