影響(xiang)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)壽(shou)命(ming)的(de)(de)(de)(de)因素: a、 工作環(huan)境(jing)溫度(du): 環(huan)境(jing)溫度(du)過(guo)高有(you)損(sun)于(yu)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)的(de)(de)(de)(de)壽(shou)命(ming)。延時(shi)(shi)(shi)型(xing)(慢熔斷(duan)型(xing))保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)如(ru)錫球(qiu)型(xing),溫度(du)約(yue)等(deng)于(yu)160℃(150~170℃)時(shi)(shi)(shi)錫開始向金屬(shu)絲(si)(si)(si)(si)(si)(si)擴散(san)(san);快(kuai)速(su)熔斷(duan)型(xing)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)的(de)(de)(de)(de)可(ke)熔體(金屬(shu)絲(si)(si)(si)(si)(si)(si))開始較劇烈氧(yang)(yang)化(hua)的(de)(de)(de)(de)溫度(du)約(yue)等(deng)于(yu)200℃(175~225℃)。隨熔絲(si)(si)(si)(si)(si)(si)由(you)外向里(li)的(de)(de)(de)(de)氧(yang)(yang)化(hua)、多(duo)次的(de)(de)(de)(de)擴散(san)(san)、熱(re)應(ying)力疲勞等(deng),保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)的(de)(de)(de)(de)壽(shou)命(ming)將逐(zhu)漸縮(suo)短(duan)。 因而(er)建議延時(shi)(shi)(shi)型(xing)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)熔絲(si)(si)(si)(si)(si)(si)不(bu)應(ying)長(chang)時(shi)(shi)(shi)間在(zai)150℃以上(shang)工作,快(kuai)速(su)熔斷(duan)型(xing)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)不(bu)應(ying)長(chang)時(shi)(shi)(shi)間在(zai)175~225℃以上(shang)工作。 b、脈沖(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)流: 不(bu)斷(duan)的(de)(de)(de)(de)脈沖(chong)(chong)(chong)沖(chong)(chong)(chong)擊(ji),會(hui)產(chan)生熱(re)循環(huan),從而(er)致使(shi)熔絲(si)(si)(si)(si)(si)(si)的(de)(de)(de)(de)擴散(san)(san)、氧(yang)(yang)化(hua)、熱(re)應(ying)力等(deng)產(chan)生,甚至加速(su)。保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)將 隨著脈沖(chong)(chong)(chong)能量(liang)和次數的(de)(de)(de)(de)增加而(er)漸漸老化(hua)。 保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)的(de)(de)(de)(de)抗(kang)沖(chong)(chong)(chong)擊(ji)壽(shou)命(ming),取決(jue)于(yu)脈沖(chong)(chong)(chong)的(de)(de)(de)(de)I2t占保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)本身I2t的(de)(de)(de)(de)百分比(bi);通常情(qing)況(kuang),應(ying)小(xiao)(xiao)于(yu)20%,那樣保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)可(ke)承受10萬次以上(shang)的(de)(de)(de)(de)沖(chong)(chong)(chong)擊(ji)。 c、其它(ta): 如(ru)與(yu)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)接(jie)觸的(de)(de)(de)(de)管(guan)夾(jia)、及連接(jie)電(dian)(dian)(dian)(dian)(dian)線的(de)(de)(de)(de)長(chang)度(du)、截(jie)面積等(deng)。保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)與(yu)管(guan)夾(jia)的(de)(de)(de)(de)接(jie)觸電(dian)(dian)(dian)(dian)(dian)阻大,有(you)損(sun)于(yu)壽(shou)命(ming),UL標(biao)準(zhun)中規(gui)定,試驗時(shi)(shi)(shi)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)與(yu)管(guan)夾(jia)的(de)(de)(de)(de)接(jie)觸電(dian)(dian)(dian)(dian)(dian)阻小(xiao)(xiao)于(yu)3mΩ。當(dang)接(jie)觸電(dian)(dian)(dian)(dian)(dian)阻大時(shi)(shi)(shi),管(guan)夾(jia)不(bu)是散(san)(san)熱(re)而(er)是產(chan)生熱(re)并(bing)向熔絲(si)(si)(si)(si)(si)(si)傳送(song)。 2、 保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)老化(hua)后對(dui)使(shi)用的(de)(de)(de)(de)影響(xiang): 保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)老化(hua)后,不(bu)會(hui)產(chan)生應(ying)切(qie)斷(duan)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流而(er)保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)不(bu)熔斷(duan)的(de)(de)(de)(de)危險(xian)(xian)(xian)(xian)。保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si) 老化(hua)后,相當(dang)于(yu)是額定值(電(dian)(dian)(dian)(dian)(dian)流)的(de)(de)(de)(de)下降而(er)非上(shang)升,因而(er)在(zai)電(dian)(dian)(dian)(dian)(dian)路中不(bu)會(hui)產(chan)生安全性問題,只是會(hui)在(zai)較小(xiao)(xiao)的(de)(de)(de)(de)過(guo)載(zai)電(dian)(dian)(dian)(dian)(dian)流或脈沖(chong)(chong)(chong)下即切(qie)斷(duan)電(dian)(dian)(dian)(dian)(dian)路。 3、 保(bao)(bao)(bao)(bao)險(xian)(xian)(xian)(xian)絲(si)(si)(si)(si)(si)(si)壽(shou)命(ming)的(de)(de)(de)(de)測試評估: 在(zai)IEC標(biao)準(zhun)中規(gui)定有(you)“耐久(jiu)性試驗法”,而(er)UL標(biao)準(zhun)中無(wu)類似的(de)(de)(de)(de)規(gui)定。

IEC標(biao)準中(zhong)的(de)耐久(jiu)性試驗即(ji)是(shi)壽命試驗,其方法是(shi),在正常(chang)溫(wen)度下使用直流電源(yuan)測(ce)試:
1、額電(dian)流直(zhi)到溫度穩(wen)定下(xia)測電(dian)壓降;
2、1.2倍額定電流1h 切斷電流15min。循環100次;
3、通電1.5In 1h 測電壓降;
4、同1法測電壓降。 要求:試驗前后電壓降變化不應超過10%,且標識仍清楚可辯,端帽焊點不出現任何劣變。