background image

Processes

Description

MIG (GMAW) Welding

Flux Cored (FCAW) Welding

Arc Welding Power Source

and Wire Feeder

OM-1326

205 654P

January 2004

Millermatic 251

And M-25 Gun

R

Visit our website at

www.MillerWelds.com

Summary of Contents for Millermatic 251

Page 1: ...ocesses Description MIG GMAW Welding Flux Cored FCAW Welding Arc Welding Power Source and Wire Feeder OM 1326 205 654P January 2004 Millermatic 251 And M 25 Gun R Visit our website at www MillerWelds com ...

Page 2: ...nue the tradition They re just as committed to providing equipment and service that meets the high standards of quality and value established in 1929 This Owner s Manual is designed to help you get the most out of your Miller products Please take time to read the Safety precautions They will help you protect yourself against potential hazards on the worksite We ve made installation and operation q...

Page 3: ...Welding Gun Duty Cycle And Overheating 10 4 4 Volt Ampere Curves 11 4 5 Installing Work Cable And Clamp 11 4 6 Installing Welding Gun 11 4 7 Connecting A Spoolmatic 15A Or 30A Gun 12 4 8 Setting Gun Polarity For Wire Type 12 4 9 Installing Gas Supply 13 4 10 Installing Wire Spool And Adjusting Hub Tension 14 4 11 Positioning Jumper Links 14 4 12 Electrical Service Guide 15 4 13 Selecting A Locatio...

Page 4: ...Good Weld Bead Characteristics 34 8 8 Troubleshooting Excessive Spatter 35 8 9 Troubleshooting Porosity 35 8 10 Troubleshooting Excessive Penetration 35 8 11 Troubleshooting Lack Of Penetration 36 8 12 Troubleshooting Incomplete Fusion 36 8 13 Troubleshooting Burn Through 36 8 14 Troubleshooting Waviness Of Bead 37 8 15 Troubleshooting Distortion 37 8 16 Common MIG Shielding Gases 38 8 17 Troubles...

Page 5: ...onnect box or that cord plug is connected to a properly grounded receptacle outlet D When making input connections attach proper grounding conduc tor first double check connections D Frequently inspect input power cord for damage or bare wiring replace cord immediately if damaged bare wiring can kill D Turn off all equipment when not in use D Do not use worn damaged undersized or poorly spliced ca...

Page 6: ...r or cut off welding wire at contact tip when not in use D Wear oil free protective garments such as leather gloves heavy shirt cuffless trousers high shoes and a cap D Remove any combustibles such as a butane lighter or matches from your person before doing any welding FLYING METAL can injure eyes D Welding chipping wire brushing and grinding cause sparks and flying metal As welds cool they can t...

Page 7: ...nsible for having a qualified electrician prompt ly correct any interference problem resulting from the installa tion D If notified by the FCC about interference stop using the equipmentat once D Have the installation regularly checked and maintained D Keep high frequency source doors and panels tightly shut keep spark gaps at correct setting and use grounding and shielding to minimize the possibi...

Page 8: ...02269 9101 phone 617 770 3000 website www nfpa org and www sparky org OSHA Occupational Safety and Health Standards for General Indus try Title 29 Code of Federal Regulations CFR Part 1910 Subpart Q and Part 1926 Subpart J from U S Government Printing Office Super intendent of Documents P O Box 371954 Pittsburgh PA 15250 there are 10 Regional Offices phone for Region 5 Chicago is 312 353 2220 webs...

Page 9: ...cordon d alimentation est bien raccordé à la borne de terre du sectionneur ou que la fiche du cordon est raccordée à une prise correctement mise à la terre D Pour exécuter les branchements d entrée fixer d abord le conducteur de mise à la terre adéquat et contre vérifier les connexions D Vérifier fréquemment le cordon d alimentation et s assurer qu il n est ni endommagé ni dénudé le remplacer immé...

Page 10: ...xempts d huile tels que des gants en cuir une chemise en tissu épais des pantalons sans revers des chaussures montantes et un masque D Avant de souder retirer tout produit combustible de ses poches tel qu un briquet au butane ou des allumettes LES PARTICULES PROJETÉES peu vent blesser les yeux D Le soudage le burinage le passage de la pièce à la brosse métallique et le meulage provoquent l émissio...

Page 11: ...ouvrements et dispositifs de protection LE RAYONNEMENT HAUTE FRÉ QUENCE H F risque de causer des interférences D Le rayonnement haute fréquence peut causer des interférences avec les équipements de radio navigation et de communication les services de sécurité et les ordinateurs D Ne demander qu à des personnes qualifiées familiarisées avec les équipements électroniques de faire fonctionner l insta...

