在(zai)實際上(shang)工作(zuo)上(shang)，有的(de)(de)(de)新手(shou)會簡易(yi)(yi)地覺得零線(xian)就(jiu)是說接地線(xian)(又稱:避雷線(xian))，對供(gong)電系(xi)統中常常采用的(de)(de)(de)PE線(xian)、PEN線(xian)等的(de)(de)(de)差別不太掌握。在(zai)低壓(ya)安裝維(wei)護保(bao)(bao)養和(he)維(wei)修中經(jing)常把電器(qi)產品的(de)(de)(de)所(suo)述各(ge)種各(ge)樣保(bao)(bao)護布線(xian)混(hun)為一談，造成電器(qi)的(de)(de)(de)保(bao)(bao)護布線(xian)錯亂(luan)、不正(zheng)確，導致多余的(de)(de)(de)不便，比較嚴重的(de)(de)(de)乃至引(yin)起安全(quan)事故。因此，網編將(jiang)380V/220V金屬(shu)材料表箱系(xi)統中各(ge)種各(ge)樣“線(xian)”的(de)(de)(de)含意(yi)，作(zuo)一簡易(yi)(yi)詳細介紹，僅供(gong)參考。

相線

相(xiang)線(xian)(xian)，別名火線(xian)(xian)零(ling)線(xian)(xian)，是相(xiang)對(dui)(dui)性(xing)(xing)于中(zhong)性(xing)(xing)線(xian)(xian)（零(ling)線(xian)(xian)）而(er)言的(de)(de)，指的(de)(de)是三(san)(san)相(xiang)交流(liu)電(dian)(dian)路(lu)中(zhong)的(de)(de)三(san)(san)根(gen)(gen)(gen)相(xiang)線(xian)(xian)L1，L2，L3中(zhong)的(de)(de)隨意一根(gen)(gen)(gen)。一般 家中(zhong)用電(dian)(dian)量僅用三(san)(san)相(xiang)交流(liu)電(dian)(dian)的(de)(de)在其中(zhong)一相(xiang)，相(xiang)線(xian)(xian)對(dui)(dui)地（中(zhong)性(xing)(xing)線(xian)(xian)）的(de)(de)工(gong)作電(dian)(dian)壓為220V，叫(jiao)相(xiang)電(dian)(dian)壓，這是與中(zhong)性(xing)(xing)線(xian)(xian)組成控(kong)制回路(lu)，使電(dian)(dian)流(liu)量根(gen)(gen)(gen)據電(dian)(dian)器(qi)產品而(er)工(gong)作中(zhong)的(de)(de)。不(bu)一樣相(xiang)的(de)(de)相(xiang)線(xian)(xian)中(zhong)間的(de)(de)工(gong)作電(dian)(dian)壓為380V，叫(jiao)相(xiang)電(dian)(dian)壓。一般來說，三(san)(san)相(xiang)電(dian)(dian)路(lu)中(zhong)三(san)(san)根(gen)(gen)(gen)相(xiang)線(xian)(xian)L1，L2，L3各自應(ying)用黃、綠、紅三(san)(san)種色調標識。

中性線

三相四線(xian)制或(huo)三相五線(xian)制低壓供配電(dian)(dian)系統中(zhong)(zhong)(zhong)，中(zhong)(zhong)(zhong)性(xing)線(xian)也(ye)稱中(zhong)(zhong)(zhong)心線(xian)、零線(xian)、工作中(zhong)(zhong)(zhong)零線(xian)、N線(xian)，路線(xian)上(shang)放灰(hui)黑色標(biao)識。一般 中(zhong)(zhong)(zhong)性(xing)線(xian)就是指從(cong)變(bian)壓（標(biao)準氣壓自變(bian)量)器中(zhong)(zhong)(zhong)性(xing)點引出(chu)來的一條線(xian)。對接地裝置電(dian)(dian)力網(wang)而言，變(bian)電(dian)(dian)器(Transformer)中(zhong)(zhong)(zhong)性(xing)點也(ye)要(yao)接地裝置，其接地線(xian)電(dian)(dian)阻一般不(bu)容許超過4Ω。

