1、 CENELEC EN+b1302 95 3404583 OLbLL3 79l BRITISH STANDARD Electrical insulating materials - Method to evaluate the resistance to tracking and erosion - Rotating wheel dip test The European Standard EN 61302 : 1995 has the status of a British Standard NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMIT
2、TED BY COPYRIGHT LAW BS EN 61302 : 1996 IEC 1302 : 1995 COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling ServicesBS EN 61302 : 1996 Amd. No. The foiowing BSI references relate to the work on this standard Committee reference GEW15 Draft for comment 91
3、/26630 DC ISBN O 580 24899 2 Committees responsible for this British Standard Date Text affected The preparation of this British Standard was entrusted to Technical Committee GEU15, Insulating materials, upon which the following bodies were represented British Ceramic Research Ltd. British Industria
4、l Ceramic Manufacturers Association British Telecommunications plc Department of Trade and Industry (National Physical Laboratory) Electrical and Electronic Insulation Association (BEAMA Ltd.) Electricity Association Federation of the Electronics Industry Ministry of Defence Rotating Electrical Mach
5、ines Association (BEAMA Ltd.) Ransmission and Distribution Association (BEAMA Ltd.) The following bodies were also represented in the drafting of the standard, through subcommittees and panels: AEX Technology British Cable Mmufacturem Association British Industrial Ceramic Manufacturem Association B
6、ritish Plastics Federation COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling ServicesCENELEC ENbb1302 95 3Y04583 OLb9LL5 560 BS EN 61302 : 1996 Contents page Committees responsible Inside front cover National foreword u Foreword 2 Text of EN 61302 3 O
7、BSI 1996 i COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling Services _ CENELEC EN*bL302 95 m 3404583 OLb9LLb 4T7 M BS EN 61302 : 1996 National foreword This British Sandard has been prepared by Technical Committee GEIJ15 and is the English language ve
8、rsion of EN 61302 : 1995 Electrical insulating materials - Method to maim until flashover occurs, or the leakage current exceeds a specified value2). The time to flash- over, or to exceed the specified leakage current, and observation of the nature and severity of degradation are the criteria used t
9、o compare materials. The test conditions described in this international standard lead to longer failure times than obtained from other tracking and erosion tests. IEC 112 and IEC 587 (see annex B) describe tests of much shorter duration, on smaller samples, to assess the ability of materials to wit
10、hstand electric stress when exposed to liquid contamination on one surface. These tests may rate materials differently from tests of longer duration. Salt-fog tersts (not yet standardized by IEC) are also in use. Such tests permit comparison of materials in the form in which they will be used in ser
11、vice. The test results are then dependent both on the materials used and the design of the test specimens. Such tests may also evaluate materials differently. ) Different specimen shapes, dimensions and electrode spacings may be needed in special cases. Results with such non-standard test specimens
12、shall be used only for comparison with similar specimens. 2, In order to obtain a sufficient acceleration of the degradation process, the test conditions described in this standard are such as to cause surface discharges on all insulating materials. Under less severe conditions. materials show a dif
13、ferent ability to resist the formation of surface discharges. An assessment of this ability would be of considerable practical interest, but no standardized test for this purpose is available at the present time. COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Informatio
14、n Handling Services - CENELEC ENwbL302 95 = 3404583 OLbL20 928 Page 4 EN 61302 : 1995 As the test conditions cause surface discharges on all insulating materials, it is only necessary to clean the surface of specimens before tests. If specimens are subjected to any conditioning prior to the test, su
15、ch as exposure to UV radiation, or to high humidity, the conditioning procedures should be described in detail. 2 Normatlve reference The following normative document contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi
16、cation, the edi- tion indicated was valid. All normative documents are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possi- bility of applying the most recent edition of the normative document indicated below. Members of IEC and
17、 IS0 maintain registers of currently valid International Standards. IEC 493-1: 1974, Guide for the statistical analysis of ageing test data - Pat? 1: Methods based on mean values of normally distributed test results 3 Definitlons For the purpose of this International Standard, the following definiti
