DSH 560A
Subject: Temperature limits of optoelectronic devices used for separation
Question:
During the tests of subclause 4.5.1 and 5.3, the temperatures of critical components shall be evaluated and shall be compared to their limiting values. For certain materials and components, the standard provides detailed instructions (e.g. in Table 4B, Table B.1, Table C.1) and for others only general compliance statements are provided (e.g. Note 3 of Table 4B part 2, subclause 5.3.8).
Optocouplers are often located in proximity to heat sources (e.g. transformers). The reliability of the materials used as insulator can degrade if thermally overstressed. IEC 60950-1 does not provide limit values for opto- couplers, nor does Annex P provide a reference to relevant component standards.
a: What are the limit values for optocouplers during normal operation of the EUT?
b: What are the limit values for optocouplers during fault operation of the EUT?
Decision:
Temperature ratings as shown on the corresponding component certificate ( refer to “Explanatory Notes” below for the relevant component standards) shall be taken as limit values. For optocouplers bridging safety isolation, the maximum temperature Ts shall not be exceeded during normal operation.
Additional information from IEC TC 108:
The requirements for optocouplers during fault testing are considered adequately covered by subclauses 5.3.9.1 and 5.3.9.2 of the standard. There was no intention by TC108/MT2 that temperature measurements be applied to optocouplers during fault testing. TC108 does not support placing a minimum limit for Ts, such as the proposed 100 ℃, on optocouplers for either normal or fault operation.
问题：
在4.5和5.3条款试验中，应评估关键零部件的温度并与它们的极限值进行比较。对于某些材料和组件，标准提供了详细说明，而对于其他材料和组件，仅提供了一般符合性声明。
光电耦合器通常靠近热源（例如变压器）。如果热应力过大，用作绝缘的材料可靠性会降低。IEC 60950-1未提供光电耦合器的温度限值，附录P也未提供相关标准参考。
问题a：EUT正常工作时，光电耦合器的温度限值是多少？
问题b：EUT故障运行时，光电耦合器的温度限值是多少？
决定：
相应零部件的规范上显示的额定温度值（参考IEC 60747）应作为限值。对于桥接安全隔离的光电耦合器，正常工作时不得超过最高温度Ts。
来自 IEC TC 108的附加信息：
标准5.3.9.1和5.3.9.2条款充分涵盖了故障试验对光电耦合器的要求。TC108/MT2 无意在故障试验中测量光电耦合器温度。TC108 不支持在正常或故障状态时对光电耦合器设置有关Ts的最小限制。
光电耦合器的温度限值为100 ℃。
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DSH 590
Subject: Rule for creepage across grooves and similar surface discontinuities
Question:
As can be seen from examples 2 and 6 of IEC 60664-1 sub clause 4.2 corners with angles greater or equal than 90 degrees are not bridged. IEC 60664-1 does not contain specific information at which angle less than 90 degrees bridging shall be applied. Some of the above mentioned standards specify that bridging shall be applied for angles less than 80 degrees.
Can this 80 degree rule be applied in general for all standards?
Decision:
Yes. The 80 degree rule shall be applied in general for all standards.
问题：
从 IEC 60664-1的4.2条款示例2和6中可以看出，角度大于或等于90度的角没有被桥接。IEC 60664-1不包含小于90度桥接角度的特定信息。很多标准提到，桥接应用于小于80度的角度。
80度规则可以普遍适用于所有标准吗？
决定：
是的。80度规则应普遍适用于所有标准。
以下标准完全适用80度角规则
IEC 60664-1
IEC 60335-1
IEC 61010-1
IEC 61058-1
IEC 61008-1
IEC 60947-1
IEC 60598-1
IEC 60065
IEC 60950-1
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