In the supply system normally the power factor is lower then 0.8 for the overall load. Low Power factor is very undesirable, because it hampers the economic parameters for the power generation and distribution. Now, some short important causes are as follows,
· In the low lagging factor some electrical equipment such as electric discharge lamps, Arc lamps and the industrial heating furnaces are running.
· The power factor is also depending on the load conditions. The load is varying time to time. The supply voltage is increasing in the low load period which increases the amount of the magnetization current. This magnetizing current is resulting in the decreased power factor.
· The single phase and three phase ac motors have low lagging power factor and they are induction type also. The power factor is varying for these types of motor. It can run from 0.2 to 0.9 values depends on load. In the heavy load the power factor can be 0.8 or 0.9 and in the light load the power factor can be 0.2 to 0.3.
