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电动机在运行中避免烧毁,除(chu)了运行前采取必(bi)要的各种(zhong)技术保护措施外,主要有以下6点。
1、经常(chang)检查电(dian)(dian)动(dong)机(ji)三(san)(san)(san)相电(dian)(dian)流是(shi)否平衡三(san)(san)(san)相异步电(dian)(dian)动(dong)机(ji),其(qi)三(san)(san)(san)相电(dian)(dian)流任何一相电(dian)(dian)流与其(qi)它(ta)两相电(dian)(dian)流平均(jun)值之差不允许超过10%,这样才能保证电(dian)(dian)动(dong)机(ji)安全运行。如(ru)果超过则表明电(dian)(dian)动(dong)机(ji)有故障(zhang),必(bi)须查明原因(yin)及时(shi)排除。
2、观察电动机(ji)有无振动、噪声和异常(chang)气味电动机(ji)若出现(xian)振动,会(hui)引起与之相连的负(fu)载部分不同心度增高,形成(cheng)电动机(ji)负(fu)载增大(da),出现(xian)超负(fu)荷运行,***会(hui)烧毁电动机(ji)。因(yin)此,电动机(ji)在运行中(zhong),尤其是(shi)大(da)功率电动机(ji)更(geng)要经常(chang)检查(cha)地(di)脚螺栓、电动机(ji)端盖、轴承压(ya)盖等是(shi)否(fou)松(song)动,接地(di)装(zhuang)置是(shi)否(fou)可靠,发现(xian)问题及时解决(jue)。
3、噪(zao)场声和异(yi)味(wei)是电动机运转异(yi)常、随即(ji)出(chu)现(xian)(xian)严重(zhong)故障(zhang)的(de)前兆(zhao),必须随时发现(xian)(xian)开查明原因而排除。
保(bao)证启(qi)(qi)动(dong)(dong)(dong)设(she)(she)备正常工作电动(dong)(dong)(dong)机(ji)(ji)启(qi)(qi)动(dong)(dong)(dong)设(she)(she)备技术状(zhuang)态的(de)好坏,对电动(dong)(dong)(dong)机(ji)(ji)的(de)正常启(qi)(qi)动(dong)(dong)(dong)起(qi)着决定性的(de)作用。实践证明,绝(jue)大多数(shu)烧(shao)毁(hui)(hui)的(de)电动(dong)(dong)(dong)机(ji)(ji),其原因大都是启(qi)(qi)动(dong)(dong)(dong)设(she)(she)备工作不(bu)(bu)正常造(zao)成的(de)。如(ru)(ru)启(qi)(qi)动(dong)(dong)(dong)设(she)(she)备出(chu)现缺相启(qi)(qi)动(dong)(dong)(dong),接(jie)触(chu)(chu)器触(chu)(chu)头拉(la)弧、打火等。而启(qi)(qi)动(dong)(dong)(dong)设(she)(she)备的(de)维(wei)护(hu)主要(yao)是清洁、紧固。如(ru)(ru)接(jie)触(chu)(chu)器触(chu)(chu)点不(bu)(bu)清洁会(hui)使(shi)接(jie)触(chu)(chu)电阻增(zeng)大,引起(qi)发(fa)热烧(shao)毁(hui)(hui)触(chu)(chu)点,造(zao)成缺相而烧(shao)毁(hui)(hui)电动(dong)(dong)(dong)机(ji)(ji);接(jie)触(chu)(chu)器吸(xi)合(he)线(xian)(xian)(xian)圈(quan)的(de)铁芯(xin)锈蚀和尘积,会(hui)使(shi)线(xian)(xian)(xian)圈(quan)吸(xi)合(he)不(bu)(bu)严,并发(fa)生强烈噪声(sheng),增(zeng)大线(xian)(xian)(xian)圈(quan)电流(liu),烧(shao)毁(hui)(hui)线(xian)(xian)(xian)圈(quan)而引发(fa)故(gu)障。
4、经(jing)常保持(chi)电动机的清(qing)洁
