Lincoln Electric SVM128-A service manual Interpole and Series Coils Fine Current Adjustment

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THEORY OF OPERATION

 

INTERPOLE AND SERIES COILS

FINE CURRENT ADJUSTMENT

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The generator armature rotates within the magnetic field created by the field shunt windings. A DC voltage is induced in the armature and is transferred, through the armature commutator and brushes, to the series and interpole coils. The interpole coils, which are con- nected in series with the positive output terminal, are located so as to counteract any magnetic influences that could cause mechanical distortion in the rotating armature. The series coils are designed to oppose or “buck” the DC voltage that is generated in the arma- ture.

CURRENT RANGE SELECTOR

The selector switch acts as a coarse current adjust- ment by allowing for varying amounts of series wind- ings to be included in the welding current path. The series coils and selector switch are connected in series with the negative output terminal.

The field rheostat control functions as a fine output cur- rent adjustment by controlling the current through the shunt windings. In this way it controls the amount of magnetism created in the field shunt windings. Open circuit weld voltage can also be controlled by the field rheostat control.

ENGINE IDLER CIRCUIT

The idler solenoid is mechanically connected to the engine governor linkage. When welding current is being drawn, the reed switch CR2 is closed. This sig- nals the idler PC board to release (deactivate) the idler solenoid, which then lets the machine go to a high speed condition. Also, when auxiliary power is being used, the current is passed through the current trans- former, which signals the idler PC board to release the idler solenoid.

When welding ceases or the auxiliary load is removed, a preset time delay of about 15 seconds starts. After approximately 15 seconds, the idler PC board activates the idler solenoid, and the machine will return to a low idle speed condition.

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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-250Location and Ventilation Safety PrecautionsStoring PRE-OPERATION Engine Service Cooling System MufflerExhaust Spark Arrester TrailerElectrical Output Connections Welding Cable ConnectionsMachine Grounding Auxiliary Power RECEPTACLES, PLUGS, and HAND-HELD EquipmentCircuit 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 tankCold Weather Starting Stopping the EngineBREAK-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 ALTERNATOR, and Protection Theory of OperationCircuits Excitation Flashing Auxiliary and Field Feedback CoilsCurrent Range Selector Interpole and Series Coils Fine Current AdjustmentEngine Idler Circuit DC Generator Machines Mechanical CouplingSA-250 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 Field Shunt Winding Test Output Problems Function Problems Function Problems Troubleshooting & Repair Problems Possible Areas Symptoms Misadjustments Course of ActionWelding Problems Test Description Alternator Rotor TestMaterials 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 holderNormal Open Circuit Voltage Waveform 115VAC 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 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

SVM128-A specifications

The Lincoln Electric SVM128-A is a cutting-edge welding machine designed to meet the demands of both professional welders and DIY enthusiasts. This versatile welding power source brings together advanced technology and robust design, making it a reliable choice for various welding applications.

One of the standout features of the SVM128-A is its capability to perform multiple welding processes. It supports MIG, TIG, and stick welding, allowing users to tackle a wide range of projects with ease. This multi-functionality makes it ideal for professionals working in different industries, as well as for hobbyists who enjoy diverse welding tasks.

The SVM128-A is equipped with inverter technology, which enhances its performance by providing a more stable arc and improved energy efficiency. This technological advancement contributes to lower operational costs and allows for a more consistent weld quality across different materials and thicknesses. Additionally, the inverter technology enables the machine to be lightweight and portable, making it convenient for jobs that require mobility.

Another prominent characteristic of the SVM128-A is its user-friendly interface. The machine features intuitive controls and a digital display that allows operators to easily set the desired welding parameters. This simplified setup helps reduce the learning curve for new users while also offering precise control for experienced professionals.

The Lincoln Electric SVM128-A is designed with durability in mind. Its robust construction ensures that it can withstand the rigors of frequent use in demanding environments. The machine is also equipped with various safety features, including thermal overload protection and a duty cycle rating that prevents overheating, ultimately extending its lifespan.

For optimal performance, the SVM128-A provides adjustable output options, allowing users to customize the welding parameters based on their specific needs. This flexibility makes it suitable for welding various metals, including steel, aluminum, and stainless steel.

In summary, the Lincoln Electric SVM128-A combines versatility, advanced technology, and a user-friendly design. With its capability to perform multiple welding processes, lightweight construction, and durable features, it stands out as an excellent option for anyone looking to achieve high-quality welds. Whether for professional or personal use, the SVM128-A is poised to deliver reliable performance and exceptional results.
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