地(di)線在(zai)國(guo)家規范里的專業(ye)稱叫喊“保(bao)護線”，用英(ying)文字母(mu)PE標明。PE線在(zai)供電(dian)(dian)系統中的首要(yao)作用是(shi)：地(di)線可以把(ba)漏電(dian)(dian)電(dian)(dian)流變為短路(lu)電(dian)(dian)流，迫使斷(duan)路(lu)器跳閘斷(duan)電(dian)(dian)；它也(ye)可以在(zai)設備漏電(dian)(dian)時供應漏電(dian)(dian)回路(lu)，讓漏電(dian)(dian)開(kai)關動作，然(ran)后減少觸電(dian)(dian)的危險性。
地線截面積大小
我們日子中的用電(dian)一(yi)般都是(shi)選用TN供電(dian)系統。從(cong)上面地(di)線(xian)的作用里，我們可(ke)以得到(dao)一(yi)個(ge)要(yao)害信息：“漏電(dian)的時分(fen)，前方電(dian)流(liu)(liu)會(hui)通過地(di)線(xian)流(liu)(liu)向(xiang)變壓(ya)器，相當(dang)于電(dian)壓(ya)短路迫使斷路器跳閘。”也就是(shi)說PE線(xian)要(yao)能承擔缺點電(dian)流(liu)(liu)的沖擊而不(bu)被燒掉。
假定(ding)該插座前方零線(xian)選用4平(ping)(ping)方銅線(xian)，地線(xian)選用1.5平(ping)(ping)方銅線(xian)；那么4平(ping)(ping)方銅線(xian)對應的空開(kai)額定(ding)電流應該為32A，1.5平(ping)(ping)方銅線(xian)長期安(an)全載(zai)流量(liang)大(da)約16A左右。
插(cha)座上的(de)用(yong)(yong)電(dian)(dian)(dian)設備正常(chang)時，地線沒有(you)電(dian)(dian)(dian)流，整個系統看起(qi)來沒什(shen)么問題。但是(shi)當用(yong)(yong)電(dian)(dian)(dian)設備發(fa)生漏(lou)電(dian)(dian)(dian)時，前方電(dian)(dian)(dian)流通過(guo)用(yong)(yong)電(dian)(dian)(dian)設備外殼，地線回到電(dian)(dian)(dian)源。當用(yong)(yong)電(dian)(dian)(dian)設備發(fa)生了嚴峻漏(lou)電(dian)(dian)(dian)缺(que)點（接觸電(dian)(dian)(dian)阻為零(ling)）時，缺(que)點電(dian)(dian)(dian)流不足以推動32A的(de)空開瞬間跳閘，但是(shi)卻(que)遠超過(guo)1.5平(ping)方銅(tong)線的(de)安全(quan)載流量，所以畢竟作(zuo)用(yong)(yong)就是(shi)地線被(bei)燒(shao)斷。
地線大小國家規范
地(di)(di)線(xian)(xian)(xian)太(tai)小要(yao)害時(shi)(shi)刻起不(bu)到應有(you)的保護作用(yong)(yong)，但是選(xuan)(xuan)擇偏大又不(bu)經濟(ji)，那么具體該(gai)怎么選(xuan)(xuan)擇呢？ 依照國家規范，當前方(fang)(fang)(fang)(fang)(fang)截(jie)(jie)面(mian)積(ji)(ji)(ji)為16平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)及以下(xia)時(shi)(shi)，地(di)(di)線(xian)(xian)(xian)截(jie)(jie)面(mian)積(ji)(ji)(ji)有(you)必要(yao)和(he)前方(fang)(fang)(fang)(fang)(fang)相(xiang)等。比如插(cha)座零前方(fang)(fang)(fang)(fang)(fang)選(xuan)(xuan)用(yong)(yong)4平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)銅(tong)線(xian)(xian)(xian)，那么地(di)(di)線(xian)(xian)(xian)也有(you)必要(yao)選(xuan)(xuan)用(yong)(yong)4平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)銅(tong)線(xian)(xian)(xian)，當前方(fang)(fang)(fang)(fang)(fang)截(jie)(jie)面(mian)積(ji)(ji)(ji)在16到35（含）平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)之間時(shi)(shi)，地(di)(di)線(xian)(xian)(xian)截(jie)(jie)面(mian)積(ji)(ji)(ji)可(ke)以選(xuan)(xuan)16平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)，比如前方(fang)(fang)(fang)(fang)(fang)選(xuan)(xuan)用(yong)(yong)25平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)銅(tong)線(xian)(xian)(xian)時(shi)(shi)，那么地(di)(di)線(xian)(xian)(xian)可(ke)以選(xuan)(xuan)用(yong)(yong)16平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)銅(tong)線(xian)(xian)(xian)，當前方(fang)(fang)(fang)(fang)(fang)大于35平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)時(shi)(shi)，地(di)(di)線(xian)(xian)(xian)截(jie)(jie)面(mian)積(ji)(ji)(ji)可(ke)以選(xuan)(xuan)前方(fang)(fang)(fang)(fang)(fang)的一半。 家庭(ting)電線(xian)(xian)(xian)截(jie)(jie)面(mian)積(ji)(ji)(ji)一般都小于10平(ping)(ping)方(fang)(fang)(fang)(fang)(fang)，所(suo)以根據規范，地(di)(di)線(xian)(xian)(xian)和(he)前方(fang)(fang)(fang)(fang)(fang)截(jie)(jie)面(mian)積(ji)(ji)(ji)有(you)必要(yao)相(xiang)等。
雖然有(you)國家規(gui)范(fan)可以(yi)參看，但并不意(yi)味著一切的(de)電(dian)線(xian)(xian)都符合國家規(gui)范(fan)，所以(yi)在(zai)選(xuan)(xuan)購(gou)地(di)線(xian)(xian)時一定要購(gou)買有(you)質量確保及國標認證(zheng)的(de)產品，例(li)如慶豐(feng)電(dian)纜(lan)的(de)國標產品，均選(xuan)(xuan)用高純度無氧銅制造出產，比較(jiao)同規(gui)范(fan)的(de)電(dian)線(xian)(xian)，慶豐(feng)電(dian)纜(lan)的(de)產品能做到(dao)電(dian)阻更(geng)小載流量更(geng)大，這樣符合國標的(de)線(xian)(xian)纜(lan)才華真實地(di)確保我們的(de)生命安全，安全無小事！切不可抱有(you)走運的(de)心思，一旦發(fa)生意(yi)外，追悔莫及！
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電線電纜