1、Designation: D 1711 08An American National StandardStandard Terminology Relating toElectrical Insulation1This standard is issued under the fixed designation D 1711; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis terminology is used in connection with testing and specifying solid electrical insulatingmaterials. Modifications to th
3、is terminology, reflecting common usage, may appear in particular testmethods, material specifications, practices, or other standards. Included herein are terms pertinent togeneral applications, electrical insulating papers, mica, mica processing, processed mica forms,hookup wire insulation, and par
4、tial discharge (corona).1. Scope*1.1 This terminology is a compilation of technical termsused in conjunction with testing and specifying solid electricaland electronic insulating materials in standards under thejurisdiction of Committee D09 on Electrical and ElectronicInsulating Materials.1.2 It is
5、intended that all definitions in this terminology areidentical to definitions of the same terms as printed in standardsof originating technical subcommittees, with the exceptions of:(1) deletion of any part of the Discussion included in anotherstandard that refers specifically to the use of a term i
6、n thatstandard; (2) figure numbers and corresponding references; and(3) in this terminology, a parenthetical addition of a referenceto one or more technical standards in which the term is usedand the year in which the term was added to this compilation.1.3 It is permissible to include symbols as par
7、t of therepresentation of terms, where appropriate.1.4 It is not intended that this terminology include descrip-tions of terms or symbols (except as noted in 1.3). It is alsopermissible to include acronyms and abbreviations referringdirectly to defined terms.1.5 Revisions and additions to the defini
8、tions in this termi-nology are to be made as a product of a collaborative effortbetween Subcommittee D09.94 and the various technicalsubcommittees of Committee D09, with Subcommittee D09.94providing editorial advice to the technical subcommittees. Newdefinitions and revisions of existing definitions
9、 must first beapproved by the cognizant technical subcommittee (or subcom-mittees) before inclusion in this terminology.2. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power Fre
10、quenciesD 150 Test Methods for AC Loss Characteristics and Per-mittivity (Dielectric Constant) of Solid Electrical Insula-tionD 3426 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating MaterialsUsing Impulse WavesD 3636 Practice for Sampling and Judging
11、 Quality of SolidElectrical Insulating Materials2.2 Other Standards:ANSI/ASQC A2-198733. Terminologyacceptable quality level (AQL), nthe maximum percentnonconforming which, for purposes of sampling inspection,is considered satisfactory as a process average.acceptance number, nthe maximum allowable n
12、umber ofnonconformities for a given AQL and sample size (lot-sample size).air chain, nin mica, a series of air inclusions in the form ofa chain or streak.arc propagation, nthe movement of an electric arc from itspoint of inception to another location. (1996) D 3032arc tracking, nthe process producin
13、g tracks when arcs occur1This terminology is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.94 on Editorial.Current edition approved May 1, 2008. Published June 2008. Originallyapproved in 1960. Last p
14、revious edition approved in 2002 as D 1711 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from
15、 American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.on or c
16、lose to the insulation surface.Arrhenius plot, na graph of the logarithm of thermal life asa function of the reciprocal of absolute temperature.DISCUSSIONThis is normally depicted as the best straight line fit,determined by least squares, of end points obtained at aging tempera-tures. It is importan
17、t that the slope, which is the activation energy of thedegradation reaction, be approximately constant within the selectedtemperature range to ensure a valid extrapolation.ash content of paper, nthe solid residue remaining aftercombustion of the paper under specified conditions, ex-pressed as a perc
18、entage of the dry mass of the original paper.(1996) D 202average discharge (corona) current (It), nthe sum of theabsolute magnitudes of the individual discharges during acertain time interval divided by that time interval.DISCUSSIONWhen the discharges are measured in coulombs and thetime interval in
19、 seconds, the calculated current will be in amperes.It5(t0t1Q11 Q21222222Qnt12 t0(1)where:It= average current, A,t0= starting time, s,t1= completion time, s, andQ1,Q2,Qn= partial discharge quantity in a corona pulse1 through n,C.binder tapesee core wrap (binder tape).bond strength, na measure of the
