Relation of insulation resistance and deteriorated ratio of reference voltage of oil-immersed surge arrester elements enclosed in pole transformers

About. t,en years have passed since oil immersed surge arrester elements enclosed in 6.GkV pole transformers been used. At, present, technical developments are being demanded t,o judge t,he soundness of these oil immersed surge arrester element,s by a simple method and easily judge whet.her t,hese elements can he usecl or not. on site The authors empirically investigat,ed correlation bet,ween t.he insulation resist,ance and the rleteriorat,ecl ratio of t,he reference volt,age of t.hese oil-immersed surge arrester elements. It was found that t,he det,eriorat,ion of the oil-immersed surge arrester elements can be det,ectecl by measuring t,he insulation resistance by a megger.