Comparative Multi Stress Aging of Thermoplastic Elastomeric and Silicone Rubber Insulators in Pakistan

Polymeric materials, both thermoset and thermoplastic are making inroads into the high voltage outdoor insulator applications. Long term investigation of these insulators under conditions that simulate the service environment is of practical interest to effectively utilize them. This paper presents the results of a multistress aging on polymeric insulators. Both the thermoplastic elstomeric (TPE) and thermoset (silicone rubber, SiR) Insulators were studied for this purpose. They were aged under same stresses in a chamber simulating the day / night and summer / winter weather cycles. The weather conditions of Hattar, a heavily polluted industrial area of Pakistan (near Islamabad) were simulated. The various environmental stresses include UVA, heat, salt fog, and acid rain. 10 kV distribution class full scale insulators were for this study. The analyses were made using electrical (leakage current), physical (discoloration, hydrophobicity classification) variables, and sophisticated material analysis techniques, such as fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It is expected that these results will help decide the application of the suitable polymeric insulators for the field environment studied.