Don't think so. Distilled water eats copper like candy.

Something's not right.

Most transformers I have seen are cooled with oil.

Some big transformers are cooled with both oil and water, where we have a pump to help circulate the water through the copper buss bars of the transformer

Oil is filled in the transformer and all the air is bleeded as it is bleeded out from the Baking System of Vehicles

And

If Water is used for cooling it will be circulated in casings-Radiattors as in automobiles.

People working in Power generation may comment please.

Distilled water is generally used for cooling purpose to extend the life the equipment by reducing corrosion related problems. Maintenance manual of the equipment is the right guidance to find out the frequency of replacing the water.

Where did you hear that distilled water, "extend the life the equipment by reducing corrosion related problems." This is not right.

Distilled water will eat/corrode/erode/pit/generally just ruin copper.

Stainless steels or plastic are always recommended with distilled water. Get the facts right.

No it's just opposit. I agree with Lyn.

...because distilled water is not an electrolyte.

I would have thought it would be a glycol product diluted with DW.

That's what the manuals tell me to fill my high power semiconductor cooling systems with. DW still boils...not good. Maybe transformer intercoolers are different.

There is special oil for Transformer cooling + maintaining Good insulation.

Quote:

From wikipedia

Transformer oil or insulating oil is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage switches and circuit breakers. Its functions are to insulate, suppress corona and arcing, and to serve as a coolant.