1過熱維護電氣原因形成的毛病*zhongdouhuoxudaozhidianjidingziraozuguoreerfenhui。yinci,zhixubimiandianjiraozuguore,yejiuweihuledianji。danshishishang,dianjizishenyoujueyuannairedengjibutongdechayi。*高允許溫度A級105X:、E級120C、B級13(TC、F級1551:、H級18(TC.關於形成電機過熱原因中的軸承損壞、定轉子相擦、通風不暢等該屬電工定期檢查和巡視檢查有必要發現解決的,不屬維護技能主要的討論範圍。別的,電機升溫、降溫是個緩慢改變的過程,因此隻要對大中型、重(zhong)要(yao)崗(gang)位(wei)作(zuo)業(ye)的(de)電(dian)機(ji)加(jia)裝(zhuang)溫(wen)升(sheng)監(jian)視(shi)和(he)過(guo)熱(re)維(wei)護(hu)設(she)備(bei)才(cai)是(shi)必(bi)要(yao)的(de)。至(zhi)於(yu)小(xiao)型(xing)電(dian)機(ji)選(xuan)用(yong)過(guo)熱(re)維(wei)護(hu)設(she)備(bei)並(bing)不(bu)一(yi)定(ding)合(he)算(suan)。在(zai)起(qi)重(zhong)機(ji)的(de)相(xiang)關(guan)規(gui)範(fan)中(zhong),並(bing)沒(mei)有(you)對(dui)過(guo)熱(re)維(wei)護(hu)做(zuo)出(chu)強(qiang)製(zhi)性(xing)規(gui)則(ze)。
2過載(過流)維護過載(過流)是shi指zhi電dian動dong機ji的de作zuo業ye電dian流liu超chao越yue其qi額e定ding值zhi,如ru果guo時shi刻ke久jiu了le,就jiu會hui使shi電dian機ji過guo熱re損sun壞huai電dian機ji。過guo電dian流liu時shi,電dian流liu仍reng由you正zheng常chang途tu徑jing流liu轉zhuan,其qi值zhi比bi短duan路lu電dian流liu值zhi要yao小xiao。過guo電dian流liu一yi般ban是shi因yin為wei負fu載zai過guo大da或huo是shi啟qi動dong不bu正zheng確que形xing成cheng。為wei了le避bi免mian影ying響xiang電dian動dong機ji正zheng常chang作zuo業ye,過guo電dian流liu維wei護hu動dong作zuo值zhi應ying該gai依yi據ju不bu同tong電dian動dong機ji型xing式shi而er設she定ding。過guo電dian流liu維wei護hu一yi般ban選xuan用yong過guo電dian流liu繼ji電dian器qi、主動斷路器、熱繼電器、電機內部設置超溫報警跳閘設備等。
關於負載簡直恒定不變的電機,過流維護是沒有必要的。但起重機電機負載常常改變,產生過載、堵du轉zhuan的de或huo許xu性xing大da,以yi至zhi焚fen毀hui電dian機ji繞rao組zu。關guan於yu這zhe樣yang運yun轉zhuan的de電dian機ji有you必bi要yao加jia裝zhuang過guo流liu維wei護hu設she備bei。三san相xiang異yi步bu電dian動dong機ji雖sui有you較jiao強qiang的de過guo載zai才cai能neng,但dan因yin為wei負fu載zai改gai變bian大da,對dui電dian機ji過guo載zai實shi行xing反fan時shi限xian特te性xing維wei護hu是shi必bi要yao的de,也ye是shi起qi重zhong機ji械xie相xiang關guan規gui範fan所suo規gui則ze的de。
在2002版起重機檢規中規則:起qi重zhong機ji上shang的de每mei個ge組zu織zhi均jun應ying獨du自zi設she置zhi過guo流liu維wei護hu。溝gou通tong繞rao線xian式shi異yi步bu電dian動dong機ji能neng夠gou選xuan用yong過guo電dian流liu繼ji電dian器qi。籠long型xing溝gou通tong電dian動dong機ji可ke用yong熱re繼ji電dian器qi或huo帶dai熱re脫tuo扣kou器qi的de主zhu動dong斷duan路lu器qi做zuo過guo載zai維wei護hu。
