Why you should consider making the switch from mineral oil to FR3

December 3, 2018

Recently, power companies and large industrial and commercial end users are making the switch from mineral oil to FR3. Solomon Corporation can provide reconditioned equipment, or can retrofill your existing electrical equipment – including transformers, with FR3 fluid, replacing standard mineral oil. When you consider the many benefits, FR3 can provide a safer, more cost-effective alternative than petroleum-based oils.

Developed by McGraw Edison in 1985, FR3 is a dielectric insulating fluid designed to replace the high molecular weight hydrocarbon fluids used at the time. FR3 offers five distinct advantages compared to mineral oil:
• Reduced fire risk – zero fire history
• Increased life expectancy
• Optimized transformer performance
• Improved environmental footprint
• Lowered total cost of ownership

Reduced fire risk
FR3 is a K-class fluid with the highest fire point – 360℃ compared to mineral oil at 160℃. It can drastically reduce separation between transformers, other equipment, and structures versus other fluids. FR3 reduces the requirements for secondary containment, blast walls, and fire suppression systems. In certain situations, the potential exists to lower insurance premiums.

Increased life expectancy
Moisture in a dielectric liquid like mineral oil can contribute to low dielectric strength and cause dielectric failure. FR3 has a high water saturation point and can extend the life of an insulation system by five to eight times. It has a unique ability to draw out retained moisture while demonstrating the ability to absorb more water versus mineral oil, 10x more. This slows down the aging process of cellulose paper, thus increasing the longevity for transformers and other equipment.

Optimized transformer performance
With FR3’s ability to preserve cellulose paper insulation systems, even at elevated temperatures, transformers can be designed to operate up to 20℃ higher than standard mineral oil-filled units. This allows kVA ratings to be increased accordingly, improving overall performance.

Another way FR3 helps companies save money stems from this high temperature capability. “We can design smaller transformers while delivering the same kVA output,” said Mike Riley, East Region Field Service Sales Manager. “They use up to 15 percent less fluid and up to 3 percent less construction materials – copper, steel, and/or aluminum, insulation material, etc. – supporting the sustainable supply chain initiatives.”

Improved environmental footprint
FR3 is a natural ester fluid derived from vegetable oils, like soybeans. It includes additives to help with oxidation stability, operation at cold temperatures, and a green dye to differentiate it from other fluids. It is an eco-friendly fluid, designated as biodegradable by the Environmental Protection Agency offering a non-toxic alternative with 98.5 percent biodegradable content, and free of petroleum, halogens, sulfurs, and silicones.

If a spill were to occur, the environmental impact is minimal and remediation costs are lower since the fluid is biodegradable, non-toxic, and non-hazardous in soil or water.

Lowered total cost of ownership
While the initial purchase price of equipment with FR3 can be up to 20 percent higher, FR3 can extend the asset life of the transformer, which can significantly reduce the total life cycle cost of the asset.

Organizations can buy smaller transformers, yet maintain the same load capacity, which helps reduce initial costs. In these cases, the present value total ownership costs can be as much as 34 percent lower. Transformer designs can require a smaller footprint, which saves on initial cost while helping to address space constraints (e.g. electric rooms, existing installations, etc.)

FR3 units may also negate the need to stock and use certain sizes of transformers. “Companies can reduce transformer inventory by using the base load through the upper load capacity of FR3 fluid-filled transformers on dual-rated designs,” Riley explained. This unit flexibility may enable design consolidation and improved inventory management.

FR3 is not compatible when retrofilling units filled with silicone or PERC fluids. Solomon recommends FR3 retrofills:
• For locations in environmentally sensitive locations near waterways and parks, in close proximity to buildings, and transformers located within buildings.
• For overall reliability of critical loads
• For transformers loaded to nameplate ratings to gain additional overload capacity
• To delay transformer replacements based on age

Offering FR3 adds value to Solomon’s customers in several other ways. Beyond the individual transformer performance, there are broader organizational operational efficiencies to be considered. They can eliminate costly fire mitigation, deluge systems, and fire walls because FR3 fluid is a FM-approved, UL-classified less flammable fluid. It saves precious real estate because transformers can be placed closer to buildings. It also simplifies spill containment systems, such as earthen berms versus expensive cement systems. And, because FR3 fluid is ultimately biodegradable, spill clean-up can be less intrusive with bioremediation.

Riley provided a real-life example of how FR3 helped a Solomon customer. “A customer in Michigan got a letter from its insurance carrier stating that if the fluid in the transformer wasn’t FM-approved, they would have to relocate the transformer 15 feet away from the building,” he said. “That would be cost-prohibitive.”

He explained that if the customer could provide a document stating the type of fluid and that it is FM approved, five feet would be sufficient. The unit had Standard Type II mineral oil and retrofilling it with FR3 eliminated the need for costly relocation of a large 3750 kVA padmount transformer and associated underground cabling.