Silicone Gel-Injection: Extending the Life of Secondary Service Cable

Secondary (service) cables operate at less than 600V and form the last link in the power grid by interconnecting the distribution transformer to the end user's service meter. For many utilities with underground services, failures on this class of cable are on the rise and account for over half of their total cable-failure count. Traditionally, utilities would be faced with a decision to create a replacement program or continue to make ad-hoc repairs. This paper introduces silicone-gel injection as a third option for utilities to consider. Silicone-gel injection is an effective solution for increasing the reliability of aged secondary (service) type cables. The injection of silicone-gel purges water from the conductor and forms a physical barrier against water intrusion that protects the conductor from corrosion. Silicone-gel injection is a non-invasive solution that causes minimal disruption to neighborhood homes and businesses. Compared to the alternatives, silicone-gel injection is cost effective and can easily be integrated into reliability programs as a capitalized expense.