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MEK2
Servicemanual
0740800094 020531
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LISTOFCONTENTS Page READTHISFIRST .................................. 2 COMPONENT DESCRIPTION ........................ 4 CONNECTION DIAGRAM............................ 5 DESCRIPTION OF OPERATION ...................... 6 1 Power supply ......................................... 7 2 2--stroke / 4--stroke .................................... 8 3 Start / Stop ........................................... 8 4 Current relay, Creep start / Normal start .................. 9 5 Motor driving / braking........
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WARNING! STATICELECTRICITYcandamagecircuit boardsandelectroniccomponents. SSSS Observeprecautionsforhandling electrostatic sensitivedevices. ESD SSSS Useproperstatic--proof bagsand boxes. WARNING ARCWELDINGANDCUTTINGCANBEINJURIOUSTOYOURSELFANDOTHERS.TAKEPRECAU- TIONSWHENWELDING.ASKFORYOUREMPLOYER’SSAFETYPRACTICESWHICHSHOULDBE BASEDONMANUFACTURERS’HAZARDDATA. ELECTRICSHOCK -- Cankill S Installandearththeweldingunitinaccordancewithapplicablestandards. S Donottouchliveelectricalparts orelectrodes w
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COMPONENT DESCRIPTION Thiscomponent descriptionreferstotheconnectiondiagram. Inthedescriptionof operation onpage7thereisamoredetaileddescriptionof thecomponentsandtheir function. AP01 Maincircuit boardwithcontrol electronics. C01 Capacitor 0.1←F 125VAC, decoupling. G01 Tachogenerator, incorporatedinmotor M01. M01 Motor, ratedvoltage24V. R3 Potentiometer, for settingtheburn--backtime. RP01 Potentiometer, 10kτ, for settingthewirefeedspeed. SW1 Switch, 2/4--strokechangeover. SW2 Switch, creepstart
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CONNECTIONDIAGRAM MEK2 The numerals 1 -- 11 refer to the description of operation. R3 0V cmek2e01 cmek2de1 -- 5 --
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DESCRIPTIONOFOPERATION cmek2e02 Component positions, circuit board AP01 -- 6 -- cmek2de1
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Sections1to11belowrefertothediagramonpage5. Thecircuit boardisscreenedbyametal casing, connectedto0Vinthewirefeedunit. 1 Powersupply cmek2e09 Thefeeder obtainsa42Vsupplyfrom thecontrol power supplytransformer inthe power unit viacontact XP01. Itspower demandat maximum loadis3.5A. 42VACisusedfor theweldingtorchtrigger switchandasthepower supplytothe gassolenoidvalveandthemaincontactor. Inaddition, 42Visalsoavailableon contactsH01andH02. Rectifier BR1rectifiesthe42Vsupplyto60V. Capacitor C28smooth
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2 2--stroke/4--stroke cmek2e08 2--STROKE WhenSW1isopen, theunit operatesin2--strokemode. Operatingthetrigger onthe weldingtorchstartsthemotor, opensthegasvalveandenergisesthepower unit contactor. Releasingthetrigger stopsthemotor, de--energisesthecontactor andclosesthegas valve. If burn--backisinoperation, weldingceaseswhentheburn--backtimehas elapsed. 4--STROKE WhenSW1isclosed, theunit operatesin4--strokemode. Operatingthetrigger on theweldingtorchopensthegasvalve: releasingthetrigger thenstart
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4 Current relay, Creep start / Normal start cmek2e03 Thecurrent relayisactivatedwhentheweldingcurrent exceeds20A. Creepstartmeansthatthemotor runsat1.9m/minuteuntilthecurrentrelay operates, after whichthespeedincreasestotheset speed. If thecurrent relaydoes not operatewithinonesecondafter starting, themotor speedincreasestotheset speed in any case. Selector switchSW2onthecircuit boardselectsCreepStart On/Off. Closingthe switchontothe0Vrail disengagescreepstart. cmek2de1 -- 9 --
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5 Motordriving/braking cmek2e12 DRIVING Themotor ispoweredfrom thesmoothed+60Vsupply. Motor speediscontrolled bypulsewidthmodulationof transistor Q1. Thepulsefrequencyis12kHz, andthe maximum on--timeis97% of thepulsecycletime. Duringthepulsespaces, the motor current freewheelsthroughdiodeD8. At 24Vmotor supplyvoltage, thewirefeedrollers’ speedis160r/min. Awirefeed speedof 20m/min. requiresaroller speedof 212r/min. Resistor R19producesavoltagedropproportional tothemotor current. If the current ex
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6 Tachometerinput cmek2e06 Tachometer G01isfittedinthemotor casing. Tachometer output frequencyis 796Hzfor awirefeedspeedof 20metersper minute. Comparator IC4:2convertsthesinewavesignal from thetachometer toasquare waveat thesamefrequency. 7 Burn--backtime cmek2e05 Theburn--backtimeisthetimefromwhenmotor brakingstartsuntilthemain contactor inthepower unit opens. It canbeadjustedbetween0and0.5secondsby potentiometer R3, whichismountedonthecircuit board. 8 Wirefeed speed cmek2e04 Thewirefeedspeedr
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9 Gasvalve cmek2e11 ThegasvalveisconnectedtoboardcontactsG04andG05. Thevalveisenergised viatriacTC1. 10 Activation,contactor cmek2e10 Thestart signal tothepower unit isconnectedtoboardcontact G03. Thecontactor isenergisedviatriacTC2. 11 Processor Theprocessor incorporatesEPROMmemoryinwhichthemachine’sprogram is stored. Theprocessor monitorsthewirefeedspeed. If thespeeddeviatesfrom theset speed bymorethan1.5m/minutefor morethanfiveseconds, wirefeedwill bestopped.. -- 12 -- cmek2de1
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TECHNICAL DATA Power supply 42 V 50 -- 60 Hz Power requirement 150 VA Feed speed 1.9 -- 20 m/min Pistol connection EURO Max. diameter of wire bobbin 300 mm Weight 15 kg Dimensions (l x w x h) 645 x 240 x 480 mm WARNING There is a risk of tipping if the MEK 4 is fitted with a counterbalance arm. Secure the equipment, especially if used on an uneven orsloping surface. Limit the angle of rotation of the wire feed cabinet using the straps supplied. When moving the equipment, do NOTpullon the torch.
