一、保險絲電阻一般是多大

保險絲作(zuo)為保障電路安全的元器件，一般是(shi)熔點較低的金屬材(cai)質的，其(qi)本身具有一定(ding)的電阻(zu)，那(nei)么保險絲電阻(zu)多大呢？

正(zheng)常(chang)情況下，導線(xian)(xian)可以(yi)通(tong)(tong)過(guo)電(dian)(dian)(dian)流，它的電(dian)(dian)(dian)阻是(shi)比較小的，在一般的電(dian)(dian)(dian)路計算中(zhong)通(tong)(tong)常(chang)不計，而保(bao)險絲的電(dian)(dian)(dian)阻要比等(deng)長的導線(xian)(xian)更大，這樣才(cai)能在短路時(shi)及時(shi)熔斷，保(bao)護電(dian)(dian)(dian)路，普通(tong)(tong)的保(bao)險絲電(dian)(dian)(dian)阻一般是(shi)在0.33Ω-1Ω范(fan)圍內。

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二、保險絲電阻大還是小好

保(bao)(bao)險(xian)(xian)絲(si)的(de)電阻(zu)有(you)(you)大有(you)(you)小(xiao)，不同(tong)電阻(zu)大小(xiao)的(de)熔斷器(qi)在實際應用(yong)過程中的(de)表現也有(you)(you)所不同(tong)，那么大電阻(zu)的(de)保(bao)(bao)險(xian)(xian)絲(si)好還是(shi)小(xiao)電阻(zu)的(de)保(bao)(bao)險(xian)(xian)絲(si)好呢？

一般來說(shuo)，保(bao)(bao)(bao)險絲(si)(si)電(dian)(dian)阻(zu)的(de)選擇要(yao)根據實際情況(kuang)選，總(zong)體來說(shuo)，建議選大點(dian)電(dian)(dian)阻(zu)的(de)保(bao)(bao)(bao)險絲(si)(si)，主要(yao)原因是(shi)：根據保(bao)(bao)(bao)險絲(si)(si)的(de)熔(rong)(rong)(rong)斷原理，保(bao)(bao)(bao)險絲(si)(si)利用電(dian)(dian)流(liu)的(de)熱(re)(re)效應來控制通(tong)(tong)過(guo)的(de)電(dian)(dian)流(liu)大小，當(dang)通(tong)(tong)過(guo)的(de)電(dian)(dian)流(liu)超過(guo)限定值(zhi)時，保(bao)(bao)(bao)險絲(si)(si)就會熔(rong)(rong)(rong)斷；根據公式Q=I2RT可(ke)知，保(bao)(bao)(bao)險絲(si)(si)的(de)電(dian)(dian)阻(zu)越大，在電(dian)(dian)流(liu)相同和通(tong)(tong)電(dian)(dian)時間相同的(de)情況(kuang)下，產生(sheng)的(de)熱(re)(re)量(liang)就會越大，越容易熔(rong)(rong)(rong)斷，對于保(bao)(bao)(bao)護電(dian)(dian)路更好。如果保(bao)(bao)(bao)險絲(si)(si)的(de)電(dian)(dian)阻(zu)比(bi)較小的(de)話，那么(me)即使通(tong)(tong)過(guo)大電(dian)(dian)流(liu)也無法及時熔(rong)(rong)(rong)斷，不安全(quan)。

當然，保險絲的電阻(zu)(zu)也不宜太大了(le)，不然稍微(wei)過一(yi)些大的電流就熔斷了(le)，影響家用電器(qi)(qi)的正常使(shi)用，一(yi)般建議(yi)根據電線(xian)大小和家用電器(qi)(qi)的負荷來選擇合適電阻(zu)(zu)大小的保(bao)險絲。