Authors : A.M.O. Obiazi, F.I. Anyasi and P.A. Otubu
Abstract: Tropical countries across Africa, Asia and America suffer from high ambient temperatures leading to high operating temperatures for electrical machines. Under this adverse temperature condition, it is taxing for insulating materials to maintain electrical and mechanical integrity sufficiently to prevent turn-to-turn and turn to ground shorts during operation. The study presents an experimental study of 10 sample varieties of Nigerian wood species to evaluate their suitability for use as electrical machine insulating materials for high temperature operations. Impregnated samples of the wood species 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, the 10 wood species Abeza, Afara, Agbagum, Aper, Danta, Gameliana, Iroko, Mahogany, Obeche and Opepe had insulation resistance above 6 MΩ at 170°C, thus, making them suitable as machine insulating materials for operations at temperatures not exceeding 170°C. Four of the wood species Aper, Danta, Iroko and Opepe had insulation reistance of 9 MΩ at 170°C. They are thus, more thermally stable and suitable wood insulating materials at the elevated temperature of 170°C than the other 6.
A.M.O. Obiazi, F.I. Anyasi and P.A. Otubu, 2009. Suitability of Nigerian Wood Species as Insulating Materials for High Temperature Machine Operations. Journal of Engineering and Applied Sciences, 4: 103-105.