Lincoln Electric SVM128-A service manual Field Shunt Winding Test

Page 60

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F-6

 

 

 

 

 

 

F-6

 

TROUBLESHOOTING & REPAIR

 

 

 

 

 

 

Observe Safety Guidelines

 

TROUBLESHOOTING GUIDE

 

detailed in the beginning of this manual.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PROBLEMS

POSSIBLE AREAS OF

RECOMMENDED

 

 

 

(SYMPTOMS)

MISADJUSTMENT(S)

COURSE OF ACTION

 

 

 

 

 

 

 

 

 

 

 

 

OUTPUT PROBLEMS

 

 

 

 

 

 

 

 

The welding output varies abnor-

1. May be a normal condition. The

1.

Check

 

the

Fine

Current

 

mally. The auxiliary output remains

machine will normally lose

 

Adjustment rheostat for resis-

 

constant. The engine is operating

some output as the components

 

tance

and proper operation.

 

correctly.

get heated.

 

Normal resistance is 64 ohms.

 

 

2. Check for loose, worn, dirty, or

 

Check

associated wires for

 

 

 

loose

or

faulty connections.

 

 

poorly seated DC generator

 

 

 

 

See the Wiring Diagram.

 

 

brushes.

 

 

 

 

 

 

 

 

 

 

 

 

3. The armature commutator may

2.

Perform

the

Field

Shunt

 

 

 

Winding Test.

 

 

 

 

need cleaned.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Check for loose or faulty weld-

3.

Check

the

Current

Range

 

 

 

Selector switch and contacts for

 

 

ing cables.

 

 

 

 

proper operation.

 

 

 

 

 

 

 

 

 

 

 

4. While the machine is loaded,

 

 

 

 

check the interpole and series

 

 

 

 

coils for signs of “arcing” This

 

 

 

 

condition would point to shorted

 

 

 

 

turns in the “arcing” coil.

 

 

 

5. The main armature may be

 

 

 

 

faulty. Check for grounds.

 

 

 

 

 

 

 

 

 

 

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con- tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.

SA-250

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Contents SHIELD-ARCTMSA-250 Safety SA-250Electric 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 SA-250Safety Precautions Location and VentilationStoring PRE-OPERATION Engine Service Cooling System MufflerExhaust Spark Arrester TrailerElectrical Output Connections Welding Cable ConnectionsAuxiliary Power RECEPTACLES, PLUGS, and HAND-HELD Equipment Machine GroundingCircuit Breakers SA-250 Table of Contents Operation Section Safety Instructions OperationOperating Instructions General DescriptionOperational Features and Controls Design FeaturesRecommended Applications WelderWelding Capability LimitationsControls and Settings WELDER/GENERATOR ControlsControl of Welding Current Current Range SelectorDiesel Engine Controls Figure B.3 Diesel Engine ControlsEngine Operation Before Starting the EngineStarting the Engine Check and fill the engine fuel tankStopping the Engine Cold Weather StartingBREAK-IN Period Welding Operation After you finish weldingTable B.1 Range Settings for Wire SIZE/SPEED Auxiliary Power 12B-12Table of Contents Accessories OPTIONS/ACCESSORIES TIG Welding Accessories Semiautomatic Welding AccessoriesConnection of Lincoln Electric Wire Feeders Connection of the LN-7 toPIN Amphenol Connection of the LN-25 to Unused Lead IndividuallyFigure C.4 SA-250/LN-25 Across the ARC Connection Diagram Control K487-25 Table of Contents Maintenance Routine and Periodic Maintenance Engine MaintenanceFigure D.1 OIL Drain and Refill Eliminate Air from the Fuel System HOW to Eliminate AIR from the Fuel System Self-vent method Figure D.4 Eliminating AIR from the Fuel SystemFigure D.5 Engine Coolant Drain Plug Figure D.6 Tightening the FAN Belt Daily or Before Starting EngineFirst 25-50 Hours EveryBattery Maintenance Cleaning the BatteryWELDER/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 Excitation Flashing Auxiliary and Field Feedback CoilsInterpole and Series Coils Fine Current Adjustment Current Range SelectorEngine Idler Circuit DC Generator Machines Mechanical CouplingSA-250 Table of Contents Troubleshooting & Repair Section Troubleshooting & Repair HOW to USE Troubleshooting Guide PC Board Troubleshooting Procedures PC Board can be damaged by static electricityTroubleshooting 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 Problems Possible Areas Symptoms Misadjustments Course of ActionWelding Problems Alternator Rotor Test Test DescriptionMaterials Needed Test Procedure Slip Rings BrushesFigure 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 Engine Throttle Adjustment Test Strobe Tach MethodFrequency Counter Method Oscilloscope MethodAdjusting Screw Locking NUT Flashing the Fields DescriptionProcedure Do not remove brush holderScope Settings Normal Open Circuit Voltage Waveform 115VAC SupplyHigh Idle no Load Fine Current Control Rheostat AT Maximum Normal Open Circuit DC Weld Voltage Waveform Machine Loaded Selector Switch AT Maximum Position Typical DC Weld Output Voltage WaveformAlternator Rotor Removal Replacement Replacement Alternator Rotor RemovalLoosen Screws Alternator Cover Slip Rings Brushes Figure F.13 Rotor Removal Replacement Alternator Stator Removal and Replacement Procedure Alternator Stator RemovalField Bridge Rectifier VAC Receptacle Circuit Breaker Genernator Brush HOLDER/COIL Cables Figure F.18 Drill Spot Locations Generator Frame Removal and Replacement Generator Frame Removal See Figure F.19 for steps 4Figure 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 Generator Armature Removal Figure F.23 Blower Paddle RemovalAC Auxiliary Power Receptacle Output Retest After RepairEngine Output Welder DC OutputSA-250 Electrical Diagrams Section Section G SA-250 Electrical Diagrams Wiring DiagramWire Feed Module Wiring Diagram Idler PC Board M13708 Schematic Idler PC Board M13708 Components SVM Error Reporting Form
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