1、 Approved as an American National Standard ANSI Approval Date: December 18, 2012 Insulated Cable Engineers Association, Inc. Publication No. ICEA S-93-639 NEMA Standards Publication No. WC 74-2012 5-46kV Shielded Power Cable for Use in the Transmission and Distribution of Electric Energy Prepared an
2、d Sponsored by: Insula te d Cable Engineers Associa tion , Inc. P.O. Box 1568 Carrollton, Georgia 30112 Published by: National Electrical Manufacturers Association 1300 North 17th Street Rosslyn, Virginia 22209 www.nema.org Copyright 2012 by the National Electrical Manufacturers Association and the
3、 Insulated Cable Engineers Association, Incorporated. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions.ANSI/NE
4、MA WC 74/ICEA S-93-639-2012 Page ii Copyright 2012 by National Electrical Manufacturers Association and the Insulated Cable Engineers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and appr
5、oval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document. The National Electrical Manufacturers Association (NEMA) and the Insulated Cable Engineers Association (ICEA)
6、 standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together persons who have an interest in the topic covered by this publication. While NEMA and ICEA administers the pro
7、cess and establishes rules to promote fairness in the development of consensus, they do not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in its standards and guideline publications. NEMA and ICEA disclaims liabili
8、ty for personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA and ICEA disclaims and makes no guaranty or warranty,
9、 expressed or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA and ICEA do not undertake to guarantee the performance of any individua
10、l manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA and ICEA are not undertaking to render professional or other services for or on behalf of any person or entity, nor are NEMA and ICEA undertaking to perform any
11、duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. Information and other standards
12、on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA and ICEA have no power, nor do they undertake to police or enforce compliance with the contents of this document.
13、 NEMA and ICEA do not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safety-related information in this document shall not be attributable to NEMA and ICEA and is solely the responsibi
14、lity of the certifier or maker of the statement. ANSI/NEMA WC 74/ICEA S-93-639-2012 Page iii Copyright 2012 by National Electrical Manufacturers Association and the Insulated Cable Engineers Association CONTENTS Page SECTION 1 GENERAL .1 1.1 SCOPE. 1 1.2 GENERAL INFORMATION 1 1.3 INFORMATION TO BE S
15、UPPLIED BY PURCHASER. 1 1.3.1 Characteristics of System on Which Cable is to be Used 1 1.3.2 Quantities and Description of Cable 2 1.4 DEFINITIONS AND SYMBOLS. 2 SECTION 2 CONDUCTOR5 2.1 PHYSICAL AND ELECTRICAL PROPERTIES 5 2.1.1 Copper Conductors.5 2.1.2 Aluminum Conductors .5 2.2 OPTIONAL WATER BL
16、OCKING COMPONENTS FOR STRANDED CONDUCTORS 6 2.3 CONDUCTOR SIZE UNITS 6 2.4 CONDUCTOR DC RESISTANCE PER UNIT LENGTH . 6 2.4.1 Direct Measurement of dc Resistance6 2.4.2 Calculation of dc Resistance Per Unit Length6 2.5 CONDUCTOR DIAMETER 7 SECTION 3 CONDUCTOR SHIELD (STRESS CONTROL LAYER) . 13 3.1 MA
17、TERIAL .13 3.2 PHYSICAL REQUIREMENTS .13 3.3 ELECTRICAL REQUIREMENTS .13 3.3.1 Extruded Semiconducting Material 13 3.3.2 Extruded Nonconducting Material (For EPR Insulation Only) . 13 3.3.2.1 Withstand Test. 13 3.3.3 Semiconducting Tape . 14 3.4 CROSSLINKED (THERMOSET) REQUIREMENTS 14 SECTION 4 INSU
18、LATION 15 4.1 MATERIAL .15 4.2 INSULATION THICKNESS .16 4.2.1 Selection of Proper Thickness 16 4.3 INSULATION REQUIREMENTS 16 SECTION 5 INSULATION SHIELDING 22 5.1 SHIELDING OF INSULATED CABLE22 5.1.1 Insulation Shield. 22 5.2 REMOVABILITY OF INSULATION SHIELD .23 5.2.1 Discharge-Free Cable Designs
