在(zai)導(dao)體(ti)上、絕緣(yuan)層(ceng)上、電(dian)(dian)纜(lan)芯上或電(dian)(dian)線電(dian)(dian)纜(lan)外層(ceng)，為(wei)了(le)防(fang)止外界電(dian)(dian)磁波干擾或是(shi)起均勻電(dian)(dian)埸作用(yong)，還包有(you)金屬帶、絲或半導(dao)電(dian)(dian)塑(su)料等材料。這些都(dou)稱為(wei)屏蔽層(ceng)。電(dian)(dian)纜(lan)就是(shi)利用(yong)導(dao)體(ti)來傳(chuan)導(dao)電(dian)(dian)流(liu)的(de)(de)，因而電(dian)(dian)線電(dian)(dian)纜(lan)的(de)(de)規(gui)格都(dou)以導(dao)體(ti)的(de)(de)截面表示。電(dian)(dian)力電(dian)(dian)纜(lan)的(de)(de)導(dao)體(ti)，可以制(zhi)成整根實心的(de)(de)，或是(shi)由多根單線絞合而成，形狀可以是(shi)圓形的(de)(de)和扇(shan)形的(de)(de)結(jie)構(gou)。為(wei)了(le)檢(jian)驗(yan)是(shi)否漏焊(han)，生產廠(chang)家又加了(le)一項中間檢(jian)驗(yan)裝置，將整盤焊(han)接后的(de)(de)電(dian)(dian)纜(lan)進(jin)行(xing)浸(jin)水氣密(mi)性試驗(yan)，且進(jin)行(xing)的(de)(de)檢(jian)驗(yan)。

為了檢驗是否漏焊，生產(chan)廠家又加了一(yi)(yi)(yi)項中間(jian)檢驗裝(zhuang)置，將整盤焊接后的電(dian)(dian)(dian)纜(lan)(lan)(lan)進(jin)行浸水氣(qi)密性試驗，且進(jin)行的檢驗。WDZ與(yu)WDZN電(dian)(dian)(dian)纜(lan)(lan)(lan)主(zhu)要(yao)的區別就是WDZN耐火電(dian)(dian)(dian)纜(lan)(lan)(lan)導體(ti)繞包(bao)一(yi)(yi)(yi)層云母帶，使電(dian)(dian)(dian)纜(lan)(lan)(lan)具(ju)有燃(ran)燒情(qing)況下(xia)保持(chi)正常(chang)通(tong)電(dian)(dian)(dian)一(yi)(yi)(yi)段時(shi)(shi)間(jian)。WDZ阻(zu)燃(ran)電(dian)(dian)(dian)纜(lan)(lan)(lan)的主(zhu)要(yao)特點(dian)是電(dian)(dian)(dian)纜(lan)(lan)(lan)不(bu)易(yi)著(zhu)火或(huo)著(zhu)火時(shi)(shi)延燃(ran)僅局限在一(yi)(yi)(yi)定(ding)范圍內，適用于電(dian)(dian)(dian)纜(lan)(lan)(lan)敷設密集程度較(jiao)高的發電(dian)(dian)(dian)站、地(di)鐵、隧道、高層建(jian)筑、大型工礦(kuang)企業、油田(tian)、煤礦(kuang)等場(chang)所(suo)。電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)(lan)(lan)主(zhu)要(yao)考查導體(ti)的材(cai)質和截面積(ji)，若導體(ti)的材(cai)質不(bu)好或(huo)截面積(ji)嚴重不(bu)足，就會(hui)造成導體(ti)直流(liu)電(dian)(dian)(dian)阻(zu)嚴重超標，這種電(dian)(dian)(dian)纜(lan)(lan)(lan)鋪設在線(xian)路中就會(hui)增加電(dian)(dian)(dian)流(liu)在線(xian)路上(shang)通(tong)過時(shi)(shi)的損耗(hao)。

成(cheng)品電(dian)(dian)(dian)(dian)壓(ya)試驗及絕(jue)緣(yuan)線芯間電(dian)(dian)(dian)(dian)壓(ya)試驗不(bu)(bu)光要(yao)求(qiu)電(dian)(dian)(dian)(dian)纜有足夠的絕(jue)緣(yuan)能(neng)力(li)，還要(yao)求(qiu)絕(jue)緣(yuan)或(huo)護(hu)(hu)(hu)套(tao)(tao)材料均勻無雜質、厚度足夠均勻，電(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)纜生產，表面(mian)不(bu)(bu)能(neng)有看不(bu)(bu)見的、等，否則(ze)就會造(zao)成(cheng)耐壓(ya)試驗時局部擊穿。扇形芯的中央導線必(bi)須(xu)位(wei)于(yu)扇形芯的中心線上，否則(ze)，當線芯彎曲(qu)時，位(wei)于(yu)中心線上部導線將被拉伸，而下(xia)部的將受(shou)壓(ya)縮(suo)而可能(neng)擠出，這將引起扇形破壞而損傷絕(jue)緣(yuan)。交聯電(dian)(dian)(dian)(dian)纜護(hu)(hu)(hu)層主要(yao)有裸護(hu)(hu)(hu)套(tao)(tao)和(he)鎧(kai)裝(zhuang)型兩種，在不(bu)(bu)經(jing)受(shou)機械外力(li)情況下(xia)，選用(yong)裸護(hu)(hu)(hu)套(tao)(tao)，即直接(jie)在絕(jue)緣(yuan)線芯外面(mian)擠包一層塑料，如(ru)果用(yong)于(yu)直埋或(huo)要(yao)經(jing)受(shou)一定(ding)的機械外力(li)，需(xu)要(yao)包上金屬帶鎧(kai)裝(zhuang)；110kV高壓(ya)交聯電(dian)(dian)(dian)(dian)纜或(huo)其它電(dian)(dian)(dian)(dian)纜埋設(she)在水(shui)下(xia)，則(ze)需(xu)要(yao)防水(shui)護(hu)(hu)(hu)層，包上一層鉛套(tao)(tao)、鋁套(tao)(tao)或(huo)鋁塑綜合防水(shui)層。