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　　密集母(mu)線(xian)(xian)槽通常是(shi)測量外(wai)殼(ke)和(he)(he)(he)穿芯螺栓的(de)(de)溫升、進線(xian)(xian)箱的(de)(de)接(jie)頭(tou)(tou)溫升等，電(dian)(dian)(dian)(dian)(dian)纜因其材料易于磨損、易老(lao)化、壽命(ming)較短等因素(su)限制，需要定(ding)期進行(xing)檢查和(he)(he)(he)維(wei)護，甚至更換(huan)。但凡是(shi)低壓線(xian)(xian)穿墻敷設時，必需用穿墻套管(guan)。穿墻套管(guan)分(fen)室內和(he)(he)(he)露天兩種，也(ye)部分(fen)叫戶內和(he)(he)(he)戶外(wai)穿墻套管(guan)。數(shu)據中心列頭(tou)(tou)柜(ju)形式的(de)(de)供(gong)配(pei)電(dian)(dian)(dian)(dian)(dian)系統是(shi)典型(xing)的(de)(de)放(fang)射式供(gong)配(pei)電(dian)(dian)(dian)(dian)(dian)系統,總配(pei)電(dian)(dian)(dian)(dian)(dian)柜(ju)直接(jie)供(gong)電(dian)(dian)(dian)(dian)(dian)給列頭(tou)(tou)柜(ju)與(yu)(yu)(yu)負載的(de)(de)配(pei)電(dian)(dian)(dian)(dian)(dian)方式。優點是(shi)各負荷(he)獨立受(shou)電(dian)(dian)(dian)(dian)(dian),一(yi)旦(dan)發生故障只(zhi)局限于本身而不(bu)影響其他(ta)回(hui)路,充分(fen)滿足現行(xing)規范對(dui)重要用電(dian)(dian)(dian)(dian)(dian)負荷(he)的(de)(de)技術要求(qiu)。缺點是(shi)線(xian)(xian)路多、金屬導體(ti)消耗量大、施工復(fu)雜。列頭(tou)(tou)柜(ju)通常以放(fang)射式的(de)(de)配(pei)電(dian)(dian)(dian)(dian)(dian)形式連接(jie)到上(shang)游配(pei)電(dian)(dian)(dian)(dian)(dian)柜(ju)或與(yu)(yu)(yu)采用樹干狀配(pei)電(dian)(dian)(dian)(dian)(dian)形式采用主干母(mu)線(xian)(xian)與(yu)(yu)(yu)上(shang)游電(dian)(dian)(dian)(dian)(dian)源配(pei)電(dian)(dian)(dian)(dian)(dian)柜(ju)連接(jie)。