Lincoln Electric V250-S service manual Troubleshooting & Repair

Page 87

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F-55	TROUBLESHOOTING & REPAIR	F-55
	TROUBLESHOOTING & REPAIR

INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT (continued)

7.Carefully remove the input rectifier bridge.

8.When installing a new input rectifier apply a thin coating of Dow Corning 340 Heat Sink Compound (Lincoln E1868) to the mating surfaces. Torque the mounting cap screws and nuts to 44 IN-LBS.

9.Reconnect the eight leads to the cor- rect terminals and torque the phillips head screws to 31 IN-LBS.

INVERTEC V250-S

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Contents Invertec V250-S Safety Electric Shock can kill ARC Rays can burnFumes and Gases can be dangerous Welding Sparks can cause fire or explosion Cylinder may explode if damagedSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Table of Contents Installation Section InstallationTechnical Specifications Invertec V250-S Three Phase Single PhaseThree Phase Safety Precautions Input ConnectionsSelect Suitable Location Input Voltage Reconnect Procedure Input Fuse and Supply WirePower Input Connection for 50/60 HZ Machines Output Cables Remote Control ReceptacleOutput Connections Quick Disconnect PlugsInvertec V250-S Operation Gouging Sparks Safety InstructionsFigure B.1 Case Front Controls Controls and SettingsTIG Welding Constant Current ProcessesManual ARC Welding Stick AIR Carbon ARC CuttingParallel Operation Overload ProtectionThermal Protection Invertec V250-S Table of Contents Accessories Section AccessoriesOptions / Accessories Remote ControlsCable Plugs Table of Contents Maintenance Section MaintenanceFigure D.1 Location of Input Filter Capacitor Terminals Input Filter Capacitor Discharge ProcedureFilter Capacitor Conditioning Routine MaintenanceFigure D.2 Location of Maintenance Components Theory of Operation Table of Contents Theory of Operation SectionInput Line Voltage General DescriptionFigure E.2 Protection and PRE-CHARGE Circuits Precharge and ProtectionFigure E.3 Main Transformer Main TransformerFigure E.4 Output Rectification and Control Output Rectification ControlOverload Protection Protection CircuitsInsulated Gate Bipolar Transistor Igbt Operation Pulse Width Modulation Minimum OutputMaximum Output Troubleshooting & Repair Oscilloscope Warning HOW to USE Troubleshooting GuideBoard can be dam- aged by static electricity PC Board Troubleshooting ProceduresCourse of Action Possible Areas Recommended SymptomsPerform the Control Board Voltage Checks Possible AreasCapacitor Balance Test Troubleshooting & Repair Perform the Output Diode Test Welding Problems Invertec V250-S Auxiliary Transformer Test Test DescriptionMaterials Needed Auxiliary Transformer Test Test ProcedureTable F.1 Auxiliary Transformer Test Points Auxiliary Transformer TestInvertec V250-S Input Rectifier Test Input Rectifier Test Test ProcedureTest Point Terminals Analog Meter X10 Range Table F.2 Input Rectifier Test PointsInvertec V250-S Power Board Resistance Test Test Description Power Board Resistance TestTable F.3 Power Board Resistance Test Points Power Board Resistance TestInvertec V250-S Output Diodes Test Figure F.4 Machine Output Terminals Output Diodes TestInvertec V250-S Diode Modules Power Board Voltage Test Figure F.8 Plug J6 on Power Board Power Board Voltage TestTable F.4. Power Board Voltage Test Points Acceptable Test DescriptionTest Conditions Invertec V250-S Control Board Voltage Test Figure F.9 Plugs J1-J5 on Control Board Control Board Voltage Test18VAC Table F.5. Control Board Voltage Test PointsInvertec V250-S Protection Circuit Test Figure F.10 Control Board Plug J2 Test Points Protection Circuit TestProtection Circuit Simplified Invertec V250-S Capacitor Balance Test Capacitor Balance Test Figure F.12 Power Board and Capacitor Test LocationsTable F.6 Capacitor Voltages Invertec V250-S Control Board Removal and Replacement Control Board Removal and Replacement ProcedureV250S Control Power Board Removal and Replacement Figure F.14 Power Board Lead Locations Power Board Removal and ReplacementPower Board Replacement Procedure Invertec V250-S Matched Parts Filter Capacitor Removal and ReplacementFigure F.15 Heatsink/Power Board Removal Filter Capacitor Removal and ReplacementPerform Power Board Replacement Procedure in this section Invertec V250-S Input Rectifier Bridge Removal and Replacement Figure F.16 Input Rectifier Lead Locations Input Rectifier Bridge Removal and ReplacementTroubleshooting & Repair Invertec V250-S Materials Needed Snubber Resistors Locking Tabs Invertec V250-S Wrench Allen type wrench Torque wrench Mounting Bolts Diode Modules Bolted Connections Troubleshooting & Repair Invertec V250-S Main Transformer Removal and Replacement Machine Codes below T3 Current Transformer Main Transformer Main Transformer Secondary Leads Figure F.22 Main Transformer Mountings Clear all leads and secure for case wrap-around assembly Invertec V250-S Main Transformer Removal and Replacement Machine Codes Above Figure F.23 Main Transformer Right Side Figure F.24 Main Transformer Left Side Figure F.25 Main Transformer Mountings Troubleshooting & Repair Invertec V250-S Input Idle Amps and Idle Watts Maximum Acceptable Output AT Minimum Output SettingsMinimum Acceptable Output AT Maximum Output Settings Retest After RepairInvertec V250-S Electrical Diagrams Invertec V250-S Invertec V250S Wiring Diagram Codes 10102Return to Section Wiring Diagram Codes 10187G2666 Control PC Board G2666 LayoutPower P.C. BD. Asbly Power PC Board G2684 LayoutRelay Coils Control PC Board G2666 SchematicFrom Control BD Power PC Board G2684 Schematic