在實(shi)際(ji)上工作(zuo)上，有(you)的(de)(de)新手會(hui)簡(jian)易地覺得零線(xian)(xian)(xian)就是說接地線(xian)(xian)(xian)(又(you)稱:避雷線(xian)(xian)(xian))，對供電系統中(zhong)常(chang)常(chang)采用(yong)的(de)(de)PE線(xian)(xian)(xian)、PEN線(xian)(xian)(xian)等的(de)(de)差別不太掌握。在低壓安裝維(wei)(wei)護(hu)保養和維(wei)(wei)修中(zhong)經常(chang)把電器(qi)產品的(de)(de)所(suo)述(shu)各(ge)(ge)種各(ge)(ge)樣保護(hu)布線(xian)(xian)(xian)混為一(yi)談，造成電器(qi)的(de)(de)保護(hu)布線(xian)(xian)(xian)錯亂、不正確(que)，導致多余的(de)(de)不便，比較嚴重的(de)(de)乃(nai)至引起安全事故。因此，網編將380V/220V金屬材(cai)料表箱系統中(zhong)各(ge)(ge)種各(ge)(ge)樣“線(xian)(xian)(xian)”的(de)(de)含意，作(zuo)一(yi)簡(jian)易詳細介(jie)紹，僅供參考。

相線

相(xiang)(xiang)線(xian)(xian)，別名火(huo)線(xian)(xian)零(ling)(ling)線(xian)(xian)，是相(xiang)(xiang)對性(xing)于中(zhong)(zhong)性(xing)線(xian)(xian)（零(ling)(ling)線(xian)(xian)）而言的(de)(de)，指的(de)(de)是三(san)(san)相(xiang)(xiang)交(jiao)流(liu)電(dian)(dian)路中(zhong)(zhong)的(de)(de)三(san)(san)根(gen)相(xiang)(xiang)線(xian)(xian)L1，L2，L3中(zhong)(zhong)的(de)(de)隨意一根(gen)。一般(ban) 家中(zhong)(zhong)用(yong)(yong)電(dian)(dian)量(liang)僅(jin)用(yong)(yong)三(san)(san)相(xiang)(xiang)交(jiao)流(liu)電(dian)(dian)的(de)(de)在其中(zhong)(zhong)一相(xiang)(xiang)，相(xiang)(xiang)線(xian)(xian)對地（中(zhong)(zhong)性(xing)線(xian)(xian)）的(de)(de)工作電(dian)(dian)壓(ya)(ya)為220V，叫相(xiang)(xiang)電(dian)(dian)壓(ya)(ya)，這是與中(zhong)(zhong)性(xing)線(xian)(xian)組成控制回路，使電(dian)(dian)流(liu)量(liang)根(gen)據電(dian)(dian)器產品而工作中(zhong)(zhong)的(de)(de)。不一樣相(xiang)(xiang)的(de)(de)相(xiang)(xiang)線(xian)(xian)中(zhong)(zhong)間的(de)(de)工作電(dian)(dian)壓(ya)(ya)為380V，叫相(xiang)(xiang)電(dian)(dian)壓(ya)(ya)。一般(ban)來(lai)說，三(san)(san)相(xiang)(xiang)電(dian)(dian)路中(zhong)(zhong)三(san)(san)根(gen)相(xiang)(xiang)線(xian)(xian)L1，L2，L3各自應用(yong)(yong)黃、綠、紅三(san)(san)種色調標識。

中性線

三相(xiang)四線(xian)(xian)(xian)制(zhi)或三相(xiang)五(wu)線(xian)(xian)(xian)制(zhi)低壓供配電系統中，中性(xing)線(xian)(xian)(xian)也稱中心線(xian)(xian)(xian)、零線(xian)(xian)(xian)、工作中零線(xian)(xian)(xian)、N線(xian)(xian)(xian)，路(lu)線(xian)(xian)(xian)上(shang)放灰黑色標識。一(yi)般(ban) 中性(xing)線(xian)(xian)(xian)就(jiu)是(shi)指從(cong)變(bian)壓（標準氣(qi)壓自變(bian)量)器中性(xing)點(dian)引出來的一(yi)條線(xian)(xian)(xian)。對(dui)接地裝置電力網而言，變(bian)電器(Transformer)中性(xing)點(dian)也要接地裝置，其接地線(xian)(xian)(xian)電阻一(yi)般(ban)不容(rong)許超過4Ω。