3短路維護-電動機短路一般指的是定子線圈匝間短路、極(ji)相(xiang)組(zu)間(jian)短(duan)路(lu)和(he)相(xiang)間(jian)短(duan)路(lu),短(duan)路(lu)未(wei)加(jia)維(wei)護(hu)的(de)成(cheng)果(guo)是(shi)燒(shao)壞(huai)斷(duan)路(lu)。對(dui)起(qi)重(zhong)機(ji)來(lai)說(shuo),引(yin)起(qi)製(zhi)動(dong)器(qi)通(tong)電(dian)翻(fan)開(kai),而(er)電(dian)動(dong)機(ji)不(bu)作(zuo)業(ye)的(de)失(shi)速(su)事(shi)故(gu)。短(duan)路(lu)維(wei)護(hu)是(shi)運(yun)用(yong)短(duan)路(lu)時(shi)產(chan)生(sheng)電(dian)流(liu)很(hen)大(da)的(de)原(yuan)理(li),可(ke)選(xuan)用(yong)熔(rong)斷(duan)器(qi)維(wei)護(hu)和(he)長(chang)延(yan)時(shi)或(huo)瞬(shun)時(shi)式(shi)斷(duan)路(lu)器(qi)來(lai)維(wei)護(hu)。
熔rong斷duan器qi的de原yuan理li是shi運yun用yong電dian流liu流liu經jing導dao體ti會hui使shi導dao體ti發fa熱re,到dao達da導dao體ti的de熔rong點dian後hou導dao體ti消xiao融rong所suo以yi斷duan開kai電dian路lu維wei護hu用yong電dian器qi和he線xian路lu不bu被bei燒shao壞huai。一yi旦dan熔rong體ti焚fen毀hui就jiu要yao更geng換huan熔rong體ti。斷duan路lu器qi也ye能neng夠gou實shi現xian線xian路lu的de短duan路lu和he過guo載zai維wei護hu,不bu過guo原yuan理li不bu一yi樣yang,它ta是shi通tong過guo電dian流liu底di磁ci效xiao應ying(電磁脫扣器)實現斷路維護,通過電流的熱效應實現過載維護(不是熔斷,多不必更換器材)。熔(rong)斷(duan)器(qi)的(de)熔(rong)斷(duan)是(shi)電(dian)流(liu)和(he)時(shi)刻(ke)共(gong)同(tong)效(xiao)果(guo)的(de)成(cheng)果(guo),而(er)斷(duan)路(lu)器(qi),隻(zhi)需(xu)電(dian)流(liu)一(yi)過(guo)其(qi)設(she)定(ding)值(zhi)就(jiu)會(hui)跳(tiao)閘(zha),時(shi)刻(ke)效(xiao)果(guo)簡(jian)直(zhi)能(neng)夠(gou)不(bu)必(bi)考(kao)慮(lv)。斷(duan)路(lu)器(qi)是(shi)現(xian)在(zai)低(di)壓(ya)配(pei)電(dian)常(chang)用(yong)的(de)元(yuan)件(jian)。
兩(liang)者(zhe)的(de)不(bu)同(tong)是(shi)挑(tiao)選(xuan)斷(duan)路(lu)器(qi)時(shi)應(ying)考(kao)慮(lv)其(qi)極(ji)限(xian)短(duan)路(lu)通(tong)斷(duan)才(cai)能(neng)。當(dang)短(duan)路(lu)電(dian)流(liu)大(da)於(yu)斷(duan)路(lu)器(qi)極(ji)限(xian)短(duan)路(lu)才(cai)能(neng)時(shi),斷(duan)路(lu)器(qi)觸(chu)頭(tou)會(hui)產(chan)生(sheng)粘(zhan)連(lian)的(de)狀(zhuang)況(kuang),比(bi)較(jiao)風(feng)險(xian)。
在zai起qi重zhong機ji相xiang應ying安an全quan技ji能neng規gui範fan和he規gui範fan中zhong沒mei有you對dui電dian機ji的de短duan路lu維wei護hu作zuo強qiang製zhi性xing規gui則ze,隻zhi是shi規gui則ze在zai其qi電dian氣qi線xian路lu中zhong使shi閑xian與yu坩gan爐lu有you必bi要yao設she置zhi一yi級ji短duan路lu維wei護hu,以yi對dui整zheng個ge電dian氣qi線xian路lu的de維wei護hu。
