Power factor correction capacitors are typically wired in parallel with the motor load at various points in the distribution system. In situations where a variety of inductive motors or loads are being switched on and off independently, it is desirable to apply the capacitance to the individual load. For that reason, it is important that power factor correction be specifically matched to the inductive load with which it is associated.
In an ideal system, a motor is corrected when its inductive reactance equals the capacitive reactance at the line frequency … over or under correction of the load will result in poor performance and possible damage to the capacitors and motors. Over correction occurs when the resonance frequency is less than the line frequency.
Each inductive load—especially electric motors—requires a properly sized power factor correction capacitor. While a helpful starting point may be found in standard look-up tables or other theoretical predictors of optimum capacitance, the better practice is to specifically match the capacitance to the measured characteristics of the particular motor design.
APFusion automatic power factor correction units are suitable for use where harmonic generating loads are less than 15% of the total connection load.