FR3 Fluid increases load capability up and extends transformer life and improves fire safety

Envirotemp FR3 Fluid is a renewable, natural ester dielectric fluid formulated to optimise transformer performance and enhance overall grid efficiency.

FR3 Fluid can increase load capability up to 20%, extend transformer life and improve fire safety – enabling utilities to minimise cost and risk and maximise operational efficiencies, states Wilec.


The high-performance, fire safety and environmental characteristics of Envirotemp FR3 Fluid enables utilities to optimise their transformer performance and gain cost efficiencies that cross many areas of the organisation.

Increase load capability by taking advantage of the high-temperature capability of Envirotemp FR3 Fluid.

Improve performance:

  • Uses up to 15% less fluid and up to 3% less construction materials
  • Increases loadability up to 20%
  • Increases reliability
  • Twice the fire and flash point as mineral oil. Significantly increases fire safety for workers and the community


FR3 Fluid gives utilities the ability to increase overload capacity or extend asset life. This results in significant cost savings over the life of each transformer.

Gain cost efficiencies:

  • Slows asset replacement
  • Reduces routine maintenance
  • No need for fire-mitigation systems
  • Potentially reduces insurance premiums due to increased fire safety
  • Minimises the need for concrete basins
  • Supports supply-chain sustainability
  • Optimises inventory management

Take advantage of environmental benefits:

  • Ultimately, biodegradable and non-toxic materials make spill remediation easier and faster
  • Carbon neutral
  • Made from renewable vegetable oil


Envirotemp FR3 Fluid is a natural ester fluid derived from renewable vegetable oils – providing environmental benefits that are superior to mineral oil and unsurpassed by any other dielectric coolants.

• Ultimately biodegradable as designated by the EPA.
• Reduced carbon footprint – 56 times less carbon emissions than mineral oil.
• Non-toxic – contains no petroleum, halogens, silicones or sulfurs.
• High-saturation point removes water from the insulating paper.
• Maintains dielectric strength in cold temperatures.

FR3 Fluid possesses a 100%-fire safety record, making it the ideal choice for transformers positioned indoors, underground, and in close proximity to buildings and other equipment:

• Prevent costly replacements due to fires (transformers, property damage, etc.)
• No fire mitigation or deluge systems required.
• Exceptionally high fire and flash points of 360°C and 330°C, respectively.
• Highest ignition resistance of any high fire point dielectric fluid available.
• FR3 Fluid is FM Global approved and Underwriters Laboratories has classified it as a less flammable dielectric liquid.

Trusted worldwide for both new transformers and retrofilling existing transformers.
Some of the largest utilities and transformer manufacturers around the world use Envirotemp FR3 Fluid.

You will find FR3 Fluid in power and distribution transformers of all sizes and applications through to 420kV.


ASTM D6871 Standard Specification for Natural (Vegetable Oil) Ester Fluids Used in Electrical Apparatus IEC 62770: Fluids for electrotechnical applications – Unused natural esters liquids for transformers and similar electrical equipment.

NOTE: Specifications should be written referencing only the defined ASTM or IEC industry standard acceptance values and test methods.

The listed ‘typical’ values are average values summarised from a significant number of data points over many years; they are not to be identified as acceptance values.