電(dian)(dian)(dian)(dian)(dian)纜(lan)的(de)(de)種(zhong)類很多，按其(qi)用途(tu)可(ke)分(fen)為(wei)電(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)纜(lan)和信號、控制電(dian)(dian)(dian)(dian)(dian)纜(lan)兩(liang)大類，按其(qi)絕(jue)緣(yuan)(yuan)材料(liao)的(de)(de)不同，則可(ke)分(fen)為(wei)油浸紙絕(jue)緣(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)纜(lan)、橡(xiang)皮絕(jue)緣(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)纜(lan)和塑(su)料(liao)絕(jue)緣(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)纜(lan)三(san)大類。每一(yi)種(zhong)電(dian)(dian)(dian)(dian)(dian)纜(lan)都有各自(zi)不同的(de)(de)結構特點(dian)，但每種(zhong)電(dian)(dian)(dian)(dian)(dian)纜(lan)都由導(dao)電(dian)(dian)(dian)(dian)(dian)線(xian)芯、絕(jue)緣(yuan)(yuan)層(ceng)和保護層(ceng)三(san)個主要部分(fen)組成。圖4-1是常用油浸紙絕(jue)緣(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)纜(lan)的(de)(de)結構。

　　1。導(dao)電(dian)線(xian)芯導(dao)電(dian)線(xian)芯通(tong)常用(yong)銅或鋁(lv)制(zhi)成(cheng)，線(xian)芯的(de)截面有(you)統一的(de)標稱(cheng)規(gui)格，電(dian)力電(dian)纜(lan)線(xian)芯有(you)1.0,1.5, 2.5, 4, 6, 10,16,25,35,50,70,95,120,150,185,240, 300, 400, 500, 625,800平方毫米等21種規(gui)格:信號和(he)控制(zhi)電(dian)纜(lan)線(xian)芯有(you)0.75, 1.0,1.5,2.5,4,6,10平方毫米等7種規(gui)格，每種具體型號的(de)電(dian)纜(lan)都(dou)有(you)相應(ying)的(de)截面范(fan)圍。

　　導電(dian)(dian)(dian)線芯(xin)的(de)芯(xin)數(shu)，也有(you)一(yi)定(ding)(ding)的(de)規(gui)定(ding)(ding)，電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)有(you)單芯(xin)、雙芯(xin)、三(san)(san)芯(xin)和(he)四(si)芯(xin)等(deng)(deng)幾種。單芯(xin)電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)一(yi)般用(yong)(yong)于(yu)輸送(song)直流(liu)(liu)電(dian)(dian)(dian)、高壓靜電(dian)(dian)(dian)設(she)備的(de)引線等(deng)(deng)，雙芯(xin)的(de)用(yong)(yong)于(yu)直流(liu)(liu)和(he)單相交流(liu)(liu)電(dian)(dian)(dian)路;三(san)(san)芯(xin)的(de)于(yu)三(san)(san)相交流(liu)(liu)電(dian)(dian)(dian)路，應用(yong)(yong)最為(wei)廣泛(fan)。只有(you)額(e)定(ding)(ding)電(dian)(dian)(dian)壓1千伏以(yi)下的(de)電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)有(you)雙芯(xin)和(he)四(si)芯(xin)的(de)規(gui)格，四(si)芯(xin)電(dian)(dian)(dian)纜(lan)用(yong)(yong)于(yu)巾性(xing)點接地的(de)三(san)(san)相四(si)線供電(dian)(dian)(dian)網絡(luo)，第四(si)根線芯(xin)主要用(yong)(yong)于(yu)通(tong)過不平衡負荷(he)時的(de)中線電(dian)(dian)(dian)流(liu)(liu)或用(yong)(yong)于(yu)保護接地、接零用(yong)(yong)，因此截面積(ji)僅(jin)為(wei)主線芯(xin)的(de)40-60%。信號、控(kong)制電(dian)(dian)(dian)纜(lan)的(de)芯(xin)數(shu)有(you)2,3,4,5,7,9,10,14,16,19,21,24,27,30,37……等(deng)(deng)多種。

