IEC60950中遇到的问题,请大家解答.谢谢
我是新手,不是很懂电路和安规,大家多帮忙啊.在什么产品中会有limited current circuit这种电路?我公司的产品是XDSL.PLC会有这种电路吗? 接着问:
2: 含TNV-2,TNV-3电路的器具属于CLASS 3 类器具吗?我看CLASS 3 器具的定义是依靠SELV 电压保护的器具. 接着:
3: Working voltage, RMS working voltage,peak working voltage
RMS 是有效值的意思吗?
Working voltage已经是绝缘或元器件可以承受的最大电压了,那么峰值工作电压又怎么解释呢?是超越电压正弦波顶点的值吗?有点糊涂了 接着
4:SOLID INSULATION,DISTANCES THROUGH INSULATION怎么理解?
标准里说附加绝缘和加强绝缘的最小绝缘穿透距离是0.4mm.
是这样理解吗?比如,两导电体之间有一层隔膜,这个隔膜是起附加绝缘和加强绝缘作用的,那么这层隔膜的厚度最小要为0.4mm. 接着:
5:什么上基本绝缘,附加绝缘,双重绝缘,加强绝缘?怎么定.定义我知道,可是用在产品上我不知道怎么判断,有谁可以具体讲解一下或附图上来吗?谢谢 引用第0楼zihui于2007-07-19 14:23发表的 IEC60950中遇到的问题,请大家解答.谢谢 :
我是新手,不是很懂电路和安规,大家多帮忙啊.
在什么产品中会有limited current circuit这种电路?我公司的产品是.XDSLPLC会有这种电路吗?
标准里对LCC电路定义得很明白了, 请参考 IEC 60950-1 的2.4条。
另外，（以下引用于EN 60950-1-2006）
Clause 1.5.6
If an accessible conductive part or circuit is separated from another part by DOUBLE INSULATION or REINFORCED INSULATION that is bridged by a capacitor or capacitors, the accessible part or circuit shall comply with the requirements for a LIMITED CURRENT CIRCUIT in 2.4. This requirement applies after electric strength testing of the insulation with the bridging capacitor or capacitors in place.
Clause 1.5.7.2
If an accessible conductive part or circuit is separated from another part by DOUBLE INSULATION or REINFORCED INSULATION that is bridged by a resistor or group of resistors, the accessible part or circuit shall comply with the requirements for a LIMITED CURRENT CIRCUIT in 2.4. If a group of resistors is used, the current measurement in 2.4.2 is made with each resistor short-circuited in turn, unless the group passes the resistor test below. This current is measured after electric strength testing of the insulation with the bridging resistor or group of resistors in place.
如果你的产品有电阻,电容桥接了一次电路和二次电路,那么二次电路的可触及部件就要符合LCC的要求.
不好意思，偶对XDSL, PLC不熟悉。 引用第1楼zihui于2007-07-19 14:33发表的:
接着问:
2: 含TNV-2,TNV-3电路的器具属于CLASS 3 类器具吗?我看CLASS 3 器具的定义是依靠SELV 电压保护的器具.
含TNV-2,TNV-3电路的器具当然不一定属于Class III类设备。
请注意CLASS III 类设备的定义...
以下引用于EN 60950-1-2006
1.2.4.3
CLASS III EQUIPMENT
equipment in which protection against electric shock relies upon supply from SELV CIRCUITS and in which HAZARDOUS VOLTAGES are not generated.
NOTE:For CLASS III EQUIPMENT, although there is no requirement for protection against electric shock, all other requirements of the standard apply. 引用第3楼zihui于2007-07-19 15:14发表的:
接着
4:SOLID INSULATION,DISTANCES THROUGH INSULATION怎么理解?
标准里说附加绝缘和加强绝缘的最小绝缘穿透距离是0.4mm.
是这样理解吗?比如,两导电体之间有一层隔膜,这个隔膜是起附加绝缘和加强绝缘作用的,那么这层隔膜的厚度最小要为0.4mm.
以下引用于EN 60950-1-2006 Clause 2.10.5
SOLID INSULATION shall be:
− so dimensioned that overvoltages, including transients, that enter the equipment, and peak voltages that may be generated within the equipment, do not break down the SOLID INSULATION; and
− so arranged that the likelihood of breakdown occurring due to the presence of pinholes in thin layers of insulation is limited.
固体绝缘的例子很多：PVC片、塑胶外壳、PCB板材料 等等。
2.10.5.2 Distances through insulation
If a design is based on distances through insulation, these distances shall be dimensioned according to the application of the insulation (see 2.9) and as follows (see Figure F.14):
− if the PEAK WORKING VOLTAGE does not exceed 71 V, there is no requirement for distance through insulation;
− if the PEAK WORKING VOLTAGE exceeds 71 V, the following rules apply:
• for FUNCTIONAL INSULATION and BASIC INSULATION there is no minimum distance through insulation;
• SUPPLEMENTARY INSULATION or REINFORCED INSULATION shall have a distance through insulation that is 0,4 mm or greater, provided by a single layer.
For compliance criteria, see 2.10.5.1.
附加绝缘和加强绝缘的最小绝缘穿透距离是0.4mm，你说得没错。
如果，两导电体之间有一层隔膜,这个隔膜是起附加绝缘和加强绝缘作用的,那么这层隔膜的厚度最小要为0.4mm。这个也对。。。 引用第4楼zihui于2007-07-19 17:57发表的:
接着:
5:什么上基本绝缘,附加绝缘,双重绝缘,加强绝缘?怎么定.定义我知道,可是用在产品上我不知道怎么判断,有谁可以具体讲解一下或附图上来吗?谢谢
如果你有比较详细的产品示意图，我可以讲给你听。。。
因为对你的产品不熟，所以就不多说了。。。