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SETTINGTHEWIREFEEDPRESSURE Start bycheckingthat thewirecanrunfreelythroughthewireliner, andthenadjust the pressureof thewirefeedrollers. Itisimportantthatthepressureisnottoohigh. Figure 1 Figure 2 Tocheckfor correct feedpressure, feedthewireout against apieceof insulatingmaterial, suchasapieceof wood. Withthepistol heldabout 5mm from thewood(Figure1), thedriverollersshouldslip. Withthepistol heldfurther awayfrom thewood(about 50mm, asshowninFigure2), the wireshouldcontinuetofeedout, bendingasit
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CONTROL PANEL ANDCONNECTIONS 1. Coolingwater connections (only --883model). 2. Gasconnection. 3. Connector for control cablefrom the power unit. 4. Connector for weldingcurrent cablefrom thepower unit. 5. Potentiometer, wirefeedspeed1.9 -- 20 meter per minute. 6. Coolingwater connectionsto/from the weldinggun(only --883model). 7. Strapsecuringpoints. Thestrapmust be usedtosecurethewirefeedunit tothe power unit duringtransport. 8. Holefor fittingwireliner fromtheESAB MarathonPac. 9. Weldingguncon
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ACCESSORIES Item Orderingno. Denomination no. 1 469789--880 Liftingeye Connectionset,1.7meter. WhenconnectedtoLAX 2 469836--880 320/380 2 469836--885 Connectionset,1.7meter. WhenconnectedtoLAX 380W 469836--881 Connectionset,8meter. WhenconnectedtoLAX 320/380 469836--886 Connectionset,8meter. WhenconnectedtoLAX 380W 4 469786--880 Trolley 5 156654--883 Guidepin(includedinLAX) 6 469792--881 Counter balancedeviceandmast 7 469967--880 Water connectionset 8 455410--001 Adapter for 5kgbobbin 9 01567468
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MEK2Edition020531 Sparepartslist Valid forserial no. 510 --xxx--xxxxto serial no. 826--xxx--xxxx OrderingnumbersforMEK2 0455 590 881 MEK 2 Without water connection 0455 590 883 MEK 2 With water connection Spare parts are to be ordered through the nearest ESAB agency as per the list on the back of the cover. Kindly indicate type of unit, serial number, denominations and ordering numbers according to the spare parts list. Maintenance and repair work should be performed by an experienced person, an
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MEK2Edition020531 Item Qty Orderingno. Denomination Notes 101a 1 0455693001 Cover 101b 1 0456352001 Plate Withtext 102 1 0467176001 Handle 103 4 0192230105 Cover 104 1 0192230112 Cover 105 1 0469959001 Sidecover 106 4 0467695001 Rubber foot 107 2 0469823001 Hook 108 2 0369561002 Clamp 109 2 0369561001 Lock 110 1 0469960001 Sidecover 111 1 0192562104 Cagenut M5 112a -- Chassis Replacedby item112b 112b 1 0469779880 Chassis New design,fits allversions ofMEK 4 113 1 0146967881 Brakehub 114 1 0416236
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MEK2Edition020531 bm17s11a -- 19 --
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MEK2Edition020531 C=componentdesignationinthecircuitdiagram Item Qty Orderingno. Denomination Notes C 201 1 0321475882 Knob 202 1 0469776001 Cover 203 1 0193260092 Cover For 3--poleconnector 204 1 0193260062 Connector 3--pole XS07,XS08, XS09,XS10 205 1 0191870616 Potentiometer 10kτ RP01,RP02, RP03,RP04 206 1 0368543005 Pinsocket 23--pole XP01 14 0323945004 Pin 207 1 0190315106 Hose L=2x0.65metre, D=16/9.5mmreinforcedPVC. Tobeorderedper metre. 208a 1 0365803008 Quick connector Female,red 1 036580
