1、Designation: D 470 05An American National StandardStandard Test Methods forCrosslinked Insulations and Jackets for Wire and Cable1This standard is issued under the fixed designation D 470; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods
3、 cover procedures for testingcrosslinked insulations and jackets for wire and cable. Todetermine the test to be made on the particular insulation orjacket, refer to the product specification for that type. Thesetest methods do not apply to the class of products known asflexible cords.1.2 This standa
4、rd does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardssee Secti
5、on 4.1.3 Whenever two sets of values are presented, in differentunits, the values in the first set are the standard, while those inthe parentheses are for information only.1.4 In many instances the insulation or jacket cannot betested unless it has been formed around a conductor or cable.Therefore,
6、tests are done on insulated or jacketed wire or cablein these test methods solely to determine the relevant propertyof the insulation or jacket and not to test the conductor orcompleted cable.1.5 The procedures appear in the following sections:SectionsAC and DC Voltage Withstand Tests 22 to 29Capaci
7、tance and Dissipation Factor Tests 38 to 44Cold Bend 128Cold Bend, Long-Time Voltage Test on Short Specimens 51 to 57Double AC Voltage Test on Short Specimens 45 to 50Electrical Tests of Insulation 17 to 64Heat Distortion Test 127Horizontal Flame Test 100 to 104Insulation Resistance Tests on Complet
8、ed Cable 30 to 37Mineral Filler Content, Determination of 111 to 115Ozone Resistance Test 87 to 99Partial-Discharge Test 58 to 64Physical Tests of Insulation and Jacket Compounds 5 to 16Surface Resistivity Test 116 to 120Track Resistance Test 129 to 132U-Bend Discharge Test 121 to 125Water Absorptio
9、n Test 65 to 71Water Absorption Test, Accelerated 72 to 86Water Absorption Test on Fibrous Coverings 105 to 1102. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD
10、 150 Test Methods for AC Loss Characteristics and Per-mittivity (Dielectric Constant) of Solid Electrical Insulat-ing MaterialsD 257 Test Methods for D-C Resistance or Conductance ofInsulating MaterialsD 412 Test Methods for Vulcanized Rubber and Thermo-static ElastomersTensionD 454 Test Method for
11、Rubber-Deterioration by Heat andAir PressureD 572 Test Method for Rubber-Deterioration by Heat andOxygenD 573 Test Method for Rubber-Deterioration in anAir OvenD 1193 Specification for Reagent WaterD 1711 Terminology Relating to Electrical InsulationD 2132 Test Method for Dust-and-Fog Tracking and E
12、ro-sion Resistance of Electrical Insulating MaterialsD 3755 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating MaterialsUnder Direct-Voltage StressD 5025 Specification for a Laboratory Burner Used forSmall-Scale Burning Tests on Plastic MaterialsD 5207
13、 Practice for Calibration of 20-mm (50-W) and125-mm (500-W) Test Flames for Small-Scale BurningTests on Plastic MaterialsD 5423 Specification for Forced-Convection LaboratoryOvens for Evaluation of Electrical Insulation2.2 ICEA Standard:T-24-380 Guide for Partial-Discharge Procedure31These test meth
14、ods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee D09.18 on Solid Insulations, Non-Metallic Shieldings, and Cover-ings for Electrical and Telecommunications Wire and Cables.Current edition approved S
15、eptember 1, 2005. Published September 2005.Originally approved in 1937. Last previous edition approved in 1999 as D 470 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, re
16、fer to the standards Document Summary page onthe ASTM website.3Available from the Insulated Cable Engineers Assoc., P.O. Box 440, SouthYarmouth, MA 02664.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 DefinitionsFo
17、r definitions of terms used in these testmethods, refer to Terminology D 1711.3.2 Definition of Term Specific to this Standard:3.2.1 aging (act of), nexposure of material to air or oil ata temperature and time as specified in the relevant materialspecification for that material.3.3 Symbol:3.3.1 kcmi
18、lthousands of circular mils.4. Hazards4.1 Mercury:4.1.1 Mercury metal vapor poisoning has long been recog-nized as a hazard in industry. The exposure limits are set bygovernmental agencies and are usually based upon recommen-dations made by the American Conference of GovernmentalIndustrial Hygienist
19、s.4The concentration of mercury vaporover spills from broken thermometers, barometers, and otherinstruments using mercury can easily exceed these exposurelimits. Mercury, being a liquid with high surface tension andquite heavy, will disperse into small droplets and seep intocracks and crevices in th