 中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)的(de)功效是使星形連(lian)接的(de)三(san)相(xiang)(xiang)不一(yi)樣(yang)負(fu)荷(he)(he)的(de)相(xiang)(xiang)電(dian)(dian)壓(ya)維持對稱性(xing)(xing)(xing)(xing)(xing)。針對三(san)相(xiang)(xiang)對稱性(xing)(xing)(xing)(xing)(xing)負(fu)荷(he)(he)，因中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)電(dian)(dian)流量(Electron flow)為零(ling)，因此能(neng)夠省掉中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)。針對三(san)相(xiang)(xiang)不一(yi)樣(yang)負(fu)荷(he)(he)，因存(cun)有(you)中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)電(dian)(dian)流量，務(wu)必有(you)中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)均衡三(san)相(xiang)(xiang)負(fu)載的(de)工(gong)作電(dian)(dian)壓(ya)，不然(ran)，三(san)相(xiang)(xiang)不一(yi)樣(yang)負(fu)荷(he)(he)的(de)各相(xiang)(xiang)電(dian)(dian)壓(ya)就已不相(xiang)(xiang)同（均衡）了，特(te)性(xing)(xing)(xing)(xing)(xing)阻(zu)抗較小的(de)相(xiang)(xiang)其負(fu)荷(he)(he)工(gong)作電(dian)(dian)壓(ya)低，特(te)性(xing)(xing)(xing)(xing)(xing)阻(zu)抗很大的(de)相(xiang)(xiang)其負(fu)荷(he)(he)工(gong)作電(dian)(dian)壓(ya)高，易造成(cheng)電(dian)(dian)器產品毀壞(huai)。因此，在三(san)相(xiang)(xiang)負(fu)載不一(yi)樣(yang)的(de)低壓(ya)供配電(dian)(dian)系統中(zhong)，不容許在中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)上安裝(zhuang)斷(duan)路器（Fuse)和獨立操縱(zong)（control)的(de)電(dian)(dian)源開關設備(bei)，并且中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)常(chang)見(jian)鋼芯鋁絞(jiao)線(xian)(xian)(xian)做成(cheng)，以防中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)斷(duan)掉產生(sheng)安全事(shi)故。相(xiang)(xiang)線(xian)(xian)(xian)和中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)的(de)差別取(qu)決于，他們對地(di)的(de)工(gong)作電(dian)(dian)壓(ya)不一(yi)樣(yang)，相(xiang)(xiang)線(xian)(xian)(xian)對地(di)工(gong)作電(dian)(dian)壓(ya)為220V，通常(chang)情況下(xia)中(zhong)性(xing)(xing)(xing)(xing)(xing)線(xian)(xian)(xian)對地(di)工(gong)作電(dian)(dian)壓(ya)為零(ling)。

保護線

保護(hu)線(xian)（也(ye)叫PE線(xian)，英(ying)語(yu)全名是(shi)(shi)GOOGLE PRotecting earthing），是(shi)(shi)根(gen)據掩(yan)埋的(de)金(jin)屬電(dian)(electrode)與地面短(duan)路故障(電(dian)流量沒(mei)經大(da)功率電(dian)器、立即連開(kai)關電(dian)源(yuan)兩方面)聯接(jie)(jie)的(de)輸(shu)電(dian)線(xian)，也(ye)就(jiu)是(shi)(shi)說(shuo)人(ren)們一般 常說(shuo)的(de)接(jie)(jie)地線(xian)(又稱:避雷線(xian))，是(shi)(shi)用(yong)以將(jiang)電(dian)氣設備(bei)設備(bei)露出導電(dian)性一部分接(jie)(jie)地裝置(zhi)的(de)電(dian)導體。

