90 kW at 400 V — heavy pump, fan, or compressor duty
The 6SL3220-3YD44-0UB0: That 164 A rated current (LO) at 400 V maps directly to constant-torque loads like positive-displacement pumps or screw compressors where the motor pulls full current across the speed range. Line voltage acceptance is 380... 440 V +10 % -20 % — the drive handles a sag down to about 304 V without tripping, which matters on weak utility feeds or long cable runs. Input is 3-phase, 47... 63 Hz.
Current ratings — which one governs the BOM line
The LO current is the continuous rating for the standard duty cycle; the IN figure at 380 V is what you'd use for a derated install on a lower-voltage grid. The 181 A max output is the short-term ceiling — useful for accelerating high-inertia loads but not for continuous sizing.
Output frequency range — V/f vs vector control
V/f control goes to 550 Hz, covering high-speed spindle or centrifuge applications. Vector control tops out at 240 Hz, which is the ceiling for closed-loop torque or speed regulation on standard induction motors. The 4 kHz pulse frequency is the default — raising it quiets the motor but derates output current; lowering it reduces switching loss at the cost of audible noise.