Direct on Line

 

Direct On Line (DOL) Motor Starter Posted APR 22 2012 by  JI GU PA RM AR in MAIN!NAN"! #   MOOR $it% 2 "OMM!NS

T r a ns l at e» • • • • • •

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Di r e ctOnl i n eMo t orSt ar t e r-Sq uar eD

Di ffer ents t ar t i ngmet hodsar eempl oy edf ors t ar t i ngi nduct i onmo mot or sb ec a us eI n du c t i o nMo t o rd r a ws mor es t ar t i ngc ur r entdur i ngs t ar t i ng.T opr e ventdamaget ot hewi ndi ngsduet ot hehi ghs t ar t i ngc ur r ent fl ow,wee mpl mp o ydi ff er e ntt y pesofs t ar t er s . Thes i mpl es tf or m ofmot ors t ar t erf ort hei nduc t i onmot ori st heDi r e c tOnLi nes t ar t er .TheDi r ec tOn Li n eMo t orSt ar t er( DOL)c ons i s taMCCBorCi r c ui tBr e ak er ,Co nt ac t oran da no v er l oadr el a yf or pr ot ec t i on.El ec t r omagnet i cc ont ac t orwhi c hc anbeopenedbyt het her mal ov er l oadr el a yunderf aul t c ondi t i ons . T ypi c al l y ,t hec ont ac t orwi l l bec ont r ol l edbysepar at es t ar tands t opbut t ons ,andanaux i l i ar ycont ac ton t hec ont ac t ori sus ed,ac r o sst hes t ar tbut t on,asahol di nc ont ac t .I . e.t hec ont ac t ori sel ec t r i c al l y l at c hedc l os edwhi l et hemot ori soper at i ng.

Princi&'e o Direct On Line Starter (DOL)

 

r olofI nduc t i onMot or s( Engi ne e r i ng) Cont Tos t ar t ,t hec ont ac t ori scl os ed,appl y i ngf ul l l i nev ol t aget ot he  mot or   wi ndi n gs .Themo mo t orwi l l dr a wa v er yhi ghi nr us hc ur r entf orav er yshor tt i me,t hemagnet i cfiel di nt hei r on,andt hent hec ur r entwi l lbe l i mi t edt ot h eLoc k edRot orCur r en toft hemot or .Th emo t o rwi l l de v el opL oc k edRot orT or qu ean dbegi n t oac c el er at et owar dsf ul l s peed. Ast hemot ora c cel er at es ,t hec ur r entwi l l begi nt odr op,butwi l lnotdr ops i gni fi cant l yunt i l t hemot ori s atahi ghs pe ed,t y pi c al l yabo ut85% ofs y nc hr on ouss pe ed.Th eac t ual s t ar t i ngc ur r e ntc ur v ei sa f unc t i onoft hemot ordes i gn,andt het er mi nal v ol t age,andi st ot al l yi ndependentoft hemo t orl oad. Themot orl oadwi l laffec tt het i met ak enf ort hemot ort oac c el er at et of ul l s peedandt her ef or et he dur at i onoft hehi ghs t ar t i ngc ur r ent ,butnott hemagni t udeoft hes t ar t i ngc ur r ent . Pr o vi de dt het or quede v el o pedb yt hemo t o re x c eed st hel oadt or queatal l s pe edsdur i ngt hes t ar t c y cl e,t hemot orwi l l r eac hf ul ls peed.I ft het or quedel i v er edbyt hemot ori sl es st hant het or queoft he l oadatanyspeeddur i ngt hes t ar tc yc l e,t hemot orwi l l s t opsac cel er at i ng.I ft hes t ar t i ngt or quewi t ha DOLst ar t eri si ns uffic i en tf ort h el oad ,t h emo t ormus tb er e pl ac edwi t hamo t orwhi c hc ande v el opa hi ghers t ar t i ngt or que. Theac c el er at i ont or qu ei st het or qued ev el o pe db yt hemo t ormi nust hel o adt or que,a ndwi l l c han gea s t hemo mo t orac c el er at esdu et ot hemo mo t ors pee dt o r quec ur v eandt hel oads peedt or quec ur v e.Th es t ar t t i mei sdependentont heac c el er at i ont or queandt hel oadi ner t i a. DOLst ar t i nghaveamaxi mum st ar tcur r entandma maxi mum st ar tt or que. Thi sma ma yca us ea nel ec t r i c alpr obl em wi t ht h es uppl y ,ori tma ycaus eame mec ha ni c al pr obl em wi t ht h e dr i v enl oad.Sot hi swi l l bei nc onv eni entf ort heus er soft hes uppl yl i ne,al way sex per i enc eav ol t age dr opwhens t ar t i ngamo t or .Buti ft hi smo mot ori sno tahi ghp owero nei tdo esno taff ec tmuc h.

