How to maintain dry transformer winding?

Question

I have an old xray machine with a large step down transformer.

Its not shorted but the paper insulation looks to dry. Is there a special oil for this? Thanks.

Answer 1

there is no oil for transformers. they are kept dry by all the heat they generate. it "cooks" the moisture out.  if there is a specific reason you are worried, please do tell. is it going to be stored or go unused for a while? is there a lot of moisture in the area of operation? if not, i would not worry about it. it sounds as if it might be near the end of its life cycle as is.  on the bright side transformers dont just burn out. there must be a reason for the failure. moisture is not too bad, but water is.

Answer 2

The manufacture of the transformer would have provided environmental protection.

There are many ways to provide protection but most involve large pressure cookers that are designed to apply high pressure to the transformer will drying. Various waxes and epoxies are used and the pressure makes certain the sealer is driven into the transformers windings, then allowed to set. As far as I know, except for certain types of large transformers where the entire transformer is installed in a bath, oil is not used.