1、BRITISH STANDARD Environmental testing Part 2. Tests %est Q. Sealing The European Standard EN 60068-2-17 : 1994 has the status of a British Standard This Part should be read on conjunction with BS 2011 : Part 1.1 : 1989 General and guidance UDC 621.3 : 620.193 : 620.162.4 BS EN 1995 1994 6068-2-17 :
2、 IEC 68-2-17 : This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 May 1995 O BSI 1995 Amd. No. The following BSI references relate to the work on this standard: Com
3、mittee reference GEL/5O Draft for comment 92121483 DC ISBN O 680 23680 7 Date Text affected Committees responsible for this British Standard The United Kingdom participation in the preparation in this British Standard was entrusted to Rchnical Committee GEL/50, Environmental testing of electrotechni
4、cal products, upon which the following bodies were represented Federation of the Electronics Industry GAMBICA (BEAMA Ltd.) Ministry of Defence Society of Environmental Engineers Society of Motor Manufacturers and Traders Limited Amendments issued since publication CENELEC EN*bb8-2 -17 94 I 3404583 0
5、354665 146 I BS EN 60068-2-17 : 1995 Contents Page Committees responsible Inside front cover National foreword 11 Foreword 2 Ext of EN 60068-2-17 3 i - CENELEC EN*b00b8-2 -17 94 W 3404583 Ol154bbb O82 = BS EN 60068-2-17 : 1995 National foreword This British Standard has been prepared by Rchnical Com
6、mittee GEL/50 and is the English Language version of EN 60068-2-17 : 1994 Environmental testing, Part 2. Tests, Test they are not recommended, however, for components in which electrical changes become effective only after a long time (for instance, after the test is terminated). Protected against s
7、olid greater than 2,5 mm Protected against solid objects greater than 1 ,O mm Dust-protected Tools, wires, etc., of diameter or thickness greater than 2,5 mm. Solid objects exceeding 2,5 mm in diameter Wires or strips of thickness greater than 1.0 mm. Solid objects exceeding 1 ,O mm in diameter Ingr
8、ess of dust is not totally prevented but dust does not enter in sufficient quantity to interfere with satisfactory operation of the equipment Dst-tight No ingress of dust The tests for external detection are further subdivided according to their application. Test Qa is a bubble test which is used to
9、 determine the air tightness of bushes, spindles and gaskets. The other tests, Qc, Qd, Qk and Qm are used to determine leaks in containers (metallic cases, housings, etc.); Test Qc is a bubble test again including three methods with different sensitivities (leaks not less than 1 Pa cm3/s bar - cm3/s
10、). Test Qk and Qm are the most sensitive of this series. Their sensitivity ranges from 1 Pa - cm3/s (1 O-5 bar cm3/s) to about Pa - cm3/s (1 O- bar - cm3/s). Test Qd is a liquid seepage test which may be applied to specimens filled during manufacture with a liquid or a product becoming liquid at the
11、 test temperature. Tests in IEC 529 In IEC 529, degrees of protection are established by tests and identified by numerals as follows: I , I Short description Definition I Fingers or similar objects not exceeding 80 mm in length. objects greater than 12 mm I Solid objects exceeding 12 mm in diameter
12、2 Protected against solid II - CENELEC EN+bOOb!-Z -17 94 3404583 0354674 159 D Second I charac- Page 8 EN 60068-2-17 : 1994 Degree of protection Table 2 - Degrees of protection indicated by the second characteristic numeral Short description Definition teristic numeral i 7 Protected against the effe
13、cts Ingress of water in a harmful quantity shall not be of immersion possible when the enclosure is immersed in water under I O I Non-protected 1 NO special protection 8 Dripping water (vertically falling drops) shall have no I harmful effect Protected against dripping Protected against submersion P
14、rotected against dripping water when tilted up to 15“ water Verticaiiy dripping water shall have no harmful effect when the enclosure is tilted at any angle up to 15“ from its normal position Water falling as a spray at an angle up to 60“ from the vertical shall have no harmful effect Protected agai
15、nst splashing I I water Protected against water jets 15 I Water splashed against the enclosure from any direction shall have no harmful effect Water projected by a nozzle against the enclosure from any direction shall have no harmfuf effect 1-6- I PFtGLd against heavy seas Water from heavy seas or w
16、ater projected in powerful jets shall not enter the enclosure in harmful quantities defined conditions of pressure and time The equipment is suitable for continuous submersion in water under conditions which shall be specified by the manufacturer NOTE - Normally. this will mean that the equipment is
17、 hermetically sealed. However with certain types of equipment it can mean that water can enter but only in such a manner that it produces no harmful effects I I I I CENELEC EN*b00b8-2 -17 74 3404583 O154b75 095 = Page 9 EN 6068-2-17 : 1994 BASIC ENVIRONMENTAL TESTING PROCEDURES - Part 2: Tests - Tes