中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)的功效是使星形連接的三(san)(san)(san)相(xiang)(xiang)(xiang)不一(yi)(yi)樣(yang)負(fu)(fu)荷(he)的相(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)維持對(dui)(dui)稱性(xing)(xing)(xing)(xing)。針對(dui)(dui)三(san)(san)(san)相(xiang)(xiang)(xiang)對(dui)(dui)稱性(xing)(xing)(xing)(xing)負(fu)(fu)荷(he)，因(yin)中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)電(dian)(dian)(dian)(dian)流(liu)(liu)量(Electron flow)為(wei)零，因(yin)此能夠省掉中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)。針對(dui)(dui)三(san)(san)(san)相(xiang)(xiang)(xiang)不一(yi)(yi)樣(yang)負(fu)(fu)荷(he)，因(yin)存有中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)電(dian)(dian)(dian)(dian)流(liu)(liu)量，務(wu)必有中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)均衡(heng)(heng)三(san)(san)(san)相(xiang)(xiang)(xiang)負(fu)(fu)載的工(gong)作電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，不然，三(san)(san)(san)相(xiang)(xiang)(xiang)不一(yi)(yi)樣(yang)負(fu)(fu)荷(he)的各相(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)就已不相(xiang)(xiang)(xiang)同（均衡(heng)(heng)）了，特性(xing)(xing)(xing)(xing)阻抗較小的相(xiang)(xiang)(xiang)其負(fu)(fu)荷(he)工(gong)作電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)低(di)，特性(xing)(xing)(xing)(xing)阻抗很(hen)大的相(xiang)(xiang)(xiang)其負(fu)(fu)荷(he)工(gong)作電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)高，易造成電(dian)(dian)(dian)(dian)器產(chan)品(pin)毀壞。因(yin)此，在三(san)(san)(san)相(xiang)(xiang)(xiang)負(fu)(fu)載不一(yi)(yi)樣(yang)的低(di)壓(ya)(ya)(ya)(ya)供配電(dian)(dian)(dian)(dian)系統中(zhong)(zhong)，不容許在中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)上(shang)安(an)裝(zhuang)斷路器（Fuse)和(he)獨立操(cao)縱（control)的電(dian)(dian)(dian)(dian)源(yuan)開關設備，并(bing)且中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)常(chang)見(jian)鋼芯鋁絞(jiao)線(xian)做成，以防中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)斷掉產(chan)生安(an)全事故。相(xiang)(xiang)(xiang)線(xian)和(he)中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)的差(cha)別(bie)取決于，他(ta)們對(dui)(dui)地的工(gong)作電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)不一(yi)(yi)樣(yang)，相(xiang)(xiang)(xiang)線(xian)對(dui)(dui)地工(gong)作電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)為(wei)220V，通常(chang)情(qing)況下中(zhong)(zhong)性(xing)(xing)(xing)(xing)線(xian)對(dui)(dui)地工(gong)作電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)為(wei)零。

保護線

保護線(xian)（也叫PE線(xian)，英語(yu)全名是(shi)GOOGLE PRotecting earthing），是(shi)根據掩埋的(de)金屬電(dian)(dian)(dian)(electrode)與(yu)地面(mian)短路故障(zhang)(電(dian)(dian)(dian)流量(liang)沒經大功率電(dian)(dian)(dian)器、立即連(lian)開關電(dian)(dian)(dian)源兩(liang)方面(mian))聯接(jie)的(de)輸電(dian)(dian)(dian)線(xian)，也就是(shi)說(shuo)人(ren)們一(yi)(yi)般(ban) 常說(shuo)的(de)接(jie)地線(xian)(又稱:避雷(lei)線(xian))，是(shi)用以將(jiang)電(dian)(dian)(dian)氣設(she)備設(she)備露出(chu)導電(dian)(dian)(dian)性(xing)一(yi)(yi)部分接(jie)地裝置的(de)電(dian)(dian)(dian)導體(ti)。

