73 A rated current — what it means for the load
The 73 A rated current (LO) on the 6SL3220-2YD36-0UB0 is the continuous output rating at the low-overload duty cycle. For a SINAMICS G120XA, this typically supports a motor load around 37-45 kW at 400 V, depending on the application profile and ambient conditions. The LO rating is the ceiling for constant-torque loads like conveyors or screw feeders; if the driven load demands higher peak current for starting or short-term overload, the drive's overload capability (usually 110% for 60 s) must be checked against the motor's starting current.
Line voltage and frequency tolerance
The drive accepts 380... 440 V +10 % -20 % at 47... 63 Hz, 3-phase input. The -20 % tolerance means it can operate down to 304 V without tripping on undervoltage — useful on weak grids or long cable runs where voltage drop is significant. The +10 % tolerance (484 V max) covers most 400 V-class industrial supplies including those with regenerative braking on the same bus.