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K-factor rated transformers are designed to meet the non-linear load demands caused by computers and other modern electronic equipment. These types of loads can cause severe overheating in distribution transformers designed to meet the needs of a pre-electronic era. The Jefferson line of non-linear transformers provides safe and efficient operation in non-linear load environments.

  • 15 – 750 kVA (some restrictions on larger kVA units)


  • For electronic load demands caused by modern office equipment
  • For indoor/outdoor applications
Information sheet
Catalog Section 3


  • K-4, K-13, K-20 units standard
  • Meets DOE-2016 standard for energy efficiency
  • Cores of high quality, low loss, electrical steel
  • Aluminum windings
  • Cores designed for reduced flux densities to compensate for harmonic voltage distortion
  • NEMA 3R-rated enclosures standard
  • Heat-cured ASA-61 gray powder coat finish
  • Electrostatically shielded
  • 150°C temperature rise
  • 220°C insulation class standard

Features, Functions, Benefits

  • Designed with lower weight and smaller size for easier handling and installation
  • Large connection compartment for ease of wiring and installation
  • Quiet operation for installation flexibility
  • Hassle-free front cover installation
  • Primary taps provided to compensate for voltage variations
  • Seismic certifications for all units


Options and Accessories

  • CE Marked units available
  • Other sizes, voltages, and connections available as custom
  • Other K-factor rated units available as custom
  • Wall mount brackets available through 75 kVA

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