絕(jue)緣(yuan)也要(yao)具有一定(ding)的(de)機械(xie)物(wu)理(li)性(xing)能和加(jia)(jia)(jia)工(gong)制(zhi)造(zao)的(de)工(gong)藝性(xing)能。例如(ru)制(zhi)造(zao)低壓電(dian)(dian)纜(lan)時，盡(jin)管從電(dian)(dian)氣性(xing)能方面(mian)(mian)(mian)考慮可(ke)以(yi)采用很(hen)薄的(de)絕(jue)緣(yuan)，但從機械(xie)性(xing)能與(yu)加(jia)(jia)(jia)工(gong)工(gong)藝考慮，仍以(yi)稍厚一些為好，原(yuan)因是絕(jue)緣(yuan)過薄，電(dian)(dian)力(li)電(dian)(dian)纜(lan)報價，加(jia)(jia)(jia)工(gong)較困難，容易損壞。電(dian)(dian)力(li)電(dian)(dian)纜(lan)主要(yao)考查導體的(de)材質(zhi)(zhi)和截(jie)面(mian)(mian)(mian)積(ji)，若導體的(de)材質(zhi)(zhi)不好或截(jie)面(mian)(mian)(mian)積(ji)嚴重不足，就(jiu)會(hui)造(zao)成導體直流電(dian)(dian)阻(zu)嚴重超標，這(zhe)種電(dian)(dian)纜(lan)鋪(pu)設(she)在線(xian)路中就(jiu)會(hui)增加(jia)(jia)(jia)電(dian)(dian)流在線(xian)路上通過時的(de)損耗。耐(nai)火(huo)電(dian)(dian)纜(lan)與(yu)阻(zu)燃電(dian)(dian)纜(lan)的(de)原(yuan)理(li)不同：含鹵(lu)(lu)電(dian)(dian)纜(lan)阻(zu)燃原(yuan)理(li)是靠(kao)鹵(lu)(lu)素的(de)阻(zu)燃效應，無鹵(lu)(lu)電(dian)(dian)纜(lan)阻(zu)燃原(yuan)理(li)是靠(kao)析(xi)出水降(jiang)低溫(wen)度來熄滅火(huo)焙；耐(nai)火(huo)電(dian)(dian)纜(lan)是靠(kao)耐(nai)火(huo)層中云(yun)母材料的(de)耐(nai)火(huo)、耐(nai)熱的(de)特(te)性(xing)，保證電(dian)(dian)纜(lan)在火(huo)災時也工(gong)作正常。

絕(jue)緣(yuan)(yuan)層的(de)(de)(de)材料必須具有良好的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)氣(qi)絕(jue)緣(yuan)(yuan)性能，主要表現為承受電(dian)(dian)(dian)(dian)(dian)(dian)壓的(de)(de)(de)大小。一(yi)般地講，同一(yi)質量的(de)(de)(de)絕(jue)緣(yuan)(yuan)層愈厚，耐電(dian)(dian)(dian)(dian)(dian)(dian)壓也(ye)越高。引起電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)導(dao)體(ti)本身發熱(re)，引起包覆導(dao)體(ti)的(de)(de)(de)絕(jue)緣(yuan)(yuan)老化開裂，造(zao)(zao)成供電(dian)(dian)(dian)(dian)(dian)(dian)線路漏電(dian)(dian)(dian)(dian)(dian)(dian)、短路，甚至造(zao)(zao)成火(huo)災，危及人身、財產的(de)(de)(de)安(an)全(quan)。標準(zhun)對不(bu)同規格(ge)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)的(de)(de)(de)導(dao)體(ti)直流電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值(zhi)均(jun)有嚴格(ge)的(de)(de)(de)規定，不(bu)得(de)大于(yu)標準(zhun)規定的(de)(de)(de)值(zhi)。WDZ電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)比WDZN電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)價格(ge)略低(di)10~20%。這個(ge)看每家電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)廠工藝和成本價格(ge)不(bu)一(yi)，綠寶電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)為您提供，安(an)全(quan)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)線電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)。

由于(yu)它經(jing)受(shou)不住機械損傷(shang)，因而還需包上鋼(gang)(gang)絲、鋼(gang)(gang)帶。鋼(gang)(gang)絲、鋼(gang)(gang)帶容(rong)易(yi)被腐蝕，鉛(qian)(qian)套(tao)、鋁(lv)套(tao)在惡劣環境下(xia)也容(rong)易(yi)被腐蝕，因而還需包上各種防腐材料(liao)，如瀝青、黃麻、塑(su)料(liao)等。這些都統稱為外護層(ceng)。其中(zhong)鋼(gang)(gang)絲、鋼(gang)(gang)帶稱為鎧裝層(ceng)，瀝青、黃麻、塑(su)料(liao)稱為防護層(ceng)。每層(ceng)單線的絞合(he)方向(xiang)應和前(qian)一(yi)層(ceng)方向(xiang)相反，外層(ceng)應用(yong)左向(xiang)絞合(he)。這種結構可(ke)保證電(dian)纜(lan)導電(dian)線芯的穩定(ding)性和一(yi)定(ding)的柔軟性。油紙(zhi)電(dian)纜(lan)均采(cai)用(yong)壓(ya)(ya)鉛(qian)(qian)機和壓(ya)(ya)鋁(lv)機擠包金屬(shu)(shu)套(tao)，對于(yu)中(zhong)低壓(ya)(ya)交聯電(dian)纜(lan)一(yi)般(ban)在有化學腐蝕的環境或水底敷(fu)設時才采(cai)用(yong)。但(dan)對于(yu)高壓(ya)(ya)電(dian)纜(lan)一(yi)般(ban)規定(ding)使用(yong)金屬(shu)(shu)護套(tao)。