跌落式(shi)(shi)(shi)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)根(gen)據其運作電(dian)(dian)壓分為高壓型和(he)低壓型。根(gen)據保護政策(ce)可(ke)分為保護變(bian)壓器(qi)(qi)(qi)(qi)用(yong)和(he)一般(ban)電(dian)(dian)氣設備用(yong)的(de)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)、保護電(dian)(dian)壓互感器(qi)(qi)(qi)(qi)的(de)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)、保護電(dian)(dian)力電(dian)(dian)容器(qi)(qi)(qi)(qi)的(de)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)、保護半(ban)導體(ti)元(yuan)件的(de)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)、保護電(dian)(dian)動機的(de)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)和(he)保護家用(yong)電(dian)(dian)器(qi)(qi)(qi)(qi)的(de)熔(rong)斷(duan)(duan)器(qi)(qi)(qi)(qi)等。根(gen)據結構可(ke)分為敞(chang)開式(shi)(shi)(shi)、半(ban)封閉式(shi)(shi)(shi)、管式(shi)(shi)(shi)和(he)跌落式熔(rong)斷器。

敞開式熔斷器結構極(ji)為簡略，其(qi)熔體(ti)完全露(lu)出(chu)于(yu)空(kong)氣(qi)中，由瓷柱作支撐(cheng)，沒有絕緣支座，適于(yu)野(ye)外的低壓(ya)電路運用。分斷電流時會產生(sheng)較大的聲(sheng)光。

半封閉式熔斷器的(de)熔體(ti)裝于瓷(ci)架上，刺(ci)進(jin)兩(liang)端(duan)帶有金屬(shu)插座的(de)瓷(ci)盒中(zhong)，適于低壓(ya)戶內(nei)運用。分斷電流時，所(suo)產生的(de)聲光(guang)被(bei)瓷(ci)盒擋住。

管(guan)(guan)(guan)式(shi)熔(rong)(rong)斷器(qi)的(de)熔(rong)(rong)體裝在熔(rong)(rong)斷體內。然(ran)后插在支座或(huo)直接連在電(dian)路上運(yun)用。熔(rong)(rong)斷體是兩(liang)端套有金屬(shu)帽或(huo)帶(dai)有觸刀的(de)完全密封的(de)絕(jue)緣管(guan)(guan)(guan)。這(zhe)種熔(rong)(rong)斷器(qi)的(de)絕(jue)緣管(guan)(guan)(guan)內若(ruo)充(chong)以石英砂，則分(fen)斷電(dian)流(liu)時具有限(xian)流(liu)作用，可大(da)大(da)提高(gao)分(fen)斷功(gong)用，故又稱作高(gao)分(fen)斷熔(rong)(rong)斷器(qi)。若(ruo)管(guan)(guan)(guan)內抽(chou)真空，則稱作真空熔(rong)(rong)斷器(qi)。若(ruo)管(guan)(guan)(guan)內充(chong)以SF6氣體(ti)，則稱作(zuo)SF6熔斷器，其目的是改進滅弧(hu)功(gong)用(yong)。由于石英砂，真空(kong)和SF6氣(qi)體均具有較好(hao)的絕緣功用(yong)，故(gu)這種熔斷器不但適用(yong)于低壓(ya)也適用(yong)于高壓(ya)。

跌落式熔(rong)(rong)(rong)斷(duan)(duan)器(qi)是將(jiang)熔(rong)(rong)(rong)體(ti)裝(zhuang)在(zai)(zai)由(you)固體(ti)產(chan)氣(qi)(qi)材料(liao)(liao)制成的絕(jue)緣(yuan)(yuan)管(guan)內。固體(ti)產(chan)氣(qi)(qi)材料(liao)(liao)可(ke)采用電(dian)(dian)(dian)工(gong)反白(bai)紙板或有機玻璃材料(liao)(liao)等(deng)。當短路電(dian)(dian)(dian)流(liu)通過熔(rong)(rong)(rong)體(ti)時，熔(rong)(rong)(rong)體(ti)隨(sui)即熔(rong)(rong)(rong)斷(duan)(duan)產(chan)生(sheng)電(dian)(dian)(dian)弧，高溫電(dian)(dian)(dian)弧使(shi)固體(ti)產(chan)氣(qi)(qi)材料(liao)(liao)靈敏分解(jie)產(chan)生(sheng)許多高壓氣(qi)(qi)體(ti)，從而(er)將(jiang)電(dian)(dian)(dian)離的氣(qi)(qi)體(ti)帶電(dian)(dian)(dian)弧在(zai)(zai)管(guan)子兩(liang)端噴出(chu)，宣布極大的聲(sheng)光，并在(zai)(zai)交流(liu)電(dian)(dian)(dian)流(liu)過零時熄滅電(dian)(dian)(dian)弧而(er)分斷(duan)(duan)電(dian)(dian)(dian)流(liu)。絕(jue)緣(yuan)(yuan)管(guan)通常是裝(zhuang)在(zai)(zai)一個絕(jue)緣(yuan)(yuan)支架(jia)上(shang)，組成熔(rong)(rong)(rong)斷(duan)(duan)器(qi)整體(ti)。有時絕(jue)緣(yuan)(yuan)管(guan)上(shang)端做(zuo)成可(ke)活動式，在(zai)(zai)分斷(duan)(duan)電(dian)(dian)(dian)流(liu)后隨(sui)即斷(duan)(duan)開跌落，此種(zhong)熔斷器俗(su)稱就是跌落式熔斷器。一般可適用于電壓高于6千伏的野外場合。

此外(wai)，熔(rong)(rong)斷(duan)器(qi)根據(ju)分斷(duan)電流規劃(hua)還可分為一般用途熔(rong)(rong)斷(duan)器(qi)，后備熔(rong)(rong)斷(duan)器(qi)和(he)全規劃(hua)熔(rong)(rong)斷(duan)器(qi)。一般用途熔(rong)(rong)斷(duan)器(qi)的分斷(duan)電流規劃(hua)指從過(guo)載(zai)電流大于(yu)額定電流1.6～2倍起，到(dao)最大分斷(duan)(duan)電(dian)(dian)流(liu)的規劃。這(zhe)種熔(rong)斷(duan)(duan)器首(shou)要用(yong)于(yu)保護電(dian)(dian)力(li)變壓器和一般電(dian)(dian)氣設備。后備熔(rong)斷(duan)(duan)器的分斷(duan)(duan)電(dian)(dian)流(liu)規劃指從過(guo)載電(dian)(dian)流(liu)大于(yu)額(e)定電(dian)(dian)流(liu)4～7倍起至最大(da)分斷電(dian)流的(de)規劃。這種熔斷器常與(yu)接觸器串(chuan)聯運用，在過(guo)載(zai)電(dian)流小于額定電(dian)流4～7倍(bei)的(de)規劃時(shi)，由接觸器來完成分斷保護。首要用于保護電動機。

現(xian)在工業發展的需(xu)求，還制造出(chu)適于各種(zhong)不同要(yao)求的特(te)別熔(rong)(rong)(rong)(rong)斷器(qi)，如電子熔(rong)(rong)(rong)(rong)斷器(qi)、熱熔(rong)(rong)(rong)(rong)斷器(qi)和自復(fu)熔(rong)(rong)(rong)(rong)斷器(qi)等。