scope:

This guide describes three methods used in the measurement of the power factor of inductive low-voltage (1000 volts and below) test circuits. These methods may be used at any frequency; however, the values in the tables are specifically for 60 Hz test circuits. These methods are:

1) Ratio method

2) DC decrement method

3) Phase relationship method

Table 1 lists the preferred method to be used for different levels of test currents and for different levels of power factor. While this guide is primarily intended for use on low-voltage test circuits, the methods discussed are also usable at higher voltages.