　　電(dian)統線(xian)(xian)芯的截面形(xing)狀有(you)圓形(xing)、半圓形(xing)和(he)扇(shan)形(xing)等，單芯電(dian)纜(lan)(lan)及16平方毫(hao)米以下的多芯電(dian)纜(lan)(lan)的線(xian)(xian)芯是圓形(xing)的，大截面多芯電(dian)纜(lan)(lan)則采用多股導線(xian)(xian)絞合(he)壓制(zhi)成半圓形(xing)和(he)扇(shan)形(xing)，這樣(yang)可以增加電(dian)纜(lan)(lan)的柔軟(ruan)性(xing)(xing)和(he)結構穩(wen)定(ding)性(xing)(xing)。

　　2、絕(jue)緣(yuan)層電纜的絕(jue)緣(yuan)層通常采用紙(zhi)(zhi)、橡皮或聚抓乙烯等材(cai)料制成(cheng)，紙(zhi)(zhi)絕(jue)緣(yuan)應用很(hen)廣，它(ta)是將電纜紙(zhi)(zhi)經(jing)過真空(kong)干燥后(hou)，放(fang)在松香(xiang)和礦物油混合的液休(xiu)中浸漬，再纏繞在線芯上，構成(cheng)分(fen)相(xiang)絕(jue)緣(yuan)，低壓電纜則有很(hen)多是用橡皮和塑料作為分(fen)相(xiang)絕(jue)緣(yuan)材(cai)料的。

　　在(zai)多芯電纜(lan)中，為(wei)了區別(bie)各線(xian)芯，在(zai)分(fen)相(xiang)絕(jue)緣的外(wai)層紙(zhi)帶上(shang)分(fen)別(bie)打印有."1","2","3，字樣，或用不(bu)同顏色的分(fen)相(xiang)絕(jue)緣分(fen)別(bie)表示(shi)不(bu)同線(xian)芯。

　　將分相絕緣后的線芯紋合，再在外面用絕緣材料包上，稱(cheng)為(wei)統(tong)包絕緣。

　　3.保(bao)(bao)護(hu)層(ceng)(ceng)(ceng)電統的(de)保(bao)(bao)護(hu)層(ceng)(ceng)(ceng)可分為內(nei)護(hu)層(ceng)(ceng)(ceng)和外(wai)護(hu)層(ceng)(ceng)(ceng)兩部(bu)分。內(nei)護(hu)層(ceng)(ceng)(ceng)用(yong)(yong)以防止(zhi)電纜(lan)絕緣受(shou)潮或(huo)電纜(lan)浸演(yan)劑外(wai)流，一(yi)般(ban)的(de)方法(fa)是(shi)(shi)(shi)在統包絕緣層(ceng)(ceng)(ceng)外(wai)面包上一(yi)定厚(hou)度(du)的(de)鉛包或(huo)鋁包，也(ye)有(you)(you)用(yong)(yong)塑(su)料保(bao)(bao)護(hu)的(de)。外(wai)護(hu)層(ceng)(ceng)(ceng)是(shi)(shi)(shi)用(yong)(yong)來保(bao)(bao)護(hu)內(nei)護(hu)層(ceng)(ceng)(ceng)的(de)，防止(zhi)內(nei)護(hu)層(ceng)(ceng)(ceng)受(shou)到機械損(sun)(sun)傷(shang)和強(qiang)烈(lie)的(de)化學(xue)腐蝕(shi)，通常是(shi)(shi)(shi)在內(nei)護(hu)層(ceng)(ceng)(ceng)外(wai)面包上浸演(yan)過瀝青混合(he)物的(de)黃麻(ma)、鋼(gang)帶或(huo)鋼(gang)絲。沒有(you)(you)外(wai)護(hu)層(ceng)(ceng)(ceng)的(de)電纜(lan)，只可用(yong)(yong)于不會(hui)受(shou)到機械損(sun)(sun)傷(shang)的(de)場(chang)所。