18、ons apply. 3.1 tracklng: Progressive degradation of the surface of a solid insulating material by local discharges to form conducting or partially conducting paths. 3.2 track: Conducting or partially conducting path created by tracking. 3.3 electrical eroslon: Wearing away of a solid insulating mate
19、rial by the action of elec- trical discharges without the formation of tracks. 1 3.4 rotatlng wheel life: Median time to failure under the specified test conditions. A failure occurs when a flashover of the test specimen takes place or the r.m.s. leakage current exceeds 300 mA. 4 Test specimen 4.1 S
20、pecimen configuration As a standard test specimen a rod tube of circula The outer diameter shall be 25 mm k 1 mm. r cro section shall be used. Rods shall be used whenever practically possible. If a tube is used, the wall thickness must be sufficient to prevent the test liquid from leaking through th
21、e tube wall due to electric erosion during the test. The ends of the tube shall be carefully sealed to pievent ingress of the test liquid into the interior of the tube. The sealing material must not be able COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Hand
22、ling ServicesPage 5 EN 61302 : 1995 to diffuse along the outer surface of the tube and thus influence the test result. When needed to obtain sufficient mechanical rigidity, a supporting rod of insulating material may be used inside the tube. A tubular electrode of stainless steel (see 5.1) is mounte
23、d at each end of the test specimen. The edge of the electrode facing the opposite electrode shall be square-cut and have a close fit to the test specimen. The high-voltage electrode shall have an extension of 0,2 mm stainless-steel plate to form a sliding electrode that connects the specimen intermi
24、ttently to the test voltage (see 5.1). The distance between the electrodes shall be 140 mm i 2 mm. An example of a specimen meeting this standard is shown in figure A.l of annex A. If specimens with other shapes and dimensions than specified in this standard are used, they shall be clearly described
25、 in the test report. The results obtained on such specimens shall be compared only with results obtained on similarly shaped specimens. 4.2 Preparation The surface of the specimens shall be cleaned with a suitable solvent). 5 Test apparatus Up to 10 specimens are mounted on a 1.0 m to 1,l m diameter
26、 pitch circle of a rotating wheel as outlined in figure A.3 of annex A. The wheel rotates three revolutions per minute. The specimens are mounted parallel to the axis of rotation with an inclination of 15 f 2 to the horizontal with the high-voltage electrode in the lower position. The test voltage i
27、s applied intermittently to each specimen through a sliding electrode which slides along a semicircular busbar to which the voltage source is connected. The earth electrode of each specimen is connected to the voltage source through an individual overcurrent relay which disconnects the test voltage
28、when the r.m.s. current exceeds 300 mA. Provisions can be made to measure the current continuously or intermittently during the test. An open container holding approximately 150 I of salt solution is positioned so that the midpoint of the centreline of each test specimen is submerged during 1/6 (60)
29、 of each revolution. After submersion the specimen is rotated during 116 O“), and the test voltage is then applied during 1/2 (180“) of each revolution. Then the voltage is disconnected during 1/6 (60“) of a revolution before the specimen is submerged in the test liquid again, and the test cycle is
30、repeated. ) The solvent should not soften or otherwise alter the test specimen. Isopropyl alcohol (propanol-2) is suitable for many materials, but xylene may be needed to remove silicone-mould release agents. Xylene should not be used on materials that swell in xylene, which may be the case, e.g., f
31、or rubber materials. COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling ServicesCENELEC EN*bL302 95 3404583 OLb9L22 7T0 Page 6 EN 61302 : 1995 All metal parts that are exposed to the test liquid shall be made of stainless steel containing approximately
32、18 % chromium and 8 % nickel. An example of a test apparatus that meets the requirements specified in this standard is shown in figures A.2 to A.5 of annex A. 5.2 Electrical circuit 5.2.1 The test voltage is supplied from a 48 Ht to a 62 Hz a.c. power supply with an out- put r.m.s. voltage of 10 kV
33、+, 03 kV. The test voltage shall be measured with an accuracy of 1.5 %. The (transient) r.m.s. short-circuit current of the voltage source shall be at least 10 A at 10 kV. 5.2.2 The voltage source shall be equipped with a tripping device which disconnects the test voltage when a failure occurs witho
