Retro-fill of Mineral Oil – immersed transformers with Synthetic esters
Miscibility Synthetic esters are miscible with mineral oil as well as ester oils in any proportion. Synthetic esters can not be used to retro-fill silicone oil-filled units. Silicone oil mixed with esters can cause foaming during the filling of a transformer under a vacuum. The mixture of mineral oil and synthetic esters differ from both…