FR3® Vegetable-Oil Based Fluid Insulator for High-Voltage Transformers
Natural ester dielectric fluid. PCBs were traditionally used as fluid insulators in transformers and were eventually banned due to their high toxicity. PCBs were then replaced with petroleum-based mineral oil. Unfortunately, mineral oil is highly flammable and has a low affinity for water. Additionally, other insulator materials within transformers are made of cellulose. Thus, water inside the transformers was mostly absorbed by the cellulose-based insulator materials, catalyzing their degradation and reducing the lifetime of the transformers.