Lincoln Electric SVM128-A service manual Excitation Flashing, Auxiliary and Field Feedback Coils

Page 51

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E-3

E-3

THEORY OF OPERATION

FIGURE E.3 – ENGINE GENERATOR ARMATURE AND FRAME, ALTERNATOR STATOR AND ROTOR

 

PROTECTION

 

 

 

SELECTOR

 

 

 

 

 

RELAY

 

 

 

 

 

 

 

 

 

 

 

 

SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

REED

 

 

 

 

IDLER

 

 

 

 

 

RELAY

NEGATIVE

 

 

BOARD

 

 

 

 

 

CR2

 

 

 

 

 

 

 

 

 

 

OUTPUT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TERMINAL

 

 

 

 

 

 

 

 

115 & 230VAC

 

 

 

 

 

 

 

 

 

 

RECEPTACLES

 

 

 

 

IDLER

 

 

 

 

 

 

 

 

 

SOLENOID

 

 

 

 

 

 

 

 

 

OIL

 

 

GENERATOR

 

 

 

 

 

TEMPERATURE

PRESSURE

 

 

 

FRAME

 

 

 

 

 

GAUGE

SWITCH

 

 

 

 

 

CURRENT

 

 

FUEL

 

 

SERIES

 

 

 

 

 

 

INJECTION

 

 

COILS

 

 

 

 

TRANSFORMER

 

 

PUMP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BRUSHES & COMMUTATOR

 

ALTERNATOR

STATOR

 

SWITCH

ENGINE

 

 

ARMATURE

 

 

SLIP

 

 

 

ENGINE

MECHANICAL

GENERATOR

 

ARMATURE

ROTOR

 

 

IGNITION

 

 

COUPLING

 

 

 

SHAFT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ALTERNATOR

 

 

 

 

 

 

 

RINGS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INTERPOLE

 

 

 

 

 

 

 

 

 

COILS

RESIDUAL

 

 

 

 

 

 

STARTER

 

 

MAGNETISM

FLASHING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MOTOR

 

 

FIELD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SHUNT

 

 

 

 

 

 

 

 

 

WINDINGS

 

 

 

 

 

 

 

 

 

 

 

 

FIELD

 

 

 

BATTERY

 

 

 

 

 

RECTIFIER

 

 

 

 

 

 

 

GENERATOR

 

 

 

 

 

 

 

 

 

FIELD CONTROL

 

 

POSITIVE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OUTPUT

 

 

 

 

 

 

 

 

 

 

TERMINAL

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ENGINE, GENERATOR ARMATURE AND FRAME, ALTERNATOR STATOR AND ROTOR

EXCITATION (FLASHING)

When the engine is started and running, the residual magnetism voltage is applied to the alternator rotor via a brush and slip ring configuration. This excitation (“flashing”) voltage magnetizes the rotor lamination. The alternator rotor is connected to the armature shaft, which is mechanically coupled to the engine. This rotating magnet (rotor) induces a voltage in the station- ary windings of the alternator stator.

AUXILIARY AND FIELD FEEDBACK COILS

There are two isolated windings incorporated in the sta- tor lamination assembly. One of these windings is tapped and provides 115VAC and 230VAC of auxiliary power to the appropriate receptacles. The other 115VAC isolated winding is rectified to a DC voltage and is used to supply field feedback voltage to the rotor. It also, through the generator field rheostat control, sup- plies voltage to the field shunt windings in the main generator frame.

