This is a Siemens axial fan, order code 6SL3994-6FC00-0AA0, identified on the nameplate as W2D250-GA04-15. It is a dedicated cooling component for the regulation/filter section of SINAMICS drive cabinets — the fan that pulls air across the power stack and line filter, not a general-purpose ventilation unit.
What the fan does in the drive cabinet
Mounted inside a SINAMICS drive enclosure, this axial fan forces air across the regulation electronics and the line filter choke — the hottest zones in the cabinet. If this fan fails, the drive derates or faults on overtemperature. The W2D250-GA04-15 designation points to a 250 mm diameter, 4-pole external-rotor motor, typically 230 VAC or 400 VAC three-phase, with a sealed ball-bearing system rated for continuous duty in a 40 °C ambient.