详细介绍
3A99859G01好价格价格好
3A99859G01好价格价格好
3A99859G01好价格价格好
dcs系统接地的基本要求
dcs系统接地是为了保证当进入dcs系统的信号、供电电源或dcs系统设备本身出现问题时,可靠的接地系统能承受过载电流并可以迅速将过载电流导入大地。接地系统能够为dcs提供屏蔽层,消除电子噪声干扰,并为整个控制系统提供公共信号参考点(即参考零电位)。当接地系统发生问题时(接地电阻过大,多点接地控制工程网版权所有,接地线断线或接地线与高电压、大电流设备相接触等),会造成人员的触电伤害及设备的损坏,还会造成dcs系统经常“死机"(或不明原因的“死机"),大多是因为接地系统不良或存在问题所引起的。
因此,完善、可靠、正确的接地,是dcs 系统能够安全、可靠和良好运行的关键。
d cs系统的接地方法
4.1 分散布置的dcs设备接地方法
分散布置dcs系统设备之间的连接一般是网络(通讯)线,例如:现场控制站分散到现场,而操作员站位于不同的控制室,分散直径在500米的范围内,各站点间使用多模光纤或5类双绞线或dp屏蔽双绞线等连接。
(1) 使用光纤连接的站点:各站点内的接地方法同集中布置的dcs设备。
(2) 使用5类双绞线或dp屏蔽双绞线连接的站点:
(3) 控制室的各类地线先连接到公共连接板,公共连接板通过接地总干线与公共接地极相连。从公共接地极看过去,整个接地网络是一个星型结构。
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