LED显示屏是的主体元件是LED和驱动芯片,属于微电子产品的集合体,LED的工作电压在5V左右,一般工作电流为20毫安以下。它的工作特性决定了它面对静电和异常电压或电流冲击的抗性十分脆弱。这就需要我们在生产和使用过程中认识到这一点并给予足够的重视，采取措施对led显示屏进行保护。而电源接地是LED显示屏最常用的一种保护方法。为什么电源要接地？下面电子显示屏厂家来告诉大家吧！

这(zhei)个(ge)和开关电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)的(de)(de)工(gong)作模式有关，我们(men)LED显(xian)(xian)示(shi)(shi)屏(ping)开关电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)是(shi)一(yi)种通过(guo)滤(lv)(lv)波(bo)—整流(liu)—脉冲调制—输出整流(liu)—滤(lv)(lv)波(bo)等一(yi)系列(lie)手段将交流(liu)（AC）220V市(shi)电(dian)(dian)(dian)(dian)(dian)转化(hua)成直(zhi)流(liu)(DC)5V直(zhi)流(liu)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)稳(wen)定输出的(de)(de)一(yi)种设备(bei)。为了(le)保(bao)(bao)证(zheng)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)AC/DC转化(hua)的(de)(de)稳(wen)定性，电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)厂(chang)家(jia)按照国家(jia)3C强制标准在(zai)AC220V输入端(duan)的(de)(de)电(dian)(dian)(dian)(dian)(dian)路(lu)设计中，从火(huo)线至地(di)(di)线跨(kua)接(jie)一(yi)个(ge)EMI滤(lv)(lv)波(bo)电(dian)(dian)(dian)(dian)(dian)路(lu)。以保(bao)(bao)证(zheng)AC220V输入的(de)(de)稳(wen)定性，所以所有的(de)(de)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)在(zai)工(gong)作是(shi)都会存在(zai)滤(lv)(lv)波(bo)漏电(dian)(dian)(dian)(dian)(dian)，单个(ge)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)的(de)(de)漏电(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)3.5mA左右。漏电(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)压约为110V。在(zai)显(xian)(xian)示(shi)(shi)屏(ping)不(bu)接(jie)地(di)(di)的(de)(de)情况下，漏电(dian)(dian)(dian)(dian)(dian)流(liu)不(bu)但可能引起芯片损坏(huai)或者灯管烧坏(huai)。如果使用20个(ge)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)以上，累(lei)加的(de)(de)漏电(dian)(dian)(dian)(dian)(dian)流(liu)达到70mA以上。足以导(dao)致漏电(dian)(dian)(dian)(dian)(dian)保(bao)(bao)护器(qi)动作，切断供电(dian)(dian)(dian)(dian)(dian)。这(zhei)个(ge)也是(shi)为什么(me)我们(men)显(xian)(xian)示(shi)(shi)屏(ping)无法(fa)使用漏电(dian)(dian)(dian)(dian)(dian)保(bao)(bao)护器(qi)的(de)(de)原因(yin)。如果不(bu)接(jie)漏保(bao)(bao)而且(qie)显(xian)(xian)示(shi)(shi)屏(ping)不(bu)接(jie)地(di)(di)，电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)叠(die)加的(de)(de)漏电(dian)(dian)(dian)(dian)(dian)流(liu)将超(chao)过(guo)人(ren)(ren)体安(an)全(quan)电(dian)(dian)(dian)(dian)(dian)流(liu)，110V的(de)(de)电(dian)(dian)(dian)(dian)(dian)压足以致人(ren)(ren)死地(di)(di)！而接(jie)地(di)(di)后，电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)外壳电(dian)(dian)(dian)(dian)(dian)压对人(ren)(ren)体接(jie)近0。表明(ming)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)与(yu)人(ren)(ren)体之间不(bu)存在(zai)电(dian)(dian)(dian)(dian)(dian)位差，漏电(dian)(dian)(dian)(dian)(dian)流(liu)被导(dao)入大地(di)(di)。所以,LED显(xian)(xian)示(shi)(shi)屏(ping)必(bi)须(xu)接(jie)地(di)(di)。

但是经常有客户采用(yong)错误的接地方法为显示(shi)屏接地，常见的有：

1、认为户外立(li)柱式结构的立(li)柱下端是与大(da)地(di)连接，所(suo)以不需要在做显示(shi)屏(ping)接地(di)；

2、认为电源是锁(suo)在箱(xiang)体上，而箱(xiang)体之(zhi)间(jian)是相互用锁(suo)扣与结(jie)构(gou)连接(jie)，所以结(jie)构(gou)接(jie)地(di)就代表电源也(ye)接(jie)地(di)。