Parts o DOL Starters "ontactors  "oi'

 

ar tCo nt a c t o r DOLp

Magnet i ccont act or s  ar eel ec t r omagnet i c al l yoper at edswi t c hest hatpr o vi deas af eandconv eni ent meansf orc onnec t i ngandi nt er r upt i ngbr anc hc i r c ui t s . Mag ne t i cmo t orc ont r ol l er sus eel ec t r oma gne t i cen er gyf orc l os i ngs wi t c hes .Th eel ec t r omagn et c ons i s t sofac oi l ofwi r epl ac edonani r onc or e.Whenac ur r entfl owt hr ought hec oi l ,t hei r onoft he magnetbec omesma magnet i z ed,at t r ac t i ngani r onbarc al l edt hear mat ur e.Ani nt er r upt i onoft hecur r ent fl owt hr ou ght h ec oi l o fwi r ec aus est h ear mat ur et odr opo utd uet ot hepr es enc eo fa nai rg api nt he magnet i cc i r c ui t . Li nev ol t agemagnet i cmo mot ors t ar t er sar eel ec t r omec hani c al de vi c est hatpr o vi deas af e,c onv eni ent , a nde c on omi c a lme an so fs t ar t i n ga nds t o pp i n gmo t o r s ,a ndh av et h ea dv a nt a geo fb ei n gc o nt r o l l e d r emot el y .Thegr eatbul kofmot orc ont r ol l er ssol dar eoft hi st y pe. Cont ac t or sar emai nl yus edt oc ont r ol mac hi ner ywhi c hus esel ec t r i cmo mot or s .I tc ons i s t sofac oi l whi c h c on nec t st oav ol t a ges our c e.Ver yof t enf orSi n gl ep ha seMo t or s ,2 30 Vc oi l sar eus eda ndf ort hr ee p ha s emo t o r s ,4 15 Vc o i l sa r eus e d.Th ec o nt a ct o rh ast h r e ema i nNO c o nt a ct sa ndl e ss e rp owe rr at e d c on t ac t sname dasAux i l i ar yCont ac t s[ NO andNC]u se df ort h ec ont r olc i r c ui t .Ac ont a cti sc on duc t i ng met al par t swhi c hc ompl et esori nt er r uptanel ec t r i c al c i r c ui t .   NOnor mal l yopen   NCn or ma l l yc l o s ed

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O*er Load Re'ay (O*er'oad &rotection) Ov er l o adpr ot e ct i o nf oranel ec t r i cmo mot ori sne ces s ar yt opr e v entbur nou tan dt oen sur ema max i mum oper at i ngl i f e. Undera nyc ondi t i o no fo v er l oa d,amo mo t ordr awse x c es s i v ecur r e ntt hatc aus eso v er h eat i ng.Si nc emo t or wi ndi ngi ns ul at i ondet er i or at esduet oov er heat i ng,t her ear ees t abl i s hedl i mi t sonmo mot oroper at i ng t emp er at ur est opr o t ec tamo t orf r om o v er he at i ng.Ov er l oadr el a y sa r eempl o y edonamo t orc ont r ol t o l i mi tt heamountofc ur r entdr a wn.

 

Theov er l oa dr e l a ydoe snotpr ov i deshor tc i r c ui tpr ot e ct i on.Thi si st hef unc t i onofov erc ur r e nt  pr ot ect i veequi pmentl i kef usesandci r cui tbr eaker s,gener al l yl ocat edi nt hedi sconnect i ng swi wi t chencl osur e.

