Hygroscopic Resin Cast CT

I think anti-tracking paints/coats/compounds are available in the market.

Elantas (Dr.Beck) has an epoxy resin that they have specially developed for use in coils for windmills that are subjected to very harsh conditions of weather. I do not recall the cat number right away.

DuPont also has similar resins that I have seen in use for dipped coating.

What Partial Discharge tests do you do for your CTs? What is your method of Resin Casting? What Resin do you use for casting?

Thanks el..65 & so..hi

We are only the user of the particular CT. We don't know the actual material used for casting. However a good insulation value in terms of several MΩ is required to put it into service.

Could anyone suggest some anti tracking paint, etc. that commonly available in Indian market?

You need a casting or moulding compound with lower moisture absorption. Tell us what you currently use and we may be able to suggest something better, or contact a supplier of such materials. In general, epoxies are pretty good, silicones are not so good. Some plastics are excellent but not available as casting compounds. You could have covers moulded from a good material and pot the CTs inside these protective enclosures.

It is epoxy resin cast CT.

Apart from applying coating on the epoxy surfaces of the CTs, please check whether the heaters installed inside the panels are in operative condition. Also please arrange to install 4/5 nos 400watt sodium vapour lamps( depending on total panel length ) in bare condition i.e. without lamp fittings; only fixing with lamp holders, on the top surface of the panel i.e hanging from ceiling and will be glowing for all the times. The heat generated by the sodium vapour lamps will increase ambient temperature and water condensation either will be stopped or greatly reduced and this may solve your tracking problem.

Manindra

You may be able to mitigate your problem by covering your resin cast CT with a hydrophobic coating. http://en.wikipedia.org/wiki/Hydrophobe