贵(gui)州电(dian)线(xian)电(dian)缆使用寿命低(di)(di)的(de)(de)最直接原(yuan)因是绝缘(yuan)降低(di)(di)而被击穿。导(dao)敏电(dian)缆绝缘(yuan)降低(di)(di)的(de)(de)凶(xiong)素(su)很(hen)多，根据(ju)实际运行经验，分为(wei)以下几种情况： 

1.外力损(sun)伤(shang)(shang)：很(hen)多的电(dian)(dian)(dian)缆(lan)故(gu)障都是(shi)由于机(ji)械损(sun)伤(shang)(shang)引起的。在(zai)电(dian)(dian)(dian)缆(lan)敷设(she)安(an)装时不规(gui)范施工，造成(cheng)机(ji)械损(sun)伤(shang)(shang)；在(zai)直埋电(dian)(dian)(dian)缆(lan)上搞(gao)土建(jian)施工也极易(yi)将运行中的电(dian)(dian)(dian)缆(lan)损(sun)伤(shang)(shang)，等。如果损(sun)伤(shang)(shang)不严重(zhong)，可(ke)能要(yao)几个月甚至几年(nian)才(cai)会导致损(sun)伤(shang)(shang)部位(wei)彻(che)底击穿(chuan)形成(cheng)故(gu)障；如果破坏严重(zhong)的，可(ke)能直接引发(fa)线路(lu)短(duan)路(lu)故(gu)障，直接影响用电(dian)(dian)(dian)安(an)全。

2.绝缘受潮：一(yi)般发生(sheng)在(zai)直埋(mai)或(huo)(huo)排(pai)管里的电(dian)缆接头处。电(dian)缆接头制作不合(he)格和在(zai)潮湿的气候条(tiao)件(jian)下做接头，会使接头进水(shui)或(huo)(huo)混入(ru)水(shui)蒸气，时间久了(le)在(zai)电(dian)场作用下形(xing)成水(shui)珠，逐(zhu)渐损害(hai)电(dian)缆的绝缘强(qiang)度而(er)造成故障。 

3.化学腐蚀(shi)(shi)：贵州线(xian)缆厂家直接埋(mai)在有酸碱作(zuo)用的(de)地区(qu)，往往会(hui)造成电(dian)缆的(de)铠(kai)装、铅皮(pi)或外护(hu)层(ceng)(ceng)(ceng)被腐蚀(shi)(shi)，保护(hu)层(ceng)(ceng)(ceng)因(yin)长期遭受化学腐蚀(shi)(shi)或电(dian)解腐蚀(shi)(shi)，致(zhi)使保护(hu)层(ceng)(ceng)(ceng)失效，绝缘降低(di)，导致(zhi)电(dian)缆故(gu)障。

4.长期超负荷(he)(he)运行(xing)：由于电(dian)(dian)(dian)流的(de)(de)(de)(de)热(re)效应，负载电(dian)(dian)(dian)流通过电(dian)(dian)(dian)缆时必然(ran)导致导体发热(re)，同时电(dian)(dian)(dian)荷(he)(he)的(de)(de)(de)(de)集肤效应以(yi)及(ji)钢(gang)铠的(de)(de)(de)(de)涡流损耗、绝(jue)缘(yuan)介质损耗也会产(chan)生附加(jia)(jia)热(re)量，从而使电(dian)(dian)(dian)缆温度升(sheng)高(gao)。长期超负荷(he)(he)运行(xing)时，过高(gao)的(de)(de)(de)(de)温度会加(jia)(jia)速绝(jue)缘(yuan)的(de)(de)(de)(de)老化，以(yi)至绝(jue)缘(yuan)被(bei)击穿。尤其在炎热(re)的(de)(de)(de)(de)夏季(ji)，电(dian)(dian)(dian)缆的(de)(de)(de)(de)温升(sheng)常常导致电(dian)(dian)(dian)缆绝(jue)缘(yuan)薄(bo)弱处首先被(bei)击穿，因此在夏季(ji)，电(dian)(dian)(dian)缆的(de)(de)(de)(de)故(gu)障也就特别多。 

贵州线(xian)缆厂(chang)家(jia)所处的(de)外(wai)界环境和热源(yuan)都会造成电缆温度(du)过(guo)高、绝缘击穿(chuan)，甚至爆炸起(qi)火。