低壓石板閘配用的熔斷管，膠木內部多以石英砂做填充物，目的是(shi)電弧在石英砂中燃燒，熔件(jian)蒸發(fa)形成熾(chi)熱空氣滲(shen)入(ru)填料中迅速凝結，增加滅弧效果。

填(tian)料在熔管(guan)中(zhong)較為重要(yao)，更換熔件時需要(yao)注意(yi)以下幾點：

1、填料要如數裝進熔(rong)管，不(bu)能撒棄(qi)少裝或不(bu)裝；

2、在(zai)野外更換(huan)熔件時，填料中不可混合泥土和雜草；

3、兩側的螺旋帽蓋(gai)需要擰緊(jin)、不可(ke)使填料泄漏。

低壓(ya)熔(rong)斷器的種類(lei)和技術特性：

有填料熔斷器

有填料熔(rong)斷(duan)(duan)器常用的有RL1系(xi)列(lie)(lie)螺旋式(shi)熔(rong)斷(duan)(duan)器、RTO系(xi)列(lie)(lie)封(feng)閉管(guan)式(shi)熔(rong)斷(duan)(duan)器，RSO、RS3系(xi)列(lie)(lie)封(feng)閉管(guan)式(shi)快速熔(rong)斷(duan)(duan)器等。

1、RL1系列螺旋式熔斷器

該型熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)器(qi)(qi)俗(su)稱“螺(luo)旋保險器(qi)(qi)”，適(shi)用(yong)于交流(liu)(liu)380V、直流(liu)(liu)440V及以下(xia)，額定電(dian)流(liu)(liu)200A以下(xia)的(de)電(dian)路，RL1系列螺(luo)旋式熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)器(qi)(qi)由瓷(ci)制底座(zuo)、帶螺(luo)紋螺(luo)帽、熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)管(guan)(guan)和瓷(ci)套(tao)制成。熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)管(guan)(guan)內有熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)絲，并裝(zhuang)滿石(shi)英砂。熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)管(guan)(guan)上蓋中有一(yi)熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)指示器(qi)(qi)，當熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)器(qi)(qi)熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)體(ti)熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)時(shi)，指示器(qi)(qi)跳出，顯示熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)器(qi)(qi)熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)，可(ke)從瓷(ci)帽頂部的(de)玻璃(li)圓(yuan)孔中看到。熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)管(guan)(guan)內的(de)石(shi)英砂用(yong)于熄滅電(dian)弧。當熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)體(ti)熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)產生(sheng)電(dian)弧時(shi)，電(dian)弧在石(shi)英砂的(de)砂粒中通過，受到強(qiang)烈冷卻而熄滅。因此這種熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)器(qi)(qi)具(ju)有較高的(de)分斷(duan)(duan)(duan)能力，上限分斷(duan)(duan)(duan)能力可(ke)達50kA。由于熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)體(ti)具(ju)有較大的(de)熱慣(guan)性(xing)，過負荷熔(rong)(rong)(rong)(rong)(rong)(rong)(rong)斷(duan)(duan)(duan)時(shi)間較長，因此也常用(yong)作電(dian)動機的(de)保護(hu)裝(zhuang)置。

2、RLS系(xi)列螺旋式快速(su)熔斷器

此類熔斷(duan)器在過載(zai)倍數達到3-6倍額定電流(liu)時(shi)，熔斷(duan)時(shi)間不大于0.3-0.02s，可用(yong)作保護半導體(ti)整(zheng)流(liu)元件(jian)和晶閘管的設備之用(yong)。其結構與RL1相似，快速(su)特性通過熔體(ti)采取(qu)變(bian)(bian)截面和冶金效(xiao)應獲得(de)。所謂變(bian)(bian)截面是將片狀熔體(ti)上(shang)沖(chong)以小圓(yuan)孔，或沖(chong)出條形網狀，使熔體(ti)截面局(ju)部變(bian)(bian)小，當通過過載(zai)電流(liu)時(shi)易(yi)于熔斷(duan)。