此(ci)两类做法存(cun)在误区，我(wo)们(men)的(de)(de)(de)立柱是(shi)与地(di)基的(de)(de)(de)地(di)脚螺栓保持(chi)连接(jie)(jie)(jie)，而地(di)脚螺栓是(shi)预埋(mai)在混凝土里面的(de)(de)(de)，混凝土的(de)(de)(de)电阻(zu)在100-500Ω的(de)(de)(de)范围内(nei)，接(jie)(jie)(jie)地(di)电阻(zu)过(guo)高(gao)将(jiang)(jiang)导(dao)(dao)(dao)致漏电流(liu)(liu)泄放不及时或(huo)(huo)存(cun)在残留。我(wo)们(men)的(de)(de)(de)箱体(ti)表面有喷涂油漆，而油漆是(shi)电的(de)(de)(de)不良导(dao)(dao)(dao)体(ti)，将(jiang)(jiang)会(hui)导(dao)(dao)(dao)致箱体(ti)连接(jie)(jie)(jie)接(jie)(jie)(jie)地(di)的(de)(de)(de)接(jie)(jie)(jie)触不良或(huo)(huo)接(jie)(jie)(jie)地(di)电阻(zu)升高(gao)，有可能出现电火花干扰屏体(ti)信号。随着(zhe)时间的(de)(de)(de)推移，箱体(ti)或(huo)(huo)结(jie)构(gou)表面将(jiang)(jiang)会(hui)出现氧化(hua)和(he)锈蚀，螺丝等(deng)固定件也随着(zhe)温差变(bian)化(hua)导(dao)(dao)(dao)致的(de)(de)(de)热胀冷缩逐渐(jian)松动。将(jiang)(jiang)会(hui)导(dao)(dao)(dao)致结(jie)构(gou)接(jie)(jie)(jie)地(di)的(de)(de)(de)效果减弱(ruo)甚至完(wan)全(quan)失效。形(xing)成安全(quan)隐患。导(dao)(dao)(dao)致漏流(liu)(liu)触电、芯片受(shou)干扰损坏(huai)等(deng)安全(quan)事故的(de)(de)(de)发生。

那么，标准的接(jie)(jie)(jie)(jie)地(di)(di)(di)应该是(shi)怎样(yang)的呢？电子(zi)(zi)(zi)显示屏厂家来告诉你，电源输入端有3个接(jie)(jie)(jie)(jie)线(xian)(xian)(xian)端子(zi)(zi)(zi)，分别是(shi)火线(xian)(xian)(xian)端子(zi)(zi)(zi)、零线(xian)(xian)(xian)端子(zi)(zi)(zi)和(he)接(jie)(jie)(jie)(jie)地(di)(di)(di)端子(zi)(zi)(zi)。正(zheng)确的接(jie)(jie)(jie)(jie)地(di)(di)(di)做法是(shi)使用接(jie)(jie)(jie)(jie)地(di)(di)(di)专(zhuan)用的黄绿(lv)双色线(xian)(xian)(xian)将所有电源地(di)(di)(di)线(xian)(xian)(xian)端子(zi)(zi)(zi)串接(jie)(jie)(jie)(jie)并锁紧(jin)，然后引(yin)出连接(jie)(jie)(jie)(jie)至接(jie)(jie)(jie)(jie)地(di)(di)(di)端。

如(ru)果现(xian)场(chang)没有接(jie)地(di)端子，可以(yi)连(lian)接(jie)至铁质自(zi)来水管(guan)或铁质下水管(guan)道(dao)等埋设与(yu)大地(di)并与(yu)大地(di)保(bao)持良好接(jie)触的管(guan)道(dao)上(shang)，为(wei)保(bao)证接(jie)触良好应(ying)在此类自(zi)然接(jie)地(di)体(ti)上(shang)焊接(jie)接(jie)线(xian)端子，然后将地(di)线(xian)紧锁在接(jie)线(xian)端子上(shang)，不得(de)捆(kun)绑(bang)连(lian)接(jie)。但煤气等易(yi)燃易(yi)爆和(he)的管(guan)道(dao)不得(de)使用(yong)。或者现(xian)场(chang)埋设接(jie)地(di)体(ti)。接(jie)地(di)体(ti)可以(yi)采用(yong)角钢或者钢管(guan)，水平(ping)或者竖直埋入大地(di)中作(zuo)为(wei)简易(yi)接(jie)地(di)点，接(jie)地(di)点应(ying)选择偏僻(pi)的地(di)方，以(yi)免行(xing)人或者车辆(liang)破坏(huai)接(jie)地(di)体(ti)。

