For more than 30 years, FR3® natural ester fluid has set the benchmark for transformer performance. From its earliest validation tests and growing to 5+ million installations worldwide today, FR3 oil continues to lead the industry in fire safety, reliability, and resilience. Its higher flash point (compared to mineral oil) delivers a significant fire safety advantage, while its proven dielectric performance supports longer-lasting, higher-performing transformers than transformers using mineral oil.
Mineral oil may have been the traditional choice, but it’s no longer the optimal one. Across the globe, utilities and manufacturers alike have turned to FR3 natural ester fluid as the superior alternative—one backed by decades of leadership and real-world experience. With FR3 oil, you gain the confidence and performance today’s power systems demand.
Why FR3 Fluid
FR3 fluid outperforms mineral oil in overall grid resiliency, superior performance, sustainability benefits, and cost savings. Discover why more utilities and manufacturers are making the switch – and how FR3 oil delivers measurable impact from day one.
Grid resiliency that pays in more ways than one
A transformer’s operating limits are constrained by the thermal properties of solid insulation and dielectric fluid. Because of FR3 fluid’s high thermal properties and its ability to reduce the aging rate of paper insulation, transformers containing FR3 fluid can operate up to 20 °C warmer than mineral-oil-filled equivalents – enabling increased loading capability by up to 20% or more, especially when the transformer is purpose-built for FR3 fluid. This added thermal margin gives utilities the flexibility to respond to fluctuation power demand without accelerating insulation aging, and in many cases, may extend overall transformer life.
Average total cost of ownership savings
Up to 20% more load capacity than mineral oil
Up to 8X longer insulation life
Mineral oil's flash and fire points
Reported fires
Installations worldwide
FR3 fluid applications
Battery energy storage systems
Battery energy storage systems (BESS)
Battery Energy Storage Systems (BESS) are essential for grid stability and maximizing renewable energy value. Pairing them with FR3 fluid elevates fire safety, reliability, and long-term performance—delivering the confidence modern energy storage demands. Explore how FR3 fluid can strengthen your BESS strategy.
Data centers
Data centers
As data centers scale to meet the demands of AI and infrastructure digital growth, energy networks are being pushed harder than ever. FR3 fluid is engineered to support what matters most: uninterrupted operation. In emergency or overload conditions, it can handle up to 20% more load than mineral oil—without compromising long-term transformer reliability.
Retrofilling
Retrofilling
FR3 fluid-filled transformers can extend paper insulation life by up to 8 times compared to mineral oil units, thanks to FR3 fluid’s superior moisture-handling capabilities. It also delivers significantly improved fire safety, with a fire point more than twice that of mineral oil. When you retrofill a mineral-oil-filled transformer with FR3 fluid, you gain both extended asset life and a significantly reduced risk of fire.
Solar power
Solar power
FR3 fluid is widely used in both land-based and floating solar applications across the globe.
Solar farm transformers benefit from FR3 fluid’s higher flexible loading capacity and minimal maintenance needs. The fluid’s sustainability advantages reduce environmental impact while allowing for smaller installation footprints and improved fire safety compared to mineral oil.
Power Transmission and distribution
Power Transmission and Distribution
FR3 fluid is proven across power generation and distribution transformers in every voltage class. Compared to mineral oil, it delivers superior performance and measurable cost efficiencies for utilities. Choosing FR3 fluid strengthens grid flexibility and resilience—benefiting your business and your community.
Wind power
Wind power
Demand for wind power continues to grow, and turbines for large scale wind farms are becoming more powerful than ever. This makes it essential to specify compact, lightweight, low-maintenance transformers that can keep pace with these demands. FR3 fluid helps wind turbine transformers—onshore and offshore—meet these requirements while delivering meaningful cost and performance advantages.
Validation
FR3 fluid has been tested and proven by numerous internal tests, third-party research organizations and universities, and customers many times over, and for decades. See why its superiority to mineral oil is beyond question.
Technical Details
Higher flash and fire points (compared to mineral oil). High dielectric strength even at very cold temperatures. Chemical interactions that extend the life of a transformer’s solid insulation. 100% biodegradable in as little as 10 days according to OPPTS 835.3100. See FR3 fluid’s technical details.
In the News
Browse the latest Cargill power systems news and headlines from around the globe. Catch up on recently published case studies and articles including our industry experts to learn best practices and how FR3® fluid is being used in the field.
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