3、RTO系列(lie)有填料封閉管式熔斷器

此系列熔斷器適(shi)用于交流(liu)(liu)380V、直流(liu)(liu)440V及以下要(yao)求分斷能力較(jiao)高的場合，并有(you)一定(ding)限(xian)流(liu)(liu)特性。在供(gong)電線路、變壓(ya)器的出線保(bao)護中(zhong)得到廣泛采用。

 RTO熔(rong)(rong)斷(duan)器的結構由熔(rong)(rong)斷(duan)管、動作指示器等組成。熔(rong)(rong)斷(duan)管內裝有(you)熔(rong)(rong)體(ti)和石英砂。石英砂的作用是(shi)，當熔(rong)(rong)體(ti)熔(rong)(rong)斷(duan)產(chan)生電(dian)(dian)(dian)弧(hu)時，石英砂能吸(xi)收電(dian)(dian)(dian)弧(hu)能量，冷卻電(dian)(dian)(dian)弧(hu)，使電(dian)(dian)(dian)弧(hu)快速熄滅，從(cong)而提高了分斷(duan)電(dian)(dian)(dian)路的能力。熔(rong)(rong)體(ti)由紫(zi)銅片沖成柵狀，中間(jian)部分用錫橋連接(jie)，具有(you)良好(hao)的安秒特性。

RTO熔斷器的動作(zuo)指示(shi)器為(wei)—機械信號裝置(zhi)，指示(shi)器有一(yi)與熔體并(bing)聯(lian)的康銅(tong)絲(si)(si)。當熔體熔斷后，電流(liu)流(liu)經康銅(tong)絲(si)(si)，使康銅(tong)絲(si)(si)立即燒斷，依靠彈(dan)(dan)簧釋放的彈(dan)(dan)力彈(dan)(dan)出一(yi)個紅色(se)指示(shi)器，表示(shi)熔體已熔斷。

RTO熔斷器有以下(xia)優點：

（1）具有一定的限流作(zuo)用，能在一個半(ban)周(zhou)波峰值以前分斷電路；

（2）熔(rong)斷器的絕(jue)緣操作手柄可在(zai)帶電情(qing)況下調換熔(rong)體，手柄具有鎖扣結構，操作方便；

（3）斷(duan)(duan)流(liu)能力高，在額定斷(duan)(duan)流(liu)范圍內，熔體分(fen)斷(duan)(duan)短(duan)路電流(liu)時，無聲光(guang)現(xian)象；

（4）熔(rong)斷器熔(rong)體裝有熔(rong)斷指示信(xin)號(hao)，便于識別(bie)故障線路，有利于事故處理的(de)迅速進行。

4、RS0、RS3系列有填料(liao)封閉管式快速熔(rong)斷器

這(zhe)兩(liang)種熔(rong)(rong)(rong)斷器主要作(zuo)為(wei)硅(gui)整流(liu)元件及其成(cheng)套(tao)裝置中的(de)過載(zai)保護和短路(lu)保護的(de)保護裝置用，而(er)(er)額定電(dian)壓750V，額定電(dian)流(liu)至(zhi)480A以下。其結構與(yu)RTO系(xi)列熔(rong)(rong)(rong)斷器相似，也由熔(rong)(rong)(rong)斷管、紅色動作(zuo)指(zhi)示器等組(zu)成(cheng)。熔(rong)(rong)(rong)斷管內也是(shi)裝有(you)熔(rong)(rong)(rong)體和石英砂填料。所不同的(de)是(shi)RSO、RS3系(xi)列熔(rong)(rong)(rong)斷器的(de)熔(rong)(rong)(rong)體采用銀片(pian)沖制而(er)(er)成(cheng)，為(wei)單片(pian)或(huo)多片(pian)變截面熔(rong)(rong)(rong)片(pian)，其窄部特(te)別細(xi)，較易熔(rong)(rong)(rong)斷，保證了(le)熔(rong)(rong)(rong)斷器的(de)快(kuai)速熔(rong)(rong)(rong)斷。采用銀作(zuo)為(wei)熔(rong)(rong)(rong)體與(yu)采用銅相比，銀的(de)導電(dian)性(xing)能(neng)好(hao)，而(er)(er)熔(rong)(rong)(rong)點較銅低，熔(rong)(rong)(rong)化系(xi)數(shu)較低，在高溫工作(zuo)下性(xing)能(neng)較穩(wen)定。