IEC · IEC · IEC · IEC · IEC · IEC ; Show all». IEC Standard | Guide for the determination of thermal endurance properties of ekectrical insulating materials – Part 2: List of. IEC , Electrical insulating materials – Thermal endurance properties – Part 2: Determination of thermal endurance properties of electrical.
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If you need international and foreign standards from other Standards Development Organizations, hard copies can be ordered from our Customer Services team. However, in many cases, the deviations arise from the ageing behavior of the material; this happens with many thermoplastic materials or other materials where the ageing temperature range includes, or is close to, a transition temperature of some kind, or where there is more ieec one ageing mechanism at work.
Since processing conditions may significantly affect the ageing characteristics of some materials, it shall be ensured that, for example, sampling, cutting sheet from the supply roll, cutting of anisotropic material in a given direction, molding, curing, pre-conditioning, are performed in the same manner for all specimens. These further tests may be at lower or intermediate temperatures but should not generally be at higher temperatures than originally selected.
TC – Evaluation and qualification of electrical insulating materials and systems rss. Table 1 gives guidance in making initial selections. However, there is often a need for such information related to other longer or shorter times.
End-points of proof tests are predominantly given in the form of fixed values 6021-62 the property. If the decision to extend the original test programme is taken after its completion, the duration of the complete procedure may become prohibitive.
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Buying standards You can buy and download PDF versions of BSI publications, including British and adopted European and international standards, through our website at bsigroup. If necessary, determine the initial value of the property as specified ie 5. After successive delays see footnote in Table B.
Ageing data of materials with different thicknesses are not always comparable.
In the official version, for Bibliography, the following notes have to be added for the standards indicated: In cases of longer times, for example, the times given as requirements or recommendations in the text of this standard for example, 5 h for the minimum value of the longest time to end-point shall be increased in the ratio of the actual specification time to 20 h.
Consequently, a material may be assigned more than one temperature index, derived, for example, from the measurement of different properties and the use of different end-point times. Very long specification times may also lead to non-linearity see also Annex A.
The thermal endurance characteristics are as derived in the calculations of 6. Establish the exposure temperatures and times in accordance with the instructions of 5. This approach will provide comparisons among materials but bears a poorer relationship than item b to the property values required in normal service.
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_百度文库
Throughout the rest of this standard the term “insulating materials” is always taken to mean “insulating materials and simple combinations of such materials”. For the valid application of the standard, no transition, in particular no first-order transition should occur in the temperature range under study. In the case of destructive tests 6. The format of the TI is then: Screening measurements ensure that specimens are of uniform quality and typical of the material to be tested.
Accelerated ageing 6016-2 test procedures were therefore required to obtain the necessary information.
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In such cases, the thickness after each ageing period may need to be determined and reported if required in the relevant specification. In addition to the above-mentioned basic assumption, some general assumptions regarding the chemical mechanisms of the thermal ageing need to be satisfied: About us We bring together business, industry, government, consumers, iiec and others to shape their combined experience and expertise into standards -based solutions.
Times to end-point, x – and y -values General 6. Instructions for calculating thermal endurance characteristics IEC all Parts 4Electrical insulating materials — Thermal 06216-2 properties — Part 4: NOTE The term Arrhenius is widely used and understood to indicate a linear relationship between the logarithm of a time and the reciprocal of the thermodynamic absolute or Kelvin temperature.
The general calculation procedures outlined here and detailed in IEC are based on the principles set out in IEC Unless otherwise stated in the method for determining the diagnostic property for example, parts of material specifications dealing with methods of test, or a method listed in IECthe initial value is the arithmetic mean of the test results. In the same way, calculate the temperature? These tests have been designed to test all important aspects of the data which might invalidate derivation of thermal endurance characteristics, as well as to decide whether a failure to satisfy the 602162- requirements is of practical significance.
Continue the cycles of temperature exposure, cooling and application of the test until the average measured value for the specimens in the group has reached the end-point specified and provided at least one point 60261-2 the end-point. In such cases, it may be possible to obtain an acceptable result by further testing at a lower temperature.
Such complications may arise, for example, if the thermal endurance relationship turns out to be non-linear, or if specimens are lost due to thermal runaway of an oven.