1、Designation:D213211 Designation: D2132 12An American National StandardStandard Test Method forDust-and-Fog Tracking and Erosion Resistance of ElectricalInsulating Materials1This standard is issued under the fixed designation D2132; the number immediately following the designation indicates the year
2、oforiginal 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. Scope1.1 This test method is intended to differentiate solid elect
3、rical insulating materials with respect to their resistance to the actionof electric arcs produced by conduction through surface films of a specified contaminant containing moisture. Test Methods D2302and D2303 may also be used to evaluate materials. are also useful to evaluate materials.1.2 The val
4、ues stated in inch-pound units are the standard, except in cases where SI units are more appropriate. The values inparentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of th
5、is standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. Specific precautionary statements are given in 12.4.NOTE 1There is no equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D709 Specification for Lami
6、nated Thermosetting MaterialsD1711 Terminology Relating to Electrical InsulationD2302 Method of Test for Differential Wet Tracking Resistance of Electrical Insulating Materials with Controlled Water-to-Metal Discharges3D2303 Test Methods for Liquid-Contaminant, Inclined-Plane Tracking and Erosion of
7、 Insulating Materials3. Terminology3.1 Definitions:3.1.1 For definitions pertinent to this test method see Terminology D1711.4. High Voltage Hazard4.1 Lethal voltages are a potential hazard during the performance of this test. It is essential that the test apparatus, and allassociated equipment elec
8、trically connected to it, be properly designed and installed for safe operation.4.2 Solidly ground all electrically conductive parts which it is possible for a person to contact during the test.4.3 Provide means for use at the completion of any test to ground any parts which were at high voltage dur
9、ing the test or havethe potential for acquiring an induced charge during the test or retaining a charge even after disconnection of the voltage source.4.4 Thoroughly instruct all operators as to the correct procedures for performing tests safely.4.5 When making high voltage tests, particularly in co
10、mpressed gas or in oil, it is possible for the energy released at breakdownto be sufficient to result in fire, explosion, or rupture of the test chamber. Design test equipment, test chambers, and test specimensso as to minimize the possibility of such occurrences and to eliminate the possibility of
11、personal injury.NOTE 2If the potential for fire exists, have fire suppression equipment available. See section 12.1This test method is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of SubcommitteeD09.18 on Solid Insula
12、tions, Non-Metallic Shieldings and Coverings for Electrical and Telecommunication Wires and Cables.Current edition approved April 15, 2011. Published June 2011. Originally approved in 1962. Last previous edition approved in 2003 as D213203. DOI:10.1520/D2132-11.Current edition approved Jan. 1, 2012.
13、 Published February 2012. Originally approved in 1962. Last previous edition approved in 2011 as D213211. DOI:10.1520/D2132-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume informatio
14、n, refer to the standards Document Summary page on the ASTM website.3Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have b
15、een 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 appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official docume
16、nt.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Summary of Test Method5.1 With electrodes mounted as shown in Fig. 1, coat test specimens with a synthetic dust and test in a chamber shown in Fig.2. Direct a water spray at the te
17、st specimen. After the surface has been wetted, apply a 60-Hz voltage between the electrodes.Arcing occurs across localized high-resistance areas produced by nonuniform evaporation of the water from the contaminant.These arcs produce high temperatures in the underlying insulation with resultant carb
18、onization of most organic materials. Thecarbonization concentrates the electric field. Further It is possible further carbonization canwill occur in the direction of the field.In such cases, a carbon track is formed which spans the distance between the electrodes and causes failure. Materials It is
19、possiblethat materials that do not track canwill erode under the action of the arcing. Such erosion usually progresses from an upperelectrode through the thickness of the specimen towards the underlying electrode.5.2 Rate materials that track in terms of the time required to form a track between the
20、 electrodes.5.3 Rate materials that do not track in terms of the time required to erode to failure.5.4 Failure will be indicated when the current increases sufficiently to actuate an overcurrent device.NOTE2The 3The conditions of this test favor the formation of a track for several possible reasons.