Page 12: ...Health Standards for General Indus try Title 29 Code of Federal Regulations CFR Part 1910 Subpart Q and Part 1926 Subpart J de l U S Government Printing Office Super intendent of Documents P O Box 371954 Pittsburgh PA 15250 il y a 10 bureaux régionaux Téléphone pour la Région 5 Chicago 312 353 2220 site Web www osha gov 2 5 Information sur les champs électromagnétiques Données sur le soudage élect...

Page 13: ... Output 60 Duty Cycle 50 or 60 Hz Single Phase Rated Output Circuit Voltage 200 208 V 230 V 400 V 460 V 575 V KVA KW 250 A at 28 VDC 40 Duty Cycle 200 A at 28 VDC 60 Duty Cycle 38 48 2 3 42 2 24 1 2 21 1 17 0 8 9 8 0 46 7 5 0 13 Wire Type and Diameter Wire Feed Speed Dimensions Net Weight Solid Steel Stainless Steel Flux Cored 25 700 IPM 65 17 8 m min H 32 in 813 mm W 19 in 483 mm 215 lb 98 kg 023...

Page 14: ...200 Amperes 10 20 30 40 50 60 70 80 90 100 50 100 150 200 250 300 350 400 450 500 DUTY CYCLE WELD AMPERES 4 3 Welding Gun Duty Cycle And Overheating CAUTION WELDING LONGER THAN RATED DUTY CYCLE can damage gun and void warranty Do not weld at rated load longer than shown below Using gasless flux cored wire reduces gun duty cycle warn7 1 8 93 Duty Cycle is percentage of 10 minutes that gun can weld ...

Page 15: ...g Work Cable And Clamp Ref 802 474 E Tools Needed 3 4 in 3 2 1 1 Work Cable 2 Boot Route cable through front panel opening Slide boot onto work cable 3 Negative Output Terminal Connect cable to terminal and cover connection with boot Close door 4 6 Installing Welding Gun 1 Drive Assembly 2 Gun Securing Knob 3 Gun End Loosen securing knob Insert gun end through opening until it bottoms against driv...

Page 16: ...ns are pulled at the same time the weld output and wirefeed motor are disabled 4 8 Setting Gun Polarity For Wire Type 1 Polarity Changeover Label Information Always read and follow manufacture s recommendedpolarity 1 3 4 11 16 in Ref 190 821 A Changing Polarity D D Wire Drive Assembly Lead Work Clamp Lead Positive Terminal Shown as shipped Electrode Positive DCEP For solid steel stainless steel al...

Page 17: ...Cylinder 4 Regulator Flowmeter Install so face is vertical 5 Regulator Flowmeter Gas Hose Connection 6 Welding Power Source Gas Hose Connection Connect customer supplied gas hose between regulator flowmeter gas hose connection and fitting on rear of welding power source 7 Flow Adjust Typical flow rate is 20 cfh cubic feet per hour Check wire manufacturer s recommended flow rate 1 1 8 5 8 in 1 2 3 ...

Page 18: ...procedure as shown in the illustration Remove these components from spindle Spindle Spindle Install these components onto spindle Order extra spring Part No 186 437 4 11 Positioning Jumper Links Ref 802 476 D Check input voltage available at site 1 Jumper Links Access Door Open door 2 Jumper Link Label Check label only one is on unit 3 Input Voltage Jumper Links Move jumper links to match input vo...

Page 19: ...ing general purpose no intentional delay fuses are UL class K5 up to and including 60 amp and UL class H 65 amp and above Y Caution Failure to follow these fuse and circuit breaker recommendations could create an electric shock or fire hazard 4 13 Selecting A Location And Connecting Input Power 1 Rating Label Supply correct input power 2 Plug NEMA Type 6 50P 3 Receptacle NEMA Type 6 50R Connect pl...

Page 20: ...e assembly Pull and hold wire cut off end Push wire thru guides into gun continue to hold wire Close and tighten pressure assembly and let go of wire Remove gun nozzle and contact tip Turn On Press gun trigger until wire comes out of gun Reinstall contact tip and nozzle Feed wire to check drive roll pressure Tighten knob enough to prevent slipping Cut off wire Close and latch door Ref 802 064 D S ...

Page 21: ...To Table Of Contents Ref 802 726 A 1 Side Panel 2 Latch 3 Cable Holder Press latch down to release and open door 4 Holster 2 Wrap cable around cable holder and place gun nozzle into holster 1 2 4 15 Using Gun Cable Holder 3 4 ...

