電機(ji)維(wei)修分析高壓電機(ji)過熱保護(hu)方法
一(yi)、高壓(ya)電動機過熱(re)保護(hu):
1、JWl型(xing)雙金屬溫(wen)(wen)度繼電器(qi)由測溫(wen)(wen)元件(jian)(溫(wen)(wen)控管)及執行元件(jian)(出口繼電器(qi))兩(liang)部分組成(cheng)。
2、溫(wen)(wen)控(kong)管用雙金屬片(pian)作為感(gan)溫(wen)(wen)元件,用三只溫(wen)(wen)控(kong)管串聯對(dui)稱埋人電(dian)動(dong)機(ji)定子繞組端(duan)部(bu),并用環氧樹(shu)脂膠(jiao)粘牢。將連接(jie)導線(用屏(ping)蔽導線,屏(ping)蔽層(ceng)與電(dian)動(dong)機(ji)外殼(ke)相接(jie))引至電(dian)動(dong)機(ji)高壓控(kong)制柜。
3、由于JWl型專用繼電(dian)(dian)器(qi)(qi)容量(liang)較(jiao)小(xiao),溫(wen)控管(guan)觸點允許通過(guo)的(de)電(dian)(dian)流(liu)在60mA以下,繼電(dian)(dian)器(qi)(qi)線(xian)圈(quan)(quan)(quan)電(dian)(dian)壓為-220V,因此,執行元件選用DZ-31B中(zhong)間(jian)(jian)繼電(dian)(dian)器(qi)(qi)(線(xian)圈(quan)(quan)(quan)電(dian)(dian)壓-220V,線(xian)圈(quan)(quan)(quan)電(dian)(dian)阻12.75kΩ,觸點斷開容量(liang)50W,觸點允許通過(guo)電(dian)(dian)流(liu)5A),三只溫(wen)控管(guan)與(yu)中(zhong)間(jian)(jian)繼電(dian)(dian)器(qi)(qi)線(xian)圈(quan)(quan)(quan)串聯后接至電(dian)(dian)動機控制回(hui)路。
4、電動機(ji)正常運行時溫(wen)(wen)控(kong)管雙(shuang)金屬片(pian)觸(chu)(chu)點打開(kai),中間繼電器(qi)無電源不(bu)動作。當電動機(ji)因(yin)故過熱并達(da)到溫(wen)(wen)控(kong)管溫(wen)(wen)度(du)(du)整定動作值(該電動機(ji)為(wei)(wei)F級絕(jue)緣(yuan),溫(wen)(wen)度(du)(du)整定值為(wei)(wei)120℃,為(wei)(wei)可靠起見,實(shi)際選用(yong)動作值為(wei)(wei)105℃的溫(wen)(wen)控(kong)元件)時,溫(wen)(wen)控(kong)管雙(shuang)金屬片(pian)受(shou)熱伸(shen)長使觸(chu)(chu)點閉合。
5、此時中(zhong)間繼(ji)電(dian)(dian)(dian)器線圈得電(dian)(dian)(dian)吸合場觸點閉合,而該觸點已接至電(dian)(dian)(dian)動機跳閘回(hui)路(lu),使斷路(lu)器跳閘,切斷電(dian)(dian)(dian)動機高壓(ya)電(dian)(dian)(dian)源(yuan),使高壓(ya)電(dian)(dian)(dian)動機停止運轉。
6、過熱保護回路信號繼(ji)電(dian)器亦有指示,從而達到(dao)保護電(dian)動(dong)機的目的。當溫度降至(zhi)小于溫控管動(dong)作值(zhi)5℃以下時(shi),雙金屬(shu)片觸點(dian)又打開(kai)。
二、低壓(ya)電動機過熱保護:
低壓(ya)電(dian)動(dong)機過熱(re)保(bao)護亦(yi)選(xuan)用JWl型雙(shuang)金屬溫度繼電(dian)器(qi)。其(qi)組成結構(gou)及工作原理與高壓(ya)電(dian)動(dong)機過熱(re)保(bao)護裝置基本相同。
服(fu)務熱線:
聯(lian)系(xi)人:(江先生)
公司網站://maituwangluo.com/
公司地址:重慶市(shi)白市(shi)驛(yi)凈龍(long)