3THEORY of Operation | Lincoln Electric SP-100 guide

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E-3THEORY OF OPERATION

FIGURE E.3 – Trigger, Gas Solenoid and Wire Drive

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TRIGGER, GAS SOLENOID AND WIRE DRIVE

Closure of the trigger circuit (pulling the gun trigger) signals the control board to start several functions. 115 vac is applied to the gas solenoid to allow shielding gas to flow. The SCRs are activated and voltage is applied to the main transformer. Output volt- age is developed at the output terminals and fed back to the control board. This welding output voltage is also used to power the wire drive motor.

The welding output voltage that powers the wire drive motor is varied and controlled on the control board. The control board moni- tors the drive motor armature current and voltage and compares the feedback infor- mation with the commands sent from the wire speed control. The control board varies and controls power to the drive motor, which, in turn, controls the speed of the wire drive. The SP-100 also has an automatic protection circuit which protects the wire drive motor from excessive motor over- loads.

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NOTE: Unshaded areas of block logic diagram are the subject of discussion.

SP-100

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Lincoln Electric SP-100 service manual 3THEORY of Operation, TRIGGER, GAS Solenoid and Wire Drive

Contents

SP-100 ARC Rays can burn SafetyElectric Shock can kill Fumes and Gases can be dangerous Cylinder may explode if damaged Welding Sparks can cause fire or explosion Electric and Magnetic Fields May be dangerous Précautions DE Sûreté Sûreté Pour Soudage a L’Arc Master Table of Contents for ALL Sections Table of Contents Installation Section Installation Technical Specifications SP-100 Installation Safety PrecautionsRead entire installation section before starting Identify and Locate Components Output Connections Work Clamp InstallationSelect Suitable Location Tilting Connecting GUN Cable to the SP-100 GUN InstallationGAS Connection Gas Solenoid Inlet Fitting PowerInput Connections Input Requirements for CSA Rated Output Code Requirements for Input ConnectionsRequirements for Maximum Output Requirements for Rated Output SP-100 Table of Contents Operation Wear eye, ear and body protec- tion General Description Operational Features and ControlsDesign Features Advantages Off Process Guidelines Wire LoadingWelding Operations Sequence of Operation Friction Brake Adjustments Refer to Figure B-4 Shielding GAS Making a Weld Overload Protection SP-100 Accessories Section Lincoln GAS Regulator Kits K467 Input Line Cord 1ACCESSORIESReplacement Parts Innershield Welding Kits Maintenance Section Items Requiring no Maintenance MaintenanceRoutine and Periodic Maintenance Changing Drive Roll Changing the Contact TIPLiner trim length for the Magnum 100L gun red trigger Figure D.3 SP-100 SUB Assemblies SP-100 Theory of Operation Figure E.1 Input Power Circuits Input Line VOLTAGE, FAN Motor and Main Transformer Output CONTROL, RECTIFICA- Tion and Voltage Feedback Figure E.2 Output Circuits TRIGGER, GAS Solenoid and Wire Drive 3THEORY of Operation SCR Operation Figure E.4 SCR Operation Thermostat protects the machine from Troubleshooting Section Oscilloscope Waveforms 1TROUBLESHOOTING & Repair HOW to USE Troubleshooting Guide Troubleshooting & Repair PC Board Troubleshooting Procedures Authorized Field Service Troubleshooting GuideFacility Below Code 9794 only Recommended Course of Action Problems SymptomsPossible Areas of Misadjustments Code 9794 and Above Feeding Problems Troubleshooting Guide PC Board Connector Locations Codes 9794 and above 6J1 10J2 1J1 1J2 Codes below SP-100 Volts Volts/Div 9TROUBLESHOOTING & RepairScope Settings Normal Open Circuit Voltage Waveform Volts Typical Output Voltage Waveform Machine Loaded Abnormal Open Circuit Voltage Waveform FAN Blade and Motor Removal Procedure DescriptionProcedure Tools Required 1A. for Codes Above Wire Drive Assembly RemovalMotor Removal Procedure 1B. for Codes below Main Transformer Secondary Voltages Test Points Wire Speed RangeRetest After Repair Input Amps AT Rated Output Input Amps AC @ Output DC SP-100 Electrical Diagrams Section Wiring Wiring DiagramsDiagram SP-100 Wiring Diagram Codes Below 4 5 1 M Electrical Diagrams Electrical Diagrams Control P.C. Board G1842 Control P.C. Board G2314 Control P.C. Board G2314 SCR1, SCR2 SCR 81 Heatsink Asbly Machine Schematic Codes 9794 and Above Error Machine Schematic Codes Below 86R R63R64 1 5 K SVM Error Reporting Form