Oklahoma Gas & Electric Underground Cable Failure Data ...

1 Oklahoma Gas & Electric Underground Oklahoma Gas & Electric Underground Cable Failure data Base and Failure RatesCable Failure data Base and Failure RatesbybyDale T MetzingerDale T MetzingerOklahoma Gas and Electric Gas and Electric at thePresented at theIEEE/ICC Education Program Statistical IEEE/ICC Education Program Statistical analysis of URD Cable Failures analysis of URD Cable Failures November 3, 2004 November 3, 2004 ContentsContents OG&E UG Distribution SystemOG&E UG Distribution System Why collect data on Cable Failures?Why collect data on Cable Failures? Brief Overview of OG&E (FACTS) Overview of OG&E (FACTS) database. analysis of 15kV URD Cable Failures analysis of 15kV URD Cable Failures Collected by the RealCollected by the Real--time Database.

2 GEMS View FACTS as a Decision ToolGEMS View FACTS as a Decision Tool Additional Results from the RealAdditional Results from the Real--time time Database FACTS Database FACTS ConclusionsConclusionsOG&E UG Cable Distribution System?OG&E UG Cable Distribution System? ,000 Segments of Underground Primary 60,000 Segments of Underground Primary Cable . Present Growth approx. to 4% Cable . Present Growth approx. to 4% A A SegmentSegmentis that is that length of Cable that length of Cable that connects two devices connects two devices Riser disconnect to a transformer,Riser disconnect to a transformer, Transformer to transformer, orTransformer to transformer, or Transformer to switch cubicle, etc.

3 Transformer to switch cubicle, etc.) Average segment Length Average segment Length approximately 450 to 500 450 to 500 Cable , 35kV(URD Cable , 35kV(19841984--Present): 430 MilesPresent): 430 Miles Average of Average of failures/100 failures/100 miles/yearmiles/year This URD Cable will not be included in This URD Cable will not be included in remaining UG Cable Distribution System?OG&E UG Cable Distribution System?(Continued)(Continued) Cable , 15kVURD Cable , 15kV 2/C2/C--#2AL(Bare Conc. Neut.)#2AL(Bare Conc. Neut.)::15041504milesmiles(1970 to 1983/1984)(1970 to 1983/1984) 2/C2/C--#2AL(Conc. Neut. Jkt)#2AL(Conc. Neut. Jkt): : 528528milesmiles(1984 to Present)(1984 to Present) 2/C2/C--#0AL(Bare Conc.

4 Neut.)#0AL(Bare Conc. Neut.): : 398398milesmiles(1970 to 1983/1984)(1970 to 1983/1984) 2/C2/C--#0AL(Conc. Neut. Jkt)#0AL(Conc. Neut. Jkt): : 113113milesmiles(1984 to Present)(1984 to Present) 2/C2/C--#4CU & Others (Late 1960 s)*#4CU & Others (Late 1960 s)*: : 4242milesmiles*Not included in remainder of presentation.*Not included in remainder of and other Large cables at 15, 24, and 35kV Feeders and other Large cables at 15, 24, and 35kV will not be presented. Insufficient not be presented. Insufficient and other types of failures not included Accessories and other types of failures not included in this this Collect data on Cable FailuresWhy Collect data on Cable Engineering to assess Failure data Allows Engineering to assess Failure data coming from the field in order to change coming from the field in order to change or correct materials, construction or correct materials, construction standards and/or and/or use decisionCrews use decision--making tools that are making tools that are driven by the database ( loop trace in driven by the database ( loop trace in FACTS).

5 FACTS). collected from the field is Information collected from the field is used to correct data information in GEMS used to correct data information in GEMS and other other Overview of the OG&E Database: Brief Overview of the OG&E Database: FFailed ailed AAccessories and ccessories and CCable able TTracking racking SSystemystem FACTS is driven by the OG&E Graphical FACTS is driven by the OG&E Graphical Database (Oracle database). Database (Oracle database). OnOn--line yr2000line yr2000 data is collected from crews through reports data is collected from crews through reports (TD(TD--99 s).99 s). Reports are entered are entered daily. The realThe real--time database can be interrogated time database can be interrogated by Crews to assess URD cables through by Crews to assess URD cables through Trace Tools.

