Natural esters: Redefining transformers

By DS Roesser, K Rapp, J Luksich, CP McShane, A Sbravati, CM Tanger, Cargill


Published in:

Electricity+Control April 2015 (pages 47 – 48)

Enquiries: Louis Blom. Wilec  email


Download the full article on Natural esters: Redefining transformers in PDF format.


Envirotemp FR3 fluid enables a new class of transformer – smaller, safer, and more reliable – while better protecting the environment. Across the globe, bio-based Envirotemp FR3 fluid dielectric coolant is improving overall equipment and bottom line performance. Learn how you can improve transformer capacity by as much as 20 %, and provide the highest level of fire resistance, with reduced carbon emissions.

The science behind this powerful capability is the way in which natural esters like Envirotemp FR3 fluid interact with water. Natural esters like Envirotemp FR3 fluid have significantly higher water saturation limits compared to conventional transformer liquids. In a transformer system, the solid cellulose insulation is the limiting factor for transformer life and must work in harmony with the fluid. The higher water saturation limits of natural esters, coupled with their ability to remove water, provide conditions that allow higher operating temperatures. For natural esters, higher operating temperatures are not a problem for safety, since their flash and fire point temperatures are two times higher than conventional transformer oils. Furthermore, natural esters are considered self-extinguishing Class K fluids. Utilising this technology means a shift in conventional wisdom for the transformer industry. If asked for the keys to maintaining optimal transformer life, many industry professionals would reply by saying ‘keep them dry and cool’. However, natural esters turn these constraints upside down.


Take note

  • Compared to mineral oil, Envirotemp FR3 fluid enables longer lasting transformer insulation systems.
  • Envirotemp FR3 fluid has improved temperature management during peak energy demand.
  • The science behind this capability is the way in which natural esters like Envirotemp FR3 fluid interact with water.