Many factories operate electric motors to move air, run compressors or operate pumps to name a few. Traditionally these motors are on or off and run at full speed. Frequent stops and starts reduce motor life.
The mechanical applications needed to control outcomes are expensive and hard to maintain in the factory environment. A variable frequency drive can replace the mechanical device and extend motor life by allowing speeds to vary.
In a pump application, running a motor at 50% of speed consumes only 12.5% of the power compared to running full speed full time.