一、保險絲電阻一般是多大
保(bao)險絲作(zuo)為(wei)保(bao)障電(dian)(dian)路安全的(de)元器件,一(yi)(yi)般是熔點較低的(de)金(jin)屬材質的(de),其本身具有一(yi)(yi)定的(de)電(dian)(dian)阻,那么保(bao)險絲電(dian)(dian)阻多(duo)大(da)呢(ni)?
正常情況下,導線(xian)(xian)可以通(tong)過電(dian)(dian)(dian)流(liu),它的電(dian)(dian)(dian)阻(zu)是比較小的,在一般的電(dian)(dian)(dian)路(lu)計(ji)算(suan)中通(tong)常不計(ji),而保(bao)險絲(si)的電(dian)(dian)(dian)阻(zu)要比等(deng)長的導線(xian)(xian)更大,這樣才能在短路(lu)時及(ji)時熔斷,保(bao)護電(dian)(dian)(dian)路(lu),普通(tong)的保(bao)險絲(si)電(dian)(dian)(dian)阻(zu)一般是在0.33Ω-1Ω范圍內。
二、保險絲電阻大還是小好
保(bao)險絲(si)的(de)(de)電(dian)(dian)(dian)阻有(you)大(da)有(you)小,不同(tong)電(dian)(dian)(dian)阻大(da)小的(de)(de)熔(rong)斷器在實際應用過程中(zhong)的(de)(de)表(biao)現也有(you)所不同(tong),那(nei)么大(da)電(dian)(dian)(dian)阻的(de)(de)保(bao)險絲(si)好還是(shi)小電(dian)(dian)(dian)阻的(de)(de)保(bao)險絲(si)好呢(ni)?
一般來說,保險絲電(dian)(dian)(dian)阻的(de)(de)(de)(de)選(xuan)擇要(yao)(yao)根據(ju)實際情況選(xuan),總體(ti)來說,建議選(xuan)大(da)點電(dian)(dian)(dian)阻的(de)(de)(de)(de)保險絲,主要(yao)(yao)原(yuan)因是:根據(ju)保險絲的(de)(de)(de)(de)熔斷(duan)原(yuan)理,保險絲利(li)用電(dian)(dian)(dian)流的(de)(de)(de)(de)熱效應來控制通過的(de)(de)(de)(de)電(dian)(dian)(dian)流大(da)小(xiao),當通過的(de)(de)(de)(de)電(dian)(dian)(dian)流超過限定(ding)值時,保險絲就(jiu)(jiu)會熔斷(duan);根據(ju)公式(shi)Q=I2RT可(ke)知,保險絲的(de)(de)(de)(de)電(dian)(dian)(dian)阻越大(da),在電(dian)(dian)(dian)流相同和通電(dian)(dian)(dian)時間(jian)相同的(de)(de)(de)(de)情況下,產生的(de)(de)(de)(de)熱量就(jiu)(jiu)會越大(da),越容易熔斷(duan),對于保護電(dian)(dian)(dian)路更好(hao)。如(ru)果保險絲的(de)(de)(de)(de)電(dian)(dian)(dian)阻比(bi)較小(xiao)的(de)(de)(de)(de)話,那么即使通過大(da)電(dian)(dian)(dian)流也(ye)無法及時熔斷(duan),不安全。
當然,保險絲的電(dian)阻(zu)也(ye)不宜太大(da)了,不然稍微過一些(xie)大(da)的電(dian)流就熔斷了,影響家用(yong)電(dian)器的正常使用(yong),一般建議(yi)根(gen)據電(dian)線大(da)小和家用(yong)電(dian)器的負荷來選擇合適電(dian)阻(zu)大(da)小的保險絲。