Thei deal andeas i es twa yf orov er l oadpr ot ec t i onf oramot ori sanel ementwi t hc ur r ent s ens i ng pr oper t i esv er ys i mi l art ot heheat i ngcur v eoft hemot orwhi c hwoul dac tt oopent hemot orc i r c ui twhen f ul l l oadc ur r enti sex c eeded.Theoper at i onoft hepr ot ec t i v ede vi c es houl dbes uc ht hatt hemot ori s al l o we dt oc ar r yhar ml e ssov er l oa dsbuti squi c k l yr emo v edf r om t hel i newh ena no v er l oa dh as per s i s t edt ool ong.

DOLp ar t-T e r ma lOv e r l o adRe l a y

Nor mal l yf us esar enotdes i gnedt opr ov i deov er l oadpr ot ec t i on.Fus ei spr ot ec t i ngagai ns ts hor tc i r c ui t s ( o verc ur r entpr ot ec t i on) .Mot or sdr awahi ghi nr us hc ur r entwhens t ar t i ngandc on vent i onal f us eshav e n owa yo fd i s t i n gu i s hi n gb et we ent h i st e mp mp or a r ya ndh ar ml e ssi n r u s hc u r r e nta ndad ama gi n go v er l o ad . Sel ec t i onofFus ei sdependonmot orf ul l l oadc ur r ent ,woul d“ bl ow”ev er yt i met hemot ori ss t ar t ed.On t heot herhand,i faf us ewer ec hos enl ar geenought opas st hes t ar t i ngori nr us hc ur r ent ,i twoul dnot pr ot ec tt hemot oragai ns ts mal ma l ,har mf ul ov er l oadst hatmi ghtoc curl at er . Theov er l oadr el ayi st hehear tofmot orpr ot ec t i on.I thasi nv er s et r i pt i mec har ac t er i s t i c s,per mi t t i ngi t t ohol di ndur i ngt heac cel er at i ngper i od( wheni nr us hc ur r enti sdr awn) ,y etpr ov i di ngpr ot ec t i onon s mal ma l ov er l oadsabo v et hef ul l l oadcur r entwhent hemo mot ori sr unni ng.Ov er l oadr el a ysar er enewabl e an dc anwi t hs t andr ep eat e dt r i pa ndr es etc y c l eswi t hou tne edofr e pl ac ement .Ov er l oa dr el a y sc anno t , howev er ,t ak et hepl ac eofo verc ur r entpr ot ec t i onequi pment . Theo ver l oadr el a yc ons i s t sofac ur r ent s ens i nguni tc onnec t edi nt hel i net ot hemot or ,pl usa mec hani s m,ac m, t uat edbyt hes ens i nguni t ,whi c hs er v es ,di r ec t l yori ndi r ec t l y ,t obr eakt hec i r c ui t . Ov er l oadr el a y sc anbec l as s i fi edasbei ngt her mal ,magne t i c ,orel ec t r oni c : 1.   Ther malRel ay:Ast henamei mpl i es ,t her malo ver l oadr el a ysr el yont her i s i ngt emper at ur es causedbyt heo eo ve r l oa dc ur r e ntt ot r i pt heo v er l oadmec hani s m.Th m. er mal o v er l oa dr el a y sc an bef ur t hers ubdi v i dedi nt ot wot y pes :mel t i ngal l oyandbi met al l i c . 2.   Magnet i cRel ay:Ma gne t i cov er l o adr e l a y sr e ac ton l yt oc ur r e nte x c es s esandar eno taff ec t ed b yt e mp mp er a t u r e .

 

3.   El e ct r oni cRe l a y:El ec t r oni cors ol i ds t at eov er l oadr el ay s,pr ov i det hec ombi nat i onofhi ghs peedt r i p,adj us t abi l i t y ,andeas eofi ns t al l at i on.Theycanbei deal i nmanypr ec i s eappl i c at i ons .

+irin, o DOL Starter 1- Main "ontact   Co nt a ct o ri sc o nn ec t i n ga mo mo ngSu pp l yVo l t a ge ,Re l a yCo i la ndTh er ma lOv e r l o adRe l a y .

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  L1ofCont act orConnect( NO)t oRPhaset hr oughMCCB

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  L2ofCont act orConnect( NO)t oYPhaset hr oughMCCB

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  L3ofCont act orConnect( NO)t oBPhaset hr oughMCCB.