20、e floor. This increased area ofexposure adds significantly to the mercury vapor concentrationin air. The use of a commercially available emergency spill kitis recommended whenever a spill occurs. Mercury vaporconcentration is easily monitored using commercially avail-able sniffers. Make spot checks
21、periodically around operationswhere mercury is exposed to the atmosphere. Make thoroughchecks after spills. See 8.3.2 and 8.3.3.4.2 High Voltage:4.2.1 Lethal voltages may be present during these tests. It isessential that the test apparatus, and all associated equipmentthat may be electrically conne
22、cted to it, be properly designedand installed for safe operation. Solidly ground all electricallyconductive parts that any person might come in contact withduring the test. Provide means for use at the completion of anytest to ground any parts which: were at high voltage during thetest; may have acq
23、uired an induced charge during the test; mayretain a charge even after disconnection of the voltage source.Thoroughly instruct all operators in the proper way to conducttests safely. When making high voltage tests, particularly incompressed gas or in oil, the energy released at breakdownmay be suffc
24、ient to result in fire, explosion, or rupture of thetest chamber. Design test equipment, test chambers, and testspecimens so as to minimize the possibility of such occurrencesand to eliminate the possibility of personal injury. See Sections20, 27, 33, 42, 48, 54, 62, 68, 76, 118, 123 and 130.4.3 Ozo
25、ne:4.3.1 Ozone is a physiologically hazardous gas at elevatedconcentrations. The exposure limits are set by governmentalagencies and are usually based upon recommendations madeby the American Conference of Governmental Industrial Hy-gienists.4Ozone is likely to be present whenever voltages existwhic
26、h are suffcient to cause partial, or complete, discharges inair or other atmospheres that contain oxygen. Ozone has adistinctive odor which is initially discernible at low concen-trations but sustained inhalation of ozone can cause temporaryloss of sensitivity to the scent of ozone. Because of this
27、it isimportant to measure the concentration of ozone in theatmosphere, using commercially available monitoring devices,whenever the odor of ozone is persistently present or whenozone generating conditions continue. Use appropriate means,such as exhaust vents, to reduce ozone concentrations toaccepta
28、ble levels in working areas. See Section 90.PHYSICAL TESTS OF INSULATIONS ANDJACKETS5. Significance and Use5.1 Physical tests, properly interpreted, provide informationwith regard to the physical properties of the insulation orjacket. The physical test values give an approximation of howthe insulati
29、on will physically perform in its service life.Physical tests provide useful data for research and develop-ment, engineering design, quality control, and acceptance orrejection under specifications.6. Physical Tests6.1 Physical tests shall include determination of the follow-ing:6.1.1 Tensile streng
30、th,6.1.2 Tensile stress,6.1.3 Ultimate elongation,6.1.4 Permanent set,6.1.5 Accelerated aging,6.1.6 Tear resistance,6.1.7 Effects of oil immersion, and6.1.8 Thickness of insulations and jackets.7. Sampling7.1 Number of SamplesUnless otherwise required by thedetailed product specification, wire and c
31、able shall be sampledfor the physical tests, other than the tests for insulation andjacket thickness, as follows:7.1.1 Sizes Less than 250 kcmil (127 mm2)One sampleshall be selected for each quantity ordered between 2000 and50 000 ft (600 and 15 000 m) of wire or cable and oneadditional sample for e
32、ach additional 50 000 ft. No sampleshall be selected from lots of less than 2000 ft.7.1.2 Sizes of 250 kcmil (127 mm2) and OverOne sampleshall be selected for each quantity ordered between 1000 and25 000 ft (300 and 7600 m) of wire or cable and one additionalsample for each additional 25 000 ft. No
33、sample shall beselected from lots of less than 1000 ft.7.2 Size of SamplesSamples shall be at least 6 ft (2 m) inlength when the wire size is less than 250 kcmil (127 mm2),and at least 3 ft (1 m) in length when the wire size is 250 kcmilor over.8. Test Specimens8.1 Number of SpecimensFrom each of th
34、e samples se-lected in accordance with Section 7, test specimens shall beprepared as follows:4American Conference of Governmental and Industrial Hygienists, 6500 Glen-way Ave., Building D-7, Cincinnati, OH 45211.D470052Number of TestSpecimensFor Determination of Initial Properties (Unaged):Tensile s
