描述
當(dāng)電動(dòng)機(jī)的外殼接地不良，人體觸摸機(jī)殼時(shí)，會(huì)經(jīng)電動(dòng)機(jī)的繞組接地點(diǎn)通過(guò)人身及大地與電源變壓器構(gòu)成電流回路，會(huì)造成人身觸電事故。但對(duì)電動(dòng)機(jī)本身而言，由于僅有一處接地，機(jī)殼又不接地，所以不能構(gòu)成回路。因此，電動(dòng)機(jī)仍然可繼續(xù)運(yùn)行，然而若不及時(shí)排除此故障，如再有一處接地，就會(huì)造成匝間短路或相間短路事故了
如果電動(dòng)機(jī)外殼接地，雖有一相漏電時(shí)，但接地電流可以構(gòu)成回路如虛線所示，這時(shí)對(duì)人身較為安全，但對(duì)電動(dòng)機(jī)本身危險(xiǎn)較大。因?yàn)閷?duì)于接地相的繞組匝數(shù)會(huì)相應(yīng)地減少。所以，會(huì)使該相電流增加。接地點(diǎn)越靠近繞組的引出線端，情況越嚴(yán)重，甚至有燒壞繞組絕緣的危險(xiǎn)。所以在電動(dòng)機(jī)運(yùn)行電路中必須裝設(shè)漏電保護(hù)器。
三相異步電動(dòng)機(jī)對(duì)地短路可分為三相異步電動(dòng)機(jī)定子對(duì)地和三相異步電動(dòng)機(jī)轉(zhuǎn)子對(duì)地兩種，按修復(fù)情況又分為可修復(fù)對(duì)地和不可修復(fù)對(duì)地(死對(duì)地)。
產(chǎn)品承諾
保?證?全新原裝進(jìn)口,
保?證?安全準(zhǔn)時(shí)發(fā)貨，
保?證售后服務(wù)質(zhì)量，
優(yōu)勢(shì)價(jià)格，大量現(xiàn)貨。
主營(yíng)DCS系統(tǒng)配件
機(jī)器人系統(tǒng)配件
大型伺服系統(tǒng)配件
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SHIVA LPE57-AS-US-8 ETHERNET CONNECTOR 153042
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15天包退換 一年質(zhì)保 大量現(xiàn)貨? 國(guó)內(nèi)實(shí)力庫(kù)存商家
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