19、With Extruded Insulation Shields . 23 5.2.2 Discharge-Resistant Cable Designs With Extruded Insulation Shields 23 SECTION 6 METALLIC SHIELDING (SEE APPENDIX G) 26 6.1 GENERAL26 6.2 METAL TAPES .26 6.2.1 Helically Applied Tape(s) . 26 6.2.2 Longitudinally Applied Corrugated Tape. 26 6.3 COPPER WIRES,
20、 STRAPS, SHEATH OR ARMOR 26 6.4 MULTIPLE-CONDUCTOR CABLES .27 SECTION 7 COVERINGS 28 7.1 JACKETS.28 ANSI/NEMA WC 74/ICEA S-93-639-2012 Page iv Copyright 2012 by National Electrical Manufacturers Association and the Insulated Cable Engineers Association 7.1.1 Crosslinked and Thermoplastic Jackets - G
21、eneral . 28 7.1.2 Neoprene, Heavy-Duty Black (CR-HD) 28 7.1.3 Neoprene, General Purpose (CR-GP). 28 7.1.4 Polyvinyl Chloride . 28 7.1.5 Low and Linear Low Density Polyethylene (LDPE III can be used in either the “DISCHARGE-FREE” design or the “DISCHARGE-RESISTANT” design; IV is for use only in cable
22、s of the “DISCHARGE-RESISTANT“ design. All of the insulations are suitable for use on cables in wet or dry locations at voltages 5 through 46 kV between phases at the 100, 133 and 173 percent insulation level. The conductor temperature shall not exceed the following: Table 4-1 CONDUCTOR MAXIMUM RATE
23、D TEMPERATURES Insulation Material Normal Operation Emergency Overload* Short Circuit* XLP E , TRXLP E , and EPR Classes I, II & IV 90 qC 130 qC 250 qC XLPE Class III, TRXLPE Class III & EPR Class III 105 qC* 140 qC 250 qC * See Appendix B * Lower temperatures for normal operation may be required be
24、cause of the type of material used in the cable joints and terminations or because of cable environmental conditions. Cable users should be aware that all of the jackets described in Section 7 are not necessarily suitable for cables having this maximum temperature rating. Consult cable manufacturer
25、for further information. * Conductor fault current shall be determined in accordance with ICEA P-32-382. Other insulation materials composed of Ethylene and Alkene units, which are designated as EAM, may be available and can meet the same physical and electrical requirements as the insulation materi
26、als described in this standard. See Appendix J and/or contact the manufacturer for further information. ANSI/NEMA WC 74/ICEA S-93-639-2012 Page 16 Copyright 2012 by National Electrical Manufacturers Association and the Insulated Cable Engineers Association 4.2 INSULATION THICKNESS The insulation thi
27、cknesses given in Table 4-4 are based on the rated circuit voltage, phase-to-phase, conductor size and on the cable insulation level. The minimum thickness and maximum thickness of the insulation shall be as specified in Table 4-4. (See 9.2.2 for method of measurement.) For identification, nominal t
28、hicknesses are shown in Section 8 Table 8-3. 4.2.1 Selection of Proper Thickness The thickness of insulation for various systems shall be determined as follows: 4.2.1.1 For Three-Phase Systems with 100, 133 or 173 Percent Insulation Level Use the thickness values given in the respective columns of T
29、able 4-4. 4.2.1.2 For Delta Systems Where One Phase May Be Grounded For Periods Over One Hour Use the 173 percent thickness values given in Table 4-4. Also, see the 173 percent level note following Table 4-4. 4.2.1.3 For Single- and Two-Phase Systems with 100 Percent Insulation Level Multiply the vo
30、ltage to ground by 1.73 and use the resulting voltage value or next higher rating to select the corresponding insulation thickness in the 100 percent insulation level column of Table 4-4 4.2.1.4 For Single- and Two-Phase Systems with 133 Percent Insulation Level Multiply the voltage to ground by 1.7
31、3 and use the resulting voltage value or next higher rating to select the corresponding insulation thickness in the 133 percent insulation level column of Table 4-4. 4.3 INSULATION REQUIREMENTS Insulations used in both DISCHARGE-FREE and DISCHARGE-RESISTANT cable designs are described in 4.3.1. 4.3.
