One contributing element to power quality is power factor. Power Factor Correction (PFC) aims to improve power factor, utilising capacitors to offset usually inductive loads, for example motors. PFC systems increase the efficiency of power supply, delivering immediate cost savings on electricity.

Power Factor is a measure of how effectively incoming power is used in your electrical system and is defined as the ratio of Real to Apparent (total) power where:

• Real Power is the power that actually powers the equipment and performs useful, productive work.

• Reactive Power is required by some equipment (e.g. transformers, motors and relays) to produce a magnetic field for operation; however it does not perform any real work.

• Apparent Power is the vector sum of Real and Reactive Power and corresponds to the total power required to produce the equivalent amount of real power for the load.

Power Factor Correction may be required where a system has a power factor of less than 90% (or 0.9). A poor power factor can contribute to equipment instability and failure, as well as significantly higher than necessary energy costs since it means that more current is required to perform the same amount of work. By optimising and improving the power factor, the demand on the electricity distribution system is reduced.

Power Factor Correction equipment achieves a decrease in the total amount of electrical demand by using a bank of capacitors to offset an inductive load (or reactors if the load is capacitive).