Which dielectric fluids classifications are important to understanding fire safety?


IEC 61039 identifies “less flammable fluids” as those with a fire point >300°C. These are designated as K class fluids.

According to IEC 61936 transformers filled with K-class fluids can have reduced fire protection measures.

In addition, certifiers such as FM Global provide a list of approved Less Flammable Transformer Fluids and guides for safe installation.

Using a high fire point fluid significantly reduces the chance of a pool fire.

What does this mean for MIDEL? There has never been an oil fire reported in the past 40 years in transformers using MIDEL ester fluids.


Fire Point Comparison: Dielectric Fluids



The use of ester transformer fluids for increased fire safety and reduced costs.

15 Questions Ester Fluid Retrofill banner.png

Download the eBook: Top 15 Questions

Retrofilling transformers with ester fluids