21、 Most important, the continuous renewal of theconducting properties of the contaminant by the water spray allows a track to grow progressively over long periods of time.6. Significance and Use6.1 MethodEIt is possible that electrical insulation in service canwill fail as a result of tracking, erosio
22、n, or a combinationof both, if exposed to high relative humidity and contamination environments. This is particularly true of organic insulations inoutdoor applications where the surface of the insulation becomes contaminated by deposits of moisture and dirt, for example, coaldust or salt spray. Thi
23、s test method is an accelerated test that simulates extremely severe outdoor contamination. It is believed thatthe most severe conditions likely to be encountered in outdoor service in the United States will be relatively mild compared to theconditions specified in this test method.6.2 Test ResultsM
24、aterials can be classified by this test method as tracking-resistant, tracking-affected, or tracking-susceptible.The exact test values for these categories as they apply to specific uses will be specified in the appropriate material specifications,but guideline figures are suggested in Note 3. Track
25、ing-resistant materials, unless erosion failure occurs first, can last manyhundreds of hours (Note 4). Erosion, though it can progress laterally, generally results in a failure perpendicular to the specimensurface. Therefore, only specimens of the same nominal thickness can be compared for resistanc
26、e to tracking-induced erosion. Theextent of erosion can be estimated from measurements of the depth of penetration of the erosion. Materials that are nottracking-susceptible can be placed in three broad categorieserosion-resistant, erosion-affected, and erosion-susceptible. Whenthe standard thicknes
27、s specimen is tested, the following times to failure typify the categories (. Tracking-resistant materials, unlesserosion failure occurs first, have the potential to last many hundreds of hours (Note 5). Erosion, though it is possible that it willprogress laterally, generally results in a failure pe
28、rpendicular to the specimen surface. Therefore, compare only specimens of thesame nominal thickness for resistance to tracking-induced erosion. Estimate the extent of erosion from measurements of the depthMetric Equivalentsin.1812 12mm 3.2 12.7 25.4 50.8FIG. 1 Test Arrangement of Electrode SystemD21
29、32 122of penetration of the erosion. Place materials that are not tracking-susceptible in three broad categorieserosion-resistant,erosion-affected, and erosion-susceptible. When the standard thickness specimen is tested, the following times to failure typify thecategories (Note 6):Erosion-susceptibl
30、e 5 to 50 hErosion-affected 50 to 200 hErosion-resistant over 200 hNOTE 34Tracking-susceptible materials usually fail within 5 h. Tracking-affected materials usually fail before about 100 h.NOTE4This 5This information is derived from the individual experiences of eight laboratories using this test m
31、ethod since its publication as asuggested test method in June 1957, and from the results of an organized test program among these laboratories.NOTE5In 6In a normal distribution approximately 68 % of all test values are included within 61 standard deviation of the mean.6.3 Interpretation of Test Resu
32、ltsThis test method provides information that allows classification as described in 6.2. Thecomparison of materials within the same group is likely to be ambiguous unless three or more replicate specimens are tested. Whenthe test method is used for specification purposes, simple minimum values shoul
33、d not be establisheddo not establish simpleminimum values without consideration of the large variance to be expected in test results. It is recommended that quality levelsand specification minima be determined by statistical techniques.7. Apparatus7.1 GeneralA schematic diagram of the power supply a
34、nd control apparatus for testing one specimen is shown in Fig. 3(a).It is generally desirable to test three or more specimens simultaneously. It is recommended but not mandatory that a separate powersupply and control be used for each test specimen. This allows “breaking-in” and recording of time to
35、 failure separately for eachspecimen.7.2 Circuit BreakerThe circuit breaker (current relay, OL) interrupts the power supply on failure and stops the timing meter.It can be usedUse it as an ON-OFF switch and as a device for interrupting air and water supply when all specimens fail. Fig. 3(b)illustrat
