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        上海人民電氣有限公司分析接觸器的故障

        2020/12/24 15:08:50      點(diǎn)擊:

        一、接觸器線(xiàn)圈燒毀或損壞的原因

        1、控制電源的電壓偏低,導(dǎo)致線(xiàn)圈接線(xiàn)端子上的控制電壓偏低,當(dāng)電壓低到一定程度,鐵芯就不能吸合,此時(shí)線(xiàn)圈中的電流是正常維持電流的幾倍(電流大小取決于電壓的大。,時(shí)間一長(zhǎng),線(xiàn)圈就會(huì)因過(guò)度發(fā)熱而燒壞。

        2、線(xiàn)圈控制線(xiàn)偏長(zhǎng),盡管控制電源是正常的,但是由于線(xiàn)路壓降的影響,導(dǎo)致線(xiàn)圈接線(xiàn)端子上的控制電壓偏低,當(dāng)電壓低到一定程度,鐵芯就不能吸合,此時(shí)線(xiàn)圈中的電流是維持電流的幾倍(電流大小取決于電壓的大。,時(shí)間一長(zhǎng),線(xiàn)圈就會(huì)因過(guò)度發(fā)熱而燒壞。

        3、線(xiàn)圈接線(xiàn)端子上的控制電壓偏高(>1.1 x Us),導(dǎo)致線(xiàn)圈過(guò)度發(fā)熱而燒壞。例如:將380V電壓施加于220V線(xiàn)圈,大約15分鐘左右就會(huì)燒壞,電壓越高,線(xiàn)圈燒壞所需的時(shí)間越短。

        4、在線(xiàn)圈制造,運(yùn)輸和安裝過(guò)程中,碰撞或產(chǎn)品跌落造成漆包線(xiàn)與接線(xiàn)端子的連接處機(jī)械損傷,工作一段時(shí)間后,損傷處燒斷。

        二、通電后接觸器的觸頭不能閉合的原因

        1、線(xiàn)圈供電線(xiàn)路斷路;

        2、線(xiàn)圈斷路;

        3、線(xiàn)圈控制電壓偏低;

        4、接觸器的線(xiàn)圈已經(jīng)燒壞,線(xiàn)圈骨架熱變形導(dǎo)致動(dòng)鐵芯無(wú)法吸合到位,最終導(dǎo)致觸頭不能閉合;

        5、主觸頭粘連;

        6、銜鐵中有異物,麻點(diǎn);

        7、主觸點(diǎn)錯(cuò)位(多見(jiàn)于大接觸器,橋式觸點(diǎn));

        8、輔助接點(diǎn)安裝不好。

        三、斷電后接觸器的觸頭不能分開(kāi)的原因?

        1、線(xiàn)圈的控制線(xiàn)過(guò)長(zhǎng),由于導(dǎo)線(xiàn)電容的影響,剩余電壓過(guò)高,足以維持鐵芯處于閉合狀態(tài),最終導(dǎo)致觸頭不能分開(kāi);

        2、接觸器的線(xiàn)圈已經(jīng)燒壞,變形的線(xiàn)圈骨架卡住動(dòng)鐵芯使之無(wú)法運(yùn)動(dòng),最終導(dǎo)致觸頭不能分開(kāi);

        3、觸頭已被熔焊;

        4、接觸器有自鎖功能,且該功能正常。

        四、接觸器出現(xiàn)噪音的原因?

        1、異物進(jìn)入鐵芯極面;

        2、鐵芯短路環(huán)斷裂;

        3、鐵芯裝配不到位,使動(dòng)靜鐵芯的極面不吻合;

        4、線(xiàn)圈控制電壓偏低;

        5、主觸點(diǎn)有異物,輔助觸電安裝是否良好;

        6、外部接線(xiàn)是否良好(緊固螺釘未擰緊,冷壓端頭壓接問(wèn)題)。

        六、接觸器觸頭熔焊的原因?

        1、接觸器負(fù)載相相或相地之間發(fā)生短路,或接觸器本身相間短路,短路電流通過(guò)觸頭,導(dǎo)致觸頭熔焊:沒(méi)有短路保護(hù)元件;短路保護(hù)元件只按1類(lèi)配合配置;短路保護(hù)元件按2類(lèi)配合配置。

        2、星-三角起動(dòng)電動(dòng)機(jī)時(shí),星型連接與三角型連接之間沒(méi)有足夠的時(shí)間間隔,雖然星形接觸器觸頭已打開(kāi),但是星形接觸器觸頭間的電弧熄滅需要時(shí)間,如果星形接觸器觸頭間電弧沒(méi)有熄滅,而此時(shí)三角接觸器立即合上,就會(huì)形成短路,短路就會(huì)引起觸頭熔焊。

        3、控制電源的電壓偏低或線(xiàn)圈控制線(xiàn)偏長(zhǎng)引起線(xiàn)圈兩端的電壓偏低,(電工技術(shù)之家 www.dgjs123.com)如果此電壓正好處于抖動(dòng)區(qū),鐵芯產(chǎn)生的磁吸力一會(huì)兒大于彈簧的反力,一會(huì)兒小于彈簧的反力,動(dòng)鐵芯來(lái)回運(yùn)動(dòng)帶動(dòng)觸頭來(lái)回抖動(dòng),觸頭時(shí)分時(shí)合,引起觸頭間不斷燃弧,導(dǎo)致觸頭熔焊。

        4、工作環(huán)境惡劣,粉塵太大,由于接觸器的防護(hù)等級(jí)一般為IP00或IP20,粉塵會(huì)進(jìn)入到觸頭的接觸面,粉塵會(huì)增加觸頭局部的接觸電阻,而沒(méi)有粉塵的部分,其電流密度會(huì)增大,最終溫度升高導(dǎo)致觸頭熔焊。

        5、設(shè)計(jì)選型不當(dāng),接觸器的容量不夠,接觸器的壽命很快終結(jié),觸頭熔焊。

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