Epoxy Polyester Mix Insulation Dry Type Current Transformer

This paper deals with design and development of solid insulation system, which can be used for current transformer (CT) without any voids and cavities at high voltages with long life and low Partial Discharge level. Polyester tape and cold coring epoxy are used for insulation system. Moulds are made on Aluminium pipe as electrode by winding polyester tape and applying epoxy resin. Each sample was subjected to visual inspection for voids and cavities and also subjected to dielectric tests. It is found that 10mm thick insulation with polyester tape and epoxy with 250 mesh silica flour filler and hardener gives best result for 11kV system voltage CT. All the routine and type tests (temperature- rise test and lightning impulse) are conducted on CT which shows that it is well suitable for its application.