大連配電箱配電(dian)(dian)柜(ju)(ju)分動(dong)力(li)柜(ju)(ju)和照明配電(dian)(dian)柜(ju)(ju)，計(ji)量柜(ju)(ju)是配電(dian)(dian)系統(tong)的(de)(de)末級設備。大連配電(dian)(dian)箱配電(dian)(dian)柜(ju)(ju)是電(dian)(dian)動(dong)機控制(zhi)中心(xin)的(de)(de)統(tong)稱。配電(dian)(dian)柜(ju)(ju)使用(yong)在負荷比較分散、回路較多的(de)(de)場(chang)合。它們把上一級配電(dian)(dian)設備某一電(dian)(dian)路的(de)(de)電(dian)(dian)能分配給就近的(de)(de)負荷。這級設備提供保護，監視(shi)和控制(zhi)。

    三相(xiang)(xiang)五線(xian)(xian)(xian)(xian)(xian)制包括三相(xiang)(xiang)電(dian)的(de)三個相(xiang)(xiang)線(xian)(xian)(xian)(xian)(xian)（A、B、C線(xian)(xian)(xian)(xian)(xian)）、中(zhong)(zhong)性線(xian)(xian)(xian)(xian)(xian)（N線(xian)(xian)(xian)(xian)(xian)）以及地(di)線(xian)(xian)(xian)(xian)(xian)（PE線(xian)(xian)(xian)(xian)(xian)）。中(zhong)(zhong)心線(xian)(xian)(xian)(xian)(xian)（N線(xian)(xian)(xian)(xian)(xian)）就是(shi)零(ling)線(xian)(xian)(xian)(xian)(xian)。三相(xiang)(xiang)負載(zai)對(dui)稱時，三相(xiang)(xiang)線(xian)(xian)(xian)(xian)(xian)路流入中(zhong)(zhong)性線(xian)(xian)(xian)(xian)(xian)的(de)電(dian)流矢量和為零(ling)，但對(dui)于單獨的(de)一相(xiang)(xiang)來講，電(dian)流不(bu)為零(ling)。三相(xiang)(xiang)負載(zai)不(bu)對(dui)稱時，中(zhong)(zhong)性線(xian)(xian)(xian)(xian)(xian)的(de)電(dian)流矢量和不(bu)為零(ling)，會(hui)產生對(dui)地(di)電(dian)壓。

    大連配電箱三(san)相五線(xian)(xian)制的特(te)點(dian)如(ru)下：1、系統(tong)正常運行時，專用(yong)(yong)(yong)(yong)保(bao)(bao)護(hu)(hu)線(xian)(xian)上(shang)不(bu)(bu)有(you)(you)電流，只是(shi)工作(zuo)零(ling)線(xian)(xian)上(shang)有(you)(you)不(bu)(bu)平衡電流。PE線(xian)(xian)對地沒有(you)(you)電壓(ya)，所以電氣設備金屬外殼接零(ling)保(bao)(bao)護(hu)(hu)是(shi)接在專用(yong)(yong)(yong)(yong)的保(bao)(bao)護(hu)(hu)線(xian)(xian)PE上(shang)，安全(quan)可靠；2、工作(zuo)零(ling)線(xian)(xian)只用(yong)(yong)(yong)(yong)作(zuo)單相照明負載(zai)回路；3、專用(yong)(yong)(yong)(yong)保(bao)(bao)護(hu)(hu)線(xian)(xian)PE不(bu)(bu)許(xu)斷線(xian)(xian)，也(ye)不(bu)(bu)許(xu)進(jin)入漏電開關；4、干線(xian)(xian)上(shang)使用(yong)(yong)(yong)(yong)漏電保(bao)(bao)護(hu)(hu)器，工作(zuo)零(ling)線(xian)(xian)不(bu)(bu)得有(you)(you)重復接地，而(er)PE線(xian)(xian)有(you)(you)重復接地，但是(shi)不(bu)(bu)經(jing)過漏電保(bao)(bao)護(hu)(hu)器，所以TN-S系統(tong)供(gong)電干線(xian)(xian)上(shang)也(ye)可以安裝漏電保(bao)(bao)護(hu)(hu)器；5、TN-S方式供(gong)電系統(tong)安全(quan)可靠，適用(yong)(yong)(yong)(yong)于工業與民用(yong)(yong)(yong)(yong)建筑等低(di)壓(ya)供(gong)電系統(tong)。