外力損(sun)(sun)傷(shang)：在電(dian)纜的(de)(de)保(bao)管、運(yun)輸、敷設和(he)運(yun)行過程中(zhong)都(dou)可能遭(zao)受外力損(sun)(sun)傷(shang)，特別是已運(yun)行的(de)(de)直埋電(dian)纜，在其他工(gong)程的(de)(de)地(di)面施工(gong)中(zhong)易(yi)遭(zao)損(sun)(sun)傷(shang)。這類(lei)事(shi)故(gu)往往占電(dian)纜事(shi)故(gu)的(de)(de)50%。為避(bi)免這類(lei)事(shi)故(gu)，除(chu)加強電(dian)纜保(bao)管、運(yun)輸、敷設等各環節(jie)的(de)(de)工(gong)作(zuo)質量外，更重要的(de)(de)是嚴格執行動土制度。

保護層腐(fu)蝕：地下雜(za)散(san)(san)電(dian)(dian)(dian)流的電(dian)(dian)(dian)化腐(fu)蝕或(huo)非中(zhong)性(xing)土壤(rang)的化學腐(fu)蝕使保護層失效，失去(qu)對絕緣的保護作用(yong)。解決辦法是(shi)，在(zai)雜(za)散(san)(san)電(dian)(dian)(dian)流密集區安裝排流設備；當電(dian)(dian)(dian)纜(lan)線路上(shang)的局部(bu)土壤(rang)含有損害電(dian)(dian)(dian)纜(lan)鉛包的化學物(wu)質(zhi)時(shi)，應將(jiang)這段電(dian)(dian)(dian)纜(lan)裝于管內(nei)，并用(yong)中(zhong)性(xing)土壤(rang)作電(dian)(dian)(dian)纜(lan)的襯墊及覆(fu)蓋，還(huan)要(yao)在(zai)電(dian)(dian)(dian)纜(lan)上(shang)涂(tu)以瀝青(qing)。

過電(dian)壓(ya)、過負(fu)荷(he)運行(xing)：電(dian)纜電(dian)壓(ya)選擇不當、在運行(xing)中突然有高壓(ya)竄入或(huo)長期超負(fu)荷(he)，都可能使電(dian)纜絕(jue)緣強度遭破壞，將(jiang)電(dian)纜擊穿(chuan)。這需要過加強巡視(shi)檢查、改善運行(xing)條件來及時解決(jue)。

戶外(wai)終(zhong)(zhong)(zhong)端(duan)頭浸(jin)水：因(yin)施工不良(liang)，絕緣膠未灌滿，致終(zhong)(zhong)(zhong)端(duan)頭浸(jin)水，最(zui)終(zhong)(zhong)(zhong)發生爆炸。因(yin)此要嚴格執行施工工藝規程，認真驗收(shou)；加(jia)(jia)強(qiang)檢(jian)查和及(ji)時維修。終(zhong)(zhong)(zhong)端(duan)頭漏(lou)油，破壞了密封結構，使(shi)電(dian)纜端(duan)部浸(jin)漬(zi)劑流(liu)失(shi)干枯(ku)，熱阻(zu)增(zeng)加(jia)(jia)，絕緣加(jia)(jia)速老化，易吸收(shou)潮氣，造(zao)成熱擊穿。發現終(zhong)(zhong)(zhong)端(duan)頭滲(shen)漏(lou)油時應(ying)加(jia)(jia)強(qiang)巡視(shi)，嚴重時應(ying)停電(dian)重做。