Lincoln Electric LF-72/74 DD-2, To verify the wire feed speed, Such as output terminals or inter

Page 78

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DD-2

MAINTENANCE

 

 

 

DD-2

 

 

 

 

 

 

 

 

 

MAINTENANCE

 

 

Calibration of the LF-74 may be required when the p.c.

Safety Precautions

 

 

board, potentiometer or motor is replaced or serviced.

 

 

Calibration matches the scale on the name plate to the

 

 

 

 

 

 

 

 

actual wire feed speed.

 

 

 

WARNING

 

 

 

 

 

To verify the wire feed speed,

 

ELECTRIC SHOCK can kill.

 

1. Assemble a .045 (1.2 mm) drive roll kit to the feed-

 

 

 

 

 

• Do not touch electrically live parts

er.

 

 

 

 

 

2. Load .045 (1.2 mm) steel wire into the feeder.

 

such as output terminals or inter-

 

3. Trim the wire to the end of the contact tip of the gun.

 

nal wiring.

 

 

 

 

 

4. Adjust the WFS knob per the Table D.1.

 

 

 

 

• When inching with gun trigger, electrode and

 

 

 

TABLE D.1

 

 

 

 

 

 

drive mechanism are “hot” to work and ground

 

 

 

 

 

 

 

 

MODEL

WFS knob setting

 

and could remain energized

several seconds

 

 

 

 

K2426-1, K2426-1

400

 

after the gun trigger is released.

 

 

 

 

K2426-3

200

 

• Turn OFF input power at welding power source

 

 

 

 

 

 

 

 

 

before installation or changing drive roll and/or

5. Activate and hold the COLD FEED switch for 10

guide tubes.

 

 

 

 

seconds.

 

 

• Welding power source must be connected to sys-

 

 

6. Measure the length of wire extending from the con-

tem ground per the National Electrical Code or

tact tip. The wire length shown in Table D.2.

any applicable local codes.

 

 

 

 

 

 

 

TABLE D.2

• Only qualified personnel should perform mainte-

 

 

 

 

 

 

 

 

 

nance work.

 

 

MODEL

 

 

WIRE LENGTH

 

 

K2426-1, K2426-1

50 inches ± 5 inches (1270 mm ± 127mm)

------------------------------------------------------------------------

K2426-3

 

25 inches ± 2.5 inches (635 mm ± 64 mm)

Observe all additional Safety Guidelines detailed

 

 

 

 

 

 

 

 

 

 

 

 

 

throughout this manual.

 

 

To calibrate the wire feed speed,

ROUTINE MAINTENANCE

 

 

Tools required:

 

 

• Clean and tighten all weld terminals.

• 5/16" nut driver

 

 

• Inspect all weld cables, control cables, gun cables

• 3/4" open end wrench

 

 

and shielding gas hoses. Repair or replace as nec-

• WFS meter or RPM meter

essary.

 

 

• Shorting plug. The shorting plug shorts pins 1 and 5

 

 

 

 

of connector J2 on the p.c. board. J2 is a 6 pin

PERIODIC MAINTENANCE

molex.

 

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•Clean drive roll grooves.

•Blow out or vacuum the inside of the feeder.

CALIBRATION SPECIFICATION

WARNING

ELECTRIC SHOCK can kill.

•Do not touch electrically live parts.

•When inching with the gun trigger, electrode, wire drive motor and drive mechanism are "hot" to work and ground and could remain energized several seconds after the gun trigger is released.

•Welding power source must be connected to system ground per the National Electrical Code or any applicable local codes.

•Only qualified personnel should perform mainte- nance work.

------------------------------------------------------------------------

1.Turn off power to the LF-74 and welding power source.

2.Disconnect the electrode lead from the feed plate and from the welding power source.

3.Remove the wraparound from the LF-74, See Figure D.1.

4.Turn on power to the LF-74 and welding power source.

5.Adjust the WFS knob per the Table D.1.

6.Insert the shorting plug into the control p.c. board J2. (shorts pins 1 and 5.) See Figure D.2.

7.Wait a minimum of 1 second.

8.Remove the shorting plug.

9.Connect J2 of the harness to p.c. board.

10.Turn off power to the LF-74 and welding power source.

11.Assemble the wraparound.

12.Connect the electrode lead.

