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A capacitor is a passive, two-terminal electronic component that stores electrical energy in an electric field. It is made of two metal plates and an insulating material called a dielectric. Its effect is known as capacitance, and while some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor adds capacitance to a circuit.

Products include two types of capacitors with the accessories and controls to form complete capacitor installations:

  • Shunt capacitors that are ? kVa and larger for power factor improvement and other low-frequency AC applications and the assemblies of capacitor units
  • Series capacitors that are ? kVa and larger for series connection in low-frequency AC circuits

NEMA provides active, effective, and organized marketing and technical programs, and related activities so that Members do not have to spend resources to track and engage independently.?



  • Develops Standards, white papers and guides that serve technical needs in the marketplace; current work includes a Standard for DC capacitors; develops white papers that promote capacitor capabilities on such issues as protection from geomagnetic disturbances and energy efficiency capabilities
  • Educates users on the selection, installation, operation, monitoring, maintenance, and decommissioning of capacitors to maximize performance and minimize costs over the product's lifetime
  • Participates in direct harmonization efforts between United States, Mexican, Latin American, and global Standards to ensure that foreign markets remain open to Members' capacitor products
  • Administers the International Electrotechnical Commission (IEC) U.S. Technical Advisory Group TC33 to promote harmonization with European and global standards 
  • Coordinates input to the National Electrical Code? (NEC), Underwriters Laboratories (UL), IEEE Power & Energy Society (PES) Capacitor Subcommittee, and other bodies


  • Provides intelligence on Mexican regulation designed to facilitate privatization of the power grid, including access to Mexico's standards regulator for the power grid


  • Common applications include local energy storage, voltage spike suppression, and complex signal filtering.
  • Power capacitors play a vital role in ensuring the reliability and efficiency of the electrical grid by providing reactive power for power factor correction applications such as volt/VAR optimization.
  • Utility distribution systems
  • Industrial substations
  • Distributed energy resources and renewable energy systems?


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