Can I use Midel fluids to retrofill transformers at high voltages?


For retrofilling transformers, it depends upon the voltage and power rating of the asset.

High Voltage Transformers using Midel fluids

Midel fluids are approved for use at transmission voltage levels by several leading OEMs. MIDEL 7131 has been used for multiple projects at 400kV and in mobile test equipment up to 500kV. In common with other ester-based fluids, some design adjustment may be needed for higher voltage levels due differences in permittivity and dielectric performance.

Although MIDEL fluids are suitable for higher voltage levels in specifically designed transformers, retrofilling depends upon the voltage and power rating. As a general guideline the table below can be utilised.




For more on the development of EHV transformers with Midel ester fluids, read our detailed article and case studies on using Midel fluids with power transformers.


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Retrofilling transformers with ester fluids