20、 force required to separatesurfaces which have been bonded together. (1996)D 2519, D 3145, D 4882braid, n(1) woven metallic wire used as a shield forinsulated conductors and cables.(2) A woven fibrous protective outer covering over aninsulated conductor or cable.breakdown voltagesee dielectric break
21、down voltage.bursting strength of paper, nthe hydrostatic pressure re-quired to produce rupture of a circular area of the materialunder specified test conditions. (1996) D 202cable wrap, npaper used for mechanical protection or forspace-filling (rather than as electrical insulation) in low-voltage c
22、ables with nonmetallic sheaths.capacitance, C, nthat property of a system of conductorsand dielectrics which permits the storage of electricallyseparated charges when potential differences exist betweenthe conductors.DISCUSSIONCapacitance is the ratio of a quantity, q, of electricity toa potential d
23、ifference, V. A capacitance value is always positive. Theunits are farads when the charge is expressed in coulombs and thepotential in volts:C 5 q/V (2)capacitor tissue, nvery thin (5 to 50 m) pure, nonporouspaper used as the dielectric in capacitors, usually in conjunc-tion with an insulating liqui
24、d.coating powder, na heat-fusible, finely-divided solid resin-ous material used to form electrical insulating coatings.(1996) D 2967, D 3214concentricity, nthe ratio, expressed in percent, of the mini-mum wall thickness to the maximum wall thickness.concentric-lay conductor, na conductor composed of
25、 acentral core surrounded by one or more layers of helicallylaid strands.DISCUSSIONIn the most common type of concentric-lay conductor,all strands are of the same size and the central core is a single strand.conductance, insulation, nthe ratio of the total volume andsurface current between two elect
26、rodes (on or in a specimen)to the dc voltage applied to the two electrodes.DISCUSSIONInsulation conductance is the reciprocal of insulationresistance.conductance, surface, nthe ratio of the current between twoelectrodes (on the surface of a specimen) to the dc voltageapplied to the electrodes.DISCUS
27、SION(Some volume conductance is unavoidably included inthe actual measurement.) Surface conductance is the reciprocal ofsurface resistance.conductance, volume, nthe ratio of the current in thevolume of a specimen between two electrodes (on or in thespecimen) to the dc voltage applied to the two elec
28、trodes.DISCUSSIONVolume conductance is the reciprocal of volume resis-tance.conducting material (conductor), na material within whichan electric current is produced by application of a voltagebetween points on, or within, the material.DISCUSSIONThe term “conducting material” is usually applied onlyt
29、o those materials in which a relatively small potential difference resultsin a relatively large current since all materials appear to permit someconduction current. Metals and strong electrolytes are examples ofconducting materials.conductivity, surface, nthe surface conductance multipliedby that ra
30、tio of specimen surface dimensions (distancebetween electrodes divided by the width of electrodesdefining the current path) which transforms the measuredconductance to that obtained if the electrodes had formed theopposite sides of a square.DISCUSSIONSurface conductivity is expressed in siemens. It
31、ispopularly expressed as siemens/square (the size of the square isimmaterial). Surface conductivity is the reciprocal of surface resistivity.conductivity, volume, nthe volume conductance multipliedby that ratio of specimen volume dimensions (distancebetween electrodes divided by the cross-sectional
32、area of theelectrodes) which transforms the measured conductance tothat conductance obtained if the electrodes had formed theopposite sides of a unit cube.DISCUSSIONVolume conductivity is usually expressed in siemens/centimetre or in siemens/metre and is the reciprocal of volumeresistivity.conductor
33、, na wire, or combination of wires not insulatedfrom each other, suitable for carrying electric current. (1996)D 1676D1711082continuous partial discharges (continuous corona),ndischarges that recur at rather regular intervals; forexample on approximately every cycle of an alternatingvoltage or at le
34、ast once per minute for an applied directvoltage.core wrap (binder tape), npaper used to wrap groups ofinsulated wire into cable configuration prior to sheathing.DISCUSSIONUsually, this term is applied to telephone communica-tion cables in which core wrap is not regularly subjected to voltagestress,
