過載保護
當電(dian)動(dong)機(ji)在(zai)過(guo)負載(zai)故障下,長(chang)時間超(chao)過(guo)其額定電(dian)流運行時,會導致電(dian)動(dong)機(ji)過(guo)熱(re),絕緣降低(di)而燒毀,保護(hu)器根據電(dian)動(dong)機(ji)的(de)發(fa)熱(re)特性(xing),計算(suan)電(dian)動(dong)機(ji)的(de)熱(re)容量,模擬電(dian)動(dong)機(ji)發(fa)熱(re)特性(xing)對(dui)電(dian)動(dong)機(ji)進(jin)行保護(hu),過(guo)載(zai)保護(hu)不(bu)同脫扣級(ji)別對(dui)應(ying)的(de)特征。
欠載保護
當電(dian)(dian)動(dong)機所帶(dai)負載(zai)為(wei)泵式負載(zai)時(shi),電(dian)(dian)動(dong)機空(kong)載(zai)或欠載(zai)運轉會產生危(wei)害,保(bao)護器提供欠載(zai)保(bao)護,當三相的平(ping)均電(dian)(dian)流(liu)與額定電(dian)(dian)流(liu)的百分比低于(yu)設定值時(shi),保(bao)護器應在動(dong)作(延時(shi))設定時(shi)間內(nei)(nei)動(dong)作或在報(bao)警(jing)時(shi)間內(nei)(nei)報(bao)警(jing)。
堵轉/阻塞保護
電(dian)動(dong)機(ji)(ji)在起動(dong)時(shi)(shi)(shi)(shi)或(huo)運行過(guo)(guo)程(cheng)中(zhong),如果由(you)于(yu)負荷過(guo)(guo)大或(huo)自身機(ji)(ji)械原因,造成(cheng)電(dian)時(shi)(shi)(shi)(shi)機(ji)(ji)軸被卡住,而未(wei)及時(shi)(shi)(shi)(shi)解除故障,將造成(cheng)電(dian)機(ji)(ji)過(guo)(guo)熱,絕(jue)緣降低而燒毀電(dian)機(ji)(ji),堵轉(zhuan)保護(hu)(hu)適用(yong)于(yu)電(dian)動(dong)機(ji)(ji)起動(dong)發(fa)生此(ci)類故障進(jin)行保護(hu)(hu),阻塞保護(hu)(hu)適用(yong)于(yu)電(dian)動(dong)機(ji)(ji)運行過(guo)(guo)程(cheng)中(zhong)發(fa)生此(ci)類故障時(shi)(shi)(shi)(shi)進(jin)行保護(hu)(hu),當(dang)電(dian)流達到(dao)動(dong)作(zuo)設(she)定電(dian)流時(shi)(shi)(shi)(shi),保護(hu)(hu)器應在動(dong)作(zuo)(延時(shi)(shi)(shi)(shi))設(she)定時(shi)(shi)(shi)(shi)間內動(dong)作(zuo)或(huo)在報警(jing)時(shi)(shi)(shi)(shi)間內報警(jing)。
斷相(不平衡)保護
斷(duan)相(不平衡)故障運行(xing)時電(dian)動(dong)(dong)機(ji)的危害很大,當電(dian)動(dong)(dong)機(ji)發生斷(duan)相或三相電(dian)流嚴重不平衡時,如(ru)不平衡率達到保護(hu)設定(ding)值時,保護(hu)器按照設定(ding)的要(yao)求(qiu)保護(hu),發出停(ting)車或報警指令,使電(dian)動(dong)(dong)機(ji)的運行(xing)更加安全。
接地/漏電保護
電動機保護器同時(shi)具備(bei)接(jie)地(di)保(bao)護和漏電(dian)(dian)保(bao)護功能。接(jie)地(di)保(bao)護電(dian)(dian)流信號取于內(nei)部電(dian)(dian)流互感器的(de)(de)矢(shi)量和,用于保(bao)護相線對電(dian)(dian)動機(ji)金屬外殼的(de)(de)短路保(bao)護,保(bao)護器可通過增加漏電(dian)(dian)互感器,檢(jian)測(ce)出(chu)30mA~50mA的(de)(de)故障電(dian)(dian)流,主要用于非直(zhi)接(jie)接(jie)地(di)的(de)(de) 保(bao)護,以保(bao)證人身安全。
