Underground Medium-Voltage Cable Rejuvenation—Part II: Pilot Projects in the Field

The present study, the second of three parts, deals with pilot projects performed on the rejuvenation of 28-kV extruded cables. Thirteen triplexed XLPE cable sections, with 500- or 750-kcmil compact conductors, on two distinct lines 1 and 1.2 km in length installed in a duct system, have been injected with silicone by a service provider. The main objective of this second part is to validate the applicability of the silicone injection technique, focusing primarily on the method to implement the technique. It was found that the silicone injection technique can be successfully used in a conduit system applying the injection by cable section, although silicone leaking occurred at some cable ends. Furthermore, the double injection method was found to be less time consuming compared to an injection done by cable section, and particularly to an injection done by line.