實際運用中,在作業等級較高的大、小車運轉組織(一般運轉速度較大),出現電機燒壞(短路、過載、過熱後絕緣下降)形(xing)成(cheng)的(de)斷(duan)路(lu)毛(mao)病(bing)不(bu)少(shao),如(ru)有(you)條(tiao)件(jian)應(ying)或(huo)許(xu)設(she)置(zhi)。而(er)起(qi)升(sheng)組(zu)織(zhi)因(yin)為(wei)速(su)度(du)較(jiao)小(xiao),操(cao)作(zuo)頂(ding)用(yong)倒(dao)檔(dang)減(jian)速(su)製(zhi)動(dong)的(de)工(gong)況(kuang)少(shao),電(dian)動(dong)機(ji)斷(duan)路(lu)毛(mao)病(bing)的(de)狀(zhuang)況(kuang)少(shao),但(dan)因(yin)為(wei)其(qi)形(xing)成(cheng)的(de)風(feng)險(xian)性(xing)大(da),*後一級短路維護盡或許照維護電動機的要求設置。
4超速維護檢規規則用於吊運熔融金屬的橋式起重機主起升組織,以及選用可控矽定子調壓、渦流製動、能耗製動、可控矽供電、直流機組供電調速及其他因為調速形成超速的門座起重機的起升組織和變幅組織、橋(qiao)式(shi)起(qi)重(zhong)機(ji)主(zhu)起(qi)升(sheng)組(zu)織(zhi),應(ying)設(she)置(zhi)超(chao)速(su)維(wei)護(hu)。主(zhu)要(yao)是(shi)為(wei)了(le)在(zai)重(zhong)要(yao)組(zu)織(zhi)產(chan)生(sheng)失(shi)速(su)狀(zhuang)況(kuang)下(xia)能(neng)停(ting)止(zhi)電(dian)動(dong)機(ji)的(de)工(gong)作(zuo)而(er)且(qie)製(zhi)動(dong)器(qi)上(shang)閘(zha)。超(chao)速(su)維(wei)護(hu)方(fang)式(shi)有(you)測(ce)速(su)發(fa)電(dian)機(ji)、磁電、光電編碼器、離心機械式超速開關、調tiao速su電dian流liu設she置zhi欠qian電dian流liu維wei護hu繼ji電dian器qi等deng幾ji種zhong,一yi般ban設she置zhi在zai電dian機ji風feng扇shan尾wei部bu。關guan於yu設she置zhi安an全quan製zhi動dong器qi的de,超chao速su開kai關guan能neng觸chu發fa支zhi持chi製zhi動dong器qi和he安an全quan製zhi動dong器qi動dong作zuo。因yin為wei超chao速su維wei護hu設she備bei的de設she置zhi位wei置zhi以yi及ji設she置zhi方fang式shi,在zai完wan結jie裝zhuang置zhi的de起qi重zhong機ji上shang是shi很hen難nan檢jian測ce其qi有you用yong性xing的de,故gu在zai出chu廠chang調tiao試shi時shi,起qi重zhong機ji製zhi造zao廠chang家jia應ying嚴yan格ge操cao控kong其qi動dong作zuo的de有you用yong性xing和he準zhun確que性xing。
5主電源斷、錯cuo相xiang維wei護hu首shou先xian,繼ji電dian接jie觸chu器qi操cao控kong的de起qi重zhong機ji當dang電dian源yuan相xiang序xu改gai變bian時shi,電dian動dong機ji的de工gong作zuo方fang向xiang也ye隨sui之zhi改gai變bian,易yi產chan生sheng電dian動dong機ji帶dai動dong的de機ji械xie越yue位wei事shi故gu,因yin此ci設she置zhi錯cuo相xiang維wei護hu。其qi次ci,斷duan相xiang維wei護hu是shi對dui電dian動dong機ji進jin行xing維wei護hu,主zhu電dian源yuan斷duan相xiang未wei加jia維wei護hu引yin起qi電dian流liu過guo大da,出chu現xian燒shao壞huai電dian動dong機ji的de毛mao病bing,所suo以yi也ye有you必bi要yao設she置zhi斷duan錯cuo相xiang維wei護hu。
6正zheng反fan相xiang接jie觸chu器qi毛mao病bing維wei護hu用yong於yu吊diao運yun熔rong融rong金jin屬shu的de橋qiao式shi起qi重zhong機ji起qi升sheng組zu織zhi的de正zheng反fan相xiang接jie觸chu的de毛mao病bing維wei護hu從cong根gen本ben上shang來lai說shuo也ye是shi為wei了le避bi免mian電dian氣qi係xi統tong出chu現xian誤wu動dong作zuo,因yin動dong作zuo組zu織zhi動dong力li元yuan件jian是shi電dian動dong機ji,實shi際ji上shang是shi對dui電dian動dong機ji操cao控kong係xi統tong元yuan件jian(接觸器)毛病的一種維護。
