Commutating Choke for Converter Duty — 900 A, 400 V AC, 3-Phase
The Siemens 4EU3921-1AA00-0A is a 3-phase commutating choke (line reactor) designed for converter front ends, rated at 900 A continuous with a maximum of 1 000 A at 400 V AC, 50 Hz. The 27 µH inductance limits di/dt and reduces harmonic distortion on the drive input, with a relative inductive voltage drop of 4 % at rated current — a standard value for line reactors in industrial converter applications.
Power Loss and Thermal Class
Total power loss is 637 W — 360 W in the coil and 277 W in the iron core — at the rated 40 °C ambient. The winding is Class H insulation per IEC 60085, rated for a 180 °C hot-spot temperature, which provides margin in a warm cabinet or near a converter heatsink.
IP00 — Open Construction, Panel Integration
Rated IP00 with no enclosure — this choke is intended for mounting inside a switchgear cubicle or drive cabinet where the enclosure provides the environmental seal. The flat-type terminals accept busbar or lug connections for the main current circuit. Dimensions are 0.41 m wide by 0.385 m tall by 0.229 m deep; plan for adequate clearance around the iron core for airflow and convection cooling.