Mechanical Basics

In many commercial, industrial, and utility applications electric
motors are used to transform electrical energy into mechanical
energy. Those electric motors may be part of a pump or fan,
or they may be connected to some other form of mechanical
equipment such as a conveyor or mixer. In many of these
applications the speed of the system is determined primarily by
its mechanical design and loading. For an increasing number of
these applications, however, it is necessary to control the speed
of the system by controlling the speed of the motor.