6 Trace Tools . Engineering can investigate both databases:Engineering can investigate both databases: RealReal--time (time (2697 records from year 1999 to 2697 records from year 1999 to presentpresent) ) Historical (Historical (3776 records dating back to 19923776 records dating back to 1992)) analysis of 15kV URD Cable Failures analysis of 15kV URD Cable Failures Note: data Collected by the RealNote: data Collected by the Real--time Databasetime DatabaseURD Cable , 15kV (Average for Years 2000 thru 2003)URD Cable , 15kV (Average for Years 2000 thru 2003) 2/C2/C--#2AL (Bare Conc. Neut.) (1970 to 1983/1984) #2AL (Bare Conc. Neut.) (1970 to 1983/1984) ::15041504miles,miles, failures/100 miles/Yrfailures/100 miles/Yr 2/C2/C--#2AL (Conc.)

7 Neut. Jkt) (1984 to Present)#2AL (Conc. Neut. Jkt) (1984 to Present): : 528528miles,miles, miles/Yrfailures/100 miles/Yr 2/C2/C--#0AL (Bare Conc. Neut.) (1970 to 1983/1984) #0AL (Bare Conc. Neut.) (1970 to 1983/1984) : : 398398miles,miles, miles/Yrfailures/100 miles/Yr 2/C2/C--#0AL (Conc. Neut. Jkt) (1984 to Present)#0AL (Conc. Neut. Jkt) (1984 to Present): : 113113miles,miles, *Average Failure rate as reported in 1994*Average Failure rate as reported in 1994: 48 utilities, : 48 utilities, * Cable Restoration and Replacement Practices in the * Cable Restoration and Replacement Practices in the presented by Richard L. Harp to the EEI T&D Meeting, Salt presented by Richard L.

8 Harp to the EEI T&D Meeting, Salt Lake City, Utah in October, 1994 Lake City, Utah in October, 1994 analysis of 15kV URD Cable FailuresAnalysis of 15kV URD Cable Failures2/C #2 Solid AL(1970 to 1984), 15kV, Bare Concentric Neutral Failures per Month01020304050607001/2000 Count03/2000 Count05/2000 Count07/2000 Count09/2000 Count11/2000 Count01/2001 Count03/2001 Count05/2001 Count07/2001 Count09/2001 Count11/2001 Count01/2002 Count03/2002 Count05/2002 Count07/2002 Count09/2002 Count11/2002 Count01/2003 Count03/2003 Count05/2003 Count07/2003 Count09/2003 Count11/2003 CountAnalysis of 15kV URD Cable FailuresAnalysis of 15kV URD Cable Failures2/C #2 Solid AL, 15kV, Concentric Neutral, Jacketed (1984 to Present)

9 Failures per Month012345601/2000 Count03/2000 Count06/2000 Count09/2000 Count02/2001 Count04/2001 Count06/2001 Count08/2001 Count11/2001 Count01/2002 Count03/2002 Count07/2002 Count10/2002 Count12/2002 Count02/2003 Count05/2003 Count07/2003 Count09/2003 Count11/2003 CountAnalysis of 15kV URD Cable FailuresAnalysis of 15kV URD Cable Failures2/C #0 Solid AL, 15kV, Bare Concentric Neutral (Yr. Manuf 1970 to 1984) Failures per Month024681012141601/2000 Count05/2000 Count07/2000 Count09/2000 Count11/2000 Count02/2001 Count04/2001 Count06/2001 Count08/2001 Count10/2001 Count01/2002 Count03/2002 Count05/2002 Count07/2002 Count09/2002 Count11/2002 Count03/2003 Count05/2003 Count07/2003 Count09/2003 Count11/2003 CountAnalysis of 15kV URD Cable FailuresAnalysis of 15kV URD Cable Failures2/C #0 Solid AL, 15kV, Concentric Neutral, Jacketed Cable , (Yr of Mfg 1984 to Present)

10 Failures Per Count05/2000 Count07/2000 Count09/2000 Count11/2000 Count06/2001 Count09/2001 Count03/2002 Count06/2002 Count08/2002 Count10/2002 Count08/2003 Count10/2003 CountGEMS View FACTS as a Decision ToolGEMS View FACTS as a Decision Tool((for Crews and Engineering)for Crews and Engineering) Allows crews or engineering to investigate every UG Allows crews or engineering to investigate every UG segment in the OG&E in the OG&E system. Before 1997,Before 1997, Crews were to replace URD halfCrews were to replace URD half--loops that had more than 2 loops that had more than 2 failures and;failures and; the complete loop if more than three complete loop if more than three failures.