18、t Q: Sealing 1 Def lnit Ions For the purpose of this standard the following definitions apply: 1.1 Leak rate The quantity of a dry gas at a given temperature that flows through a leak per unit of time and for known difference of pressure across the leak. NOTE - The basic SI unit for leak rate is pas
19、cal cubic metre per second (Pa . m3/s)*. The derived units Pa . cm3/s- and bar . cm3/s9 are used in this siandard as they better conform with the orders of magnitude used in common industrial practice. It is recalled that: 1 Pa. m3/s = lo6 Pa. cm3/s = 10 bar. cm3/s. 1.2 Standard leak rate The leak r
20、ate under standard conditions of temperature and pressure difference. For the purpose of this test, the standard conditions are 25 OC and lo5 Pa (1 bar). 1.3 Measured leak rate (R) The leak rate of a given device as measured under specified conditions and employing a specified test gas. NOTES 1 diff
21、erence of lo5 Pa (1 bar) at 25 “C. 2 must be converted to equivalent standard leak rates. Measured leak rates are often determined with helium employed as the test gas under a pressure For the purpose of comparison with leak rates determined by other methods of testing, the leak rates 1.4 Equivalent
22、 standard leak rate (L) The standard leak rate of a given device, with air as the test gas. i .5 The time required for equalization of partial pressure difference across a leak if the initial rate of change of that pressure difference were maintained. For the purpose of this test, the time constant
23、is equal to the quotient of the internal volume of the specimen and the equivalent standard leak rate. Time constant (of leakage) (O) 1.6 Gross leak Any leak the equivalent standard leak rate of which is greater than 1 Pa (1 O-5 bar . cm3/s). cm3/s - CENELEC EN*bOOb-Z -17 94 O 3404583 0154676 T2L Pa
24、ge 10 EN 6068-2-17 : 1994 1.7 Fine leak Any leak the3equivalent standard leak rate of which is smaller than 1 Pa - cm3/s (lo” bar - cm k). 1.8 Virtual leak The semblance of a leak caused by slow release of absorbed, adsorbed or occluded gas. 1.9 Leakage meter (Test Qm) Apparatus consisting of a hand
25、 probe for taking a sample of gas mixture and a meter providing a graduated display of the concentration of a predetermined type of gas in the sample. 1.1 O Volume contained between the gastight sheath collecting the leakage and the specimen. Volume of measurement fVm(Test Qm) NOTE - The tracer gas
26、concentration being small in that volume, the sealing of its sheath does not generally need to be perfect. 1.1 1 Leak detector (Test am) Apparatus consisting of a hand probe for taking a sample of gas mixture and a device sensitive to the presence of a predetermined type of gas and emitting a signal
27、, either acoustic or visual, when the concentration of a predetermined type of gas reaches a preset threshold level. I. 12 Probing sniffing: deprecated term (Test Qm) Action of slowly moving the probe of a leak detector along a specimen in order to locate the leaks. 2 Test Qa: Sealing of bushes, spi
28、ndles and gaskets 2.1 Object To determine the effectiveness of seals of bushes, spindles and similar features. NOTE - For the purpose of this test, two types of seals shall be considered: - Type A: 100 kPa (10 Nlcrn) to 110 kPa (1 1 Nlcrn) in the direction specified in the relevant Type 8: 100 kPa (
29、10 N/crn2) to 110 kPa (1 1 N/crn2) in each direction. specification. - 2.2 Scope This test can be used for the detection of gross leaks. CENELEC EN*bOOb8-2 -17 94 W 3404583 03.54677 968 m Page 11 EN 60068-2-17 : 1994 2.3 General description of the test The specimen is mounted on the lid of a pressur
30、ized test chamber which is submerged in a liquid. If the specimen leaks, the air escaping is collected. The amount of air collected per unit time is a measure of the air leakage. A suitable test apparatus is described in annex A. 2.4 Initial measurements Not required. 2.5 Conditioning 2.5.1 Unless o
31、therwise specified, an air pressure difference, as specified below, shall be applied across each seal or simultaneously across a group of seals forming an assembly. Type A: 100 kPa (10 N/cm2) to 110 kPa (1 1 N/cm2) in the direction specified in the relevant specification. Type B: 100 kPa (IO N/cm2)
32、to 110 kPa (11 N/cm2) in each direction. Where a higher pressure is required, it shall be 340 kPa (34 N/cm2 to 360 kPa (36 N/cm2). NOTE - The test apparatus described in annex A may not be suitable for these higher pressures. 2.5.2 Type B seals shall be tested both in a static condition and while be
33、ing mechanically operated as required by the relevant specification. 2.6 Final measurements The rate of leakage shall be measured. The limit shall be prescribed in the relevant specification. 2.7 Information to be given in the relevant specification When this test is included in the relevant specifi