LF-72/74

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Contents LF-72/74 Safety Electric Shock can kill Welding Sparks can cause fire or explosion IiiPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcMaster Table of Contents for ALL Sections Table of Contents Installation SectionSection A-1 Installation Amp Rating Duty CycleSafety Precaution LocationMounting Boom Mount Bench MountSwivel Mount SuspendedWeld Cable Sizes Coaxial Weld Cables Weld Cable ConnectionINSTALLATIONA-7 Analog Control CableControl Cable Connections Miller Power Source Lincoln Wire Feeder Analog Miller Control Cable Adapter K2335-1Pin Function Remote Sense Lead Specifications Wire Drive SystemsWelding GUN/WIRE Feeder Trigger Connector High Frequency ProtectionWelding GUNS, Torches and ACCES- Sories Magnum GUN and Cable AssembliesProcedure for Changing Drive and Idle Roll Sets Wire Drive ConfigurationRolls.FIGURE A.4 Pressure ARM Adjustment Gun Receiver For use With BushingSet the pressure arm as follows See Figure A.6 Wire Reel Loading Weld Wire Routing Figure A.9Shielding GAS Connection Conduit Kits Installing ElectrodeTo install Lincoln conduit See Figure A.10b For Codes 11209, 11210, 11211 and aboveAluminum Wire Preparations Figure A.12bINSTALLATIONA-18 Base Model Bench Model Standard Duty Bench Model Heavy DutyTypical System Configurations CableLF-72/74 Operation Section Section B-1Operation GAS Input Work ConnectionCommon Welding Abbreviations Product DescriptionRecommended Processes Front Panel Controls and Connections Figure B.1 Case Front Controls DescriptionStep Trigger Interlock Switch Burnback and Postflow Timer KITCold FEED/GAS Purge Switch Remote Voltage Control KITGUN Receiver Bushing K1500-2 Wire Feed Speed KnobTrigger Connector 5-PIN Amphenol Trigger InterlockAccessories Section Section C-1Accessories Optional KitsLF-72s Accessories Key LF-72/74 Maintenance Section Section D-1Calibration Specification MaintenanceMaintenance Routine MaintenanceFigure D.1 Figure D.3 Major Component Location Section AA-1 Section AAWFS Range Wire Sizes AA-2Model AA-3 Figure AA.1AA-4 AA-5 AA-6 Coaxial Weld CableINSTALLATIONAA-7 AA-7K1797-xx AA-8 Drive Roll Kits Steel or Cored Wires AA-9AA-10 Figure AA.3Lation or changing drive rolls and/or AA-11Changing the Gun Receiver Bushing GuidesAssembly of Drive Rolls and Wire Guides AA-12AA-13 Set the pressure arm as follows See Figure AA.8AA-14 AA-15 Loading 16 to 44 lb .3 20kg Spools See figure AA.8AA-16 Figure AA.11AA-17 Figure AA.12aAA-18 Figure AA.12bAA-19 AA-20INSTALLATIONAA-20 Common Equipment SET-UPSFigure AA.15 High Volume Production AA-21Figure AA.16 Portable Welding AA-22Section BB-1 Section BBBB-2 Fcaw Innershield or OutershieldRequired Equipment BB-3BB-4 Figure BB.1 Case Front Controls DescriptionBB-5 K2426-1 and K2426-2 modelsK2426-3 model Switch BB-6Section CC-1 CC-2 CC-3 CC-4 CC-5 CC-6 Section DD-1 Section DDWhen inching with gun trigger, electrode To verify the wire feed speedNal wiring WFS knob setting Could remain energized Several secondsMAINTENANCEDD-3 DD-3Figure DD.3 Major Component Location DD-4Theory of Operation Section Section E-1Theory of Operation Return to SectionControl Board LF-72/74 Troubleshooting & Repair Section Section F-1Troubleshooting & Repair HOW to USE Troubleshooting GuidePC Board Troubleshooting Procedures Function Problems Function Problems Troubleshooting & Repair Drive Motor and Tach Feedback Test Test DescriptionTest Procedure Troubleshooting and Repair GAS Solenoid TestTest Procedure Figure F.3 Leads 552, 552BDiode Bridge Test 552B + 552A Wire Speed Potentiometer Test Wire Speed Potentiometer Test 14F-14PC Board Removal and Replacement Control PC Board Removal and Replacement Procedure Removal Procedure Replacement ProcedureTroubleshooting and Repair Wire Drive Motor and Gear BOX Removal and Replacement ProcedureProcedure Replacement Procedures SET UP Operation VerificationLF-72/74 Electrical Diagrams Section Section G-1Electrical Diagrams LF-72/74Timer KIT Board Normal Speed Micro Internal panel Motor Connecter Summary High Torque Setting engages Schematic Common Analog Control PC Board G4559 Sheet Electrical Diagrams Electrical Diagrams PC Board Assembly Common Analog Control G4560-2E0
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