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NO "ontact (.//.)   ( 1 31 4or5 35 4)i san or ma l l yOp enNO c on t a ct( c l o s eswh ent h er e l a ye ne r g i z es )

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  Cont ac t orPoi nt53i sc o nnec t i ngt oSt ar tBut t onPoi nt( 94)and5 4Poi ntofCont ac t ori s

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c o nn ec t e dt oCo mmo mm nwi r eofSt a r t / St o pBu t t o n.

N" "ontact (.//.)   ( 9596)i san or mal l yc l os edNCc on t ac t( o pe nswh ent h et her malo v er l oa dst r i pi fa ss oc i a t ed

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wi t ht heo ver l oadbl oc k)

2- Re'ay "oi' "onnection   A1o fRe l a yCo i li sc on ne c t i n gt oa nyo neSu pp l yPh as ea ndA2i sc on ne c t i n gt oTh er ma lo v er

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L oa dRe l a y ’ sNCCo nn ec t i o n( 9 5) .

- %er3a' O*er'oad Re'ay "onnection   T1 , T2 , T3a r ec o nn ec tt oTh er ma lOv e r l o adRe l a y

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  Ov e r l o adRe l a yi sCo nn ec t i n gb et we enMa i nCo nt a c t o ra ndMo t o r

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  NCCo nn ec t i o n( 9 59 6)o fTh er ma lOv e r l o adRe l a yi sc o nn ec t i n gt oSt o pBu t t o na n dCo mmo mm n Connec t i onofSt ar t / St opBut t on.

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+irin, Dia,ra3 o DOL Starter

 

r e ctOnL i n eSt ar t er-Wi r i n gDi a gr am Di

+or4in, &rinci&'e o DOL Starter Thema mai nh ear to fDOLs t ar t eri sRel a yCoi l .Nor mal l yi tg et soneph as ec ons t antf r om i nc omi ngsuppl y Vo l t a ge( A1 ) . wh enCo i l g et ss ec o ndPh as er e l a yc oi l e ne r g i z esan dMa gn eto fCo nt a c t o rp r o du ce el ec t r omagne t i cfiel dandduet ot hi sPl ungerofCont ac t orwi l l mo veandMai nCont ac t orofs t ar t erwi l l c l o s edan dAu x i l i a r ywi l l c h an gei t sp os i t i o nNO b ec o meNCa me ndNCb ec o me( me s h ownRe dL i n ei n Di agr am) m).

P5s%in, Start 65tton Wh enWe WePu s ht h es t ar tBu t t o nRe l a yCo i lwi l l g ets ec o ndph as ef r o m Su pp l yPh as e Ma i nc on t a c t o r ( 5 ) Aux i l i ar yCont ac t ( 53) St ar tbut t onSt opbut t on9695T oRel a yCoi l( A2) . NowCoi l ener gi z esand Ma gn et i cfi e l dpr o du c eb yMa Ma gn eta ndPl u ng ero fCo nt a c t o rmo v e .Ma i nCo nt a c t o rc l o s esa ndMo Mo t o r g et ss u pp l ya tt h es amet i meAu x i l i ar yc o nt a c tb ec o me( me 5 35 4)f r o m NO t oNC.

Re'ease Start 65tton Re l a yc oi l g et ss up pl ye v ent h ou ghwer e l e as eSt a r t b ut t o n.Wh enWer e l e as eSt a r tPu s hBu t t o nRe l a y Coi lget sSuppl yphas ef r om Mai nc ont ac t or( 5) Aux i l i ar yc ont ac t or( 53)–Aux i l i ar yc ont ac t or( 54) St op Bu t t o n9 695Rel a yc oi l ( s hownRed/Bl u eLi nesi nDi agr am) . I nOv er l oadCondi t i onofMot orwi l l bes t oppedbyi nt er mi s si onofCont r olc i r c ui tatPoi nt9695.

 

P5s%in, Sto& 65tton Whe nwepus hSt opBut t onCont r o lc i r c ui tofSt ar t erwi l l bebr e akats t opb ut t onan dSu ppl yofRel a y c o i l i sbr o k en ,Pl u ng ermo v esan dc l o s ec o nt a c to fMa i nCo nt a c t o rb e c ome sOp en ,Su pp l yofMo t o ri s d i s c o nn ec t e d.