我们接(jie)地(di)时接(jie)地(di)电阻必(bi)须小于(yu)4欧姆，以保证漏电流(liu)的(de)及(ji)时泄放。需(xu)(xu)要(yao)(yao)注(zhu)意的(de)是(shi)，防(fang)雷(lei)接(jie)地(di)端在(zai)泄放雷(lei)击电流(liu)时由(you)于(yu)大(da)地(di)电流(liu)的(de)扩(kuo)散需(xu)(xu)要(yao)(yao)一定(ding)时间，短时间内(nei)会(hui)导致大(da)地(di)电位升高，如果LED显(xian)示屏(ping)接(jie)地(di)联接(jie)至防(fang)雷(lei)接(jie)地(di)端，这(zhei)时大(da)地(di)电位比显(xian)示屏(ping)要(yao)(yao)高，雷(lei)击电流(liu)将会(hui)沿顺这(zhei)地(di)线传递(di)至屏(ping)体，造成设备损(sun)坏。所(suo)以LED显(xian)示屏(ping)这(zhei)种保护接(jie)地(di)不得联结至防(fang)雷(lei)接(jie)地(di)端上，保护接(jie)地(di)端必(bi)须距离防(fang)雷(lei)接(jie)地(di)端20米以上。防(fang)止地(di)电位的(de)反击。

LED接地注意事(shi)项总结：

1、每(mei)个(ge)电源都必须从接(jie)地端子接(jie)地，并锁紧；

2、接地电阻不(bu)得大于4Ω；

3、地(di)线(xian)应为(wei)专属导(dao)线(xian)，严禁和(he)零线(xian)联接；

4、地(di)线(xian)上不得(de)安装(zhuang)空开或熔断器(qi)；

5、地线(xian)和(he)接(jie)地端子都应远离防雷接(jie)地端20以(yi)上；

严禁部分(fen)设备采用保护(hu)接(jie)(jie)地来代替(ti)保护(hu)接(jie)(jie)零，造(zao)成保护(hu)接(jie)(jie)地和保护(hu)接(jie)(jie)零混接(jie)(jie)错接(jie)(jie)。当某一保护(hu)接(jie)(jie)地设备的绝(jue)缘损(sun)坏，发生相线碰壳时(shi)，零线出现对(dui)地电压，于是使保护(hu)接(jie)(jie)零设备的外(wai)壳上(shang)就产(chan)生了危险电压。

因此，在同一(yi)(yi)母线供电(dian)(dian)的(de)线路中，保(bao)(bao)护(hu)接(jie)(jie)地(di)和保(bao)(bao)护(hu)接(jie)(jie)零不能(neng)混用(yong)，即不可把一(yi)(yi)部分电(dian)(dian)气设备(bei)接(jie)(jie)零，而将(jiang)另一(yi)(yi)部分电(dian)(dian)气设备(bei)接(jie)(jie)地(di)。一(yi)(yi)般(ban)市电(dian)(dian)都采(cai)(cai)用(yong)接(jie)(jie)零保(bao)(bao)护(hu)，故使用(yong)市电(dian)(dian)的(de)电(dian)(dian)气设备(bei)，应采(cai)(cai)取(qu)接(jie)(jie)零保(bao)(bao)护(hu)。

4、保护接(jie)零注意事项

（1）在(zai)保护接零(ling)(ling)的(de)电(dian)气(qi)系统中。零(ling)(ling)线(xian)起着(zhe)至关重要的(de)作用(yong)。一旦零(ling)(ling)线(xian)断(duan)开，接在(zai)断(duan)线(xian)处后面的(de)一段线(xian)路的(de)电(dian)气(qi)设(she)备(bei)相当于没有(you)了保护接零(ling)(ling)和保护接地(di)，若在(zai)零(ling)(ling)线(xian)断(duan)处后面有(you)电(dian)气(qi)设(she)备(bei)外壳漏电(dian)则不构成短(duan)路回(hui)路，而(er)使熔(rong)体熔(rong)断(duan)。不但该台设(she)备(bei)外壳带有(you)电(dian)压(ya)，而(er)且使得断(duan)线(xian)处后面的(de)所有(you)设(she)备(bei)的(de)外壳都存(cun)在(zai)接近(jin)电(dian)源(yuan)相电(dian)压(ya)的(de)对地(di)电(dian)压(ya)，触电(dian)危险性将扩(kuo)大。