32、1 Physical and Aging Requirements When tested in accordance with Section 9, the insulation shall meet the requirements given in Table 4-2: ANSI/NEMA WC 74/ICEA S-93-639-2012 Page 17 Copyright 2012 by National Electrical Manufacturers Association and the Insulated Cable Engineers Association Table 4-
33、2 INSULATION PHYSICAL REQUIREMENTS Physical Requirements Insulation Type XLPE and TRXLPE XLPE Class III and TRXLPE Class III EPR Class I II III IV Unaged Requirements Tensile Strength, Minimum Psi (MPa) 1800 (12.5) 700 (4.8) 1200 (8.2) 700 (4.8) 550 (3.8) Elongation at Rupture, Minimum Percent 250 2
34、50 Aging Requirements After Air Oven Aging for 168 hours Aging Temperature, qC 1 qC 121 136 121 136 121 Tensile Strength, Minimum Percentage of Unaged Value 75 75 80 75 Elongation, Minimum Percentage of Unaged Value Minimum Percent at Rupture 75 - 75 - 80 - 75 - - 175 Hot Creep Test at 150 qC 2 qC U
35、nfilled Filled *Elongation, Maximum Percent 175 100 50 *Set, Maximum Percent 10 5 5 *For XLPE and TRXLPE insulations if this value is exceeded, the Solvent Extraction Test (see 9.11) may be performed and will serve as a referee method to determine compliance (a maximum of 30 percent weight loss afte
36、r 20 hours drying time). 4.3.2 Electrical Requirements 4.3.2.1 Partial-Discharge Extinction Level for Discharge-Free Designs Only. (See 9.8.2) Each length of completed cable shall be subjected to a partial discharge test. For cables shielded with a nonmetallic semiconducting layer extruded directly
37、over the insulation, the partial discharge shall not exceed 5 picocoulombs at the ac test voltage given in Table 4-4 or 4-4 (Metric). For cables shielded with a semiconducting coating and a semiconducting tape, the partial discharge shall not exceed 5 picocoulombs at the ac test voltage given in Tab
38、le 4-3: ANSI/NEMA WC 74/ICEA S-93-639-2012 Page 18 Copyright 2012 by National Electrical Manufacturers Association and the Insulated Cable Engineers Association Table 4-3 PARTIAL DISCHARGE REQUIREMENTS FOR SEMICONDUCTING COATING AND TAPE DESIGNS ONLY Rated Circuit Voltage, Phase to Phase, Volts Mini
39、mum Partial Discharge Extinction Level, kV 100% Insulation Level 133% Insulation Level 173% Insulation Level 2001-5000 4 5*6 5001-8000 6 8 10 8001-15000 11 15 18 * Unless otherwise indicated, the cable will be rated at the 100% insulation level. 4.3.2.2 Discha rge (Corona ) Re sista nce for Discha r
40、ge -Re sista nt De signs Only. (See 10.4) The insulation shall be verified as corona discharge resistant using a 21 kV 60 Hz voltage applied for 250 hours. No failure or surface erosion visible with 15 times magnification shall occur. Partial discharge measurements are not required for DISCHARGE-RES