保護線(xian)(xian)(xian)(xian)(xian)(xian)可分成工(gong)作(zuo)中(zhong)(zhong)(zhong)電(dian)(dian)線(xian)(xian)(xian)(xian)(xian)(xian)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)頭(tou)和保護電(dian)(dian)線(xian)(xian)(xian)(xian)(xian)(xian)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)頭(tou)。低(di)壓供(gong)電(dian)(dian)系(xi)統(tong)(tong)(tong)中(zhong)(zhong)(zhong)，變壓（標(biao)準氣壓自變量)器(qi)(qi)中(zhong)(zhong)(zhong)性點(dian)與(yu)(yu)工(gong)作(zuo)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)體(ti)的(de)(de)(de)電(dian)(dian)連接(jie)(jie)(jie)(jie)(jie)(jie)(jie)線(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)工(gong)作(zuo)中(zhong)(zhong)(zhong)電(dian)(dian)線(xian)(xian)(xian)(xian)(xian)(xian)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)頭(tou)；電(dian)(dian)器(qi)(qi)產(chan)品金(jin)屬外殼與(yu)(yu)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)保護體(ti)的(de)(de)(de)電(dian)(dian)連接(jie)(jie)(jie)(jie)(jie)(jie)(jie)線(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)保護電(dian)(dian)線(xian)(xian)(xian)(xian)(xian)(xian)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)頭(tou)，用黃(huang)、綠兩(liang)色表達(da)。在(zai)TT系(xi)統(tong)(tong)(tong)中(zhong)(zhong)(zhong)，PE線(xian)(xian)(xian)(xian)(xian)(xian)立(li)即(ji)(ji)聯接(jie)(jie)(jie)(jie)(jie)(jie)(jie)至與(yu)(yu)電(dian)(dian)源點(dian)工(gong)作(zuo)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)不相干(gan)的(de)(de)(de)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)裝(zhuang)置上(shang)，又稱之(zhi)為(wei)PEE線(xian)(xian)(xian)(xian)(xian)(xian)；在(zai)TN—C系(xi)統(tong)(tong)(tong)中(zhong)(zhong)(zhong)，全部系(xi)統(tong)(tong)(tong)的(de)(de)(de)PE線(xian)(xian)(xian)(xian)(xian)(xian)與(yu)(yu)中(zhong)(zhong)(zhong)性線(xian)(xian)(xian)(xian)(xian)(xian)是(shi)合一(yi)的(de)(de)(de)；在(zai)TN—S系(xi)統(tong)(tong)(tong)中(zhong)(zhong)(zhong)，各大功率電(dian)(dian)器(qi)(qi)的(de)(de)(de)PE線(xian)(xian)(xian)(xian)(xian)(xian)立(li)即(ji)(ji)與(yu)(yu)低(di)壓供(gong)配電(dian)(dian)系(xi)統(tong)(tong)(tong)中(zhong)(zhong)(zhong)型的(de)(de)(de)公共(gong)PE線(xian)(xian)(xian)(xian)(xian)(xian)聯接(jie)(jie)(jie)(jie)(jie)(jie)(jie)，公共(gong)PE線(xian)(xian)(xian)(xian)(xian)(xian)要與(yu)(yu)變電(dian)(dian)器(qi)(qi)工(gong)作(zuo)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)靠譜聯接(jie)(jie)(jie)(jie)(jie)(jie)(jie)；在(zai) TN—C—S系(xi)統(tong)(tong)(tong)中(zhong)(zhong)(zhong)，變電(dian)(dian)器(qi)(qi)低(di)壓側至客戶開關(guan)電(dian)(dian)源三(san)相五(wu)線(xian)(xian)(xian)(xian)(xian)(xian)點(dian)間(jian)的(de)(de)(de)一(yi)段路線(xian)(xian)(xian)(xian)(xian)(xian)，PE線(xian)(xian)(xian)(xian)(xian)(xian)與(yu)(yu)公共(gong)中(zhong)(zhong)(zhong)性線(xian)(xian)(xian)(xian)(xian)(xian)聯接(jie)(jie)(jie)(jie)(jie)(jie)(jie)，客戶開關(guan)電(dian)(dian)源三(san)相五(wu)線(xian)(xian)(xian)(xian)(xian)(xian)點(dian)后各電(dian)(dian)器(qi)(qi)下設公共(gong)的(de)(de)(de)PE線(xian)(xian)(xian)(xian)(xian)(xian)，各電(dian)(dian)器(qi)(qi)的(de)(de)(de)PE線(xian)(xian)(xian)(xian)(xian)(xian)與(yu)(yu)公共(gong)的(de)(de)(de)PE線(xian)(xian)(xian)(xian)(xian)(xian)聯接(jie)(jie)(jie)(jie)(jie)(jie)(jie)。