所有电气设备接保(bao)护(hu)接零线均应(ying)以并联方(fang)式接在(zai)电源零线上(shang)，不允许串(chuan)联，并用螺栓压紧(jin)，牢(lao)固(gu)可靠，接触(chu)良(liang)好。在(zai)零线上(shang)，禁止(zhi)安装保(bao)险和(he)单(dan)独(du)开关。在(zai)特殊的环境中，零线做防(fang)腐处理也就不言而喻了。

（2）中(zhong)(zhong)性点(dian)不接(jie)地(di)(di)的三相(xiang)四(si)线(xian)(xian)制配电(dian)系(xi)(xi)统中(zhong)(zhong)，不允许(xu)用保护(hu)接(jie)零，只(zhi)能用保护(hu)接(jie)地(di)(di)。系(xi)(xi)统中(zhong)(zhong)任意一相(xiang)发生接(jie)地(di)(di)，整个系(xi)(xi)统仍(reng)照常运行，但大地(di)(di)与接(jie)地(di)(di)线(xian)(xian)等电(dian)位(wei)，则接(jie)在(zai)零线(xian)(xian)上的用电(dian)设(she)备外(wai)壳对地(di)(di)电(dian)压(ya)降(jiang)等于(yu)接(jie)地(di)(di)的相(xiang)线(xian)(xian)从接(jie)地(di)(di)点(dian)到中(zhong)(zhong)性点(dian)的电(dian)压(ya)值，是十分危(wei)险的。

（3）在(zai)采用保护接(jie)(jie)(jie)零(ling)系统中(zhong)还要在(zai)电源中(zhong)性点进(jin)行(xing)工作接(jie)(jie)(jie)地(di)和零(ling)线(xian)一定间(jian)隔距离及(ji)终端进(jin)行(xing)重(zhong)复(fu)接(jie)(jie)(jie)地(di)。在(zai)中(zhong)性点接(jie)(jie)(jie)地(di)的系统中(zhong)除将变压器中(zhong)性点做(zuo)接(jie)(jie)(jie)地(di)外，沿零(ling)线(xian)走向的一处或者多处再次将零(ling)线(xian)接(jie)(jie)(jie)地(di)叫(jiao)重(zhong)复(fu)接(jie)(jie)(jie)地(di)。

其作用是当(dang)(dang)电(dian)气(qi)设备外壳漏电(dian)时(shi)可以降低对地(di)电(dian)压。当(dang)(dang)零(ling)线(xian)断(duan)(duan)时(shi)也减轻(qing)触电(dian)危险(xian)。当(dang)(dang)电(dian)气(qi)设备外壳漏电(dian)时(shi)，经(jing)相线(xian)、零(ling)线(xian)构成短路(lu)回路(lu)，短路(lu)电(dian)流将熔(rong)(rong)断(duan)(duan)保(bao)险(xian)。设备外壳随(sui)之断(duan)(duan)电(dian)，不会(hui)出现触电(dian)危险(xian)。但是保(bao)险(xian)熔(rong)(rong)断(duan)(duan)之前设备带电(dian)，对人(ren)身(shen)还是有危险(xian)的(de)(de)。若(ruo)在接近设备处再(zai)加接地(di)装置(zhi)，即(ji)实行(xing)重复接地(di)，带电(dian)设备的(de)(de)导体部(bu)分对地(di)电(dian)压降低。

（4）保护(hu)(hu)接零必须有可靠灵敏的短路(lu)保护(hu)(hu)装置来配(pei)合，因此，熔(rong)断丝严(yan)禁用(yong)铜丝等金(jin)属(shu)材料来代替符(fu)合要求的金(jin)属(shu)熔(rong)断丝，否(fou)则(ze)接零保护(hu)(hu)将(jiang)失(shi)去其保护(hu)(hu)作用(yong)。

以上都是电子显(xian)示(shi)屏厂家(jia)(jia)为(wei)大家(jia)(jia)讲解的(de)关(guan)于(yu)LED显(xian)示(shi)屏接地的(de)重要性(xing)，希望(wang)这篇文章对大家(jia)(jia)有所帮助(zhu)！