1. Cable Rehabilitation Program By Lee Maurer Maintenance Planning SWEDE Conference April 26, 2011 - Bastrop, Tx (Second Responder Cable Treatment Program)

2. 1 27,000 Square Miles of Territory 3.2 Million Electric Service Points 3,000 Circuits Miles of Underground Primary  17,218 Cable Miles – URD  4,641 Cable Miles – Feeder  21,859 Total Miles. (Networks not included) Miles of Overhead Primary  10,608 Mainline Primary  13,026 3ø Non-Mainline  5,006 2ø Lines  27,212 Single Phase Lines  55,852 Total Miles Oncor System Overview 630 miles 390 miles 1 LM- Maintenance Planning

3. 2 Cable Components Tinned Copper Concentric Neutral Insulation Shield XLPE or HMWPE Insulation Conventional Conductor Shield Aluminum Conductor LM- Maintenance Planning Aluminum Conductor (Strand-filled) Jacket Bare Copper Concentric Neutral Insulation Shield TRXLPE Insulation Super Smooth Conductor Shield Pre-1990Since 1990

4. 3 Previous specification cable Current specification cable Primary Underground Cable (Network Excluded)

5. 4 Primary Cable Faults LM- Maintenance Planning

6. 5 Cable Rehabilitation Program - Background  System wide maintenance plan (Second Responder) for extending the life of aging infrastructure  Pre-1993 PE cable issues  8,000 cable miles – Pre-1993 PE cable –7,000 cable miles – URD –1,000 cable miles – Feeder  Cable Manufacture 1980 - 1995 –General Cable, Hendrix, Pirelli (Now Prysmian), Southwire  Capital Rehabilitation method for aged cable –235 cable miles rehabilitated (By Utilx)  Cost effective alternative to replacement of cable  Additional 600 cable miles rehabilitated in other programs LM- Maintenance Planning

7. 6 Second Responder Process When a cable faults, the troubleman (first responder) determines if the cable is loop fed and if the faulted cable can be switched out. Padmount Transformer Pole Riser Normal Open Point Fault Isolated Faulted Cable LM- Maintenance Planning

8. 7 Second Responder Process (cont’d)  If the cable can be switched and service restored to the customers, the location of the faulted cable is sent to Oncor Program Services.  Program Services will then schedule a Utilx cable repair/rehabilitation crew to the cable.  The crew will attempt to repair and inject the cable with rehabilitation fluid. LM- Maintenance Planning

9. 8 2nd Responder Process  4,291 sections of failed cables came through the process since 2008 –65% were able to be injected successfully.  235 cable miles have been rehabilitated using 2nd responder process since 2008. LM- Maintenance Planning

10. 9 Business Comparison  Cable Repair - Splicing $ X –O&M Cost –Same old cable  Rehabilitation of Span $ 4X –Capitalized Cost –Added 20+ years of life  New Cable (Bore) $ 15X –Capitalized Cost –New 40+ year asset LM- Maintenance Planning

11. 10 Business Considerations that Prevent Rehabilitation  Cable installed in conduit (except preventative)  Corroded concentric neutral of 25% or less remaining  The faulted cable section must not have been de- energized more than six months.  There cannot be more that one joint per 100 feet of cable. (Business Case)  Other Technical Reasons –Butyl rubber cable –Cable with tape conductor shield –Loss of insulation shield conductivity –Insulation shield with no adhesion LM- Maintenance Planning

12. 11 Questions Oncor Contacts Lee Maurer Senior Manager Maintenance Planning 817-215-6128 lee.maurer@oncor.com Mark Darilek Project Manager Maintenance Planning 817-215-6809 mark.darilek@oncor.com Richie Harp Consulting Engineer Distribution Standards 817-215-6008 rharp@oncor.com Fort Worth, TX Mike Sulak Program Manager Operations/Program Services 817-215-6151 michael.sulak@oncor.com