保護中性線

保護中(zhong)性線（也(ye)叫PEN線、保護中(zhong)性化電(dian)(dian)導體），標(biao)識(shi)色是豎條間距淡藍色，是將(jiang)(jiang)PE線和(he)(he)N線合二(er)為(wei)(wei)一(yi)(yi)，兼具(ju)備保護線和(he)(he)中(zhong)性線作用的(de)(de)電(dian)(dian)導體。低壓供電(dian)(dian)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)中(zhong)的(de)(de)TN—C系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)，全(quan)程(cheng)將(jiang)(jiang)PE線和(he)(he)N線合二(er)為(wei)(wei)一(yi)(yi)；TN—C—S系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)，變壓（標(biao)準(zhun)氣壓自變量)器低壓側(ce)至客戶開(kai)關電(dian)(dian)源三相五線點間的(de)(de)一(yi)(yi)段路線，將(jiang)(jiang)PE線和(he)(he)N線合二(er)為(wei)(wei)一(yi)(yi)；TN—S系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)，將(jiang)(jiang)PE線和(he)(he)N線全(quan)程(cheng)分離。供配電(dian)(dian)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)選用PEN線，一(yi)(yi)般 是以便節約(spare)原材(cai)料，但是減少了(le)供電(dian)(dian)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)可信(xin)性和(he)(he)安(an)全(quan)系(xi)數(security)。有(you)標(biao)準(zhun)的(de)(de)地區，低壓供電(dian)(dian)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)理應較大將(jiang)(jiang)會(hui)（maybe)地應用TN—S系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)，即布(bu)署單獨的(de)(de)PE保護線，而并不是這類將(jiang)(jiang)N線和(he)(he)PE線捆(kun)縛于(yu)一(yi)(yi)起的(de)(de)TN—C系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)。特別提示：對供電(dian)(dian)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)安(an)全(quan)系(xi)數規定較為(wei)(wei)高，非常是存有(you)發生(sheng)風險(xian)的(de)(de)場地，務必采(cai)用 TN—S系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)供電(dian)(dian)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)(tong)。

保護(hu)線和中性(xing)線的差(cha)別

中(zhong)性(xing)線(xian)(xian)(xian)(xian)（N線(xian)(xian)(xian)(xian)）是(shi)與(yu)變(bian)壓（標準氣壓自變(bian)量)器(qi)(Transformer)中(zhong)性(xing)點聯接，能(neng)夠具有(you)維持三相(xiang)不(bu)一(yi)樣負荷工作電壓對(dui)稱性(xing)和傳(chuan)送(song)電磁能(neng)的(de)(de)功效，在單相(xiang)電系統中(zhong)，沒有(you)它，各種各樣電器(qi)就不(bu)可以(yi)一(yi)切正(zheng)(zheng)常(chang)(chang)工作中(zhong)，從這一(yi)視角（angle)看，N線(xian)(xian)(xian)(xian)是(shi)工作中(zhong)線(xian)(xian)(xian)(xian)，必不(bu)可少。而(er)保護(hu)線(xian)(xian)(xian)(xian)（PE線(xian)(xian)(xian)(xian)），則是(shi)和用電量機(ji)器(qi)設備殼(ke)子相(xiang)互連接的(de)(de)接地線(xian)(xian)(xian)(xian)(又(you)稱:避(bi)雷(lei)線(xian)(xian)(xian)(xian))，沒有(you)它，用電量機(ji)器(qi)設備可以(yi)一(yi)切正(zheng)(zheng)常(chang)(chang)工作中(zhong)，并不(bu)是(shi)必不(bu)可少。但萬一(yi)電器(qi)殼(ke)子因常(chang)(chang)見(jian)故障感應(ying)起電，沒有(you)它，觸碰電器(qi)金屬外殼(ke)的(de)(de)人總(zong)有(you)將會產(chan)(chan)生安全(quan)事故。能(neng)夠說(shuo)，保護(hu)線(xian)(xian)(xian)(xian)的(de)(de)功效是(shi)避(bi)免安全(quan)事故的(de)(de)產(chan)(chan)生，因而(er)是(shi)保護(hu)輸(shu)電線(xian)(xian)(xian)(xian)。

因為保(bao)護線(xian)的(de)有(you)沒有(you)，不危害電(dian)(dian)(dian)器的(de)一切正常工作中(zhong)，因而，在(zai)低壓客戶中(zhong)不被高(gao)度重視(shi)(shi)。現階段(duan)，在(zai)我國一部分城區家(jia)中(zhong)和很多鄉村(cun)家(jia)中(zhong)用電(dian)(dian)(dian)量(liang)，有(you)許多該接保(bao)護線(xian)的(de)電(dian)(dian)(dian)器（Ⅰ類電(dian)(dian)(dian)器，即開關電(dian)(dian)(dian)源引出線(xian)選用三腳(jiao)電(dian)(dian)(dian)源插頭的(de)電(dian)(dian)(dian)器）也沒有(you)聯接保(bao)護線(xian)，造成(cheng)應用這(zhe)種電(dian)(dian)(dian)器時(shi)存有(you)安全風險，應造成(cheng)充足高(gao)度重視(shi)(shi)。