35、trength, tensile stress, and ultimate elongation 3Permanent set 3For Aging Tests:Air pressure, heat, or oxygen pressure 3Air oven 3For Oil Immersion 3One specimen of each three shall be tested and the other twospecimens held in reserve, except that when only one sample isselected all three specimens
36、 shall be tested and the average ofthe results reported. For the tear test, six individual specimensas described in 8.5 shall be used.8.2 Size of SpecimensIn the case of wire and cable smallerthan AWG 6 (13.3 mm2) having an insulation thickness lessthan 0.090 in. (2.29 mm), the test specimen shall b
37、e the entiresection of the insulation. When the full cross section is used,the specimens shall not be cut longitudinally. In the case ofwire and cable of AWG 6 and larger, or in the case of wire andcable smaller than AWG 6 having an insulation thicknessgreater than 0.090 in., specimens approximately
38、 square insection with a cross section not greater than 0.025 in.2(16mm2) shall be cut from the insulation. In extreme cases, use ofa segmental specimen is permitted.8.2.1 The test specimens shall be approximately 6 in. (150mm) in length. Specimens for tests on jackets shall be takenfrom the complet
39、ed wire or cable and cut parallel to the axis ofthe wire or cable. With the exception of the tear tests, the testspecimen shall be either a segment or sector cut with a suitablesharp instrument or a shaped specimen cut out with a die andshall have a cross-sectional area not greater than 0.025 in.2(1
40、6mm2) after irregularities, corrugations, and reinforcing cords orwires have been removed by buffing.8.3 Preparation of Specimens:8.3.1 The test specimen is to have no surface incisions andbe as free as possible from other imperfections. Removesurface irregularities, such as corrugations due to stra
41、nding,etc., so that the test specimen will be smooth and of uniformthickness.8.3.2 The removal of the insulation often is greatly accel-erated by using mercury. In most cases a test specimen whichis an entire section is obtained, free from surface incisions andimperfections. Warningsee 4.1. Introduc
42、e the mercury atone end of the specimen between the insulation and the tinnedsurface of the conductor, with the specimen inclined on asupport with the end to which the mercury is applied at the top.The separation of the insulation results from the amalgamationof the tin of the conductor with the mer
43、cury. The amalgamationis assisted by first immersing and rubbing the tinning on theexposed end of the conductor in the mercury. It is also possibleto facilitate the removal of the insulation by stretching theconductor to the breaking point in a tensile-strength machine.8.3.3 WarningMercury is a haza
44、rdous material. See 4.1.Care should be exercised to keep mercury from the hands. Theuse of rubber gloves is recommended for handling specimensas in 8.3.2.8.4 Specimens of Thin-Jacketed InsulationIn the case ofwires or cables having a thin jacket crosslinked directly to theinsulation, it is usually n
45、ecessary to prepare die-cut specimensof the jacket and insulation. Make an effort to separate thejacket from the insulation by slitting the covering through tothe conductor and pulling the jacket and insulation apart bypliers. (Immersing the sample in hot water for a few minutesjust prior to pulling
46、 off the jacket often facilitates this proce-dure.) If the jacket cannot be removed, prepare specimens bybuffing. Equip the buffing apparatus with a cylindrical tablearranged so that it can be advanced very gradually. Remove theconductor from two short lengths of wire by slitting thecovering. Stretc
47、h one length of covering into the clamps of thebuffing apparatus so that it lies flat, with the jacket toward thewheel. The jacket is buffed off, with due care not to buff anyfurther than necessary, or overheat the material. Repeat theprocess with the other length of covering, except that theinsulat
48、ion is buffed off. Die-cut specimens shall be preparedfrom the buffed pieces after they have been allowed to recoverfor at least 30 min. Jackets with a thickness of less than 0.030in. (0.76 mm) shall not be tested.8.5 Specimen for the Tear TestCut the specimen with asharp knife or die. After irregul
49、arities, corrugations, andreinforcing cords or wires have been removed, the test speci-men shall conform to the dimensions shown in Fig. 1. Thethickness of the test specimen shall be not greater than 0.150in. (3.81 mm) and not less than 0.040 in. (1.02 mm). Split thespecimen longitudinally with a new razor blade to a point0.150 in. from the wider end.8.6 Condition and AgeIn accordance with Section 7, takesamples of the insulated wire and cable for physical andaccelerated aging tests after crosslinking. Perform tests be-tween 24 h and 60 days after crosslinking unless
