Using an adjustable speed drive (ASD) on an AC motor can provide significant energy savings depending on the application. By varying motor speed to meet actual process requirements, ASDs help minimize wasted energy, reduce inrush current, and maintain a near-unity power factor.

In variable torque applications, such as centrifugal fans and pumps, energy consumption decreases according to the affinity laws. For example, operating at 50% speed can require only about 13% of full-load power. In many installations, these efficiency improvements can lead to a relatively short return on investment.