Lincoln Electric SVM208-A service manual Theory of Operation, ENGINE, EXCITATION, Rotor Stator

Page 46

E-2	THEORY OF OPERATION	E-2

FIGURE E.2 - ENGINE, EXCITATION, ROTOR AND STATOR

Return to Master TOC

to Master TOC

ENGINE

MAGNETO

MECHANICAL ROTATION

ROTOR

SLIP

RINGS

CAPACITOR

REACTOR

OUTPUT

TERMINALS

STATOR

ROTOR

STATOR

Return

115 AND 230VAC

RECEPTACLES

RHEOSTATBRIDGE

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

ENGINE, EXCITATION, ROTOR

AND STATOR

A small voltage developed by the engine magneto is fed through a diode to the rotating field coil in the rotor via a brush and slip ring configuration. This excitation (“flashing”) voltage magnetizes the rotor lamination. The rotor is mechanically coupled to the engine. The rotating magnet induces a voltage in the stationary windings of the main alternator (stator).

Three separate and isolated windings are incorporated in the stator lamination assembly. Each winding set has a different number of turns, producing different magnitudes of AC output voltages. The three windings are the weld winding, the auxiliary power winding and the field feedback winding. The field feedback winding provides rotor current during machine operation. The output of the BULLDOG 140 is dependent on two cri- teria: the engine RPM and the amount of current in the rotor winding.

Return to Section TOC

Return to Master TOC

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion

BULLDOG® 140

Image 46

Contents Bulldog Safety California Proposition 65 WarningsElectric Shock can kill ARC Rays can burn Can be dangerousCylinder may explode if damaged Welding and Cutting Sparks can cause fire or explosionIii Précautions DE Sûreté Sûreté Pour Soudage a L’ArcSafety Methods of Reducing Emissions Mains Supply Master Table of Contents for ALL Sections Table of Contents Installation Section Installation Technical Specifications Bulldog 140 K2708-1Storing Safety PrecautionsLocation and Ventilation Engine Exhaust can killTilting PRE-OPERATION Engine ServiceStacking OILWelding Cable Connections Electrical Output CONNEC- TionsTable A.1 Recommended Welding Cable Size and Length Electrical Connections Auxiliary Power ReceptaclesCable Installation Plugs and HAND-HELD EquipmentPremises Wiring Circuit BreakersAtion. do not RUN These BulldogTable of Contents Operation Section Operation WELDER/GENERATOR Controls LimitationsOutput Panel Controls Engine Operation Gasoline Engine ControlsBefore Starting the Engine Starting the EngineGenerator Operation Table B.1 Generator Power Applications Welding Operation Control Function / OperationStick Welding Material Thickness Electrode Type Size SettingWelding Guidelines Learning To Stick WeldWhat Happens in the Arc? Correct Welding Position Side viewDo the following PracticeUse the following Butt JointsFillet Joints PenetrationVertical-Up Welding Vertical-Down WeldingWelding Sheet Metal How to Hardface the Sharp Edge Metal to Ground WearOverhead Welding Hardfacing To Reduce WearWelding Cast Iron Cast Iron Plate PreparationLow Hydrogen Group AWS E7018 High-Speed Group AWS E6013Out-of-Position Group AWS E6011 Bulldog Table of Contents Accessories Section OPTIONS/ACCESSORIES AccessoriesLincoln Electric Accessories Table of Contents Maintenance Section Maintenance Engine Maintenance Routine and Periodic MaintenanceLocation Engine Adjustments Return to Section TOC To Section TOCSpark Plug Service Table D.1 Engine Maintenance PartsOperational Clearance GENERATOR/WELDER Maintenance Screws BrushesFigure D.7. Major Component Locations Bulldog 1TABLE of CONTENTS-THEORY of Operation Section E-1 Theory of Operation ENGINE, EXCITATION, Rotor StatorRotor Field Feedback Auxiliary Power Figure E.3 Rotor Field Feedback and Auxiliary PowerAuxiliary Power Overcurrent Protection Weld Winding and Reactor1TABLE of Contents Troubleshooting and Repair F-1 Troubleshooting and Repair HOW to USE Troubleshooting GuidePC Board Troubleshooting Procedures Output Problems Electric Authorized Field Ser vice Facility Perform the Rotor Voltage TestProblems Symptoms Troubleshooting and Repair Perform Field Diode Test Engine Problems Troubleshooting and Repair Engine Throttle Adjustment Test Bulldog Test Description Rotor Voltage TestMaterials Needed Rotor Voltage Test ProcedureLead 200A Connection Ground Stud Field Diode Bridge Test Field Diode Bridge Test + ~Rotor Flashing Circuit Test Rotor Flashing Circuit Test Figure F.3 Brush Holder Leads 201- and 202B +Moving Parts can injure Bulldog Rotor Resistance Test Rotor Resistance Test Cable TIE Brushes Figure F.6 Brushes Retained with Cable TIEBulldog Engine Throttle Adjustment Test ROBIN/SUBARU Engine Strobe-tach Method Engine Throttle Adjustment TestROBIN/SUBARU Engine Frequency Counter MethodHigh Speed Stop Screw Scope Settings Normal Open Circuit Voltage Waveform 115VAC Supply High Idle no LoadMachine Loaded Typical Weld Output WaveformMachine Loaded to 125 Amps AT 23 VAC Brush Removal and Replacement Brush Removal and Replacement Cable TIE BrushesReturn to Section Return to Section TOC Bulldog Rheostat Removal and Replacement Rheostat Removal and Replacement Figure F.11 Rheostat RemovalCapacitor AND/OR Diode Bridge Removal and Replacement Procedure Capacitor Removal and Replacement Removal and ReplacementCapacitor AND/OR Diode Bridge Procedure Field Diode Bridge Removal and Replacement Figure F.13 Field Diode Bridge LocationBulldog STATOR/ROTOR Removal and Replacement InstructionsSTATOR/ROTOR Removal and Replacement GeneratorengineFigure F.15 Generator Components Troubleshooting and Repair Stator Removal Procedure Figure F.16 Output Lead Location TIE Wrap TerminalsThru Bolts Support NutsRotor Removal Procedure Reassembly ProcedureFigure F.19 Checking ROTOR-STATOR AIR GAP Engine Output Auxiliary Power Receptacle OUTPUT1Retest After Repair WELDER/GENERATOR OUTPUT1Bulldog Table of Contents Diagram Section Wiring Diagram Bulldog S28101