外部故障保護
當保(bao)護(hu)(hu)器(qi)檢測到有外部(bu)故障出現,外部(bu)故障開關量(liang)輸(shu)入(ru)與保(bao)護(hu)(hu)器(qi)定(ding)義的開關量(liang)輸(shu)入(ru)狀態不一致(zhi)時(shi),保(bao)護(hu)(hu)器(qi)按照設定(ding)的要求保(bao)護(hu)(hu),確保(bao)電動機設備(bei)安全。
起動超時保護
在(zai)(zai)(zai)電(dian)動(dong)機起動(dong)過程(cheng)中,保護(hu)器只具有(you)斷相(不(bu)(bu)平衡),接地/漏電(dian)等(deng)保護(hu)功(gong)能,其余保護(hu)功(gong)能不(bu)(bu)起作用(yong),在(zai)(zai)(zai)起動(dong)結束后(hou),所有(you)保護(hu)功(gong)能(按用(yong)戶設(she)定(ding))均自動(dong)投入,當(dang)電(dian)動(dong)機起動(dong)時(shi)間(jian)(jian)超過用(yong)戶設(she)定(ding)的起動(dong)時(shi)間(jian)(jian),電(dian)流還大(da)于額(e)定(ding)電(dian)流1.1倍(bei)時(shi),保護(hu)器按照(zhao)設(she)定(ding)的要求(qiu)保護(hu),在(zai)(zai)(zai)動(dong)作(延時(shi))設(she)定(ding)時(shi)間(jian)(jian)內發出(chu)停車命令(ling),停止電(dian)機運(yun)行。
相序保護
具有相序(xu)保護(hu)(hu)(hu)功(gong)能的(de)保護(hu)(hu)(hu)器(qi),當其電源側(ce)的(de)電壓(ya)相位順序(xu)與設(she)定的(de)順序(xu)一致時(shi),保護(hu)(hu)(hu)器(qi)應不動(dong)作。當保護(hu)(hu)(hu)器(qi)檢測到電動(dong)d的(de)相序(xu)接錯(cuo)時(shi),電動(dong)機應不能起(qi)動(dong)。
欠壓保護
電壓過低會(hui)引起電動機(ji)(ji)轉速降(jiang)低,甚至(zhi)停止運(yun)行,當電動機(ji)(ji)運(yun)行電壓下降(jiang)至(zhi)設定(ding)的(de)欠電壓保(bao)護(hu)范圍時,保(bao)護(hu)器按設定(ding)的(de)要求進行保(bao)護(hu),在(zai)動作(zuo)(zuo)(延時)設定(ding)時間內動作(zuo)(zuo)或在(zai)報(bao)警時間內報(bao)警,以避免重要的(de)生(sheng)產工藝造成混亂(luan),嚴重影響生(sheng)產。
過壓保護
電(dian)壓(ya)過高會引起電(dian)動(dong)機絕(jue)緣程(cheng)度損(sun)傷(shang),當電(dian)動(dong)機運(yun)行(xing)電(dian)壓(ya)超過設(she)定(ding)(ding)的保(bao)(bao)(bao)護電(dian)壓(ya)時(shi)保(bao)(bao)(bao)護器按設(she)定(ding)(ding)的要(yao)求進行(xing)保(bao)(bao)(bao)護,在(zai)動(dong)作(延時(shi))設(she)定(ding)(ding)時(shi)間內(nei)動(dong)作或(huo)在(zai)報警時(shi)間內(nei)報警,以(yi)保(bao)(bao)(bao)證電(dian)動(dong)機設(she)備安(an)全(quan)。
欠功率保護
電動機由于傳動裝置損壞,失去機械輸出能力,欠載運行時,電動機功率因數較低,但電動機電流很大,大量消耗系統的無功,當負載功率與額定功率的百分比低于設定動作值時,電動機保護器在(zai)動作(zuo)(延時(shi))設(she)定(ding)時(shi)間內(nei)動作(zuo)或在(zai)報警(jing)時(shi)間內(nei)報警(jing)。
過熱保護
過(guo)熱保護(hu)采用數學方法建立電動機的(de)發熱模型,從原理上解決了低(di)壓電動機的(de)熱保護(hu)問題。