Firstly what is power factor ?

Power Factor is the ratio of active power (kW) to apparent power (kVA). This is the amount of power that is flowing to the installation (kVA) vs the amount it actually uses (kW). The waste energy component of apparent power is known as reactive power (kVAR) It is expressed as a numerical value between 0 and 1 as a way of measuring efficient power usage and the closer the power factor is to 1 (100%), the lower the amount of current needed.

For example, a load with a power factor of 0.80 means that only 80% of the power is being used effectively to do work. In the perfect world, all power drawn from the power system would be converted to useful work, but this is not so in the real world. The closer your power factor is to 1, the more efficient the installation is.

Secondly what is power factor correction ?

Power factor correction is the term for any equipment that compensates for reactive power and improves the power factor ratio,
this equipment is a technology which when installed on site allows the consumer to reduce their electricity bill by maintaining the level of reactive power consumption.

Β What are the causes of poor power factor ?

Inductive loads such as electric motors, ballast lighting and transformers contribute to poor (low) power factor. In addition, inductive loads that are not used at, or near, their design capacity contribute significantly to a low power factor.

How do i improve my power factor ?

There are a multitude of methods to improve power factor. Some include:

  • Upgrading or replacing inductive loads that do not operate close to their design capacity
  • Local power factor correction at the load
  • Centralised capacitive correction
  • Static Var Generators (active power factor correction of lagging power factor)
  • Active Power Filters (phase balancing, harmonic correction and active correction of leading and lagging power factor)
  • The use of Variable Speed Drives (VSD) to control electric motors




We have put this information together in this blog for a basic understanding of power factor and power factor correction, it is only a guide as each individual installation with poor power factor would have its own requirements in correcting the issue. It is recommended that you engage a qualified and experienced electrical engineer to conduct a full site audit to determine what is causing the issue and what is the best path forward.




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