電(dian)(dian)(dian)纜(lan)的(de)種(zhong)類很多，按其用途可分(fen)為電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)纜(lan)和信號、控(kong)制電(dian)(dian)(dian)纜(lan)兩大類，按其絕緣(yuan)(yuan)(yuan)材料的(de)不同，則可分(fen)為油浸(jin)紙絕緣(yuan)(yuan)(yuan)電(dian)(dian)(dian)纜(lan)、橡皮絕緣(yuan)(yuan)(yuan)電(dian)(dian)(dian)纜(lan)和塑料絕緣(yuan)(yuan)(yuan)電(dian)(dian)(dian)纜(lan)三大類。每一種(zhong)電(dian)(dian)(dian)纜(lan)都(dou)有各自不同的(de)結(jie)構特(te)點，但每種(zhong)電(dian)(dian)(dian)纜(lan)都(dou)由導(dao)電(dian)(dian)(dian)線芯、絕緣(yuan)(yuan)(yuan)層(ceng)和保護(hu)層(ceng)三個主要部分(fen)組成(cheng)。圖(tu)4-1是常用油浸(jin)紙絕緣(yuan)(yuan)(yuan)電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)纜(lan)的(de)結(jie)構。

　　1。導電線(xian)芯(xin)(xin)導電線(xian)芯(xin)(xin)通常用(yong)銅或(huo)鋁制成，線(xian)芯(xin)(xin)的(de)(de)截面(mian)有(you)(you)統(tong)一的(de)(de)標稱規格(ge)(ge)，電力電纜(lan)線(xian)芯(xin)(xin)有(you)(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(ping)(ping)方毫米等21種(zhong)(zhong)規格(ge)(ge):信號和控制電纜(lan)線(xian)芯(xin)(xin)有(you)(you)0.75, 1.0,1.5,2.5,4,6,10平(ping)(ping)方毫米等7種(zhong)(zhong)規格(ge)(ge)，每(mei)種(zhong)(zhong)具體型號的(de)(de)電纜(lan)都有(you)(you)相應的(de)(de)截面(mian)范圍。

　　導(dao)電(dian)(dian)(dian)(dian)線(xian)(xian)芯(xin)(xin)的芯(xin)(xin)數(shu)(shu)，也有一定(ding)的規定(ding)，電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)纜(lan)有單(dan)芯(xin)(xin)、雙芯(xin)(xin)、三(san)芯(xin)(xin)和(he)四(si)芯(xin)(xin)等幾種。單(dan)芯(xin)(xin)電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)纜(lan)一般用(yong)(yong)于(yu)輸送(song)直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)、高壓靜電(dian)(dian)(dian)(dian)設備的引線(xian)(xian)等，雙芯(xin)(xin)的用(yong)(yong)于(yu)直(zhi)流(liu)(liu)(liu)和(he)單(dan)相交(jiao)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)路;三(san)芯(xin)(xin)的于(yu)三(san)相交(jiao)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)路，應用(yong)(yong)最為(wei)廣泛(fan)。只(zhi)有額定(ding)電(dian)(dian)(dian)(dian)壓1千伏以下(xia)的電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)纜(lan)有雙芯(xin)(xin)和(he)四(si)芯(xin)(xin)的規格(ge)，四(si)芯(xin)(xin)電(dian)(dian)(dian)(dian)纜(lan)用(yong)(yong)于(yu)巾性點接地的三(san)相四(si)線(xian)(xian)供電(dian)(dian)(dian)(dian)網絡，第四(si)根線(xian)(xian)芯(xin)(xin)主要用(yong)(yong)于(yu)通過不平衡負荷時的中線(xian)(xian)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)或用(yong)(yong)于(yu)保(bao)護接地、接零用(yong)(yong)，因此截(jie)面積僅為(wei)主線(xian)(xian)芯(xin)(xin)的40-60%。信號、控制(zhi)電(dian)(dian)(dian)(dian)纜(lan)的芯(xin)(xin)數(shu)(shu)有2,3,4,5,7,9,10,14,16,19,21,24,27,30,37……等多種。

　　電(dian)(dian)統線(xian)芯的截(jie)面(mian)(mian)形(xing)狀有圓形(xing)、半(ban)圓形(xing)和扇形(xing)等，單芯電(dian)(dian)纜(lan)及16平(ping)方毫米以下的多芯電(dian)(dian)纜(lan)的線(xian)芯是圓形(xing)的，大截(jie)面(mian)(mian)多芯電(dian)(dian)纜(lan)則(ze)采用(yong)多股(gu)導線(xian)絞合壓制成半(ban)圓形(xing)和扇形(xing)，這樣可以增(zeng)加電(dian)(dian)纜(lan)的柔軟性和結構穩定性。

　　2、絕緣(yuan)(yuan)層(ceng)電纜的(de)(de)(de)絕緣(yuan)(yuan)層(ceng)通(tong)常采用紙、橡(xiang)皮(pi)或聚抓乙烯等材料制成，紙絕緣(yuan)(yuan)應用很廣，它是將電纜紙經過真空干燥(zao)后(hou)，放在(zai)松香和(he)礦物油混(hun)合的(de)(de)(de)液休中浸漬，再纏繞在(zai)線(xian)芯上(shang)，構成分(fen)相絕緣(yuan)(yuan)，低壓電纜則有很多是用橡(xiang)皮(pi)和(he)塑料作為分(fen)相絕緣(yuan)(yuan)材料的(de)(de)(de)。

　　在多(duo)芯(xin)電纜(lan)中，為了區別各(ge)線芯(xin)，在分相絕緣(yuan)的外(wai)層紙帶上(shang)分別打印有."1","2","3，字樣，或用不(bu)同(tong)顏色的分相絕緣(yuan)分別表示不(bu)同(tong)線芯(xin)。

　　將分(fen)相絕(jue)緣后的(de)線芯(xin)紋(wen)合，再在外面(mian)用絕(jue)緣材料包(bao)上，稱為統包(bao)絕(jue)緣。

　　3.保護層(ceng)電統(tong)的(de)保護層(ceng)可(ke)分為內(nei)護層(ceng)和外(wai)(wai)護層(ceng)兩部分。內(nei)護層(ceng)用(yong)以防止電纜(lan)絕緣受(shou)潮(chao)或電纜(lan)浸演(yan)劑(ji)外(wai)(wai)流，一(yi)般的(de)方法(fa)是在統(tong)包(bao)絕緣層(ceng)外(wai)(wai)面包(bao)上(shang)一(yi)定厚度的(de)鉛(qian)包(bao)或鋁(lv)包(bao)，也有(you)用(yong)塑料(liao)保護的(de)。外(wai)(wai)護層(ceng)是用(yong)來保護內(nei)護層(ceng)的(de)，防止內(nei)護層(ceng)受(shou)到機(ji)械損傷和強(qiang)烈的(de)化學(xue)腐蝕，通常(chang)是在內(nei)護層(ceng)外(wai)(wai)面包(bao)上(shang)浸演(yan)過(guo)瀝青混合物的(de)黃(huang)麻(ma)、鋼帶或鋼絲。沒(mei)有(you)外(wai)(wai)護層(ceng)的(de)電纜(lan)，只可(ke)用(yong)于不會受(shou)到機(ji)械損傷的(de)場所。