One of the main reasons why variable speed drives save energy is because they can change the speed of an electrical motor by controlling the power that is fed into the machine. Any electrical item requires a certain amount of power to be able to operate.
A variable speed drive is a piece of equipment that regulates the speed and rotational force, or torque output, of an electric motor. There are many motors in use in industry and offices around Australia; in fact, more than 65 percent of industrial electrical energy is consumed by motors.