Lincoln Electric SVM 117-A service manual SCR Output Rectifier Removal & Replacement

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F-31	TROUBLESHOOTING & REPAIR	F-31
	TROUBLESHOOTING & REPAIR

SCR OUTPUT RECTIFIER REMOVAL & 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 pre- cautions 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 (216) 383-2531 or (800) 833-9353 (WELD).

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MATERIALS NEEDED

5/16" Nut driver.

1/2" Open end wrench.

1/2" Socket wrench, universal tool, and extension. 3/8" Open end wrench.

Slot head screwdriver. Wire cutters.

WIRE-MATIC 250

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Contents WIRE-MATIC Safety Depends on YouSafety ARC Welding can be hazardousCylinder may explode if damaged Electric and MAG- Netic Fields IiiPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcWIRE-MATIC Table of Contents Table of Contents Installation Duty Cycle Amps Volts at Rated Amps Current RangeFuse Superlag Type 750C CopperSafety Precautions Select Proper LocationInput Connections StackingFuse and Wire Sizes Input Power Connections and Ground ConnectionsConnect Shielding GAS Reconnect Procedure Figure A.4 Input Air Supply ConnectionsFigure A.5 Reconnect Diagram For 208/230/1/60 Machines Installation Install the Work ClampConnect Output Components GUN Liner and Contact Output Polarity ConnectionWire Size Conversion Parts GUN and Cable InstallationWIRE-MATIC Operation Safety Instructions General DescriptionWELDING, Cutting Design Features Advantages Unit FeaturesPower Source Features Recommended Processes and EquipmentWire Feeder Features Machine CapabilityLimitations Duty Cycle Amps VoltsControls and Settings Figure B.1 Operator ControlsUsing the Wire Drive Roll Procedure for Changing Drive RollLoading the Wire Reel Proper Wire Feeding Feeding ElectrodeTo mount 10 to 30 lb. spools 8 and 12 diameter Setting Idle Roll Pressure Operating StepsStarting the Welder Making a Weld WIRE-MATIC Accessories OPTIONS/ACCESSORIES Installing the K607-1 Spool GUN Adapter KITK607-1 Spool GUN Adapter KIT Installation Spool GUN Module BoardSpool GUN Connection BOX Installation Return Return to Section TOCSpool GUN Connection Spool GUN PreparationMaking a Weld with the Spool GUN Adapter K607-1 Installed Making the WeldTimer KIT K585-1 Steel Wire Sizes Part Number Aluminum Wire SizesDrive Roll Kits To Make Spot Plug WeldsMaintenance Routine and Periodic Maintenance Perform the following dailyMaintenance Contact TIP and GAS Nozzle Installation Cable CleaningDrive Rolls and Guide Tubes GUN Tubes and Nozzles DROP-IN Reel Spindle and ClipsLiner Removal Replacement Figure D.2 Liner maintenanceGUN Handle Disassembly To open up the handleDescription English Size Metric Size WIRE-MATIC Theory of Operation Input Line Voltage and Main TransformerOutput Rectification Feedback ControlConstant Voltage Output Figure E.4 Constant Voltage OutputWire Drive Motor FeedbackThermal Protection SCR Operation Figure E.6 SCR OperationWIRE-MATIC Troubleshooting & Repair HOW to USE Troubleshooting Guide Recommended Course of ActionPC Board Troubleshooting Procedures Electric Shock can killBoard can be dam- aged by static electricity Main Transformer Rectifier Assembly Test To Section TOC Perform the SCR Rectifier Perform the Wire Drive Motor Liquid elec Trolyte in these capacitors isPerform the Output Rectifier Main Transformer Test Test DescriptionMaterials Needed Main Transformer Test Test Procedure ON/OFF Power Switch will be hot during these testsMain Transformer Test Static SCR Rectifier Assembly Test Leads Figure F.4 SCR 1 Test Points Active SCR Rectifier Assembly Test Leads Figure F.7 SCR Tester Circuit SCR connectionsWire Drive Motor and Tachometer Feedback Test Wire Drive Motor and Tachometer Feedback Test Test Procedure Test for Supply Voltage to Tachometer Test for Feedback Voltage to the Control BoardScope Settings Normal Open Circuit Voltage WaveformMachine Loaded to 250 Amps AT 26 VDC Scope Settings Typical Output Voltage Waveform Machine LoadedMachine Loaded to 220 Amps AT 22 VDC Scope Settings Troubleshooting & Repair Typical SCR Gate Voltage Waveform Control PC Board Removal and Replacement Removal and Replacement ProcedureMaterials Needed Removal and REPLACE- Ment Procedure Wire Drive Assembly Removal and Replacement Wire Drive Assembly Removal and Replacement Procedure Figure F.11 Wire Drive Assembly RemovalSCR Output Rectifier Removal & Replacement Right side heat sink See Figure F.14 Disconnection Heat Sink LeadCapacitor Bank Removal and Replacement Bank Removal Replacement ComponentsMain Transformer Removal and Replacement Power Switch FAN Motor and FAN Removal and Replacement FAN Motor and FAN Removal and Replacement Procedure Figure F.16 Fan Motor and Fan Removal ComponentsTroubleshooting & Repair Wire Speed Range Open Circuit VoltageInput Volts/Hertz 230/60 375WIRE-MATIC Table of Contents Electrical Diagrams Section WIRE-MATIC Electrical Diagrams Spool GUN Option Wiring Diagram 208/230 Code To Section Available from Lincoln Control PC Board G2332 Layout