Page 22: ...OM 1326 Page 18 Return To Table Of Contents 4 16 Weld Parameters ...

Page 23: ...OM 1326 Page 19 Return To Table Of Contents 201 202 A ...

Page 24: ...he voltage display will read and the wire feed display will read the preset Run in percentage from memory for the gun selected To return to the weld mode without making a change simply release trigger and pull the trigger again momentarily one second To change Run in settings start with the power switch OFF Press and hold the MIG or Spool Gun Trigger while turning the power switch ON The unit will...

Page 25: ...peed IPM Gun Selection The wire feed speed meter will display preset wire feed speed IPM for the appropriate gun selection either MIG or spool gun To preset desired wire feed speed connect desired gun press gun trigger for one second and release trigger The meter preset will be retained by the meter board until a different gun is connected and preset is performed or the unit is turned off and back...

Page 26: ...Apply light coat of oil or grease to drive motor shaft Ref 802 990 6 2 Unit Overload Thermistor T in SCR1 protects the unit from damage due to overheating If HL P 002 is displayed on the meters wait for unit to cool allowing fan motor to run before trying to weld If unit is cool and no weld output continues contact Factory Authorized Service Agent 6 3 Replacing Gun Contact Tip Ref 800 797 C Y Turn...

Page 27: ...ite side of the drive roll The groove closest to the motor shaft is the proper groove to thread see Section 4 14 5 Drive Roll Securing Nut Turn nut one click to secure drive roll Tools Needed 5 64 in 7 16 in Ref 802 990 1 3 2 4 5 6 5 Aligning Drive Rolls and Wire Guide Y Turn Off power View is from top of drive rolls looking down with pressure assembly open 1 Drive Roll Securing Nut 2 Drive Roll 3...

Page 28: ...tall and tighten new liner Cut liner off 3 4 in 20 mm 3 8 in 9 5 mm for aluminum from head tube Install adapter contact tip and nozzle Y Disconnect gun from unit first Tools Needed Lay gun cable out straight before installing new liner Head Tube 5 16 in Remove nozzle contact tip and adapter Blow out gun casing Remove liner 10 mm ...

Page 29: ...andle and secure with handle locking nut If replacing head tube continue to end of figure 3 Slide handle 4 Secure head tube in vice 5 Loosen jam nut Remove from vice and turn head tube out by hand 6 Install existing shock washer onto new head tube Hand tighten head tube into connector cable 7 Place head tube in vice and tighten until nuts are tight 8 Remove from vice Reposition handle and install ...

Page 30: ... trigger leads Have Factory Authorized Service Agent check Power switch Have Factory Authorized Service Agent check all board connections and main control board No Weld Output wire feeds Connect work clamp to get good metal to metal contact Replace contact tip see Section 6 3 HL P 003 appears on meters have Factory Authorized Service Agent check main control board and main rectifier Low weld outpu...

Page 31: ...overheating condition Wait for unit to cool allowing the fan to run After unit is cool If HL P 002 message remains contact Factory Authorized Service Agent see Section 6 2 HL P 004 appears on meters Reset message by releasing the trigger or removing stuck wire causing short circuit see Section 5 2 If message remains have Factory Authorized Service Agent check for shorted trigger leads HL P 005 app...

Page 32: ...OM 1326 Page 28 Return To Table Of Contents SECTION 7 ELECTRICAL DIAGRAM Figure 7 1 Circuit Diagram ...

Page 33: ...OM 1326 Page 29 Return To Table Of Contents 211 406 C ...

Page 34: ... Connections Y Weld current can damage electronic parts in vehicles Disconnect both battery cables before welding on a vehicle Place work clamp as close to the weld as possible Wire Feeder Power Source Workpiece Gun Regulator Flowmeter Gas Hose Shielding Gas Supply Work Clamp light mig 5 967 Ref 802 064 D ...

Page 35: ...es weld parameters 035 in Recommendation Wire Speed Approx Ref 802 473 B 1 8 or 0 125 in 0 001 in 1 ampere 0 125 in 125 A Wire Size Amperage Range 0 023 in 0 030 in 0 035 in Select Wire Size Wire Size 0 023 in 0 030 in 0 035 in 3 5 in per ampere 2 in per ampere 1 6 in per ampere Select Wire Speed Amperage 125 A based on 1 8 in material thickness ipm inches per minute Low voltage wire stubs into wo...

