Before the Declaration of Independence. Even after the initial battles in the Revolutionary War broke out, few colonists desired complete independence from Great Britain, and those who didâlike John Adamsâ were considered radical.
A variable-frequency drive is a device used in a drive system consisting of the following three main sub-systems: AC motor, main drive controller assembly, and drive/operator interface.ariable-frequency drives are also categorized by the following load torque and power characteristics: 1  Variable torque, such as in centrifugal fan, pump, and blower applications. 2  Constant torque, such as in conveyor and positive-displacement pump applications.
Program Scope. This program applies to Variable Frequency Drives as defined below, for which published ratings are available, and which can be tested in the Independent Third-Party Laboratory contracted by AHRI. Variable Frequency Drive.