Lincoln Electric SVM132-A service manual Figure F.1 LN-8 Electrical Sequence of Operation

Page 61

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F-11

TROUBLESHOOTING AND REPAIR

F-11

 

 

 

 

 

FIGURE F.1 – LN-8 ELECTRICAL SEQUENCE OF OPERATION (continued)

WELDING

RELEASE

BREAK

GUN TRIGGER

WELDING ARC

 

 

 

 

 

 

 

 

 

 

OPENS 2-8 (NOTE 1)

 

 

DE-ENERGIZES

 

 

 

 

 

 

2 CR

 

 

REED SWITCH

 

 

 

 

 

 

 

 

 

OPENS INTERLOCK

 

 

ON 1 CR (NOTE 2)

 

 

 

 

 

 

 

 

 

 

 

 

DE-ENERGIZES 1 CR

OPENS 2-4 CIRCUIT

OPENS 531-7

OPENS 683-32A CIRCUIT

 

CLOSES 682-683

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DE-ENERGIZES POWER SOURCE PILOT RELAY

DE-ENERGIZES POWER SOURCE CONTACTOR

ELECTRODE IS COLD TO WORK

DISCONNECTS MOTOR ARMATURE

AND CONTROL CIRCUIT FROM INPUT AC LINE - (DE-ENERGIZES AUX. EQUIPMENT IF CONNECTED)

REVERSES

3CR (NOTE 3)

MOTOR FIELD

REED SWITCH

 

 

MOMENTARILY

 

 

 

 

CLOSES

DYNAMIC BRAKE

 

 

 

 

CURRENT FLOWS

 

 

THROUGH FREE

DISCHARGES SLOW

WHEELING DIODE (D-7 ON

ACCELERATION

CONTROL BOARD)

CAPACITOR (C3 ON

 

 

CONTROL BOARD)

 

 

 

 

 

 

 

 

 

 

MOTOR STOPS

 

 

RESETS SLOW

 

 

 

 

ACCELERATION

 

 

CIRCUIT

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UNIT READY

FOR NEXT WELD

NOTE 1: When interlock is open.

NOTE 2: When interlock is closed.

NOTE 3: 3 CR is not used on units with code no. 7926 and up.

LN-8

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Contents LN-8 Semiautomatic Wire Feeder LN-8 SafetyElectric Shock can kill Iii Welding Sparks can cause fire or explosionSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Installation LN-8 with K303 Electrode DiameterLN-8 with K377 LN-8 with K378Table A.1 Work Lead Specifications Power Source ConnectionsLN-8N and LN-8NE LN-8S and LN-8SE and Converted LN-8N and LN-8NE Power Source Selection Switch Variable Voltage PC BoardTable A.2 LN-8 Power Source Connection Diagrams Power Source Connection DiagramsSection TOC Installation TOC Figure A.5 Connection of LN-8 to R3S-250 and R3S-325 9A-9Figure A.6 Connection of LN-8 to DC-600 10A-10Power Source To LN-8 Input Cable Plug Control Cable LN-8 for Same Polarity Operation Shock Can Kill LN-8 for Opposite Polarity Operation14A-14 Figure A.10 for Power Sources Other than Lincoln ElectricInput Cable Connections Cable Clamp Conductor Electrode Wire Reel BasecontrolLN-8N and LN-8S LN-8NE and LN-8SEExtension Tube Connector Connections to Wire FeederLocking ScrewSELF-TAPPING Screw Hinge Handle Figure A.14 Wire Feeder Handle InstallationGUN and Cable Assemblies Handling ProceduresLN-8S and LN-8SE Continuous Flux Feed Submerged ARC GeneralOperation Controls and Their Functions Safety InstructionsConstant Current Controls Gouging SparksCurrent Controls Voltage Constant Voltage ControlsAvoiding Ground Lead Protector GLP Activation Circuit ProtectionFigure B.3 Wire Feed Rolls and Guide Tube Installation Wire Feed Rolls and Guide TubesSetting for CV or CC Power Sources Welding with a Constant Voltage Power SourceSlots Coil Reel Mounting a 50 or 60 lb CoilK363-P READI-REEL Adapter Wire Reel Loading K1524-1 Universal Wire Reel StandAdapter 12 in./300 mm Diameter or 14 lb 6 kg To Mount 10 to 44 lb 4.5 to 20 kg SpoolsInnershield Coils READI-REELS a K438 READI-REEL Adapter Must be UsedFeeding Electrode to the LN-8NE or LN-8SE with Extension Feeding Electrode to the LN-8N or LN-8SBrass Blocks Hand Crank ARM Slow Acceleration Starting Code 7926 and Above Flux Tank LoadingAccessories General Table C.1 LN-8 Wire Feeder AccessoriesK163 Undercarriage Requires K303, K377, or K378 K161 Mechanized Travel Power PackK178 Mounting Platform K58 Magnetic SeparatorReel Mounting Accessories Constant Current Conversion Parts Welding Guns Welding GUN AccessoriesLN-8 Table of Contents Maintenance Section MaintenanceRoutine Maintenance Periodic Maintenance Theory of Operation Table of Contents Theory of Operation SectionGeneral Description Power Input CircuitsFigure E.2 GUN Trigger and 1CR Contact Control Circuits GUN Trigger and 1CR Relay Contact Control CircuitsFuse Field 5E-5 SCR OperationApplied Later CYCLE, the SCR Output Is Decreased LN-8 Troubleshooting and Repair Return to Return to Section TOC HOW to USE Troubleshooting GuidePC Board Troubleshooting Procedures Troubleshooting & RepairProblems Symptoms Troubleshooting GuideFunction 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 Test Description Trigger Transformer TestTrigger Transformer Test Internal Voltage Test Receptacle ConnectorCircuit Applied Breaker Control BoardTable F.1 Voltage Test Points Internal Voltage Test1CR Relay Test 1CR Relay Test Table F.2 Relay Test Terminal Connections 1CR Relay TestDrive Motor Test Drive Motor Test 1CR Figure F.6 GUN Terminal Jumper LocationsTable F.3 Drive Motor Test Points To further check the drive motorPotentiometer Replacement Repair Procedure Circuit Breaker Replacement Retaining NUT Ground Lead Protector Switch Mount Flatwasher Lockwasher NUTGround Lead Protector Push Button Switch Replacement Ground Lead Protector Push Button Trigger Transformer Replacement Insulation Sheet Trigger Transformer NUT Relay PC Board Roundhead ScrewPC Board Replacement Control PC Board Variable Voltage PC Board Relay PC Board Figure F.10 PC Board LocationsRelay Board Removal Control PC Board Replacement Wire Drive Assembly and Component Replacement White BlackGreen Ground Yellow Blue TWO#568 #567 ShuntGearbox Insulation Sheet Mounting Plate MotorTOC Retest After Repair Electrical Diagrams LN-8N, -8NE, -8S, and -8SE Wiring Diagram Source Power to Work Connection Schematic1CR Wire Feed Motor Field Operating SchematicControl Board L5767 Schematic Variable Voltage Board L5039 Schematic Control Control Board L5767 LayoutVariable Voltage Board L5039 Layout SVM Error Reporting Form
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