Page 36: ...e than 1 2 in 13 mm past end of nozzle and tip of wire is positioned correctly on seam NOTE 1 Hold Gun and Control Gun Trigger 2 Workpiece 3 Work Clamp 4 Electrode Extension Stickout 1 4 to 1 2 in 6 To 13 mm 5 Cradle Gun and Rest Hand on Workpiece 2 3 5 4 90 90 0 15 45 45 1 0 15 S 0421 A End View of Work Angle Side View of Gun Angle GROOVE WELDS End View of Work Angle Side View of Gun Angle FILLET...

Page 37: ... of travel electrode extension stickout travel speed thickness of base metal wire feed speed weld current and voltage NOTE Slow FILLET WELD ELECTODE EXTENSIONS STICKOUT ELECTRODE EXTENSIONS STICKOUT GUN ANGLES AND WELD BEAD PROFILES 10 10 GUN TRAVEL SPEED S 0634 Push Perpendicular Drag Short Normal Long Short Normal Long Normal Fast ...

Page 38: ... To Side Movement Along Seam 3 Weave Patterns Use weave patterns to cover a wide area in one pass of the electrode S 0054 A 3 1 2 8 6 Poor Weld Bead Characteristics 1 Large Spatter Deposits 2 Rough Uneven Bead 3 Slight Crater During Welding 4 Bad Overlap 5 Poor Penetration 5 4 2 3 1 S 0053 A 8 7 Good Weld Bead Characteristics 1 Fine Spatter 2 Uniform Bead 3 Moderate Crater During Welding Weld a ne...

Page 39: ...tive Actions Insufficient shielding gas at welding arc Increase flow of shielding gas at regulator flowmeter and or prevent drafts near welding arc Remove spatter from gun nozzle Check gas hoses for leaks Place nozzle 1 4 to 1 2 in 6 13 mm from workpiece Hold gun near bead at end of weld until molten metal solidifies Wrong gas Use welding grade shielding gas change to different gas Dirty welding w...

Page 40: ...complete Fusion Incomplete Fusion failure of weld metal to fuse completely with base metal or a preceeding weld bead S 0637 Possible Causes Corrective Actions Workpiece dirty Remove all grease oil moisture rust paint undercoating and dirt from work surface before welding Insufficient heat input Select higher voltage range and or adjust wire feed speed Improper welding technique Place stringer bead...

Page 41: ...nsteady hand Support hand on solid surface or use two hands 8 15 Troubleshooting Distortion Distortion contraction of weld metal during welding that forces base metal to move Base metal moves in the direction of the weld bead S 0642 Possible Causes Corrective Actions Excessive heat input Use restraint clamp to hold base metal in position Make tack welds along joint before starting welding operatio...

Page 42: ...ct tip if damaged Check size of contact tip and cable liner replace if necessary Wire curling up in front of the wire feed rolls bird nesting Too much pressure on wire feed rolls Decrease pressure setting on wire feed rolls wire feed rolls bird nesting Incorrect cable liner or gun contact tip size Check size of contact tip and check cable liner length and diameter replace if necessary Gun end not ...

Page 43: ...ve rolls if necessary Wrong size gun liner or contact tip Match liner and contact tip to wire size and type Incorrect voltage setting for selected wire feed speed on welding power source Readjust welding parameters Loose connections at the gun weld cable or work cable Check and tighten all connections Gun in poor shape or loose connection inside gun Repair or replace gun as necessary ...

Page 44: ...rn To Table Of Contents SECTION 9 PARTS LIST 803 008 B Hardware is common and not available unless listed 20 21 23 15 16 14 13 12 22 4 5 6 10 11 7 8 9 19 2 1 Fig 9 2 17 Fig 9 4 3 Fig 9 6 18 Fig 9 3 Figure 9 1 Main Assembly ...

Page 45: ...STER 30K 25C 2 205 946 FOOT mtg rectifier 2 PLG5 115 094 HOUSING PLUG SKTS 4 position 1 16 209 870 CASTER plstc swvl 4 in dia 2 17 Fig 9 4 PANEL front w components 1 18 169 596 GUN 12ft 030 035 wire Ilus 6 3 1 19 150 387 BAFFLE air 1 20 T1 200 514 TRANSFORMER pwr main 200 230 1 20 T1 201 081 TRANSFORMER pwr main 230 460 575 1 20 T1 205 896 TRANSFORMER pwr main 230 400 1 21 PLG2 110 760 HOUSING REC...

Page 46: ...Return To Table Of Contents 803007 D Hardware is common and not available unless listed 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 27 28 29 30 31 26 Fig 9 5 Figure 9 2 Baffle Center w Components ...

