Line reactors, also referred to as chokes, are passive-power conditioning devices.

Reactors are most often applied to correct or prevent power-line problems inherent in ASD applications.

When applied to the input of an adjustable speed drive, the line reactor is intended to protect the input of the drive from power-line problems or vice versa.

Applying line reactors is simple. There are two factors to consider when selecting the amperage and percent impedance for an application. For amperage, the line reactor must meet or exceed the current flow requirements of the application.

The percent impedance indicates the expected voltage drop across the reactor at full load. For instance, if the input voltage is 460 VAC a 5% impedance line reactor is applied, a 13.86 volt drop [(460 x .05)/1.73] will occur with a resultant 466 VAC output.