Material Compatibility in Envirotemp FR3 Fluid
Core, Coil and Insulation
Transformer materials compatibility with Envirotemp FR3 fluid is established as a technological advancement to obtain significantly greater transformer life when compared with traditional mineral oil based systems. The aging studies to determine the enhanced life of the insulation system were based on using FR3 natural ester fluid and thermally upgraded Kraft (TUK) paper at 120°C hot spot temperature (HST).
The compatibility data and results supplied in this report are summarised from transformer aging studies, and from FR3 fluid and transformer materials compatibility studies. This report provides the most current information available on FR3 natural ester fluid materials compatibility of core, coil and insulation used in new high-temperature insulation systems designated as IEEE C57.154 and IEC 60076-14. The FR3 fluid and mineral oil used in these studies comply with ASTM, IEEE and IEC International standards.
The results show that FR3 fluid filled transformers constructed of the same materials used in mineral oil filled transformers can be operated at 120°C HST to obtain expected transformer life without increasing the failure rate associated with transformer systems. These transformers qualify at a hot spot temperature of 120°C at 5 times IEEE life.
FR3 fluid is compatible with typical core, coil and insulation materials commonly used to construct mineral oil filled electrical transformers. These same materials are compatible with mineral oil, but only at a 110°C hot spot temperature. Electrical equipment manufacturers should evaluate their specific materials for compatibility with FR3 fluid. The compatibilities stated in this report are based on new unused materials. Used materials from in-service transformers were not included in these studies.