Page 47: ...V DPDT 10A 120VAC 1 VR1 144 425 VARISTOR w leads 1 18 PC1 212 360 CIRCUIT CARD control 1 PLG1 162 382 HOUSING PLUG SOCKETS 1 PLG3 130 203 HOUSING RECEPTACLE SOCKETS 1 PLG7 115 092 HOUSING RECEPTACLE SOCKETS 1 PLG8 115 093 HOUSING PLUG SOCKETS 1 19 196 894 COVER 1 20 R1 119 998 RESISTOR WW fxd 300W 5 ohm 1 21 TE1 188 910 TERMINAL ASSEMBLY pri 1ph double voltage 200 230 or 230 400 1 21 TE1 192 907 T...

Page 48: ...OM 1326 Page 44 Return To Table Of Contents Ref 800 792 C 1 2 3 4 5 6 7 8 9 10 15 18 11 12 11 12 13 9 16 17 14 Figure 9 3 M 25 Gun ...

Page 49: ...ER nozzle 1 5 170 467 RING retaining 1 6 170 468 O RING 1 7 169 730 WASHER shock 1 8 169 731 TUBE head 1 9 169 738 NUT locking handle 2 10 169 732 NUT jam 1 11 169 737 HANDLE 2 12 169 741 STRAIN RELIEF cable 2 13 180 433 CORD trigger assembly 1 14 209 486 CONNECTOR feeder 1 15 079 974 O RING 500 ID x 103CS rbr 2 16 194 011 LINER monocoil 030 035 wire x 15ft consisting of 1 16 194 010 LINER monocoi...

Page 50: ...TS 1 7 208 166 PANEL front 1 8 S1 128 755 SWITCH tgl 1 9 RC1 048 282 RECEPTACLE w SOCKETS 1 10 RC7 190 363 RECEPTACLE w SOCKETS 1 11 208 167 LABEL logo 1 12 208 164 PANEL front bezel 1 13 193 632 NUT 375 16 56 hex 34H stl 2 14 207 077 KNOB pointer 1 625dia 2 15 129 524 TERM frict 250 x 032 1 Hardware is common and not available unless listed 803 307 A 1 2 3 4 5 6 5 8 9 10 15 7 12 11 14 13 Figure 9...

Page 51: ...SHER wave 405 ID x 740 OD 2 193 635 RING rtng ext 394 shaft x 1 16 079 633 FITTING hose brs barbed M 3 16tbg 1 17 601 966 SCREW 375 16 x 1 25hexhd 2 18 604 538 WASHER flat stl SAE 312 1 19 204 585 KNOB fluted 1 20 173 619 CARRIER drive roll w components 1 21 174 609 SCREW M 4 7 x 12 1 22 174 610 SCREW M 6 1 0 x 20 soc hd 3 23 192 029 WASHER flat 250 ID x 437 OD 3 24 173 620 BUSHING motor mtg 3 25 ...

Page 52: ...ank 1 200 285 LABEL warning cylinder may 1 7 188 441 CHAIN weldless 2 0 x 31 000 lg 1 8 605 227 NUT nyl hex jam 750NPST 1 9 604 102 CONNECTOR clamp cable 690 1 070 1 Ref 803 011 Hardware is common and not available unless listed 1 2 3 4 5 6 7 8 9 Figure 9 6 Panel Rear w Components When ordering a component originally displaying a precautionary label the label should also be ordered To maintain the...

Page 53: ... hard shelled cored wires 5 Drive roll types may be mixed to suit particular requirements example V Knurled roll in combination with U Grooved Ref S 0026 B 7 91 Wire Diameter Fraction Decimal Metric 023 025 in 030 in 035 in 045 in 023 025 in 030 in 035 in 045 in 0 6 mm 0 8 mm 0 9 mm 1 2 mm Kit No 087 131 079 594 079 595 079 596 Drive Roll Part No Type 087 130 053 695 053 700 053 697 V Grooved V Gr...

Page 54: ...Notes ...

Page 55: ...trols Accessory Kits Replacement Parts No labor Spoolmate Spoolguns Canvas Covers Miller s True Blue Limited Warranty shall not apply to 1 Consumable components such as contact tips cutting nozzles contactors brushes slip rings relays or parts that fail due to normal wear Exception brushes slip rings and relays are covered on Bobcat Trailblazer and Legend models 2 Items furnished by Miller but man...

Page 56: ... complete and retain with your personal records Always provide Model Name and Serial Style Number Call 1 800 4 A Miller or see our website at www MillerWelds com to locate a DISTRIBUTOR or SERVICE AGENCY near you Welding Supplies and Consumables Options and Accessories Personal Safety Equipment Service and Repair Replacement Parts Training Schools Videos Books Technical Manuals Servicing Informati...

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