1、Designation: D2656 06D2656 13 An American National StandardStandard Specification forCrosslinked Polyethylene Insulation for Wire andCable Rated 2001 to 35 000 V1This standard is issued under the fixed designation D2656; the number immediately following the designation indicates the year oforiginal
2、adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers a crosslinked polyethylene insulation for
3、 electrical wires and cables for conductor sizes 8 AWG(8.37 mm2) and larger. The base polymer of this insulation consists substantially of polyethylene.1.2 This type of insulation is suitable for use on power cables in wet and dry locations at conductor temperatures not exceeding90 C for continuous
4、operation, 130 C for emergency overload conditions, and 250 C for short-circuit conditions. It is consideredsuitable for all sizes and voltage classifications of single- and multiple-conductor power cables at voltage ratings of 2001 to 35 000V phase-to-phase at the 100 % insulation level and at volt
5、age ratings of 2001 to 25 000 V at the 133 % insulation level as listedin Table 1C of Test Methods D470.1.3 Materials covered by this specification are not sunlight- and weather-resistant unless they are carbon black pigmented orcontain an additive system designed for this protection.1.4 In many ins
6、tances the insulation cannot be tested unless it has been formed around a conductor. Therefore, tests are doneon insulated wire in this standard solely to determine the relevant property of the insulation and not to test the conductor orcompleted cable.1.5 Whenever two sets of values are presented,
7、in different units, the values in the first set are the standard, while those inparentheses are for information only.2. Referenced Documents2.1 ASTM Standards:2D470 Test Methods for Crosslinked Insulations and Jackets for Wire and CableD1248 Specification for Polyethylene Plastics Extrusion Material
8、s for Wire and CableD1711 Terminology Relating to Electrical InsulationD2765 Test Methods for Determination of Gel Content and Swell Ratio of Crosslinked Ethylene Plastics2.2 ICEA Standard:ICEA T-28-562 Test Method for Measurement of Hot Creep of Polymeric Insulation33. Terminology3.1 Definitions:3.
9、1.1 For definitions of terms used in this specification refer to Terminology D1711.3.2 Definitions of Terms Specific to This Standard:3.2.1 aging (act of), nexposure of materials to air at 121 C for 168 h.4. Physical Properties4.1 The requirements for the insulation are listed in Table 1.1 This spec
10、ification is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of SubcommitteeD 09.18D09.18 on Solid Insulations, Non-Metallic Shieldings,Shieldings and Coverings for Electrical and TelecommunicationsTelecommunication Wire
11、s and Cables.Current edition approved Oct. 1, 2006Nov. 1, 2013. Published October 2006November 2013. Originally approved in 1967. Last previous edition approved in 20002006as D2656 00.D2656 06. DOI: 10.1520/D2656-06.10.1520/D2656-13.2 For referencedASTM standards, visit theASTM website, www.astm.org
12、, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from The Insulated Cable Engineers Association, Inc. (ICEA), P.O. Box 1568, Carrollton, GA 30112, http:/.This docume
13、nt is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as ap
14、propriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United S
15、tates15. Electrical Requirements5.1 Order of TestingPerform the partial-discharge, ac voltage, insulation resistance, and dc voltage tests in that order whenany of these tests are specified. The sequence for other testing is not specified.5.2 Partial Discharge (Corona) Extinction VoltageEach length
16、of completed power cable with shielded conductors shallcomply with the minimum level specified in Table 2. Conduct the tests in accordance with Test Methods D470.5.3 AC Voltage TestSubject the wires and cables to an ac test voltage for a period of 5 min. Unless otherwise specified, omitthis test if
