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William S. Temple General Cable, BICC Brand Utility Cables October 30, 2002

ICC Educational Program The Evolution of Medium Voltage URD Power Cable Manufacturing, Materials & Materials Handling. William S. Temple General Cable, BICC Brand Utility Cables October 30, 2002. PE & HMWPE Insulation. Thermoplastic Material 70°C Continuous Operating Temperature Rating

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William S. Temple General Cable, BICC Brand Utility Cables October 30, 2002

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  1. ICC Educational ProgramThe Evolution ofMedium Voltage URD Power CableManufacturing, Materials & Materials Handling William S. Temple General Cable, BICC Brand Utility Cables October 30, 2002

  2. PE & HMWPE Insulation • Thermoplastic Material • 70°C Continuous Operating Temperature Rating • Poor Thermal Overload Performance • Translucent (Ease of Monitoring Compound & Cable) • Few Ingredients  Lower Contaminant Risk • Undisputed Excellent Electric Properties • Utilized by France into 1990’s for cables up to 400kV

  3. XLPE Insulation • Thermosetting (Cross-Linked) Material • 90°C Continuous and 130°C Emergency Operating Temperature Ratings (105°C/140°C Class 3 Available) • Translucent (Ease of Monitoring Compound & Cable) • Few Ingredients  Lower Contaminant Risk • Low Dielectric Losses & High Dielectric Strength • Continues to be the predominant insulation used outside North America for cables rated 5 to 500kV

  4. TRXLPE Insulation • Thermosetting (Cross-Linked) Material • 90°C Continuous and 130°C Emergency Operating Temperature Ratings (105°C/140°C Class 3 Available) • Translucent (Ease of Monitoring Compound) • Few Ingredients  Lower Contaminant Risk • Low Dielectric Losses & High Dielectric Strength • Good Tree Retardant Properties • Reduction of Water Tree Growth • Retention of Dielectric Strength • Predominant insulation utilized in North America for Medium Voltage cables; very little use outside NA

  5. EPR Insulation • Thermosetting (Cross-Linked) Material • 90°C Continuous and 130°C Emergency Operating Temperature Ratings (105°C/140°C Class 3 Available) • Compared to XLPE/TRXLPE • Greater Flexibility; Lower Thermal Expansion; & Higher Dielectric Losses • Good Tree Retardant Properties • Reduction of Water Tree Growth • Retention of Dielectric Strength • Second most utilized insulation in United States for Medium Voltage cables; little use outside US. Predominant insulation utilized in US for industrial cables.

  6. MV URD Power Cables1960’s - 1970’s • PE, HMWPE & XLPE Insulation Predominant • Unclean Insulating Materials & Handling Practices • Semi-conducting Tape to Extruded Conductor Shields • Imperfections at Conductor Shield/Insulation Interface • Semi-conducting Tape to Extruded Insulation Shields • Thermoplastic to Thermosetting Extruded Insulation Shields • Poor Insulation Shields Adhesion & Stripping Properties • Imperfections at Insulation Shield/Insulation Interface • Direct Buried Unjacketed Concentric Neutral Cables • Cable Handling & Installation Damage • Concentric Neutral Corrosion (Bare & Tinned) • Water in Conductor & Outside Cable (Water Trees Flourish) • Single Head to Dual Head Extrusion Process Technology

  7. MV URD Power Cables1980’s - 2000’s • TRXLPE & EPR Insulation Predominant • Cleaner Insulating Materials & Handling Systems • Semi-conducting Extruded Conductor Shields • Smoother & Cleaner Extruded Conductor Shields • Few Imperfections at Conductor Shield/Insulation Interface • Semi-conducting Extruded Insulation Shields • Improved Extruded Insulation Shield Stripping Properties • Few Imperfections at Insulation Shield/Insulation Interface • Jacketed (Encapsulated LLDPE) Concentric Neutral Cables • Increased Care During Cable Handling & Installation • Direct Buried Predominant; Increased Use of Conduit • Water Blocked Cable Designs (Conductor & Cable Core) • Tandem to True Triple Head Extrusion Process Technology

  8. Old Material Handling Systems Insulation and semi-conducting shield materials were originally introduced to the cable manufacturing process with very basic material handling systems.

  9. Cleaner Materials Manufacturing Clean Raw Material Storage Dedicated Continuous Mixers Computerized Control Systems Trickle Sample Inspections

  10. Cleaner Materials Packaging & Inspection Extruded Tape Inspections Dedicated Clean Room Material Packaging Clean & Uniform EPR Pellets

  11. Cleaner Material Handling Systems Insulation and semi-conducting shield materials are introduced to cable manufacturing process with dedicated filtered transfer lines from the unloading point to the extruder. TRXLPE Bulk Delivery Class 10,000 Clean Box Class 10,000 Clean Room

  12. Optical TRXLPE Pellet Inspection Availability of 100% optical inspection for TRXLPE insulation material which rejects rejects speck damage and foreign material. High Resolution Cameras & Ejectors Optical Pellet Inspection Unit Example Contaminated Pellet

  13. MV URD Power Cable Manufacturing • 1960’s - 1970’s • Lower Level of Awareness • Process Issues • Material Technology & Cleanliness • Single & Dual Head Extrusion Technology • Simplistic Equipment Control Systems • 1980’s - 2000’s • Improved Material Performance • Clean Rooms & Enclosed Material Handling • Tandem to True Triple Head Extrusion; Steam to Dry Cure • Equipment Control Systems Computerized & Automated • Statistical Process Control • Weigh Loss Feeder Control • In-Line Dimensional Measurement & Control Dual Tandem (1+2) Triple Extrusion True Triple (3-in-1) Extrusion