34、ut interrupting the rotation of the wheel. Failed specimens should be removed and the test voltage re-applied as soon as practically possible. The wheel shall be inspected at least once every 24 h *. The accumulated time under voltage until failure occurs, shall be recorded for each specimen. Altern
35、atively a separate fuse for each specimen may be used. A simplified circuit diagram of a test circuit that meets the requirements of this standard Is shown as an example in figure A.6 of annex A. 5.3 Test liquid 5.3.1 The test liquid is prepared by adding sodium chloride (NaCI) to deionized or disti
36、lled water until a resistivity of 7,s Qm f 5 % at 25 OC is achieved. 5.3.2 Prior to each test the container shall be cleaned and filled with a fresh test liquid. The level of the test liquid shall be maintained constant within f10 rnm throughout the test. Necessary adjustments are made by adding dei
37、onized or distilled water. 5.3.3 The temperature of the test liquid shall be (25 f 5) OC. 5.3.4 The test liquid shall be circulated through a filter with a micron rating of 75 pm at a rate of approximately 1 i/min). 5.3.5 At intervals of one month the container shall be cleaned and filled with a fre
38、sh test liquid. ) A filter with the following data has been used with satisfactory results: acrylic-phenolic resin cartridge filter with the following dimensions: length: 248 mm; inner diameter: 26 mm; outer diameter: 66 mm. COPYRIGHT European Committee for Electrotechnical StandardizationLicensed b
39、y Information Handling Services CENELEC EN*bL302 75 W 3404583 OLb9123 637 m Page 7 EN 61302 :1995 6 Test procedure 6.1 shall be between 48 Hz and 62 Hz. The r.m.s. test voltage shall be 10 kV 4 OS kV. The frequency of the test voltage 6.2 Each test shall comprise at least five identical specimens an
40、d continue until all of them have failed, or until a predetermined maximum testing time is reached. The test shall not be terminated until at least half the number of identical specimens have failed (e.g., at least three specimens out of five). 6.3 Normally, only specimens of the same material shoul
41、d be tested simultaneously. However, different materials may be tested simultaneously if previous tests have shown that the rotating wheel life is not significantly influenced thereby. 7 Test results 7.1 The times to failure shall be measured and their median value and standard deviation should be e
42、stimated (see IEC 493-1). A failure has occurred when one of the following criteria is fulfilled: - a flashover occurs; - the individual r.m.s. leakage current exceeds 300 mA. If failure occurs on some, but not all, specimens in the specified maximum test time, the standard deviation of the times to
43、 failure shall be estimated by applying statistical methods for censored tests. 7.2 end of the test. After removal of loose debris, the maximum erosion depth shall be measured at the 7.3 At the end of the test a visual inspection shall be carried out and the presence of erosion, tracking, surface cr
44、acking and a possible accumulation of a loose contamination layer on the specimen surface shall be noted. 8 Test report The report shall include: a) identification of the materials used; b) details of the specimens: fabrication and dimensions, additives, fillers, cleaning procedures and solvents use
45、d, surface treatment if any; c) the test results as specified in clause 7. COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling Services CENELEC EN*b1302 95 3404583 0169324 573 H Page 8 EN 61302 : 1995 Annex A (informative) Examples of test specimens (fig
46、ure A.1) and a test apparatus (figures A.2 to A.6) that meet the requirements of this standard The following list of parts applies to figures A.2 to A.6: List of parts E Test specimen F1 Fuse H Hour counter J Insulator LI Worm gear motor L2 10 carbon brushes L3 Insulator L4 Bearing L5 Bearing L7 M I
47、ndicator lamp P Ammeter Ql Q2 Change switch R1-Ri0 Over-current relays S Slip-rings f Transformer V Semicircular busbar Epoxy resin board of thickness 28 mm Contactor (can be disconnected by R1 -R1 O) NOTE - Each test piece needs a separate carbon brush and slip ring. but in the drawings only one se
48、t is shown. COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling Services CEMELEC EN*bL302 75 3q04583 OLbL25 40T m Page 9 EN 61302:1995 0 e- - - o -I - L U T I 0 a COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Ha
49、ndling Services CENELEC ENmbL302 95 3404583 OLbL2b 34b = Page 10 EN 61302 :1995 COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling Services CENELEC EN*bL302 95 3404583 OLb9L2 282 Page 11 EN 61302 : 1995 4 COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling Services CENELEC EN*b1302 95 3404583 OLb9I128 119 M Page 12 EN 61302 : 1995 P a COPYRIGHT European Committee for Electrotechnical StandardizationLicensed by Information Handling Services- CENELEC
