The Siemens 4EU3921-2CA00-0A is a three-phase commutating choke designed for converter applications, also referred to as a line reactor or DC-link choke depending on the circuit position. It carries a maximum continuous current of 560 A at 50 Hz and a rated operating voltage of 750 V AC, with a peak current capability of 700 A.
Electrical and thermal ratings
The peak current is 700 A. The DC-rated current is 686.2 A, which is relevant for applications where the choke is used in the DC link rather than the AC line. The rated inductance of 0.077 mH and a relative voltage drop of 4% at rated current and frequency define the impedance characteristic for harmonic attenuation and current smoothing. Total power loss at rated conditions is 620 W, split between the coil (380 W) and the iron core (240 W). The thermal class is H per IEC 60085, which means the insulation system is rated for a maximum hot-spot temperature of 180 °C. The ambient temperature rating is 40 °C.
Construction and mounting
The enclosure is IP00 — no protection against ingress of solid objects or moisture, so it must be installed inside a panel or cabinet that provides the required environmental sealing. Dimensions are 0.41 m wide, 0.385 m high, and 0.229 m deep. The main current circuit connects via flat-type terminals, which are typical for high-current busbar or cable-lug connections. The choke is designed for converter duty and complies with EN 61558-2-20; it carries UL/CSA recognition.