Lincoln Electric LF-72/74 -OPERATION SECTION -

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POWER FEED 10M SINGLE/DUAL

Section BB-1 Section BB-1

TABLE OF CONTENTS

-OPERATION SECTION -

Operation..............................................................................................................Section BB

Safety Precautions.....................................................................................................BB-2

Graphic Symbols.......................................................................................................BB-2

Common Welding Abbreviations...............................................................................BB-2

Product Description...................................................................................................BB-3

Recommended Processes and Required Equipment...............................................BB-3

Front Panel Controls and Connections.....................................................................BB-4

1. Wire Feed Speed Knob....................................................................................BB-5

2. Remote Voltage Control Kit (Optional).............................................................BB-5

3. Burnback and Postflow Timer Kit (Optional)....................................................BB-5

4. Thermal LED, Motor Overload.........................................................................BB-5

5. Cold Feed/Gas Purge Switch...........................................................................BB-5

6. 2 Step - Trigger Interlock Switch.....................................................................BB-6

7. Gun Receiver Bushing......................................................................................BB-6

8. Trigger Connector 5-Pin Amphenol..................................................................BB-6

Contents

Main LF-72/74 SVM171-A SERVICE MANUAL Safety Depends on You FOR ENGINE powered equipment. WARNING ELECTRIC AND MAGNETIC FIELDS may be dangerous ARC RAYS can burn. ii FUMES AND GASES can be dangerous. AUG 06 ii FOR ELECTRICALLY powered equipment. iii CYLINDER may explode if damaged. Mar 95 WELDING SPARKS can cause fire or explosion. PRCAUTIONS DE SRET iv PRCAUTIONS DE SRET POUR LES MACHINES SOUDER TRANSFORMATEUR ET REDRESSEUR Mar. 93 iv MASTER TABLE OF CONTENTS FOR ALL SECTIONS vv LF-72/74 SINGLE/DUAL -INSTALLATION SECTION - TECHNICAL SPECIFICATIONS : LF-72 Wire Feeder LOCATION ELECTRIC SHOCK can kill. MOUNTING Page WELD CABLE SIZES COAXIAL WELD CABLES WELD CABLE CONNECTION Electrode Work Work ANALOG CONTROL CABLE CONTROL CABLE CONNECTIONS POWER SOURCE WIRE FEEDER NOTES ANALOG MILLER CONTROL CABLE ADAPTER K2335-1 MILLER POWER SOURCE LINCOLN WIRE FEEDER WELDING GUN/WIRE FEEDER TRIGGER CONNECTOR WIRE DRIVE SYSTEMS WELDING GUNS, TORCHES AND ACCES- SORIES WIRE DRIVE CONFIGURATION PROCEDURE FOR CHANGING DRIVE AND IDLE ROLL SETS WARNING WARNING PRESSURE ARM ADJUSTMENT WIRE REEL LOADING WELD WIRE ROUTING SHIELDING GAS CONNECTION INSTALLING ELECTRODE CONDUIT KITS "O" RING ALUMINUM WIRE PREPARATIONS Page TYPICAL SYSTEM CONFIGURATIONS Page -OPERATION SECTION - SAFETY PRECAUTIONS COMMON WELDING ABBREVIATIONS PRODUCT DESCRIPTION RECOMMENDED PROCESSES REQUIRED EQUIPMENT FRONT PANEL CONTROLS AND CONNECTIONS 1. REMOTE VOLTAGE CONTROLKIT 2. BURNBACK AND POSTFLOW TIMER KIT 5. 