17、the dc voltage test described in 5.5 is to be performed. Test at a voltage of 125 V/mil (5 kV/mm) based on the specifiednominal thickness of insulation for the rated circuit voltage, phase to phase. Conduct the test in accordance with Test MethodsD470.5.4 Insulation ResistanceThe insulated conductor
18、 shall have an insulation resistance equal to or greater than thatcorresponding to a constant of 20 000 at 60 F (15.6 C).When the temperature of the water in which the insulation is tested differsfrom 60 F, apply a correction factor. Table 2 of Test Methods D470 contains the correction factors. Each
19、 insulation manufacturercan furnish the 1 F coefficient for the insulation material by using the procedure given in Test Methods D470. Multiply themeasured value by the correction factor to obtain the insulation-resistance value corrected to 60 F.5.4.1 Where a nonconducting separator is applied betw
20、een the conductor and insulation or where an insulated conductor iscovered with a nonmetallic jacket so that the insulation resistance can be measured only on the completed assembly, the requiredinsulation resistance shall be at least 60 % of that required for the primary insulation based on the nom
21、inal thickness of thatinsulation.TABLE 1 Physical Properties for CrosslinkedPolyethylene InsulationUnaged Requirements:Tensile strength, min, psi (MPa) 1800 (12.4)Elongation at rupture, min % 250Aged Requirements:After Air Oven Test at 121 1 C for 168 h:Tensile strength, min, % of unaged value 75Elo
22、ngation at rupture, min, % of unaged value 75Heat Distortion:At 121 1 C, max, % of unaged value:4/0 Awg (107 mm2) and smaller (insulation on cable) 30Larger than 4/0 Awg (107 mm2) (buffed sample ofinsulation)15Percent Hot Creep, maxFilledA 100UnfilledB 175Percent Hot Set, maxFilledA 5UnfilledB 10TAB
23、LE 1 Physical Properties for CrosslinkedPolyethylene InsulationUnaged Requirements:Tensile strength, min, psi (MPa) 1800 (12.4)Elongation at rupture, min % 250Aged Requirements:After Air Oven Test at 121 1 C for 168 h:Tensile strength, min, % of unaged value 75Elongation at rupture, min, % of unaged
24、 value 75Heat Distortion:At 121 1 C, max, % of unaged value:4/0 Awg (107 mm2) and smaller (insulation on cable) 30Larger than 4/0 Awg (107 mm2) (buffed sample ofinsulation)15Percent Hot Creep, maxFilledA 100UnfilledB 175Percent Hot Set, maxFilledA 5UnfilledB 10AFilled indicates a crosslinked polyeth
25、ylene insulation that contains 10 % orgreater carbon black and/or mineral fillers.BUnfilled indicates a crosslinked polyethylene insulation that contains less than10 % carbon black and/or mineral fillers.D2656 1325.5 DC Voltage TestAfter the insulation resistance test has been completed, subject wir
26、es and cables rated 5001 V and aboveto a dc voltage test for a period of 15 min. Use a dc voltage three times the ac voltage based on the specified nominal thicknessof insulation for the rated circuit voltage, phase to phase. Conduct the tests in accordance with Test Methods D470.5.5.1 Upon completi
27、on of the insulation resistance test, each nonshielded insulated conductor rated up to 5000 V shall withstandfor 5 min a dc test voltage that is three times the ac test voltage specified in 5.3. Unless otherwise specified, omit this test if theac voltage test described in 5.3 has been performed.5.6
28、Accelerated Water Absorption RequirementsThe insulation shall meet the requirements of Table 3 when tested inaccordance with theAccelerated WaterAbsorption Tests in Test Methods D470. Conduct the Electrical Method Test at 60 Hz withthe water temperature at 75 6 1 C.5.7 Permittivity and Dissipation F
29、actorThis test applies to insulation rated 5001 V and above. Measure the permittivity anddissipation factor on suitable 60-Hz equipment after the test specimen has been immersed in water at room temperature for at least24 h. Make the measurements at a voltage corresponding to an average stress of 40
30、 V/mil (1.6 kV/mm), based upon the specifiednominal thickness of insulation for the rated circuit voltage, phase to phase. The insulation shall meet the following requirements:Permittivity at room temperature, max 3.5Dissipation factor at room temperature, max, 0.020TABLE 2 Partial Discharge (Corona