保(bao)護線(xian)(xian)可分成工作中(zhong)電(dian)(dian)(dian)線(xian)(xian)接(jie)頭(tou)和保(bao)護電(dian)(dian)(dian)線(xian)(xian)接(jie)頭(tou)。低壓供電(dian)(dian)(dian)系統(tong)中(zhong)，變(bian)壓（標(biao)準氣壓自變(bian)量)器(qi)(qi)中(zhong)性(xing)(xing)點(dian)與(yu)(yu)工作接(jie)地體的(de)(de)(de)(de)電(dian)(dian)(dian)連接(jie)線(xian)(xian)叫工作中(zhong)電(dian)(dian)(dian)線(xian)(xian)接(jie)頭(tou)；電(dian)(dian)(dian)器(qi)(qi)產品金(jin)屬(shu)外殼與(yu)(yu)接(jie)地保(bao)護體的(de)(de)(de)(de)電(dian)(dian)(dian)連接(jie)線(xian)(xian)叫保(bao)護電(dian)(dian)(dian)線(xian)(xian)接(jie)頭(tou)，用黃、綠(lv)兩(liang)色表達。在(zai)TT系統(tong)中(zhong)，PE線(xian)(xian)立即聯接(jie)至(zhi)與(yu)(yu)電(dian)(dian)(dian)源(yuan)點(dian)工作接(jie)地不相干(gan)的(de)(de)(de)(de)接(jie)地裝置上，又稱之為PEE線(xian)(xian)；在(zai)TN—C系統(tong)中(zhong)，全部系統(tong)的(de)(de)(de)(de)PE線(xian)(xian)與(yu)(yu)中(zhong)性(xing)(xing)線(xian)(xian)是合一的(de)(de)(de)(de)；在(zai)TN—S系統(tong)中(zhong)，各大功率電(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)PE線(xian)(xian)立即與(yu)(yu)低壓供配電(dian)(dian)(dian)系統(tong)中(zhong)型(xing)的(de)(de)(de)(de)公共(gong)(gong)PE線(xian)(xian)聯接(jie)，公共(gong)(gong)PE線(xian)(xian)要與(yu)(yu)變(bian)電(dian)(dian)(dian)器(qi)(qi)工作接(jie)地靠譜聯接(jie)；在(zai) TN—C—S系統(tong)中(zhong)，變(bian)電(dian)(dian)(dian)器(qi)(qi)低壓側(ce)至(zhi)客戶開(kai)關電(dian)(dian)(dian)源(yuan)三(san)相五(wu)線(xian)(xian)點(dian)間的(de)(de)(de)(de)一段路線(xian)(xian)，PE線(xian)(xian)與(yu)(yu)公共(gong)(gong)中(zhong)性(xing)(xing)線(xian)(xian)聯接(jie)，客戶開(kai)關電(dian)(dian)(dian)源(yuan)三(san)相五(wu)線(xian)(xian)點(dian)后各電(dian)(dian)(dian)器(qi)(qi)下設公共(gong)(gong)的(de)(de)(de)(de)PE線(xian)(xian)，各電(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)PE線(xian)(xian)與(yu)(yu)公共(gong)(gong)的(de)(de)(de)(de)PE線(xian)(xian)聯接(jie)。

保護(hu)中性線

保護中(zhong)(zhong)性(xing)(xing)線(xian)(xian)（也(ye)叫(jiao)PEN線(xian)(xian)、保護中(zhong)(zhong)性(xing)(xing)化電(dian)(dian)(dian)(dian)導(dao)體(ti)），標識(shi)色是(shi)豎(shu)條間距(ju)淡藍色，是(shi)將(jiang)(jiang)PE線(xian)(xian)和(he)(he)(he)N線(xian)(xian)合(he)二(er)為一，兼具(ju)備保護線(xian)(xian)和(he)(he)(he)中(zhong)(zhong)性(xing)(xing)線(xian)(xian)作用(yong)的(de)電(dian)(dian)(dian)(dian)導(dao)體(ti)。低(di)壓(ya)供電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)中(zhong)(zhong)的(de)TN—C系(xi)統(tong)(tong)，全程將(jiang)(jiang)PE線(xian)(xian)和(he)(he)(he)N線(xian)(xian)合(he)二(er)為一；TN—C—S系(xi)統(tong)(tong)，變壓(ya)（標準氣壓(ya)自變量)器低(di)壓(ya)側(ce)至客(ke)戶開關(guan)電(dian)(dian)(dian)(dian)源(yuan)三相五(wu)線(xian)(xian)點間的(de)一段(duan)路線(xian)(xian)，將(jiang)(jiang)PE線(xian)(xian)和(he)(he)(he)N線(xian)(xian)合(he)二(er)為一；TN—S系(xi)統(tong)(tong)，將(jiang)(jiang)PE線(xian)(xian)和(he)(he)(he)N線(xian)(xian)全程分離。供配電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)選用(yong)PEN線(xian)(xian)，一般 是(shi)以便節約(yue)(spare)原材(cai)料(liao)，但(dan)是(shi)減少了供電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)的(de)可信性(xing)(xing)和(he)(he)(he)安全系(xi)數(security)。有(you)標準的(de)地區，低(di)壓(ya)供電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)理應較(jiao)大將(jiang)(jiang)會（maybe)地應用(yong)TN—S系(xi)統(tong)(tong)，即布署單獨的(de)PE保護線(xian)(xian)，而并不是(shi)這類(lei)將(jiang)(jiang)N線(xian)(xian)和(he)(he)(he)PE線(xian)(xian)捆(kun)縛于一起(qi)的(de)TN—C系(xi)統(tong)(tong)。特別提示：對供電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)安全系(xi)數規定較(jiao)為高，非常是(shi)存有(you)發(fa)生風險(xian)的(de)場(chang)地，務必采用(yong) TN—S系(xi)統(tong)(tong)供電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)。

