Lincoln Electric SVM 117-A service manual Machine Loaded to 220 Amps AT 22 VDC Scope Settings

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F-24	TROUBLESHOOTING & REPAIR	F-24
	TROUBLESHOOTING & REPAIR

ABNORMAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED

ONE OUTPUT SCR NOT FUNCTIONING

MACHINE LOADED TO 220 AMPS AT 22 VDC

SCOPE SETTINGS

This is NOT a typical DC output voltage
waveform. One output SCR is not function-	Volts/Div	.20 V/Div.
ing. Note the increased ripple content. One
SCR gate was disconnected to simulate an	Horizontal Sweep	.5 ms/Div.
open or non-functioning output SCR. Each
vertical division represents 20 volts and	Coupling	. . . . .DC.
each horizontal division represents 5 mil-
liseconds in time. The machine was loaded	Trigger	. .Internal.
with a resistance grid bank.
Note: Scope probes connected at machine
output terminals: (+) probe to electrode, (-)
probe to work.

WIRE-MATIC 250

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Contents Safety Depends on You WIRE-MATICARC Welding can be hazardous SafetyCylinder may explode if damaged Iii Electric and MAG- Netic FieldsSûreté Pour Soudage a L’Arc Précautions DE SûretéWIRE-MATIC Table of Contents Table of Contents Installation Current Range Duty Cycle Amps Volts at Rated AmpsFuse Superlag Type 750C CopperSelect Proper Location Safety PrecautionsInput Connections StackingInput Power Connections and Ground Connections Fuse and Wire SizesConnect Shielding GAS Figure A.4 Input Air Supply Connections Reconnect ProcedureFigure A.5 Reconnect Diagram For 208/230/1/60 Machines Install the Work Clamp InstallationConnect Output Components GUN Liner and Contact Output Polarity ConnectionGUN and Cable Installation Wire Size Conversion PartsWIRE-MATIC Operation WELDING, Cutting Safety InstructionsGeneral Description Unit Features Design Features AdvantagesPower Source Features Recommended Processes and EquipmentMachine Capability Wire Feeder FeaturesLimitations Duty Cycle Amps VoltsFigure B.1 Operator Controls Controls and SettingsLoading the Wire Reel Using the Wire Drive RollProcedure for Changing Drive Roll To mount 10 to 30 lb. spools 8 and 12 diameter Proper Wire FeedingFeeding Electrode Starting the Welder Setting Idle Roll PressureOperating Steps Making a Weld WIRE-MATIC Accessories K607-1 Spool GUN Adapter KIT OPTIONS/ACCESSORIESInstalling the K607-1 Spool GUN Adapter KIT Spool GUN Module Board InstallationReturn Return to Section TOC Spool GUN Connection BOX InstallationSpool GUN Preparation Spool GUN ConnectionMaking the Weld Making a Weld with the Spool GUN Adapter K607-1 InstalledTimer KIT K585-1 Aluminum Wire Sizes Steel Wire Sizes Part NumberDrive Roll Kits To Make Spot Plug WeldsMaintenance Perform the following daily Routine and Periodic MaintenanceMaintenance Cable Cleaning Contact TIP and GAS Nozzle InstallationDrive Rolls and Guide Tubes GUN Tubes and Nozzles DROP-IN Reel Spindle and ClipsFigure D.2 Liner maintenance Liner Removal ReplacementTo open up the handle GUN Handle DisassemblyDescription English Size Metric Size WIRE-MATIC Theory of Operation Transformer Input Line Voltage and MainFeedback Control Output RectificationFigure E.4 Constant Voltage Output Constant Voltage OutputFeedback Wire Drive MotorThermal Protection Figure E.6 SCR Operation SCR OperationWIRE-MATIC Troubleshooting & Repair Recommended Course of Action HOW to USE Troubleshooting GuideBoard can be dam- aged by static electricity PC Board Troubleshooting ProceduresElectric Shock can kill Main Transformer Rectifier Assembly Test To Section TOC Perform the SCR Rectifier Perform the Wire Drive Motor Trolyte in these capacitors is Liquid elecPerform the Output Rectifier Materials Needed Main Transformer TestTest Description ON/OFF Power Switch will be hot during these tests Main Transformer Test Test ProcedureMain Transformer Test Static SCR Rectifier Assembly Test Leads Figure F.4 SCR 1 Test Points Active SCR Rectifier Assembly Test Leads SCR connections Figure F.7 SCR Tester CircuitWire Drive Motor and Tachometer Feedback Test Wire Drive Motor and Tachometer Feedback Test Test Procedure Test for Feedback Voltage to the Control Board Test for Supply Voltage to TachometerNormal Open Circuit Voltage Waveform Scope SettingsTypical Output Voltage Waveform Machine Loaded Machine Loaded to 250 Amps AT 26 VDC Scope SettingsMachine Loaded to 220 Amps AT 22 VDC Scope Settings Troubleshooting & Repair Typical SCR Gate Voltage Waveform Materials Needed Control PC Board Removal and ReplacementRemoval and Replacement Procedure Removal and REPLACE- Ment Procedure Wire Drive Assembly Removal and Replacement Figure F.11 Wire Drive Assembly Removal Wire Drive Assembly Removal and Replacement ProcedureSCR Output Rectifier Removal & Replacement Disconnection Heat Sink Lead Right side heat sink See Figure F.14Capacitor Bank Removal and Replacement Components Bank Removal ReplacementMain Transformer Removal and Replacement Power Switch FAN Motor and FAN Removal and Replacement Figure F.16 Fan Motor and Fan Removal Components FAN Motor and FAN Removal and Replacement ProcedureTroubleshooting & Repair Open Circuit Voltage Wire Speed RangeInput 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