Top 15 Questions on FR3 Fluid retrofill for mineral oil transformers

Considering natural ester fluid for retrofilling?

Get our guide to the top 15 Questions on using FR3 Fluid to retrofill mineral oil filled transformers.

In response to the many questions we get on FR3 fluid and natural esters, particularly in regard to retrofill applications, we developed this handy guide with the top 15 questions and their answers.

In addition to answering the most frequent questions on this topic, we review the reasons for retrofilling with natural ester fluid, the benefits and the many financial incentives. 

Within it you will find plenty of links to additional technical resources and reference sites.


What's covered?

When retrofilling mineral oil filled transformers with Envirotemp FR3 natural ester fluid, there are many financial incentives that support positive return on investment, over and above what can be achieved with mineral oil. 

Many of our customers have financially justified FR3 natural ester fluid retrofills based on the advantages it offers. However, we still get a lot of questions on FR3 and natural ester fluid – especially when it comes to retrofilling transformers.

This guide has been designed to help organisations better understand the challenges, myths and possibilities regarding retrofilling with FR3, and assist them to make investment decisions with greater certainty.

Questions like these

We address the questions that come up time and again from customers, including "what materials are compatible with natural esters?" and "will there be any de-rating of my transformer by changing from mineral oil for FR3 natural ester fluid?".


The top 15 Questions


#1  Fluid miscibility
Which transformer oils are compatible with FR3 fluid for retrofilling?

#3  Insulation regeneration
Will FR3 fluid heal existing problems in a transformer?

#5  Cold weather
How does FR3 fluid perform in application at cold temperatures?

#7  Acid levels
If FR3 fluid has high acid levels, how do I process my fluid?

#9  Power factor
What is the Power Factor of FR3 fluid?

#11  HV applications
Can I use FR3 fluid at high voltages?

#13  Reusability
What can I do with my used FR3 fluid?

#15  Retrofill process
Are there additional steps when retrofilling transformers with FR3?

#2  Free breathing
Can I only use FR3 fluid in hermetically sealed transformers?

#4  Fire safety
All materials burn, so which fire safety tests are important?

#6  Moisture
Since FR3 fluid attracts moisture, how does that impact performance?

#8  Dissolved gas analysis
Can I perform DGA on FR3 fluid?

#10  Materials compatibility
Is FR3 fluid compatible with all transformer materials?

#12 Interfacial tension
Is interfacial tension a meaningful property for FR3 fluid?

#14  De-rating
Will there will be any derating of the transformer by changing from MO to FR3?