Introduction to capacitors
Capacitors are used in industrial premises for two basic functions: the first, to correct the load power factor, usually to meet the supplying authority’s supply requirements and avoid tariff penalties if the required power factor is not met, and the second, to correct voltages within the plant.
Individual capacitors can also be attached to circuits feeding loads with inherently low power factors to correct for their low power factor and so improve both the overall plant’s net power factor and, at the same time, reduce the voltage drops within the plant.
Capacitor banks and individual capacitors can therefore form either fixed installations, which are always connected when that section of the plant is running, or be switched when required. A common example of application is capacitors connected directly in motor circuits that are switched with the motor and keep the net power factor for each motor circuit at an ideal level.