Transformer Retrofill Service

Transformers are critical components in power systems, which require regular maintenance to ensure optimal performance. Transformer dielectric fluid assessment is essential for proactively assessing the health of a transformer. Often the dielectric fluid is found to be in poor condition due to contamination, or the degradation of the solid insulation from oxidation, overheating, or overload conditions. That’s where RESA Power comes in.

At RESA Power we specialize in transformer maintenance, repair, and testing. Our experts ensure optimal transformer performance through a wide range of services, including dielectric fluid assessment, promoting longevity and proactive health assessment.

Get a Quote for Retrofill Services

RESA Power Transformer Fluid Retrofill Services

Retrofilling a transformer is the process of replacing the insulating fluid in an existing transformer with new fluid. RESA Power handles every step of this service from labor and equipment to disposal of the removed liquid.

Our turnkey retrofill service includes labor, all necessary equipment, and new replacement fluids. We also provide transportation and disposal, or recycling, of the old fluid, assuring proper processing, handling, and tracking from “cradle to grave” by a certified hazardous waste disposal company.

RESA Power treatment rigs incorporate on-board or auxiliary power generation systems which can eliminate the requirement for you to provide house power or to coordinate the delivery, operation, and return of a portable generator.

RESA Power treatment rigs include a complete oil testing lab to provide moisture and oil screen results as well as in-line moisture monitoring. This provides customers with real time moisture results obtained during the treatment operation.

Enhance Transformer Reliability

RESA Power’s transformer retrofill services effectively upgrade your transformer to meet energy demands and improve performance. We will retrofill your transformer with your choice of a high-performance Type II Inhibited Mineral Oil, an environmentally friendly natural ester like Cargill FR3® fluid, synthetic ester, or other specialty fluid.

All of your transformer insulating fluid requirements will be met with the transformer retrofill service from RESA Power. Depending on environmental conditions or the time of year RESA Power can meet your fluid pre-heating requirements as part of the Transformer Retrofill Service.

Transformer Fluid Retrofill Benefits:

Improved Efficiency: The new insulating fluid used during a retrofill can improve the heat transfer within your transformers, which can lead to better performance and increased efficiency.
Extended Lifespan: By replacing the old insulating fluid with a high-performance fluid, your transformers will last longer and reduce the need for costly replacements.
Environmental Benefits: For example, FR3® fluid is a natural ester dielectric fluid derived from vegetable oil, which can be reclaimed and recycled. FR3® fluid also offers superior life extension and fire safety.




Reduce Your Transformer Costs

Transformer retrofill is a cost-effective solution for extending the life of aging transformers and improving their performance. Retrofilling involves removing the old oil and replacing it with a new dielectric fluid that has better insulation properties. This process not only improves the transformer’s performance but also reduces the risk of failure and downtime, which can result in significant cost savings.

In addition, retrofilling can also help to reduce maintenance costs by reducing the frequency of required maintenance and repairs. With improved performance and reduced maintenance costs, companies can save money in the long run and avoid the high costs associated with unexpected downtime and repairs.

Retrofill Services by RESA Power Allow You to:

Reduce clearance to buildings which saves precious real estate, particularly in space-constrained areas.m
Retrofill older transformers with FR3® fluid instead of replacing or moving them to help comply with current fire code regulations.
For power transformers, potentially eliminate the need for expensive firewalls and deluge systems (and their ongoing maintenance costs).

Improve Transformer Lifespan

RESA Power will retrofill your transformer or equipment with your choice of new Mineral Oil, newer FR3® Fluid, or Synthetic Esters. Each oil type for transformer retrofill services offers unique benefits that can improve the performance and lifespan of the electrical equipment.


Mineral oil is a commonly used dielectric fluid that is cost-effective and widely available. It has excellent electrical and cooling properties, making it an ideal choice for retrofilling older transformers.

Mineral oil has a high specific heat capacity, which means it can absorb a lot of heat without a significant increase in temperature.

By using mineral oil as a coolant, companies can help to prevent overheating and reduce the risk of damage to the equipment.


FR3® fluid, on the other hand, is a natural dielectric fluid derived from vegetable oil and is reclaimable and recyclable.

It has a higher fire point than mineral oil, which can improve safety in certain applications.

Additionally, FR3® fluid is environmentally friendly and can help companies meet sustainability goals.


Synthetic esters are another option for transformer retrofill services and have a lower freeze point than natural esters, which enhances transformer performance in colder environments.

They also have a high fire point and excellent thermal stability, making them ideal for demanding applications.

In addition, synthetic esters are biodegradable and non-toxic, making them a sustainable choice for companies looking to reduce their environmental impact.

Overall, each oil type has its own unique benefits, and the choice of which one to use will depend on the specific needs of the equipment and the application.

Alternative to Traditional Mineral Oil-Based Fluids

Did you know Cargill FR3® fluid exceeds IEEE and IEC specifications, UL listed and has been approved by the U.S. Environmental Protection Agency (EPA)? It is readily biodegradable per OECD 301, and carbon neutral (according to BEES 4.0 lifecycle analysis).

Also Cargill FR3® fluid has the highest fire point of any dielectric fluid (360°C compared to 160°C for mineral oil)? That makes it the ideal choice for densely populated areas, where transformers are positioned indoors, underground, or in close proximity to buildings and other equipment. FR3® fluid is a K-class, less flammable fluid as certified by the Underwriters Laboratory and approved by FM Global.

FR3® fluid is an innovative and sustainable alternative to traditional mineral oil-based fluids, offering superior performance, safety, and environmental benefits. FR3® fluid-filled transformers can extend the paper insulation life up to 8X longer than mineral-oil-filled equivalents because of its superior moisture handling capabilities. There are several benefits of FR3® that make it an excellent choice for a retrofill.

High Flash Point
Highest Fire Point of any dielectric fluid
Excellent thermal stability
High oxidation resistance
Low viscosity

Experience the Transformative Benefits of Retrofilling with FR3

Did you know that in 2011, the US Federal Energy Regulatory Commission (FERC) issued a ruling allowing utility companies and transformer users to capitalize all costs associated with retrofilling a transformer using FR3 natural ester insulating fluid?

By retrofilling with FR3, you can add the costs to your depreciation expenses instead of depleting your maintenance budget. This cutting-edge, K-class less flammable insulating fluid not only extends the life of your transformer but also safeguards against overloading conditions, premature failures, and unexpected replacement and downtime costs.

All of these benefits will help improve the efficiency and lifespan of your transformer. Contact RESA Power today to discover how our dedicated Transformer Services team can cater to all of your transformer needs.

One Stop for All Your Transformers Needs

Whatever your transformer requirements, from oil sampling, minor field repairs, full transformer rebuilds and coil rewinding, to major installations, contact, or call (800) 576-RESA, for immediate assistance.

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RESA Power has more than 40 service locations across the United States and Canada, including a transformer oil testing laboratory and specialty distribution centers to ensure our customers’ critical power systems are safe, reliable, and operating at peak efficiency. Click on the service center nearest to you for more information.