harlan.tan 发表于 2013-2-27 09:35

压敏电阻问题

请问产品中压敏电阻要求满足85度,3KA/6000V的测试要求,依据是什么,标准有更新吗?

hgf397556998 发表于 2013-2-27 10:06

这个是元器件的标准要求,如果放在音视频标准中,元器件的要求要基于PCB板上,如果PCB板的限值是75K,你的这个压敏电阻85-35=50K,不符合要求,你觉得呢?:L

sharkxiao 发表于 2013-2-27 11:23

依照UL1449

harlan.tan 发表于 2013-2-27 11:39

主要是3KA/6000V的测试要求

xuxuxu 发表于 2013-2-27 12:38

看标准EN600065:
14.12 Surge suppression varistors
Surge suppression varistors used in order to prevent MAINS overvoltages coming into the
apparatus shall comply with IEC 61051-2.
Such components shall not be connected between parts connected to the MAINS and
ACCESSIBLE conductive parts or parts connected to them, except for earthed parts of
PERMANENTLY CONNECTED APPARATUS.

Reference is made to IEC 61051-2 where the following requirements apply:
– preferred climatic categories (2.1.1 of IEC 61051-2)
 maximum lower temperature: –10 °C
 minimum upper temperature: +85 °C
 minimum duration of climatic tests: 21 days
– maximum continuous voltages (2.1.2 of IEC 61051-2)

The minimum value of the maximum continuous a.c. voltage shall be 1,2 times the RATED
SUPPLY VOLTAGE of the apparatus.
– current pulse rating (IEC 61051-2, subclause 2.1.2)

Surge suppression varistors shall withstand a combination pulse of 6 kV/3 kA with voltage
waveform of 1,2/50 s and current waveform of 8/20 s.

Compliance is checked by applying the test of IEC 61051-2, group 1. After the test, the
varistor voltage (as defined in IEC 61051) shall not have changed by more than 10 % when
measured with the manufacturer’s specified current.
– fire hazard (IEC 61051-2, table I, group 6)

The coating of surge suppression varistors shall have a flammability category V-0 or better
according to IEC 60707.
Compliance is checked according to IEC 60707 or according to clause G.1.1 of annex G.
– thermal stress

For apparatus with nominal MAINS voltage of <150 V, the apparatus and a test resistor
connected in series with the apparatus shall be energised from an a.c. source of 250 V.
The voltage source shall be applied for 4 h or until the circuit path through the varistor
opens for each of the test series resistance values: 2 000 , 500 , 250 , 50 . A
separate apparatus shall be used for each resistor value, unless damage from the previous
test has been repaired.
At the end of each test, the apparatus shall comply with clause 11.

brucejbb 发表于 2013-2-27 12:48

压敏电阻3KA/6000V相关参数可以在证书中找到吗(如: VDE证书)? 如果在证书中找不到相关参数, 怎么证明该元件是满足这个要求的呢? 不可能做随机测试吧! 期待高手回复...........

harlan.tan 发表于 2013-2-27 13:39

感谢讲解,:handshake

Williamh 发表于 2013-2-28 09:50

VDE证书上可以看的到

xuxuxu 发表于 2013-2-28 12:43

brucejbb 发表于 2013-2-27 12:48 static/image/common/back.gif
压敏电阻3KA/6000V相关参数可以在证书中找到吗(如: VDE证书)? 如果在证书中找不到相关参数, 怎么证明该元件 ...

VDE 证书上都可以找到。
可以针对该项做随机测试。

xuehua_123 发表于 2013-2-28 13:08

一般VDE证书上面会有 40/085/56 这个代表在40度条件下做了56天,限定值是85度。如果有For IEC 60950-1:2005, Annex Q 字样,就是满足3KA/6000V要求的。
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