36、es the air and water supply circuit when three specimens are tested using one fog nozzle. The circuit breaker shall be ratedat 2 to 3 A, inverse-time element type, for a 115-V supply. Use a resistance, R0, to shunt the current coil during the break-in period18 in. = 458 mm 20 in. = 508 mm 28 in. = 7
37、12 mmFIG. 2 Dust and Fog Test Chamber,Minimum Recommended Size(a) Power supply and control circuit of wet tracking tests.(b) Air and water supply circuit.FIG. 3 Circuit DiagramsD2132 123so that the breaker will not actuate as a result of the bright-flash currents typical of this period. Adjust the r
38、esistance to producean effective breaker action at approximately 6 A (115-V supply). Remove or switch out the shunt resistance after break-in.7.3 Supply Transformer4Use a supply transformer, T2, capable of supplying 1500 V, 60 Hz, rms. A200-VA potentialtransformer is capable of supplying power for u
39、p to three specimens if desired. Use a transformer with a 20:1 ratio when used witha 115-V primary supply. Choose a transformer that offers an impedance between 600 and 1200 V resistance and 200 and 700 Vreactance. Accomplish this by insertion of inductance L and resistance R1in the low-voltage side
40、 and resistance R2in thehigh-voltage side.7.4 Control TransformerUse a variable-ratio autotransformer, T1, to adjust the voltage as required.7.5 VoltmeterA voltmeter, Use a voltmeter, V, can be used in the primary side to determine the specimen test voltage.Alternatively, use a high-impedance voltme
41、ter can be connected for connection in the secondary, in which case precautions shouldbe takentake precautions to prevent electric shock to an operator. If a voltmeter is used in the primary, calibrate it againstsecondary voltage with a secondary load of 10 mA.7.6 Monitoring ProvisionsUse an ac amme
42、ter, A, to monitor specimen current. Use a separate ammeter for each test specimen.Alternatively make provisions to connect an ammeter into each test-specimen circuit. Shunt the ammeter with a normally closedcontact, PB, and a capacitance, C, to protect the ammeter from the large intermittent curren
43、ts that occur during break-in. Connectthe capacitance, if used, by a switch, SA. After the break-in period, open the switch unless the values of the capacitance andammeter impedances are such as to produce negligible error in current measurement. Use terminals A, B and C, D for oscilloscopemonitorin
44、g, for current measurement with a voltmeter in combination with a resistor, or for insertion of an undercurrent relay tobe used to stop the clock if the scintillation current falls below the specified value.7.7 ElectrodesUse three copper or brass electrodes12 by2by18 in. (13 by 51 by 3.2 mm), with c
45、orners rounded to a18-in.(3.2-mm) radius on the top surface of the specimen and spaced 1 in. (25 mm) apart as shown in Fig. 1. Use a ground plate of copperor brass and of the same size as the test specimen on the bottom surface and mounted on an insulating support inclined 15 degto the horizontal as
46、 shown in Fig. 1. Clamp the electrodes firmly to the test specimen. A suggested arrangement is shown in Fig.4.7.8 Test ChamberUse a cubicle test chamber, Fig. 2, made from plastic or metal. The front wall is made of glass orpoly(methyl methacrylate), or contains viewing ports or doors made of these
47、materials. Make the cubicle at least 20 in. (510 mm)high and 28 in. (710 mm) wide. Determine the depth by the number of specimens to be tested. Three specimens require a minimumdepth of 18 in. (460 mm). Fit the chamber with means for venting near the bottom of the cubicle, preferably along the end o
48、f thechamber where the specimens are located. Limit the venting area to about 20 in.2(130 cm2) to eliminate dependence of test resultson the ambient humidity.7.8.1 Mount one or more fog nozzles (Fig. 5) to obtain the specified uniform moisture deposition on all test specimens. It issuggested that on
49、e fog nozzle, mounted approximately 25 in. (635 mm) straight line distance from the nozzle to the centerspecimen at a height of approximately 14 in. (355 mm) above these specimens, will, with a suitably adjusted deflector, producethe specified conditions for three test specimens in a single cubicle (see Fig. 2). When only one fog nozzle is used in the cubicle,4General Electric Type JE41, Model KAR-3, and Westinghouse Type VS, Style No. 687588, have been found satisfactory for this purpose.FIG. 4 Clamping Arrangement for Test-Specimen ElectrodesD2132
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