  14. Water Blocked Cable Designs Longitudinally Water Blocked Conductor meeting ICEA T-31-610 Longitudinally Water Blocked Cable meeting ICEA T-34-664

  15. Dimensional Measurements New Computerized Measuring System Old Manual Optical Comparitor Bad & Good Examples of Dimensions

  16. North American MV URD Extruded Cable Testing • AEIC Issues First Specifications to Supplement ICEA Standards in 1969; Regular Revisions Issued by ICEA and AEIC • Numerous Physical Tests Introduced and Refined • Dimensional Requirements Tightened on Extruded Layers • Void, Contaminants, Agglomerates & Gels Requirements Tightened • Limits on Protrusions from Extruded Semi-conducting Shields Tightened • ac Test Voltage Increased (5min@150v/mil to 5min@200V/mil) • PD Test from <80pC@150V/mil to <5pC@200V/mil • dc Voltage Test Included 1971; then Omitted in 1994 • Dimensional Stability replaced by Shrink Back Test • A single HVTT was expanded to a Qualification Test Procedure with Dry & Wet Aging (AWTT) Tests and multiple HVTT’s & Impulse Tests • Structural Stability replaced by CV Extrusion Test (HVTT & %DF) • ICEA & AEIC work jointly in UPSTAC to combines (TR)XLPE & EPR into New ICEA Cable Design Standards; AEIC issues New Specification to supplement New ICEA Standards • Accelerated Cable Life Tests (ACLT’s) have demonstrated Improved Cable & Material Performance through the years; New IEEE 1407 Tank Testing Guide Issued

  17. Cable Improvements Demonstrated by the Tank Test (ACLT) • Insulation • XLPE over Thermoplastic PE • TR Thermoplastic over Thermoplastic PE • EPR over XLPE • TRXLPE over XLPE • Semi-conducting Shields • Supersmooth over Conventional Conductor Shield • Process • 3-in-1 True Triple over 1+2 Triple Tandem Extrusion • Insulation & Shield Material Cleanliness • Design • Filled over Unfilled Conductor Strand • Jacketed over Unjacketed Cable

  18. Breakdown Strength of XLPE Cables with Unfilled versus Filled Conductors over Time Breakdown Strength Filled Conductor Unfilled Conductor Time 3Vg & 75°C ACLT on #1/0(19) Al 0.175” XLPE 15kV Cables Filled Conductors Filling the conductor strands to prevent the ingress of moisture extends cable life. Accelerated Cable Life Test (ACLT) data on XLPE provides a basis of similar comparative relationships for TRXLPE.

  19. ACLT Performance of XLPE Cables with Conventional & Supersmooth Conductor Shields Supersmooth Conventional 0 Time 4Vg & 90°C ACLT on #2(7) Al 0.175” XLPE 15kV Cables Supersmooth Conductor Shields ACLT results have shown that XLPE insulation with a supersmooth shield last more than two times longer than those with a conventional shield

  20. ACLT Performance of XLPE & TRXLPE Cables with Conventional Conductor Shields over Time 1990's CCS/XLPE 1980's CCS/TRXLPE 0 Time 4Vg & 90°C ACLT on #2(7) Al 0.175” 15kV Cables Insulation Improvement Over Time Over the past three decades, major improvements have been made in cable design and manufacture. These improvements include: newly formulated and cleaner manufactured raw materials; advanced extrusion technology and machinery; improved manufacturing process techniques/systems; and more stringent process and product qualification testing. The result is that today's state-of-the-art Tree Retardant Cross-Linked Polyethylene cable is significantly better than earlier designs. Testing has shown that TRXLPE designs last more than three times longer than XLPE designs.

  21. Operating Temperature versus Cable Life Relative Time to Failure 60°C 75°C 90°C TRXLPE EPR Weibull Statistical Data Insulation Operating Temperature Research data has shown that cable life is directly related to operating temperature - high operating temperatures shorten cable life. The amount of cable life lost differs between unfilled and filled insulations. Compelling test results support the position that filled insulations are better for high temperature applications.

  22. Jackets Industry data shows a significant reduction in cable failure rate as a result of using an overall jacket. As reported field data indicates, the desirability of a jacket is obvious. AEIC data from IEEE/PES ICC Task Group 5-24.

  23. Technical OverviewConclusions Based on Extensive Testing • Properly Designed & Manufactured TRXLPE & EPR Insulated Cables Provide a Long & Reliable Service Life • Blocked Conductors Significantly Increase Cable Life • Supersmooth Shields further Enhance Cable Life in TRXLPE • EPR Retains Physical Strength better than TRXLPE Under Elevated Operating Temperatures • Jackets & Proper Installation are Vital to Ensuring Long Term Reliability

  24. Select the URD Power Cable Designfor the Application • Solid or Filled Conductors • Smooth Semi-conducting Shields • TRXLPE • Normal Operating Temperature Applications • Lower purchase cost & operating expenses • Lighter weight  longer cable runs • EPR • High Operating Temperature Applications • Urban underground network systems installed in conduit or duct banks • Underground primary feeders and substation getaways • Larger conductor sizes where added flexibility may be desirable • Encapsulating Insulated Jacket

  25. THANK YOUQuestions?

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