Ageing studies on RTV coated insulator in salt-fog pollution

It is well known that pollution causes problems to the transmission systems. Many remedial measures were applied to minimise the problem than containing it. Application of room temperature vulcanizing (RTV) silicone rubber coating on porcelain insulators inherits the property of hydrophobicity and enhances the pollution performance of the insulator. To date, there is no ageing test procedure evolved in the laboratory which can reasonably duplicate the field conditions. Though various groups have conducted tests, no test procedure of one group matches with the other one and also the correlation with the field values was not considered. To supplement that gap the present research work is undertaken where in, at the first stage an exhaustive sixty hour ageing test, on eight RTV coated porcelain insulator samples, were conducted with differing test parameters viz, pressure, flow rate and salinity. The results of such studies, where the parameters were varied to arrive at the sensitivity of each parameter towards the ageing process, has been presented in this paper. The relevant test parameters which seem to show the ageing trends are almost similar to the published result of field ageing, are identified for the second stage. The results of first stage only are discussed which will be useful for development of improved laboratory ageing test procedure and to evaluate RTV coated insulators performance in contaminated conditions.