120 likes | 285 Views
Cable Rehabilitation Program. (Second Responder Cable Treatment Program). By Lee Maurer Maintenance Planning. SWEDE Conference April 26, 2011 - Bastrop, Tx. Oncor System Overview. 630 miles. 27,000 Square Miles of Territory 3.2 Million Electric Service Points 3,000 Circuits
E N D
Cable Rehabilitation Program (Second Responder Cable Treatment Program) By Lee Maurer Maintenance Planning SWEDE ConferenceApril 26, 2011 - Bastrop, Tx
Oncor System Overview 630 miles • 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 390 miles 1 LM- Maintenance Planning
Aluminum Conductor Insulation Shield Jacket Super Smooth Conductor Shield TRXLPE Insulation XLPE or HMWPE Insulation Insulation Shield Tinned Copper Concentric Neutral Bare Copper Concentric Neutral Conventional Conductor Shield Cable Components Pre-1990 Since 1990 Aluminum Conductor (Strand-filled) LM- Maintenance Planning
Primary Underground Cable (Network Excluded) Current specification cable Previous specification cable
Primary Cable Faults LM- Maintenance Planning
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
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
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
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
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
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
Questions OncorContacts Lee MaurerSenior Manager Maintenance Planning817-215-6128 lee.maurer@oncor.com Mark Darilek Project ManagerMaintenance Planning817-215-6809 mark.darilek@oncor.com Richie Harp Consulting EngineerDistribution Standards817-215-6008rharp@oncor.com Mike Sulak Program ManagerOperations/Program Services817-215-6151 michael.sulak@oncor.com Fort Worth, TX