一、熱縮電纜附件材質是什么
熱縮電纜附件所用(yong)材料一般(ban)為(wei)以聚乙(yi)烯(xi)、乙(yi)烯(xi)-醋(cu)酸乙(yi)烯(xi)(EVA)及乙(yi)丙橡膠(jiao)等多種材料組(zu)分的共混物組(zu)成。該類產品主要采用(yong)應(ying)力管處理(li)電應(ying)力集(ji)中問題。亦即采用(yong)參數控制法緩解電場應(ying)力集(ji)中。
應力管(guan)是一種體(ti)積電(dian)(dian)(dian)阻率適中(zhong)(1010-1012Ωcm),介電(dian)(dian)(dian)常數較(jiao)大(da)(20--25)的特(te)殊電(dian)(dian)(dian)性參數的熱收(shou)縮(suo)管(guan),利用(yong)(yong)電(dian)(dian)(dian)氣參數強迫電(dian)(dian)(dian)纜絕緣(yuan)屏蔽(bi)斷口(kou)處的應力疏散成沿應力管(guan)較(jiao)均(jun)勻的分布。這一技術一般用(yong)(yong)于(yu)35kV及以下電(dian)(dian)(dian)纜附件中(zhong)。因為(wei)電(dian)(dian)(dian)壓等(deng)級高(gao)時應力管(guan)將發(fa)熱而不能可靠工作。
其使用(yong)中(zhong)關鍵技術問題是:要保證應(ying)(ying)力管(guan)的電(dian)(dian)(dian)(dian)性(xing)參數必(bi)須達到(dao)上(shang)述(shu)標準規定值方(fang)能(neng)可(ke)靠工作(zuo)。另外要注意用(yong)硅脂填(tian)充(chong)電(dian)(dian)(dian)(dian)纜絕緣半導電(dian)(dian)(dian)(dian)層斷口出的氣(qi)(qi)隙(xi)以(yi)排除氣(qi)(qi)體,達到(dao)減(jian)小局部放電(dian)(dian)(dian)(dian)的目的。交(jiao)聯電(dian)(dian)(dian)(dian)纜因內(nei)應(ying)(ying)力處(chu)理(li)不良(liang)時在(zai)運(yun)(yun)行(xing)(xing)中(zhong)會發生較大收縮,因而在(zai)安(an)裝附件(jian)時注意應(ying)(ying)力管(guan)與絕緣屏(ping)蔽(bi)搭(da)蓋不少(shao)于20mm,以(yi)防(fang)收縮時應(ying)(ying)力管(guan)與絕緣屏(ping)蔽(bi)脫離。熱收縮附件(jian)因彈(dan)性(xing)較小,運(yun)(yun)行(xing)(xing)中(zhong)熱脹冷縮時可(ke)能(neng)使界面(mian)產(chan)生氣(qi)(qi)隙(xi),因此密(mi)封技術很重要,以(yi)防(fang)止潮氣(qi)(qi)浸入。
二、熱縮電纜附件的特點
熱縮電纜附件俗稱熱(re)縮電纜頭,廣泛(fan)用于(yu)35KV及以下電壓等(deng)級的交聯電纜或油浸電纜的中(zhong)間連接和(he)終(zhong)端上。與傳統(tong)電纜附件相比具有體積小、重(zhong)量輕、安全(quan)可(ke)靠(kao)、安裝方便(bian)、性能尚好(hao),價格便(bian)宜(yi)等(deng)特點。產品符合(he)GB11033標準,長期使用溫度范(fan)圍為(wei)-55℃~105℃,老化壽命長達20年,徑向收縮率(lv)≥50%,縱向收縮率(lv)<5%,收縮溫度為(wei)110℃~140℃。