These motors have been specially optimized for operation on a frequency converter. They work with the so-called corner point of 400 V voltage and 53 Hz frequency. The converter motors have a high power density and, compared to IE3 motors, require less space and are less weight. Their lower mass inertia allows quick speed changes.

The DRS ../ DR2S .. motors in operating mode S9 are only approved for operation on a frequency converter and have an adapted nameplate. Their dimensions, which are identical to the old IE1 motors, which are no longer approved in the EU27, and the definition of the base frequencies 53 Hz and 91 Hz enable comparable gear combinations and thus the problem-free exchange of DRS .. geared motors in operating modes S1 or S3 ( 75%) with geared motors DRS .. /DR2S..- in operating mode S9.