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在D级、C级SPD保护产品中,最大持续工作交流电压(Uc)的选择有什么要求?

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发表于 2008-5-30 08:57:10 | 显示全部楼层 |阅读模式
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新手求教。

发表于 2008-5-30 09:44:59 | 显示全部楼层
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[quote user="JinJiang"]

新手求教。

[/quote]

 

在GB50057-94(2000版)规定了在不同接地系统的Uc值,生产厂家一般能提供不同级别的几种Uc值供选择,对于220V/380V的电源系统,考虑到电源的波动性,D级通常选择Uc=275V,它的限制电压Up≤1200V,在C级通常选择Uc=385V或420V,它的限制电压Up≤1800V或1900V,在B级通常选择Uc=550V或510V,它的限制电压Up≤2500V。有的用户提出在D级应该选择Uc=385V,理由是当发生电源接地故障引起电压升高时,不至于损坏SPD,殊不知它的限制电压超出了1500V(Up≤1800V),设备将得不到很好的保护。接地故障引起的电源电压升高毕竟是极少出现的故障,所引起的设备损坏不属于SPD保护的范畴。

发表于 2008-5-31 16:07:15 | 显示全部楼层
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学习了,谢楼上主详细讲解。
发表于 2010-10-27 13:32:36 | 显示全部楼层
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发表于 2015-11-19 13:07:53 | 显示全部楼层
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