IEC. Fourth edition. Electrical insulating materials – +41 22 02 11 Telefax: +41 22 03 00 E-mail: [email protected] Web: 标准 IEC 电气绝缘材料 耐热性 第1部分：老化程序和试验结果的 评定_电力/水利_工程科技_专业资料。标准 IEC 电气. this publication, including its validity, is available in the IEC Catalogue of IEC Electrical insulating materials – Properties of thermal endurance.
|Published (Last):||18 December 2012|
|PDF File Size:||4.71 Mb|
|ePub File Size:||9.46 Mb|
|Price:||Free* [*Free Regsitration Required]|
A procedure which has frequently been found very useful involves the delayed introduction of test groups following the sequence in the Table B.
This approach will provide comparisons among materials but bears a poorer relationship than item b to the property values required in normal service. Groups are tested as indicated 602116-1 the table.
This model is valid when the selected end-point of the diagnostic property is correlated with a particular degree of molecular change in the material which is subject to ageing. The thermal endurance characteristics are as derived in the calculations of 6. When the criterion is an absolute property level, n d is usually given the value of zero, unless reporting of the initial value is required. The following test report forms are related: Although originally developed for use 60216–1 electrical insulating materials and simple combinations of such materials, the procedures are considered to be of more general applicability and are widely used in the assessment of materials not intended for use as electrical insulation.
If not, the thickness shall be reported. The value of its square is between 0 no correlation iex 1 complete correlation. In addition to the above-mentioned basic assumption, some general assumptions regarding the chemical mechanisms of the thermal ageing need to be satisfied: If this rule results in changes of mechanism for example, when a transformation point like melting or softening is exceededthen the maximum exposure temperature will need to be limited.
Ageing procedures and evaluation of test results 1 Scope This part of IEC specifies the general ageing conditions and procedures to be used for deriving thermal endurance characteristics and gives guidance in using the detailed instructions and guidelines in the other parts of the standard. If the results show that this time to end-point iecc likely to be reached in about 10 periods of exposure, there is no need to alter the period of exposure originally selected.
Times to end-point, x – and y -values General 6.
IEC | IEC Webstore
To reduce the uncertainties in calculating the appropriate thermal endurance characteristic, the overall temperature range of thermal exposure needs to be carefully selected, observing the following requirements if the required thermal endurance characteristics are for a projected duration of 20 If the end-point is reached for more than one specimen during the first period, discard the group and test a further group, paying particular attention to any critical points of experimental procedure.
The time interval between tests of groups should be planned so that the results of at least two groups of specimens are available before the mean time to end-point, and at least one after: Find out more about British Standards by visiting our website at bsigroup.
The intercept of this line with the end-point line gives the logarithm 6016-1 the required time to end-point see Figure 4. If necessary, irc the initial value of the property as specified in 5. Test the specimens and plot the results and the arithmetic mean of the results or a suitable transform thereof against the logarithm of exposure time as given in IEC This, or other specified conditions, shall then be reported.
These further tests may be at lower or intermediate temperatures but should not generally be at higher temperatures than originally selected. The first assumption is tested by the so-called Fisher test F -test. In such cases, or if the value of HIC is known or expected to be less than 10 K, the difference between the levels of ageing temperature may need to be reduced, but to not less than 10 K so that oven temperature tolerance effects will be acceptable.
From these values, if necessary by interpolation see Figure 2obtain the time to end-point and calculate its logarithm as the y -value to be used in 6. For dated references, only the edition cited applies.
Methods based on mean values of normally distributed test results 3 3. NOTE 2 When extending the test program by submitting 6216-1 specimens to ageing at temperatures below the lower of the originally planned ageing temperatures, a temperature interval of 10 K and a cycle duration of 42 days for TI determination should be considered.
Evaluate the results, 602161 listed in 6. This difference is dependent on the scatter of the data points, the deviations from linearity in the regression analysis, the number of data points and the extent of extrapolation.
Search results for “”
The thermal endurance of an electrical insulating material is always given for a specific property and end-point. In all cases, ageing shall be continued until more than one-half of the test specimens in each group have failed to pass the proof test. The regression analysis for slope 602161 intercept of the thermal endurance graph and the tests for deviations from linearity shall be as in 6.
At the same time, the calculation procedures were made kec comprehensive, enabling full statistical testing of data obtained using a diagnostic property of any type, including the particular case of partially incomplete data.
Screening measurements ensure that specimens are of uniform quality and typical of the material to be tested.