A tale of two fluids

For over 3 decades cable rejuvenation using dialkoxysilane fluids has been the method of choice to prevent cable failure due to aging. Early generations of rejuvenation fluids primarily consisted of phenylmethyldimethoxysilane (PM) and a catalyst. In 2006 a second generation of rejuvenation formulations was introduced. These second generation materials consist of mixtures of tolylethylmethyldimethoxysilane (TEM) and cyanoalkylmethyldimethoxysilane (CAM), along with an improved catalyst. These new formulations include antioxidants, hindered amine light stabilizers, ultraviolet absorbers, and ferrocene to address multiple modes of cable insulation degradation. A decade after the introduction of a second generation, it is now possible to compare historical failure frequency of cables rejuvenated with first and second generation fluids. The second generation enjoys post-injection reliability twice that of commercially successful first generation PM. The work presented in this paper highlights the advancements made in rejuvenation technologies over the past decade.