35、 but may be exposed to surges from lightning strokes or otheraccidental events.corona, nvisible partial discharges in gases adjacent to aconductor.DISCUSSIONThis term has also been used to refer to partialdischarges in general.critical property, na quantitatively measurable characteris-tic which is
36、absolutely necessary to be met if a material orproduct is to provide satisfactory performance for theintended use.DISCUSSIONIn some situations, specification requirements coincidewith customer usage requirements. In other situations, they may notcoincide, being either more or less stringent. More st
37、ringent sampling(for example, smaller AQL values) is usually used for measurement ofcharacteristics which are considered critical. The selection of samplingplans is independent of whether the term defect or nonconformity isappropriate.cross grains or reeves, nin mica, tangled laminationscausing impe
38、rfect cleavage.crude micamica as mined; crude crystals with dirt and rockadhering.crystallographic discoloration, nin mica, discoloration ap-pearing as bands of lighter or darker shades of basic color ofa block of mica. (1996)DISCUSSIONSuch bands are generally parallel to the crystallo-graphic faces
39、 of the crystal from which the block was separated.defect, na departure of a quality characteristic from itsintended level, or state, that occurs with a severity sufficientto cause an associated product or service not to satisfyintended normal, or reasonably foreseeable, usage require-ments.DISCUSSI
40、ONThe terms “defect” and “nonconformity” and theirderivatives are used somewhat interchangeably in the historical andcurrent literature. Nonconformity objectively describes the comparisonof test results to specification requirements, while the term defect has aconnotation of predicting the failure o
41、f a product or service to performits intended function in use. Since this latter connotation is oftenunintended, the term nonconformity is preferred in full consensusstandards. The selection of any sample plan is independent of whetherthe term defect or nonconformity is appropriate.The term defect m
42、ay be appropriate for specifications mutuallyagreed upon by a producer and a user where specific use conditions areclearly understood. Even in these cases however, use the term defectwith caution and consider substituting the term nonconformity.For additional comments, see ANSI/ASQC A2-1987 that als
43、o states:“When a quality characteristic of a product or service is “evaluated” interms of conformance to specification requirements, the use of the termnonconformity is appropriate.”dielectric, na medium in which it is possible to maintain anelectric field with little supply of energy from outsideso
44、urces.DISCUSSIONThe energy required to produce the electric field isrecoverable, in whole or in part. A vacuum, as well as any insulatingmaterial, is a dielectric.dielectric breakdown voltage (electric breakdown voltage),nthe potential difference at which dielectric failure occursunder prescribed co
45、nditions, in an electrical insulating ma-terial located between two electrodes. (See also Test MethodD 149, Appendix X1.)DISCUSSIONThe term dielectric breakdown voltage is sometimesshortened to “breakdown voltage.”dielectric constantsee relative permittivity.dielectric failure (under test), nan even
46、t that is evidencedby an increase in conductance in the dielectric under testlimiting the electric field that can be sustained.dielectric strength, nthe voltage gradient at which dielectricfailure of the insulating material occurs under specificconditions of test.dip encapsulation (a type of conform
47、al coating), nanembedding process in which the insulating material isapplied by immersion and without the use of an outercontainer.DISCUSSIONThe coating so formed generally conforms with thecontour of the embedded part.dissipation factor (loss tangent) (tan d), D, nthe ratio ofthe loss index to its
48、relative permittivity orD 5k9/k8 (3)It is also the tangent of its loss angle, d, or the cotangentof its phase angle, u. (See Fig. 1 and Fig. 2.)DISCUSSIONa:D 5 tan d5cot u5Xp/Rp5 G/vCp5 1/vCpRp(4)where:G = equivalent ac conductance,Xp= parallel reactance,Rp= equivalent ac parallel resistance,Cp= par
49、allel capacitance, andv =2pf (sinusoidal wave shape assumed).The reciprocal of the dissipation factor is the quality factor, Q,sometimes called the storage factor. The dissipation factor, D,ofthecapacitor is the same for both the series and parallel representations asfollows:FIG. 1 Vector Diagram for Parallel CircuitD1711083D 5vRsCs5 1/vRpCp(5)The relationships between series and parallel components are as follows:Cp5 Cs/1 1 D2! (6)Rp/Rs5 1 1 D2!/D25 1 1 1/D2! 5 l 1 Q2DISCUSSIONb: Series RepresentationWhile the paral