吊運熔融金屬的橋式起重機起升組織的正反相接觸器毛病維護,是為了避免電動機失電而製動器仍然在通電導致失速產生。
-2010第8.6條強製性條文規則:起升組織電動機應設置定子異常失電維護功用。當調速設備或正反接觸器毛病導致電動機失控時,製動器應立刻上閘。筆者認為是把375號文和TSGQ0002-2008起重機械安全技能監察規程-橋式起重機中關於吊運熔融金屬的橋式起重機起升組織的正反相接觸器毛病維護延伸到了一切起升組織,提出了更高的安全要求。
上shang述shu幾ji種zhong維wei護hu設she備bei一yi起qi設she置zhi時shi,為wei保bao證zheng異yi步bu電dian動dong機ji的de正zheng常chang運yun轉zhuan及ji對dui其qi進jin行xing有you用yong的de維wei護hu,有you必bi要yao考kao慮lv異yi步bu電dian動dong機ji與yu維wei護hu設she備bei之zhi間jian的de和he諧xie合he作zuo。特te別bie是shi大da容rong量liang電dian網wang中zhong運yun用yong小xiao容rong量liang異yi步bu電dian動dong機ji時shi,維wei護hu的de和he諧xie合he作zuo更geng為wei突tu出chu。主zhu要yao在zai以yi下xia兩liang種zhong:過guo載zai維wei護hu設she備bei與yu電dian動dong機ji的de和he諧xie合he作zuo過guo載zai維wei護hu設she備bei的de動dong作zuo時shi刻ke應ying比bi電dian動dong機ji起qi動dong時shi刻ke略lve長chang一yi點dian。電dian動dong機ji過guo載zai維wei護hu設she備bei的de特te性xing隻zhi要yao躲duo開kai電dian動dong機ji起qi動dong電dian流liu的de特te性xing,才cai能neng保bao證zheng其qi正zheng常chang工gong作zuo;但其動作時刻又不能太長,其特性隻能在電動機熱特性之下才能起到過載維護效果。
過guo載zai維wei護hu設she備bei瞬shun時shi動dong作zuo電dian流liu應ying比bi電dian動dong機ji起qi動dong尖jian峰feng電dian流liu略lve大da一yi點dian。如ru有you的de維wei護hu設she備bei帶dai過guo載zai瞬shun時shi動dong作zuo功gong用yong,則ze其qi動dong作zuo電dian流liu應ying比bi起qi動dong電dian流liu的de峰feng值zhi大da一yi些xie,才cai能neng使shi電dian動dong機ji正zheng常chang起qi動dong。
過載維護設備的動作時刻應比導線熱特性小一點,才能起到供電線路後備維護的功用。
過guo載zai維wei護hu設she備bei與yu短duan路lu維wei護hu設she備bei的de和he諧xie合he作zuo。一yi般ban過guo載zai維wei護hu設she備bei不bu具ju有you分fen斷duan短duan路lu電dian流liu的de才cai能neng。一yi旦dan在zai運yun轉zhuan中zhong產chan生sheng短duan路lu,需xu要yao由you串chuan聯lian在zai主zhu電dian路lu中zhong的de短duan路lu維wei護hu設she備bei(如斷路器或熔斷器等)來堵截電路。若毛病電流較小,歸於過載範圍,則仍應由過載維護設備堵截電路。故兩者的動作之間應有挑選性。
7結jie束shu語yu綜zong上shang所suo述shu在zai設she置zhi電dian氣qi維wei護hu設she備bei時shi不bu但dan要yao考kao慮lv其qi挑tiao選xuan合he理li性xing,又you考kao慮lv其qi額e定ding接jie通tong和he分fen斷duan才cai能neng,一yi起qi還hai需xu考kao慮lv電dian動dong機ji與yu電dian氣qi維wei護hu設she備bei的de和he諧xie合he作zuo性xing。
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