Potentiometer Replacement | Lincoln Electric SVM132-A guide

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F-24	TROUBLESHOOTING AND REPAIR	F-24
	TROUBLESHOOTING AND REPAIR

POTENTIOMETER REPLACEMENT

WARNING

Service and repair should be performed only by Lincoln Electric factory trained per- sonnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precau- tions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed.

Call (800) 833-9353 (WELD).

_____________________________________________________________

MATERIALS NEEDED

5/16 in. nutdriver 1/2 in. wrench 5/64 in. Allen wrench

Small slothead screwdriver Soldering iron and solder

This procedure takes approximately 10 minutes to perform.

LN-8

Image 74

Lincoln Electric SVM132-A service manual Potentiometer Replacement

Contents

LN-8 Semiautomatic Wire Feeder Safety LN-8 Electric Shock can kill Welding Sparks can cause fire or explosion Iii Précautions DE Sûreté Sûreté Pour Soudage a L’Arc Master Table of Contents for ALL Sections Installation LN-8 with K377 Electrode DiameterLN-8 with K303 LN-8 with K378 LN-8N and LN-8NE Power Source ConnectionsTable A.1 Work Lead Specifications Power Source Selection Switch Variable Voltage PC Board LN-8S and LN-8SE and Converted LN-8N and LN-8NE Power Source Connection Diagrams Table A.2 LN-8 Power Source Connection Diagrams Section TOC Installation TOC 9A-9 Figure A.5 Connection of LN-8 to R3S-250 and R3S-325 10A-10 Figure A.6 Connection of LN-8 to DC-600 Power Source To LN-8 Input Cable Plug Control Cable LN-8 for Same Polarity Operation LN-8 for Opposite Polarity Operation Shock Can Kill Figure A.10 for Power Sources Other than Lincoln Electric 14A-14 LN-8N and LN-8S Cable Clamp Conductor Electrode Wire Reel BasecontrolInput Cable Connections LN-8NE and LN-8SE Locking Connections to Wire FeederExtension Tube Connector Screw Figure A.14 Wire Feeder Handle Installation SELF-TAPPING Screw Hinge Handle LN-8S and LN-8SE Continuous Flux Feed Submerged ARC Handling ProceduresGUN and Cable Assemblies General Operation Constant Current Controls Safety InstructionsControls and Their Functions Gouging Sparks Constant Voltage Controls Current Controls Voltage Circuit Protection Avoiding Ground Lead Protector GLP Activation Wire Feed Rolls and Guide Tubes Figure B.3 Wire Feed Rolls and Guide Tube Installation Setting for CV or CC Power Sources Voltage Power Source Welding with a Constant Mounting a 50 or 60 lb Coil Slots Coil Reel Adapter Wire Reel Loading K1524-1 Universal Wire Reel StandK363-P READI-REEL Adapter Innershield Coils To Mount 10 to 44 lb 4.5 to 20 kg Spools12 in./300 mm Diameter or 14 lb 6 kg READI-REELS a K438 READI-REEL Adapter Must be Used Brass Blocks Hand Crank ARM Feeding Electrode to the LN-8N or LN-8SFeeding Electrode to the LN-8NE or LN-8SE with Extension Flux Tank Loading Slow Acceleration Starting Code 7926 and Above Accessories Table C.1 LN-8 Wire Feeder Accessories General K178 Mounting Platform K161 Mechanized Travel Power PackK163 Undercarriage Requires K303, K377, or K378 K58 Magnetic Separator Reel Mounting Accessories Welding Guns Welding GUN Accessories Constant Current Conversion Parts LN-8 Maintenance Table of Contents Maintenance Section Routine Maintenance Periodic Maintenance Table of Contents Theory of Operation Section Theory of Operation Power Input Circuits General Description GUN Trigger and 1CR Relay Contact Control Circuits Figure E.2 GUN Trigger and 1CR Contact Control Circuits Fuse Field Applied Later CYCLE, the SCR Output Is Decreased SCR Operation5E-5 LN-8 Troubleshooting and Repair HOW to USE Troubleshooting Guide Return to Return to Section TOC Troubleshooting & Repair PC Board Troubleshooting Procedures Troubleshooting Guide Problems Symptoms Function Problems Transformer Test Perform the 1CR Relay Test Feeding Problems Welding Problems LN-8 Electrical Sequence of Operation Figure F.1 LN-8 Electrical Sequence of Operation Trigger Transformer Test Test Description Trigger Transformer Test Internal Voltage Test Circuit Applied Breaker ConnectorReceptacle Control Board Internal Voltage Test Table F.1 Voltage Test Points 1CR Relay Test 1CR Relay Test 1CR Relay Test Table F.2 Relay Test Terminal Connections Drive Motor Test Drive Motor Test Figure F.6 GUN Terminal Jumper Locations 1CR To further check the drive motor Table F.3 Drive Motor Test Points Potentiometer Replacement Repair Procedure Circuit Breaker Replacement Ground Lead Protector Switch Mount Flatwasher Lockwasher NUT Retaining NUT Ground Lead Protector Push Button Switch Replacement Ground Lead Protector Push Button Trigger Transformer Replacement Relay PC Board Roundhead Screw Insulation Sheet Trigger Transformer NUT PC Board Replacement Figure F.10 PC Board Locations Control PC Board Variable Voltage PC Board Relay PC Board Relay Board Removal Control PC Board Replacement Wire Drive Assembly and Component Replacement Green Ground Yellow BlackWhite Blue TWO Shunt #568 #567 Motor Gearbox Insulation Sheet Mounting Plate TOC Retest After Repair Electrical Diagrams LN-8N, -8NE, -8S, and -8SE Wiring Diagram Connection Schematic Source Power to Work Operating Schematic 1CR Wire Feed Motor Field Control Board L5767 Schematic Variable Voltage Board L5039 Schematic Control Board L5767 Layout Control Variable Voltage Board L5039 Layout SVM Error Reporting Form