三、延長(chang)銅(tong)包(bao)鋁(lv)電線壽(shou)命的方法(fa)

1. 安裝、維護應(ying)按國(guo)家電(dian)氣安全標準規(gui)范進(jin)行，隔離和保護鋁質電(dian)線，避免(mian)接觸污(wu)染物。安裝時(shi)應(ying)考慮鋁導(dao)線熱膨脹(zhang)系數大，要進(jin)行補償，以(yi)避免(mian)因溫度變化而引起的負荷(he)不良。

2. 降低電(dian)(dian)流密度和(he)(he)更換(huan)過期電(dian)(dian)線，以避(bi)免因過載過電(dian)(dian)而(er)造成的線路過熱和(he)(he)老(lao)化(hua)。

3. 接頭處理時應(ying)以盡可(ke)能減少軸向(xiang)力(li)的方式進行，采用橋接或插接方式。

4. 常規檢(jian)(jian)查：檢(jian)(jian)查接(jie)頭部位是(shi)否發熱，檢(jian)(jian)查絕(jue)緣狀況是(shi)否良好等(deng)。

4. 在陽(yang)光下放一個U形的垂(chui)直(zhi)角隔離器等紅色塑料塊(kuai)，以防止露天陽(yang)光直(zhi)射在電線上。

綜上(shang)，銅包鋁電線的(de)壽命(ming)受多(duo)種因(yin)素影響，銅漆包線批發，預期使用壽命(ming)在20-50年不(bu)等，但通過(guo)科(ke)學的(de)安裝、使用和維護(hu)，可以延長其(qi)使用壽命(ming)。

銅包鋁電力電纜

具(ju)有良好(hao)的(de)耐腐(fu)(fu)(fu)蝕性(xing)。鋁比銅(tong)(tong)(tong)易(yi)腐(fu)(fu)(fu)蝕，但由(you)于(yu)(yu)銅(tong)(tong)(tong)包鋁材料已經完(wan)全冶金化(hua)，銅(tong)(tong)(tong)漆(qi)包線(xian)哪家(jia)好(hao)，鋁完(wan)全被(bei)銅(tong)(tong)(tong)所覆，不(bu)會被(bei)水、空氣(qi)接(jie)(jie)(jie)觸(chu)，完(wan)全達到與銅(tong)(tong)(tong)一樣(yang)的(de)性(xing)能。銅(tong)(tong)(tong)包鋁/銅(tong)(tong)(tong)復(fu)合導體還更用利于(yu)(yu)避免電纜在(zai)長期使用過程(cheng)中由(you)于(yu)(yu)腐(fu)(fu)(fu)蝕、碰傷或(huo)因緊壓(ya)、錫焊(han)接(jie)(jie)(jie)不(bu)好(hao)使導體與接(jie)(jie)(jie)線(xian)端子(zi)(zi)接(jie)(jie)(jie)觸(chu)不(bu)良、發熱引起(qi)銅(tong)(tong)(tong)層脫(tuo)落(luo)和(he)銅(tong)(tong)(tong)鋁兩種金屬之間形(xing)成(cheng)電勢差，加(jia)速電化(hua)腐(fu)(fu)(fu)蝕，造成(cheng)電纜端部(bu)燒毀的(de)隱患(huan)。對于(yu)(yu)鋁導體，特別是在(zai)沿海地區，大(da)氣(qi)中鹽(yan)霧所含有的(de)氯離(li)子(zi)(zi)會凝(ning)聚在(zai)鋁的(de)表面(mian)，易(yi)在(zai)表面(mian)的(de)雜質(zhi)和(he)缺陷周圍(wei)引起(qi)局部(bu)腐(fu)(fu)(fu)蝕，形(xing)成(cheng)孔洞、裂紋和(he)微(wei)電池，加(jia)劇鋁導體的(de)腐(fu)(fu)(fu)蝕。

