Low Power Factor Testing (Adding Inductive Load)

By adding an inductive load to the resistive load, lagging power factor can be obtained. Commercial loads, as well as generator sets, are rated at the nominal power factor of 0.8 lagging. This number is the cosine of the angle made between the KW and the KVA in the diagram below:

Low Power Factor Testing

The magnitude of inductive load required to obtain 0.8 power factor is 0.75 X the KW (1000kw + 750kvar = 1250kva at 0.8 lagging power factor). As a point of interest, 0.75 is the tangent of the aforementioned angle. Keep in mind when sizing cables that the full load current at the rated KVA must be calculated.