电(dian)动机在运(yun)行中,进风口(kou)周围(wei)至少3米(mi)内不(bu)允(yun)许有尘土、水渍和其它杂(za)物,以(yi)防止吸(xi)人电(dian)机内部,形成短(duan)(duan)路介质(zhi),或损(sun)坏导线绝缘层,造(zao)成匣间(jian)短(duan)(duan)路,电(dian)流增大,温度升高而烧毁(hui)电(dian)动机。所以(yi),要保证电(dian)动机有足够的(de)绝缘电(dian)阻,以(yi)及良好的(de)通风冷却环境(jing),才能使电(dian)动机在长时间(jian)运(yun)行中保持安全稳定的(de)工作状态。
5、检(jian)(jian)查(cha)电(dian)动机(ji)的(de)温(wen)度(du)(du)要经(jing)常(chang)检(jian)(jian)查(cha)电(dian)动机(ji)的(de)轴承(cheng)(cheng)、定子、外壳等部(bu)位的(de)温(wen)度(du)(du)有无(wu)异常(chang)变化(hua),尤其对(dui)无(wu)电(dian)压、电(dian)流和频(pin)率监(jian)视及没有过(guo)载保护的(de)电(dian)动机(ji),对(dui)温(wen)升的(de)监(jian)视更为(wei)重要。电(dian)动机(ji)轴承(cheng)(cheng)是否过(guo)热,缺油,若发现轴承(cheng)(cheng)附近的(de)温(wen)升过(guo)高,***应立即停机(ji)检(jian)(jian)查(cha)。轴承(cheng)(cheng)的(de)滚动体、滚道表面有无(wu)裂纹、划伤或损(sun)缺,轴承(cheng)(cheng)间(jian)隙(xi)是否过(guo)大晃动,内环在轴上(shang)有无(wu)转动等。出现上(shang)述任何一种现象,都必须更新轴承(cheng)(cheng)后方可再行作业(ye)。
6、保持电(dian)(dian)动(dong)机(ji)(ji)(ji)经常在(zai)额定电(dian)(dian)流(liu)下工作(zuo)电(dian)(dian)动(dong)机(ji)(ji)(ji)过载运(yun)行,主要(yao)原(yuan)因是(shi)由于拖动(dong)的(de)(de)负(fu)荷过大(da),电(dian)(dian)压过低,或被带动(dong)的(de)(de)机(ji)(ji)(ji)械卡(ka)滞(zhi)等造成的(de)(de)。若过载时间(jian)过长(zhang),电(dian)(dian)动(dong)机(ji)(ji)(ji)将从电(dian)(dian)网(wang)中(zhong)吸收大(da)量的(de)(de)有功(gong)功(gong)率,电(dian)(dian)流(liu)便(bian)急(ji)剧(ju)增(zeng)大(da),温(wen)度(du)(du)也随之上升,在(zai)高温(wen)下电(dian)(dian)动(dong)机(ji)(ji)(ji)的(de)(de)绝缘便(bian)老(lao)化(hua)失效而(er)烧毁。因此,电(dian)(dian)动(dong)机(ji)(ji)(ji)在(zai)运(yun)行中(zhong),要(yao)注意经常检查传动(dong)装置(zhi)运(yun)转(zhuan)是(shi)否(fou)灵(ling)活、可靠;连轴器的(de)(de)同心度(du)(du)是(shi)否(fou)标准;齿(chi)轮传动(dong)的(de)(de)灵(ling)活性(xing)等,若发现有滞(zhi)卡(ka)现象(xiang),应立即(ji)停机(ji)(ji)(ji)查明原(yuan)因排(pai)除故障后再运(yun)行。
另(ling)外,电气(qi)控制柜应(ying)设在干燥、通(tong)风和便于操作的位(wei)置(zhi),并定期(qi)除尘。经常(chang)检查接(jie)触(chu)器触(chu)点(dian)、线圈铁芯、各(ge)接(jie)线螺丝(si)等是(shi)否(fou)可靠,机械(xie)部位(wei)动(dong)作是(shi)否(fou)灵(ling)活(huo),使(shi)其保持良好的技术状态,从而(er)保证(zheng)启动(dong)工作顺利而(er)不烧毁(hui)电动(dong)机。