銅(tong)包鋁和純(chun)銅(tong)進行(xing)以下四方面的比較：

機械特性：

純(chun)(chun)銅(tong)(tong)(tong)(tong)導(dao)(dao)體(ti)強(qiang)度(du)、伸長率(lv)比(bi)(bi)銅(tong)(tong)(tong)(tong)包鋁(lv)導(dao)(dao)體(ti)大，也就是說純(chun)(chun)銅(tong)(tong)(tong)(tong)在(zai)機械(xie)性能方面比(bi)(bi)銅(tong)(tong)(tong)(tong)包鋁(lv)好(hao)(hao)。從電(dian)(dian)(dian)纜(lan)設計的(de)角度(du)來看，純(chun)(chun)銅(tong)(tong)(tong)(tong)導(dao)(dao)體(ti)比(bi)(bi)銅(tong)(tong)(tong)(tong)包鋁(lv)導(dao)(dao)體(ti)機械(xie)強(qiang)度(du)好(hao)(hao)的(de)優點，在(zai)實際(ji)應用(yong)過(guo)程中不一定需(xu)要(yao)。銅(tong)(tong)(tong)(tong)包鋁(lv)導(dao)(dao)體(ti)比(bi)(bi)純(chun)(chun)銅(tong)(tong)(tong)(tong)輕很多，因此銅(tong)(tong)(tong)(tong)包鋁(lv)的(de)電(dian)(dian)(dian)纜(lan)在(zai)整體(ti)重(zhong)量(liang)上(shang)比(bi)(bi)純(chun)(chun)銅(tong)(tong)(tong)(tong)導(dao)(dao)體(ti)電(dian)(dian)(dian)纜(lan)要(yao)輕，這(zhe)樣會給電(dian)(dian)(dian)纜(lan)的(de)運輸和電(dian)(dian)(dian)纜(lan)的(de)架設施工帶(dai)來方便。另外銅(tong)(tong)(tong)(tong)包鋁(lv)比(bi)(bi)純(chun)(chun)銅(tong)(tong)(tong)(tong)軟(ruan)一點，用(yong)銅(tong)(tong)(tong)(tong)包鋁(lv)導(dao)(dao)體(ti)生產(chan)的(de)電(dian)(dian)(dian)纜(lan)在(zai)柔軟(ruan)性方面比(bi)(bi)純(chun)(chun)銅(tong)(tong)(tong)(tong)的(de)電(dian)(dian)(dian)纜(lan)好(hao)(hao)一點。

電氣性能：

因(yin)為鋁的導電(dian)性比(bi)銅差，使(shi)得銅包(bao)鋁導體的直流電(dian)阻比(bi)純(chun)銅導體大，這點有無影響主要 2014年中考沖(chong)刺綜合復(fu)習(xi)指導北京地區(qu)試提 廣(guang)東地區(qu)試提

江蘇地區試提

看電纜(lan)(lan)是(shi)否會被(bei)用供電，如給放大器提供電源，如果(guo)被(bei)用來供電的(de)(de)話(hua)，銅(tong)包(bao)(bao)鋁(lv)(lv)(lv)導(dao)(dao)(dao)體將會導(dao)(dao)(dao)致額(e)外的(de)(de)電力消耗，電壓降低較多。當(dang)(dang)(dang)頻(pin)率超(chao)過(guo)5MHz時(shi)，江(jiang)蘇銅(tong)漆(qi)包(bao)(bao)線，此(ci)時(shi)的(de)(de)交流(liu)電阻衰減在(zai)這(zhe)兩種不同的(de)(de)導(dao)(dao)(dao)體下沒有明(ming)顯(xian)的(de)(de)區別。當(dang)(dang)(dang)然，這(zhe)主要是(shi)因(yin)為高(gao)頻(pin)電流(liu)的(de)(de)集膚效(xiao)應，頻(pin)率越(yue)高(gao)，電流(liu)的(de)(de)流(liu)動(dong)就越(yue)接近(jin)導(dao)(dao)(dao)體表(biao)面，在(zai)銅(tong)包(bao)(bao)鋁(lv)(lv)(lv)導(dao)(dao)(dao)體的(de)(de)表(biao)面實(shi)際(ji)上純銅(tong)材料，銅(tong)漆(qi)包(bao)(bao)線生產廠家，當(dang)(dang)(dang)頻(pin)率高(gao)到一定(ding)時(shi)候，整個(ge)電流(liu)鍍(du)在(zai)銅(tong)材質里面流(liu)動(dong)了。在(zai)5MHz情(qing)況下，電流(liu)在(zai)近(jin)表(biao)面的(de)(de)約0.025毫米厚度(du)(du)中流(liu)動(dong)，而銅(tong)包(bao)(bao)鋁(lv)(lv)(lv)導(dao)(dao)(dao)體的(de)(de)銅(tong)層厚度(du)(du)比(bi)此(ci)厚度(du)(du)多約一倍。對于同軸電纜(lan)(lan)，因(yin)為傳(chuan)輸的(de)(de)信號(hao)是(shi)在(zai)5MHz以上，因(yin)此(ci)銅(tong)包(bao)(bao)鋁(lv)(lv)(lv)導(dao)(dao)(dao)體和純銅(tong)導(dao)(dao)(dao)體傳(chuan)輸效(xiao)果(guo)是(shi)相同的(de)(de)。在(zai)實(shi)際(ji)測試電纜(lan)(lan)的(de)(de)衰減可以證明(ming)這(zhe)一點。