34、cation, the following details shall be given as far as they are applicable: Sub-clause a) Requirements for pressure 2.5.1 b) Direction of application of pressure difference 2.5.1 c) Mechanical operation during conditioning 2.5.2 d) Requirements for leakage rate 2.6 3 Test Qc: Container sealing, gas
35、leakage 3.1 Object To determine the effectiveness of seals of specimens having an included gas-filled space (e.g. specimens not completely filled with impregnant). CENELEC EN*b00b8-2 -17 94 3404583 0154678 8T4 = Page 12 EN 6MXB2-17 : 1994 3.2 Scope This test can be used for the detection of leak rat
36、es greater than 100, 10 or i Pa - cm3/s bar - cm3/s) according to the method chosen. Test Methods 1 and 3 are applicable only to specimens that are able to withstand full decompression and the compression necessary for the impregnation (see 3.3.3) without suffering distortion or permanent physical d
37、amage (see annex B, clauses B.l.B.2 and 8.3). or Test Method 2 is applicable to all specimens subject to a significant thermally generated pressure differential being achieved at the maximum ambient temperature of operation of the specimen. 3.3 General description of the test The detection of gross
38、leaks is achieved by submerging the test specimen in a suitable liquid, under controlled conditions and by observing bubbles emanating from the specimen surface (see annex B. clause B.5). A positive internal pressure within the test specimen is generated by one of the following test methods: 3.3.1 T
39、est Method i Conducting the test in a vacuum environment, thereby increasing the pfessure differential across the seals of the test specimen. 3.3.2 Test Method 2 Through immersion in a test liquid maintained at an elevated temperature (see annex B, clause B.10). 3.3.3 Test Method 3 Through immersion
40、 in a test liquid, following impregnation with another liquid having a boiling point below the test temperature. 3.4 Test Method i 3.4.1 The test chamber containing the bath required for this test shall be capable of being evacuated, and the bath shall contain sufficient liquid to enable the specime
41、ns to be immersed so that the uppermost surface of the specimen enclosure or seal to be tested is at a depth of not less than 10 mm below the surface. The test liquid (see annex B, clause 8.8) shall be maintained at a temperature between 15 OC and 35 OC. The bath should be capable of being drained o
42、f the liquid or having the specimen removed from the liquid before breaking the vacuum. 3.4.2 Specimens shall be immersed in the test liquid with their seals uppermost. The pressure within the test chamber shall then be reduced within 1 min to a value of 1 kPa (10 mbar) or as otherwise prescribed in
43、 the relevant specification. If no failure has been observed (3.4.4) maintain this pressure for a further minute or another duration prescribed in the relevant specification (see annex B, clause B.9). CENELEC EN*b0068-2 -17 74 a 3404583 0354677 730 m Page 13 EN -2-17 : 1994 3.4.3 Specimens possessin
44、g seals on more than one surface shall be tested in accordance with 3.4.2 with each surface in the uppermost position (see annex B, clause 8.4). 3.4.4 Failure criteria for this test shall be the observance at any time during the test of a definite stream of bubbles, or more than two large bubbles, o
45、r an attached bubble that grows in size (see annex B, clauses B.6 and 8.7). 3.5 Test Method 2 3.5.1 The bath required for this test shall contain sufficient liquid to enable the test specimens to be completely immersed to a depth of not less than 10 mm above the uppermost part of the enclosure or se
46、al to be tested. 3.5.2 The liquid shall be maintained at a temperature of 1 OC to 5 OC above the maximum ambient temperature of operation for the specimen under test or at the temperature required in the relevant specification. 3.5.3 The specimens, which shall be at a temperature between 15 OC and 3
47、5 OC, shall be immersed in the test liquid with their seals uppermost (see annex B, clause B.ll) for a period of at least 10 min, or as prescribed in the relevant specification (see annex B, clause B.3). 3.5.4 Specimens possessing seals on more than one surface shall be tested in accordance with 3.5
48、.3 with each surface in the uppermost position (see annex B, clause 8.4). 3.5.5 Failure criteria for this test shall be the observance at any time during the test of a definite stream of bubbles, or more than two large bubbles, or an attached bubble that grows in size (see annex B, clauses B.6 and 8
49、.7). 3.6 Test Method 3 This method consists of two steps: 3.6.1 Step 1 Step 1 shall be performed at ambient temperature. The specimens shall be enclosed in a vacuum/pressure vessel and the pressure reduced to about 100 Pa (1 mbar) for 1 h. After that time, and without breaking the vacuum, an impregnation liquid (see annex B, clauses 8.12 and 8.13) shall be drawn into the vessel until the specimens are covered by it. CENELEC ENab0068-2 -37 94 3404583 0354680 452 3 0.1 cm3 Page 14 EN tW68-2-17 : 1994 600 kPa (6 bar) lh 300 kPa (3 bar) 2h The
