APF PCS is designed to correct for harmonics and poor displacement power factor. By completing the following information, this program will define the amount of corrective current to be provided by APF PCS to meet the objective.

1. Review site carefully to determine all of the loads to which APF PCS will be applied. APF PCS is best applied to a common bus. Be sure to include all loads for proper evaluation.
2. Be sure there are no power factor capacitors downstream of the selected CT location. Any and all capacitors downstream of the CTs must be removed or APF PCS performance will be diminished greatly and/or resonance may occur.
3. Nonlinear loads with input EMI filters may interact with APF PCS to prevent proper operation of APF PCS. Removal of these filters is best. However, if removal is not possible, insertion of a series line reactor in front of the EMI filter is required.
4. Use of series line reactors in front of all SCR type converters is best for optimum reduction in harmonics. In some cases line reactors may be required due to the design of the SCR converter. Consult PQc if questions arise.
5. PWM VFDs require either a DC bus choke or an input line reactor for optimum operation with APF PCS.
6. If APF PCS is on an electrical system that contains a combination of linear and nonlinear loads, all linear loads may be grouped as if they were one load for the purposes of this selection program.
7. When TDD (total demand distortion of the current) is maintained below 5%, the upstream total harmonic voltage distortion [THD(V)] will not exceed 5% THD(V).
8. APF PCS selection is based solely upon current requirements. Be sure to select the correct model that matches your system voltage.
9. Be sure to use harmonic distortion percentages based upon the fundamental current not total 'RMS' current.