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Liquid-filled Transformers

Years of dedicated testing and research and development of Nomex® paper and pressboard products have yielded the potential for a variety of economic, environmental and safety benefits, when used in fluid-filled transformers. 

Fluid-filled transformers using Nomex® insulation can enhance many applications:

  • Mobile transformers
  • Traction transformers
  • Transformers for wind power
  • Repaired substations
  • Utility substations
  • Unit substations
  • Rectifier transformers
  • Furnace transformers
  • Pole-top distribution transformers
  • Pad mounted distribution transformers

Nomex® insulation technologies in fluid-filled transformers can:

Reduce equipment size and weight

While maintaining top oil temperatures at constant levels with only modest increases in average oil temperatures, the weight of a transformer can be reduced up to 25 percent for a given kVA output. Conversely, the kVA rating can be increased up to 50 percent for a given size and weight.

This weight reduction allows mobile substations and railway traction transformers, for example, to be designed with operating capabilities larger than before. More compactly designed transformers are revolutionizing the wind-generator marketplace in a similar manner. Use of high temperature fluids like silicone oil or ester fluids permit even greater savings in size and weight.

Increase reserve capacity

Transformers insulated with Nomex® can be designed for extra power capacity in emergency peak load situations.

Improve reliability

Insulation systems based on Nomex® technologies maintain excellent electrical and mechanical characteristics over a transformer's service life. Negligible aging, resistance to shrinkage and compression, and the superior resilience of Nomex® help coil structures remain tight and withstand short-circuit forces, even after years of service.

Customers for transformers insulated with Nomex® have included users in the power utility, industrial and railway markets. IEEE Guide 1276 and IEC Technical Specification 60076-14 provide guidance to manufacturers and users regarding the production and application of some of these tranformers.