保護線和(he)中(zhong)性線的差別

中(zhong)(zhong)性(xing)線(xian)(xian)(xian)（N線(xian)(xian)(xian)）是(shi)(shi)(shi)與變(bian)壓(ya)（標(biao)準氣壓(ya)自變(bian)量(liang))器(Transformer)中(zhong)(zhong)性(xing)點聯接，能夠具(ju)有(you)(you)維持(chi)三相不(bu)(bu)(bu)一(yi)(yi)樣負(fu)荷工(gong)(gong)作電壓(ya)對(dui)稱性(xing)和傳送電磁能的(de)(de)功(gong)效，在(zai)單相電系統中(zhong)(zhong)，沒有(you)(you)它(ta)(ta)，各種(zhong)各樣電器就不(bu)(bu)(bu)可(ke)(ke)以一(yi)(yi)切正常工(gong)(gong)作中(zhong)(zhong)，從這(zhe)一(yi)(yi)視角（angle)看，N線(xian)(xian)(xian)是(shi)(shi)(shi)工(gong)(gong)作中(zhong)(zhong)線(xian)(xian)(xian)，必(bi)不(bu)(bu)(bu)可(ke)(ke)少。而(er)保(bao)護線(xian)(xian)(xian)（PE線(xian)(xian)(xian)），則是(shi)(shi)(shi)和用電量(liang)機(ji)器設備殼子(zi)相互連接的(de)(de)接地線(xian)(xian)(xian)(又稱:避(bi)雷(lei)線(xian)(xian)(xian))，沒有(you)(you)它(ta)(ta)，用電量(liang)機(ji)器設備可(ke)(ke)以一(yi)(yi)切正常工(gong)(gong)作中(zhong)(zhong)，并不(bu)(bu)(bu)是(shi)(shi)(shi)必(bi)不(bu)(bu)(bu)可(ke)(ke)少。但萬一(yi)(yi)電器殼子(zi)因常見(jian)故(gu)障感應起電，沒有(you)(you)它(ta)(ta)，觸碰電器金屬(shu)外(wai)殼的(de)(de)人總(zong)有(you)(you)將(jiang)會產生(sheng)安全(quan)事故(gu)。能夠說，保(bao)護線(xian)(xian)(xian)的(de)(de)功(gong)效是(shi)(shi)(shi)避(bi)免安全(quan)事故(gu)的(de)(de)產生(sheng)，因而(er)是(shi)(shi)(shi)保(bao)護輸電線(xian)(xian)(xian)。

因為保護(hu)線的(de)有(you)沒有(you)，不(bu)危害(hai)電器(qi)(qi)的(de)一切正常工作(zuo)中(zhong)，因而，在低(di)壓(ya)客(ke)戶(hu)中(zhong)不(bu)被高度重(zhong)視。現階段，在我國一部(bu)分城區家中(zhong)和很多鄉村家中(zhong)用電量，有(you)許(xu)多該接(jie)保護(hu)線的(de)電器(qi)(qi)（Ⅰ類(lei)電器(qi)(qi)，即開(kai)關電源引出線選用三腳電源插頭的(de)電器(qi)(qi)）也沒有(you)聯(lian)接(jie)保護(hu)線，造成應(ying)用這種電器(qi)(qi)時存有(you)安全風(feng)險，應(ying)造成充足高度重(zhong)視。