31、) Extinction VoltageRequirementsRated Circuit VoltagePhase to Phase, VMinimum Level, kVGroundedNeutralUngroundedNeutralShielded2 001 to 5 000 4 5A5 001 to 8 000 6 88 001 to 15 000 11 1515 001 to 25 000 19 2625 001 to 28 000 2128 001 to 35 000 26TABLE 2 Partial Discharge (Corona) Extinction VoltageRe
32、quirementsRated Circuit VoltagePhase to Phase, VMinimum Level, kVGroundedNeutralUngroundedNeutralShielded2 001 to 5 000 4 5A5 001 to 8 000 6 88 001 to 15 000 11 1515 001 to 25 000 19 2625 001 to 28 000 2128 001 to 35 000 26A Unless otherwise indicated the cable shall be rated grounded neutral.TABLE
33、3 Accelerated Water Absorption TestRequirementsElectrical Method:Permittivity after one day, max 3.5Increase in capacitance, max, %:From 1 to 14 days 3.0From 7 to 14 days 1.5Stability factor after 14 days, max 1.0Alternative to stability factor:Stability factor difference, 1 to 14 days, max 0.5TABLE
34、 3 Accelerated Water Absorption TestRequirementsElectrical Method:Permittivity after one day, max 3.5Increase in capacitance, max, %:From 1 to 14 days 3.0From 7 to 14 days 1.5Stability factor after 14 days, max 1.0Alternative to stability factor:Stability factor difference, 1 to 14 days, max 0.5D265
35、6 133Permittivity at room temperature, max 3.5Dissipation factor at room temperature, max, 0.0205.8 U-Bend DischargePerform this test only on single-conductor nonshielded cables rated 2001 through 5000 V. At the endof the test period no cable dielectric failures or cracks in the cable surface are pe
36、rmitted. Conduct the test in accordance with TestMethods D470.5.9 Surface ResistivityPerform this test only on single-conductor nonshielded cables rated 2001 through 5000 V. The surfaceresistivity shall exceed 200 000 M. Conduct the test in accordance with Test Methods D470.6. Heat Distortion6.1 The
37、 requirements for heat distortion are given in Table 1 of this Specification. The test is conducted in accordance with TestMethods D470.7. Percent Hot Creep and Percent Hot Set7.1 Determine the percent hot creep for 15 min at 150 C (302 F) as follows: Meet the filled or unfilled values specified inT
38、able 1. Conduct this test in accordance with Practice ICEA T-28-562.7.2 Determine the percent hot set for 5 min at 150 C (302 F) as follows: Meet the filled or unfilled values specified in Table1. Conduct this test in accordance with Practice ICEA T-28-562.7.3 In case of dispute, the solvent extract
39、ion test in Test Methods D2765 is to be the referee method. The extractables, after adrying time of 20 h, shall be no more than 30 percent.8. Test Applicable for Sunlight and Weather Resistant Materials8.1 For insulations requiring sunlight- and weather-resistance testing, test in accordance with “W
40、eatherability for ColoredMaterials (including white and black)” in Specification D1248. Prepare the specimens in accordance with Test Methods D470 forphysical tests of insulations and jackets.9. Sampling9.1 Unless otherwise specified, sample the insulation in accordance with Test Methods D470.10. Te
41、st Methods10.1 Unless otherwise specified, test the insulation in accordance with Test Methods D470.11. Keywords11.1 ac voltage; crosslinked polyethylene; dc voltage; heat distortion; hot creep; hot set; insulation resistance; water absorption;weather resistantSUMMARY OF CHANGESCommittee D09 has ide
42、ntified the location of selected changes to this specification since the last issue,D2656 00D2656 06, that may impact the use of this specification. (Approved Nov. 1, 2013October 1, 2006)(1) Revised Table 1Section 3.ASTM International takes no position respecting the validity of any patent rights as
43、serted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time
44、by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will rece
45、ive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Inte
46、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2656 134