3. THERMAL LED, MOTOR OVERLOAD 4. COLD FEED/GAS PURGE SWITCH 6. WIRE FEED SPEED KNOB 7. GUN RECEIVER BUSHING (K1500-2) 8. TRIGGER CONNECTOR 5-PIN AMPHENOL Page Page Page Page Page Page Page MAINTENANCE Safety Precautions ROUTINE MAINTENANCE PERIODIC MAINTENANCE CALIBRATION SPECIFICATION FIGURE D.1 FIGURE D.2 Page -INSTALLATION SECTION - TECHNICAL SPECIFICATIONS : LF-74 Wire Feeder LOCATION ELECTRIC SHOCK can kill. MOUNTING Page WELD CABLE SIZES COAXIAL WELD CABLES WELD CABLE CONNECTION Electrode Work Work ANALOG CONTROL CABLE CONTROL CABLE CONNECTIONS ANALOG MILLER CONTROL CABLE ADAPTER K2335-1 MILLER POWER SOURCE LINCOLN WIRE FEEDER WELDING GUN/WIRE FEEDER TRIGGER CONNECTOR HIGH FREQUENCY PROTECTION WIRE DRIVE SYSTEMS Trigger Lead WELDING GUNS, TORCHES AND ACCES- SORIES WIRE DRIVE CONFIGURATION ASSEMBLY OF DRIVE ROLLS AND WIRE GUIDES PRESSURE ARM ADJUSTMENT SHIELDING GAS CONNECTION WIRE REEL LOADING WELD WIRE ROUTING INSTALLING ELECTRODE CONDUIT KITS ALUMINUM WIRE PREPARATIONS Page COMMON EQUIPMENT SET-UPS FIGURE AA.15 HIGH VOLUME PRODUCTION FIGURE AA.16 PORTABLE WELDING 8 7A 10 7 9 5C -OPERATION SECTION - SAFETY PRECAUTIONS RECOMMENDED PROCESSES REQUIRED EQUIPMENT PRODUCT DESCRIPTION FRONT PANEL CONTROLS AND CONNECTIONS 1. WIRE FEED SPEED KNOB 2. REMOTE VOLTAGE CONTROLKIT 3. BURNBACK AND POSTFLOW TIMER KIT 4. THERMAL LED, MOTOR OVERLOAD 5. COLD FEED/GAS PURGE SWITCH 6. 2STEP - TRIGGER INTERLOCK SWITCH 8. 7. GUN RECEIVER BUSHING (K1500-2) TRIGGER CONNECTOR 5-PIN AMPHENOL Page Page Page LF-72/74 Page Page Page MAINTENANCE Safety Precautions ROUTINE MAINTENANCE PERIODIC MAINTENANCE CALIBRATION SPECIFICATION Page Page -THEORY OF OPERATION SECTION - FIGURE E.1 LF-72/74 BLOCK LOGIC DIAGRAM CONTROL BOARD CONTROL BOARD THEORY OF OPERATION GENERAL DESCRIPTION INPUT RECEPTACLE, CONTROL BOARD AND OPERATOR CON- TROLS THEORY OF OPERATION DRIVE MOTOR, TACH FEEDBACK AND GAS SOLENOID CONTROL BOARD Page -TROUBLESHOOTING & REPAIR SECTION - HOW TO USE TROUBLESHOOTING GUIDE PC BOARD TROUBLESHOOTING PROCEDURES PROBLEMS (SYMPTOMS) POSSIBLE AREAS OF MISADJUSTMENT(S) RECOMMENDED COURSE OF ACTION FUNCTION PROBLEMS PROBLEMS (SYMPTOMS) POSSIBLE AREAS OF MISADJUSTMENT(S) RECOMMENDED COURSE OF ACTION FUNCTION PROBLEMS (Continued) Page DRIVE MOTOR AND TACH FEEDBACK TEST TEST PROCEDURE MOTOR AND TACH FEEDBACK TEST (continued) GAS SOLENOID TEST GAS SOLENOID GAS SOLENOID TEST (continued) DIODE BRIDGE TEST DIODE BRIDGE TEST (continued) WIRE SPEED POTENTIOMETER TEST WIRE SPEED POTENTIOMETER TEST (Continued) Figure F.5 PC BOARD REMOVAL AND REPLACEMENT REMOVAL PROCEDURE REPLACEMENT PROCEDURE CONTROL BOARD CONTROL PC BOARD REMOVAL AND REPLACEMENT PROCEDURE (Continued) Figure F.6 - PC Board Location WIRE DRIVE MOTOR AND GEAR BOX REMOVAL AND REPLACEMENT PROCEDURE Figure F.7 - Wire Drive Motor(s) PROCEDURE Page REPLACEMENT PROCEDURES Page Page -ELECTRICAL DIAGRAMS SECTION - ELECTRICAL DIAGRAMS WIRING DIAGRAM - ENTIRE MACHINE - CODE 11075, 11076, 11077 (L12146) LF-72 J6 P8 P5 ELECTRICAL DIAGRAMS WIRING DIAGRAM - ENTIRE MACHINE - CODE 11209, 11210, 11211,11227 (L12146-1) LF-72 J6 P8 P5 ELECTRICAL DIAGRAMS WIRING DIAGRAM - ENTIRE MACHINE - CODE 11290, 11291, 11292,11293 (L12146-2) LF-72 N.E. N.D. N.A. ELECTRICAL DIAGRAMS WIRING DIAGRAM - ENTIRE MACHINE - CODE 11195, 11196, 11197, (L12484) LF-74 N.E. L6 P4 ELECTRICAL DIAGRAMS SCHEMATIC - ENTIRE MACHINE - CODE 11075, 11076, 11077 (G4617) LF-72 is 1.5 ohms P5 J4 ELECTRICAL DIAGRAMS SCHEMATIC - ENTIRE MACHINE - CODE 11209, 11210, 11211,11227 (G4617-1) LF-72 is 1.5 ohms P5 J4 ELECTRICAL DIAGRAMS SCHEMATIC - ENTIRE MACHINE - CODE 11290, 11291, 11292,11293 (G4617-2) LF-72 on sheetpanel y r ELECTRICAL DIAGRAMS SCHEMATIC - ENTIRE MACHINE - CODE 11195, 11196, 11197, (G4942) LF-74 SheetPanel CaseBack L6