Lincoln Electric SVM134-A service manual DC Exciter Test, Test Procedure

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F-14

F-14

TROUBLESHOOTING & REPAIR

DC EXCITER TEST (continued)

FIGURE F.1 – 120VDC RECEPTACLE

SERIES COIL CONNECTION

POINT (NEGATIVE)

POSITIVE

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TEST PROCEDURE

1.Turn off the engine and remove all external loads to the welder terminals and auxiliary receptacle.

WARNING

MOVING PARTS can injure.

•Remove guards only when necessary to perform service, and replace them when the service requiring their removal is complete.

•Keep hands, hair, clothing and tools away from V-belts, gears, fans, and all other moving parts when starting, operating, or repairing equipment.

•If fan guards are missing from a machine, obtain replacements from a Lincoln Distributor. (See Parts List.) Always use greatest care when working near moving parts.

2.Start the engine and put the idler switch in the HIGH idle position.

3.Using the volt/ohmmeter, carefully check the DC voltage at the 120V receptacle. (Observe proper polarity. The large slot of the receptacle is negative. See Figure F.1.) Normal voltage is 125 - 135VDC, no load, with the engine at the high idle speed of 1600 RPM. If the voltage is normal, the DC exciter is functioning correctly. If the voltage is low or not present, proceed to the next step.

CLASSIC I

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Contents Classic I TM Safety California Proposition 65 WarningsElectric Shock can kill Welding Sparks can cause fire or explosion IiiPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcMaster Table of Contents for ALL Sections Table of Contents Installation Section Installation Technical Specifications ClassicLocation and Ventilation Safety PrecautionsStoring PRE-OPERATION Engine Service Exhaust Spark Arrester Cooling SystemMuffler TrailersMachine Grounding Figure A.1 Ground Stud LocationWelding Cable Connections Auxiliary Power Receptacle PLUGS, and HAND-HELD EquipmentElectrical Output Connections Cable size for combined lengthClassic Table of Contents Operation Section Operation Safety InstructionsOperating Instructions Welder Operational Features and ControlsRecommended Applications GeneratorControls and Settings WELDER/GENERATOR ControlsControl of Welding Current Figure B.2 Current ControlsGasoline Engine Controls Return Section TOCBefore Starting the Engine Engine OperationStarting the Engine Cold Weather Starting Stopping the EngineBREAK-IN Period Welding Operation After you finish weldingAuxiliary Power Table B.1 Range Settings for Wire SIZE/SPEEDTable of Contents Accessories OPTIONS/ACCESSORIES Semiautomatic Welding AccessoriesConnection of the LN-25 to Connection of Lincoln Electric Wire FeedersWire Feed Module see Figure C.1 Classic I Across the ARC withClassic Table of Contents Maintenance Safety Precautions Routine and Periodic Maintenance Engine MaintenanceFigure D.1 OIL Drain and Refill MAX MIN Figure D.2A Engine Coolant Drain Plug Set the terminal gap with a feeler gauge or gapping After cleaning or when installing a new spark plugGap Specifications 0.032 inch .8 mm Tool. See Figure D.4Battery Maintenance Classic I charging system is NegativeWELDER/GENERATOR Maintenance Return to Section Return to Section TOCIdler Maintenance Figure D.5 Major Component Locations Classic Table of Contents Theory of Operation Section Theory of Operation BATTERY, STARTER, Engine Alternator and OIL Switch CircuitGeneral Description Excitation Flashing ENGINE, Main Generator Armature and Frame and DC ExciterMain SHUNT, Interpole and Series Coils Current Range Selector Fine Current AdjustmentEngine Idler Circuit DC Generator Machines Return to Section TOC Table of Contents Troubleshooting & Repair Section Troubleshooting & Repair HOW to USE Troubleshooting GuidePC Board Troubleshooting Procedures PC Board can be damaged by static electricityObserve Safety Guidelines Troubleshooting GuideDetailed in the beginning of this manual Shunt Field Winding Test Main Generator Throttle Adjustment Test Output Problems Function Problems Troubleshooting & Repair Engine Problems Welding Problems Test Description DC Exciter TestMaterials Needed Test Procedure DC Exciter TestFigure F.2 Exciter Cover Removal Small Flex Lead Solid Shunt Coil and Series Coil Resistance TestsIdler Solenoid Test Troubleshooting & Repair Main Generator Shunt Field Winding Test Main Generator Shunt Field Winding Test Figure F.6 Plug P10 PIN Assignments TAB Engine Throttle Adjustment Test Engine Throttle Adjustment Test Strobe Tach MethodEngine Throttle Adjustment Test Adjust High IdleAdjust Low Idle Flashing the Fields DescriptionProcedure Flashing the FieldsFigure F.11 Brush HOLDER/BATTERY Jumper Connections Normal Open Circuit Voltage Waveform 115VDC Supply Scope SettingsHigh Idle no Load Fine Current Control Rheostat AT Maximum Normal Open Circuit DC Weld Voltage Waveform Machine Loaded Selector Switch AT Maximum Typical DC Weld Voltage WaveformDC Exciter Armature and Field Coils Removal and Replacement Reassembly DC Exciter Armature Removal ProcedureDC Exciter Armature and Field Coils Field Coils Removal Procedure Perform the DC Exciter Armature Removal ProcedureMain Generator Frame Removal and Replacement Replacement Main Generator Frame Removal Bolt / NUTPerform the DC Exciter Armature Removal Figure F.16 Selector Switch Lead Removal Terminal LeadFigure F.18 Choke Control Cable Removal Loosen Here Main Generator Frame Removal Figure F.20 Front Panel Fastener Removal Troubleshooting & Repair Feet Remove Mounting NUTS, Washers BoltsPerform the DC Exciter Armature Reassembly Procedure Main Generator Armature Removal and Replacement Main Generator Armature Removal Armature is now free to be removed from the engineEngine Output DC Auxiliary Power Receptacle OutputRetest After Repair Welder DC OutputElectrical Diagrams Section Electrical Diagrams Wiring Diagram ClassicWire Feed Module Wiring Diagram Wiring Diagram Wire Feed ModuleSchematic Idler PC Board 16990 MPC Board Assembly Idler PC Board Idler