UG Power Cable longevity

Since its introduction 20 years ago, water-tree retardant crosslinked polyethylene (TR-XLPE) from Dow Wire & Cable has rapidly replaced conventional XLPE to become the preferred medium voltage (5-46 kV) insulation for primary underground distribution cables in North America. Usage of Dow’s TR-XLPE continues to grow in Mexico, Latin America and Asia as well. Electric utilities often specify TR-XLPE rather than any other insulation due to its proven long life and lowest total cable life cycle cost. And, HFDB-4202 NT EC** made by Dow has exhibited excellent field experience for underground residential distribution (URD), underground distribution (UD), and feeder applications.

Over the past 20 years, advances in cable materials, manufacture and design, together with utility operation practices have further improved the performance of medium voltage (MV) underground distribution cables. The EPRI Digest acknowledges that current MV underground cable designs insulated with TR-XLPE insulation compound for MV applications, have an expected service life of more than 40 years.

A study covering the 20-year history of Dow’s TR-XLPE has been performed. It reviews the pertinent electrical and physical properties of HFDB-4202 NT EC from the time of its introduction to the present. Included are dielectric loss properties and performance in a wide variety of independent accelerated material and cable aging tests conducted under the full range of cable operating conditions. A technical paper on this study delivered at the May 2003 Rural Electric Power Conference (REPC) in North America is also available. To order a copy of the paper, fill out our Contact Us form and select the “20-year history of Dow TR-XLPE Technical Paper."

In addition, several evaluations of field-aged cables were reviewed to demonstrate and confirm the long life attributes of TR-XLPE. Most of the data presented were generated by independent laboratories and organizations such as CTL, EPRI, NRECA and NEETRAC, and in many cases, sponsored by various electric utilities and cable manufacturers.

Also included are the results of an in-depth study conducted with the Southern Company, NEETRAC and Dow at the Galleria Mall in Alabama, USA. Among the project objectives was a comparison between the performance of the TR-XLPE and EPR (ethylene propylene rubber) cables serving the mall – both installed in 1985. To order a copy of a technical paper focusing specifically on the Galleria Mall project, delivered at the 2003 Jicable exposition in Paris, France, fill out our Contact Us form and select the “Galleria Mall TR-XLPE and EPR Performance Comparison Technical Paper.”

Overall, the study concludes that MV underground distribution cables insulated with HFDB-4202 NT EC from Dow Wire & Cable have low initial cable cost, low operating cost (due to low dielectric loss) and longer service life, thus providing electric utilities the lowest total cable life cycle cost and the highest value. To request an electronic copy of the full report, fill out our Contact Us form and select the “Galleria Mall Full Report.”

Acronyms
CLT: Cable Testing Laboratories
EPRI: Electric Power Research Institute
NRECA: National Rural Electric Cooperative Association
NEETRAC: The National Electric Energy Testing Research and Applications Center


**Note that Dow’s TR-XLPE compound is available in all regions but may have a slightly different product number in one region versus another.