New Industry Products

High-Current AC Harmonic Filter Capacitors

January 09, 2020 by Paul Shepard

Cornell Dubilier has extended the capabilities of the PC series of high-current ac harmonic filter capacitors, including a new 85Arms rating and numerous other enhancements. Series improvements include its UL recognized construction and internal pressure interrupter system. This internal system has passed rigorous UL testing to ensure fail-open performance under high current fault conditions.

The higher current ratings improve the capacitor’s ability to handle the high levels of harmonic content encountered in inverter ac input and output filtering applications such as uninterruptable power supplies (UPS), ac tuned filters (harmonic reduction), ac input filtering, and wind turbine motoring.

Type PC capacitors are designed to meet the demands of filter applications rich in system total harmonic distortion (THD). This series has a dual protection system utilizing self healing metallized polypropylene and a mechanical pressure interrupter to ensure a safe open circuit mode in the event of overload or end of life.

The series is typically networked with inductors to filter out undesirable harmonics in both single-phase and three-phase ac power systems. As a two-terminal capacitor device, multiple PC series filter capacitors can be connected in delta or wye configurations to achieve the reactive power and harmonic tuning needed to filter out the unwanted frequencies.

The presence of multiple harmonics puts additional stress on capacitors in the form of self-heating. The CDE PC series is designed with robust terminations and low equivalent series resistance (ESR), to minimize heating. The service life objective of the PC series is 60,000 hours when operated at full rated voltage and a case hot spot of 70°C.

The PC series is offered with capacitance ratings ranging from 20µF to 125µF at voltage ratings from 300Vac to 700Vac. Case diameters vary from 63.5 to up to 116mm. Custom capacitance and voltage ratings, sizes and performance characteristics are also available. Specific application conditions, especially harmonic content profiles, are needed to properly size the capacitors for peak performance.

Features & Benefits

  • 60,000h w/94% survival rate
  • Capacitance Range - 20µF to 125µF
  • Rated Voltage 300Vac, 500Vac, 700Vac
  • Line conditioning
  • Variable speed drives
  • Extruded aluminum with steel or aluminum cover
  • Noise suppression
  • RoHS compliant