DOL-Wi r i ngscheme

Motor Startin, "%aracteristics on DOL Starter •

  Av ai l abl es t ar t i ngc ur r ent : 100%.   Peaks t ar t i ngc ur r ent : 6t o8Ful lLoadCur r ent .

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  Peaks t ar t i ngt or que:

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100%

Ad*anta,es o DOL Starter 1.   MostEconomi calandCheapestSt ar t er 2.   Si mpl et oe s t abl i s h,oper at ea ndmai nt ai n 3.   Si mpl eCont r ol Ci r c ui t r y 4.   Ea syt ou nd er s t a nda ndt r o ub l e7s h oo t . 5.  I tpr ov i des1 00% t or queatt het i meofs t ar t i ng. 6.   Onl yo nes etofc abl ei sr equi r edf r om s t ar t ert omo mot or .

 

7.   Mot ori sc onnec t edi nd el t aa tmot ort er mi nal s .

Disad*anta,es o DOL Starter 1.   I tdoesnotr educ et hes t ar t i ngc ur r entoft hemot or . 2.   Hi ghSt a r t i ngCur r e nt :Ver yHi ghSt ar t i ngCur r ent( T ypi c al l y6t o8t i mest heFL C oft he mo t or ) . 3.   Mechani cal l yHar sh:Ther malSt r es sont hemo mot or ,t her ebyr educ i ngi t sl i f e. 4. ei sabi gv ol t agedi pi nt heel ec t r i c ali ns t al l at i onbec aus eofhi ghi nr us h   Vol t a geDi p:Ther c ur r entaffec t i ngot herc us t omer sc onnec t edt ot hes amel i nesandt her ef or eno ts ui t abl ef or hi ghers i z es qui r r el c agemot or s 5.   Hi ghs t a r t i ngT or que :Un nec es s ar yhi ghs t ar t i n gt or que ,e v enwhe nno tr equi r edb yt h el oa d, t he r eb yi nc r eas edmec hani c al s t r e ssont hemec hani c al s y s t emss uc ha sr ot ors haf t ,be ar i n gs , gear bo x,c oupl i ng,c hai ndr i v e,c onnec t edequi pment s ,et c .l eadi ngt opr emat ur ef ai l ur eand p l a ntd own t i me s.

8eat5res o DOL startin,   Fo rl o w-a ndme di u mmp owe rt h r e ep ha s emo t o r s

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  Thr eec onnec t i onl i nes( c i r c ui tl ay out :s t arordel t a)

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  Hi ghs t ar t i ngt or que

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  Ve r yh i g hme ch an i c al l o ad

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  Hi g hc u r r e ntp ea k s

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  Vol t agedi ps

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  Si mpl es wi t c hi n gde vi c es

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Direct On Line Motor Starter (DOL) is s5itab'e or   Adi r ec tonl i nes t ar t erc anbeus edi ft hehi ghi nr us hc ur r entoft hemo mot ordoesn otc aus e

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e x c es s i v ev ol t a gedr o pi nt h es uppl yc i r c ui t .Themax i mum s i z eofamo t ora l l o we donad i r ec ton l i nes t ar t ermaybel i mi t edbyt hes uppl yut i l i t yf ort hi sr e as on.Forex ampl e,aut i l i t yma mayr e qui r e r ur al c us t omer st ous er educ edv ol t agest ar t er sf ormot or sl ar gert han10kW.   DOLs t a r t i n gi ss o me me t i me su s edt os t a r t s ma ma l lwa t e rp ump s ,c o mp mp r e ss o r s ,f a nsa ndc o nv e y or

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bel t s .

Direct On Line Motor Starter (DOL) is NO s5itab'e or   Thep eaks t ar t i ngc ur r entwoul dr es ul ti nas e r i ousv ol t agedr opo nt hes uppl ys y st em

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  Thee qui pmentbei ngd r i v e nc ann ott ol e r at et hee ffec t so fv er yhi g hpe akt or qu el o adi n gs

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  Th es a f e t yo rc omf o r to ft h os eu s i n gt h ee qu i p me me ntma yb ec o mpr mp o mi mi s e db ys u dd ens t a r t i n g

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as ,f orex ampl e,wi t hes cal at or sandl i f t s .