What this mains choke does on a 400V line
The Siemens 4EP3703-8DS00 is a three-phase Netzdrossel — a mains choke — rated for 400V AC at 50Hz. It carries 26.6A maximum current (24A rated operational current) with a 1.2mH inductance and a 4% relative inductive voltage drop at rated conditions. That voltage drop figure tells you the choke is sized to smooth line-side harmonics and limit inrush current without dragging the bus voltage down more than 4% under full load. The 30W coil loss plus 12W iron core loss (42W total) is what the panel ventilation needs to shed at 50°C ambient. IP00 means it's an open-frame component — no enclosure, no gasket. It mounts inside a cabinet that provides the environmental seal. The screw-type and tab terminals on the main circuit suit panel wiring with ring lugs or fork terminals; plan for a 0.105m depth, 0.178m width, and 0.153m height footprint on the mounting plate.
This part carries a mature lifecycle stage — it's an established catalog item, not newly introduced and not flagged for phase-out.
Thermal class and compliance
Insulation is Class B per IEC 60085, which means a 130°C continuous temperature limit on the winding. The choke is designed to EN 61558-2-20, the safety standard for small transformers and chokes. That standard covers dielectric strength, creepage distances, and overload behavior — relevant for panel builders who need to document the component's safety file.