What are the advantages of synthetic ester transformer oil?

Synthetic esters are valued for strong fire safety performance, good dielectric behavior, and stable chemistry across a wide temperature range. They typically offer a high fire point, making them suitable for indoor, underground, or high risk installations where fire mitigation is a priority. Synthetic esters also tend to have good moisture tolerance compared with mineral oil, which can help manage the paper oil insulation system. Tradeoffs can include higher cost and different viscosity behavior at low temperatures, so cooling design and cold climate performance must be checked during specification and retrofit decisions.