DSH 525
Subject: Applied force for internal parts
Question:
In clause 13.2, it is specified that 2N for internal parts and 30N for the outside are applied simultaneously while taking measurement of clearance. However, it is not specified that forces are applied to internal parts while taking measurements between two internal parts, ex. primary circuit component and secondary circuit component.
Which is the appropriate method to measure clearance between two internal parts ?
a) 2N forces are applied to the both parts simultaneously.
b) First, a 2N force is applied to one part and removed. And then a 2N is applied to the other one.
c) Other opinion
Decision:
First, a 2N force is applied to one part and removed. Then a 2N force is applied to the other part.
问题:
13.2条款规定在测量间隙时,内部零部件施加2N同时外壳施加30N。然而在测量两个内部零部件(例如一次电路部件和二次电路部件)时,没有规定对内部零部件施加的力。
测量两个内部零部件间隙的合适方法是什么?
a)两部分同时施加2N的力。
b)先在一个部件上施加2N的力后移开,然后另一个部件上再加2N力。
c)其他意见。
决定:
先在一个部件上施加2N的力后移开,然后另一个部件上再加2N力。
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DSH 541
Subject: Transformer overload
Question:
The standard does not specify a transformer overload test, as there is, , for example, in IEC 60950.
If it is obvious, based on engineering judgment of the technical design of the product, that due to a single fault condition (e.g. component failures, short circuit of functional insulation) an overload situation on a transformer is likely to occur, which approach should be followed?
1) The actual overload on the transformer shall be performed, taking into account the 'characteristics' of eventual protective devices.
2) All possible single fault conditions shall be performed. For those situations where the protective device reacts, the current through the protector shall be measured and the characteristic of the protector shall be taken into account.
3) No overload condition shall be created, since the standard does not specify this in wording.
4) Other possibilities.
Decision:
Following the standard option 2 from above has to be used.
问题:
标准没有与IEC 60950-1类似规定,要求变压器过载试验。
如果依据产品的技术设计判断,由于单一故障情况(如元器件故障、功能绝缘短路),变压器很可能发生过载情况,应采取哪一种方法?
1)变压器的实际过载应考虑到最终保护装置的“特性”。
2)应执行所有可能的单一故障条件。当保护装置动作时,测量通过保护装置的电流,并考虑保护装置的特性。
3)不应产生过载条件,因为标准没有明文规定。
4)其他的可能性。
决定:
必须使用上面的标准选项2。
提示:
变压器过载是最坏的故障情况,如果有发生这种情况的可能性,变压器和最终使用的保护装置的应确保过载不会导致火灾或触电危险。
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DSH 546
Subject: Relative humidity
Question:
Various IEC standards require that specific tests be performed in a humidity chamber. The specification of the relative humidity is in several formats. How should the tolerance on the relative humidity specification be interpreted?
Decision:
(1) Unless clearly noted otherwise, the tolerance specified for humidity is considered to be in percent relative humidity, % RH.
(2) It is intended that the set point of the humidity chamber controller be set within the specified range and that the humidity remains within the specified range.
(3) Confirmation that humidity is within the specified range shall be made by a humidity measuring instrument according to CTL DSH 251A.
问题:
各种IEC标准要求在湿度室中进行特定的试验。相对湿度的规格有几种格式。相对湿度规格上的容差应如何解释?
决定:
(1)除非另有明确说明,指定的湿度容差被认为是百分比相对湿度,% RH。
(2)湿度室控制器的设定点应设定在规定的范围内,湿度保持在规定的范围内。
(3)湿度在规定范围内,由湿度测量仪根据CTL DSH 251A进行确认。
提示:
CTL DSH 251已经被OD-5014替换,见以下链接
DSH 2106测量仪器有效性+OD-5014仪器精度要求