雷(lei)電流會沿(yan)著通(tong)(tong)信線纜侵入室內，引起(qi)設備的(de)損(sun)害和人員傷亡(wang)等事故。因此，在防雷(lei)工程中如(ru)何預(yu)防沿(yan)通(tong)(tong)信線路入侵的(de)雷(lei)電流是非常重要的(de)。鈞和電子(zi)就該話題做如(ru)下分享：

一、通信線(xian)路采取(qu)埋地敷設，且采用(yong)屏蔽體

為降低雷(lei)(lei)擊通(tong)信線路的(de)概率(lv)，通(tong)信線路進站前應采用直接(jie)埋地式電(dian)(dian)(dian)纜(lan)。但應注意，電(dian)(dian)(dian)纜(lan)的(de)低電(dian)(dian)(dian)阻率(lv)將為選擇性雷(lei)(lei)擊提(ti)供有利條件，使埋有電(dian)(dian)(dian)纜(lan)處大(da)地的(de)落(luo)雷(lei)(lei)概率(lv)上升。雷(lei)(lei)電(dian)(dian)(dian)可擊穿電(dian)(dian)(dian)纜(lan)上方的(de)土(tu)壤直接(jie)到(dao)電(dian)(dian)(dian)纜(lan)上，也可在集(ji)中(zhong)電(dian)(dian)(dian)纜(lan)附近的(de)物體后經土(tu)壤反擊到(dao)電(dian)(dian)(dian)纜(lan)上。另(ling)外雷(lei)(lei)擊通(tong)信電(dian)(dian)(dian)纜(lan)附近的(de)物體還會(hui)再通(tong)信電(dian)(dian)(dian)纜(lan)上形成(cheng)感(gan)應過電(dian)(dian)(dian)壓。

為減少地下電纜遭受直擊雷擊和電磁感應的危險，可在地下電纜上方約30厘米處輻射兩條與電纜平行的接地金屬導體作為屏蔽體，例如截面積小于50mm²的鍍鋅鋼線，其作用原理和架空輸電線上方的避雷線相似。

二、通信線纜(lan)采用屏(ping)蔽線纜(lan)，且(qie)兩端(duan)接地

為進一步減少(shao)感應(ying)(ying)過電(dian)(dian)(dian)壓的(de)危害(hai)，通(tong)(tong)(tong)信線(xian)(xian)(xian)纜(lan)宜采用(yong)屏蔽(bi)(bi)電(dian)(dian)(dian)纜(lan)，屏蔽(bi)(bi)層(ceng)(ceng)的(de)兩端(duan)應(ying)(ying)接(jie)地，并在(zai)電(dian)(dian)(dian)纜(lan)芯(xin)線(xian)(xian)(xian)和(he)屏蔽(bi)(bi)層(ceng)(ceng)間加(jia)(jia)裝(zhuang)金(jin)屬(shu)氧化(hua)物壓敏(min)電(dian)(dian)(dian)阻(zu)（當電(dian)(dian)(dian)纜(lan)和(he)用(yong)戶或分局的(de)低頻(pin)通(tong)(tong)(tong)信系(xi)統連接(jie)時(shi)）或氣體(ti)(ti)放電(dian)(dian)(dian)管（當電(dian)(dian)(dian)纜(lan)和(he)包括微波站(zhan)在(zai)內的(de)高頻(pin)通(tong)(tong)(tong)信系(xi)統連接(jie)時(shi)）。當電(dian)(dian)(dian)纜(lan)有(you)多(duo)余芯(xin)線(xian)(xian)(xian)時(shi)，應(ying)(ying)將多(duo)余芯(xin)線(xian)(xian)(xian)與(yu)屏蔽(bi)(bi)層(ceng)(ceng)相連以(yi)加(jia)(jia)強屏蔽(bi)(bi)效(xiao)果。如果所用(yong)通(tong)(tong)(tong)信電(dian)(dian)(dian)纜(lan)為無屏蔽(bi)(bi)層(ceng)(ceng)的(de)橡皮或全塑電(dian)(dian)(dian)纜(lan)時(shi)，或只有(you)薄(bo)金(jin)屬(shu)箔(bo)無法焊接(jie)時(shi)，應(ying)(ying)將電(dian)(dian)(dian)纜(lan)穿入埋地鐵罐中，并將備用(yong)芯(xin)線(xian)(xian)(xian)兩端(duan)接(jie)地來實現(xian)屏蔽(bi)(bi)。

三(san)、通(tong)信(xin)線路進(jin)入(ru)建筑物(wu)后要(yao)采用多級浪涌(yong)保(bao)護器

對于信(xin)號(hao)系統的(de)保(bao)(bao)護要根據電(dian)子設(she)備的(de)敏感(gan)程度來確定(ding)。不(bu)同(tong)的(de)使用條件對保(bao)(bao)護裝置(zhi)所用的(de)器(qi)件有(you)不(bu)同(tong)的(de)要求，在選(xuan)用浪涌保(bao)(bao)護器(qi)時應注意線路的(de)工作頻率、傳(chuan)輸介(jie)質(zhi)、傳(chuan)輸速率、工作電(dian)壓、接(jie)口形式、阻抗特性等參數，選(xuan)用電(dian)壓駐波比和插入損耗小的(de)適配(pei)的(de)浪涌保(bao)(bao)護器(qi)，以確保(bao)(bao)系統的(de)正(zheng)常工作。