The Siemens 4EP3801-1GK00 is a 3-phase mains choke (Netzdrossel f. FU) designed for variable-frequency drive input lines. It carries a rated current of 41.2 A with a maximum of 45.8 A at 60 Hz, operating at 400/480 V AC, 50/60 Hz. The 0.32 mH inductance and 2% relative inductive voltage drop are sized to smooth line-side harmonics and limit inrush current peaks on the drive's DC bus — the 2% drop is the standard impedance for a line reactor in this class, meaning it provides enough reactance to reduce harmonic distortion without dropping excessive voltage under load.
Sizing and thermal considerations
Rated for a 50 °C ambient with thermal class B insulation (130 °C hot-spot) per IEC 60085. Total power loss splits between the coil (41 W) and the iron core (26 W) — 67 W dissipated into the enclosure.
Physical fit and connections
Dimensions are 0.178 m wide × 0.153 m high × 0.12 m deep. The IP00 form factor means it is an open-style component; plan for a minimum clearance around the choke for airflow and to meet the creepage distances for 480 V line voltage.