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

SA-250

Image 51
Contents SHIELD-ARCTMSA-250 SA-250 SafetyElectric Shock can kill Iii Welding Sparks can cause fire or explosionSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Table of Contents Installation Section Technical Specifications SA-250 InstallationSafety Precautions Location and VentilationStoring PRE-OPERATION Engine Service Trailer Cooling SystemMuffler Exhaust Spark ArresterWelding Cable Connections Electrical Output ConnectionsAuxiliary Power RECEPTACLES, PLUGS, and HAND-HELD Equipment Machine GroundingCircuit Breakers SA-250 Table of Contents Operation Section General Description Safety InstructionsOperation Operating InstructionsWelder Operational Features and ControlsDesign Features Recommended ApplicationsLimitations Welding CapabilityWELDER/GENERATOR Controls Controls and SettingsCurrent Range Selector Control of Welding CurrentFigure B.3 Diesel Engine Controls Diesel Engine ControlsCheck and fill the engine fuel tank Engine OperationBefore Starting the Engine Starting the EngineStopping the Engine Cold Weather StartingBREAK-IN Period After you finish welding Welding OperationTable B.1 Range Settings for Wire SIZE/SPEED 12B-12 Auxiliary PowerTable of Contents Accessories OPTIONS/ACCESSORIES Semiautomatic Welding Accessories TIG Welding AccessoriesConnection of the LN-7 to Connection of Lincoln Electric Wire FeedersPIN Amphenol Unused Lead Individually Connection of the LN-25 toFigure C.4 SA-250/LN-25 Across the ARC Connection Diagram Control K487-25 Table of Contents Maintenance Engine Maintenance Routine and Periodic MaintenanceFigure D.1 OIL Drain and Refill Eliminate Air from the Fuel System HOW to Eliminate AIR from the Fuel System Figure D.4 Eliminating AIR from the Fuel System Self-vent methodFigure D.5 Engine Coolant Drain Plug Figure D.6 Tightening the FAN Belt Every Daily or BeforeStarting Engine First 25-50 HoursCleaning the Battery Battery MaintenanceWELDER/GENERATOR Maintenance Idler Maintenance Figure D.5 Major Component Locations SA-250 Table of Contents Theory of Operation Section Theory of Operation ALTERNATOR, and ProtectionCircuits Auxiliary and Field Feedback Coils Excitation FlashingInterpole and Series Coils Fine Current Adjustment Current Range SelectorEngine Idler Circuit Mechanical Coupling DC Generator MachinesSA-250 Table of Contents Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & RepairPC Board can be damaged by static electricity PC Board Troubleshooting ProceduresTroubleshooting Guide Observe Safety GuidelinesDetailed in the beginning of this manual Shunt Field Winding Test Field Shunt Winding Test Output Problems Function Problems Function Problems Troubleshooting & Repair Symptoms Misadjustments Course of Action Problems Possible AreasWelding Problems Alternator Rotor Test Test DescriptionMaterials Needed Slip Rings Brushes Test ProcedureFigure F.2 Measuring Rotor Resistance Figure F.3 Measuring Rotor Resistance to Ground Field Shunt Winding Test Field Shunt Winding Test PIN TAB Idler Solenoid Test Idler Solenoid Test Engine Throttle Adjustment Test Strobe Tach Method Engine Throttle Adjustment TestOscilloscope Method Frequency Counter MethodAdjusting Screw Locking NUT Description Flashing the FieldsDo not remove brush holder ProcedureScope Settings Normal Open Circuit Voltage Waveform 115VAC SupplyHigh Idle no Load Fine Current Control Rheostat AT Maximum Normal Open Circuit DC Weld Voltage Waveform Typical DC Weld Output Voltage Waveform Machine Loaded Selector Switch AT Maximum PositionAlternator Rotor Removal Replacement Alternator Rotor Removal ReplacementLoosen Screws Alternator Cover Slip Rings Brushes Figure F.13 Rotor Removal Replacement Alternator Stator Removal and Replacement Alternator Stator Removal ProcedureField Bridge Rectifier VAC Receptacle Circuit Breaker Genernator Brush HOLDER/COIL Cables Figure F.18 Drill Spot Locations Generator Frame Removal and Replacement See Figure F.19 for steps 4 Generator Frame RemovalFigure F.20 Wire and Selector Switch Connections Figure F.21 Case Front Removal Rope Sling ENGINE/GENERATOR Mounting Holes Troubleshooting & Repair Generator Armature Removal and Replacement Figure F.23 Blower Paddle Removal Generator Armature RemovalWelder DC Output AC Auxiliary Power Receptacle OutputRetest After Repair Engine OutputSA-250 Electrical Diagrams Section Section G SA-250 Wiring Diagram Electrical DiagramsWire Feed Module Wiring Diagram Idler PC Board M13708 Schematic Idler PC Board M13708 Components SVM Error Reporting Form