Authors : A.M.O. Obiazi, F.I. Anyasi, P.A. Otubu, O.A. Osahenvemwen and I. Abhulimen
Abstract: Two key requirements of electrical insulating materials are; high dielectric strength and non-varying characteristics, particularly at high temperatures. The study presents, an experimental study of twenty sample varieties of Nigerian cloth fabrics to evaluate their suitability for use as electrical machine insulating materials for high temperature operations. Impregnated samples of the cloth fabrics were subjected to heat-run in a sealed industrial oven. The insulation resistance of each given sample was measured at regular temperature intervals until the sample burns out. Tables show the values of weight, insulation resistance and temperature. Curves were plotted to show the variation of insulation resistance with temperature. From the results, eleven fabrics-Abada, Adire, Cashmier, Cord lace, Cotton, Galilia, George, Plain Guinea Brocade, Satin, Stone Wax and Tafeta, had insulation resistances up to 6 MΩ at 100°C, thus making them suitable machine insulating materials at temperatures not exceeding 100°C. The other nine fabrics-Ashoke, Global Lace, Hollandis, Intorica, London wax, Paper Lace, Poplin, Terelene and UNTL wax, whose insulation resistances were below 6 MΩ at 100°C had insulation resistances up to 8 MΩ at 90°C and so are suitable machine insulating materials at the limiting temperature of 90°C.
A.M.O. Obiazi, F.I. Anyasi, P.A. Otubu, O.A. Osahenvemwen and I. Abhulimen, 2009. Suitability of Nigerian Cloth Fabrics as Insulating Materials for High Temperature Machine Operations. International Journal of Electrical and Power Engineering, 3: 242-245.