41、ISTANT cables. 4.3.2.2.3 Voltage Tests (See 9.8.1) Each length of completed cable shall withstand, without failure, the ac test voltages given in Table 4-4. The test voltage shall be based on the rated voltage of the cable and the size of the conductor. Factory dc testing is not required by this spe
42、cification. However, a dc test may be performed with prior agreement between the manufacturer and the purchaser. Suggested dc test voltages are listed in Appendix D. 4.3.2.4 Accelerated Water Absorption Test, Electrical Method at 60 Hz (See 10.1.) When tested in accordance with T-27-581, the insulat
43、ion shall meet the applicable requirements given in Table 10-1. 4.3.2.5 Insulation Resistance (See 10.2.) Each insulated conductor in the completed cable shall have an insulation resistance not less than that corresponding to a constant of 20,000 megohms-1000 feet at 15.6C. ANSI/NEMAWC74/ICEAS-93-63
44、9-2012 Page 19 2012 byNationalElectricalManufacturersAssociation and the Insulated Cable EngineersAssociationTable4-4CONDUCTORSIZES,INSULATIONTHICKNESSESAND TESTVOLTAGESRatedCircuitVoltage,Phase-to-PhaseVoltageaConductorSize,(AWGorkcmil)bInsulationThickness(mils)a-cTestVoltage,kVd100 Percent Levelc1
45、33 Percent Levelc173 Percent Levelc100 %InsulationLevel133 %InsulationLevel173 %InsulationLevelMinimumMaximumMinimumMaximumMinimumMaximum2001-5000 8-1000e85120851201351701818 28 1001-3000 1351701351701351702828 28 5001-8000 6-1000 1101451351701652052328 35 1001-3000 1652051652052102503535 44 8001-15
46、000 2-1000 1652052102502452903544 52 1001-3000 2102502102502452904444 52 15001-25000 1-3000 2452903053504004505264 84 25001-28000 1-3000 2653103303754254955669 89 28001-35000 1/0-3000 3303754004605506306984 11635001-46000 4/0-3000 425495550630* * 89116150ANSI/NEMAWC74/ICEAS-93-639-2012 Page 20 Copyr
47、ight2012 byNationalElectricalManufacturersAssociation and the Insulated Cable EngineersAssociationTable 4-4(Metric)CONDUCTORSIZES,INSULATIONTHICKNESSESAND TESTVOLTAGESRatedCircuitVoltage,Phase-to-PhaseVoltageaConductor Size,(mm2)bInsulation Thickness,(mm)a-c TestVoltage,kVd100 Percent Levelc133 Perc
48、ent Levelc173 PercentLevelc100 %InsulationLevel133 %InsulationLevel173 %InsulationLevelMinimumMaximumMinimumMaximumMinimumMaximum2001-5000 8.37-506.7e2.16 3.05 2.16 3.05 3.43 4.32 18 18 28 506.8-1520 3.43 4.32 3.43 4.32 3.43 4.32 28 28 28 5001-8000 13.3-506.7 2.79 3.68 3.43 4.32 4.19 5.21 23 28 35 5
49、06.8-1520 4.19 5.21 4.19 5.21 5.33 6.35 35 35 44 8001-15000 33.6-506.7 4.19 5.21 5.33 6.35 6.22 7.37 35 44 52 506.8-1520 5.33 6.35 5.33 6.35 6.22 7.37 44 44 52 15001-25000 42.4-1520 6.22 7.37 7.75 8.89 10.12 11.4 52 64 84 25001-28000 42.4-1520 6.73 7.87 8.38 9.53 10.80 12.6 56 69 89 28001-35000 53.5-1520 8.38 9.53 10.2 11.7 13.97 16.0 69 84 116 35001-46000 107.2-1520 10.8 12.614.0 16.0 * * 89 116 150 Noteson Table 4-4 &4-4 (Metric):a The actualoperatingvoltageshallnotexceedthe rated circuitvoltage bymorethan(a)5 percentduring co
