Lincoln Electric SVM157-A Output Rectification Contactor and Control Board, Motor Control Board

Page 31

E-3

THEORY OF OPERATION

E-3

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

FIGURE E.3 – CONTROL CIRCUITS.

 

 

 

WIRE

 

 

 

GAS

 

SPEED

 

 

 

SOLENOID

 

CONTROL

 

 

 

 

 

WIRE

 

 

 

 

 

DRIVE

 

 

 

 

 

MOTOR

 

 

 

CONTROL BOARD

 

 

FAN

RECTIFIER

 

 

 

 

MOTOR

DIODE

 

 

TRANSFORMER

OUTPUT BRIDGE

 

BRIDGE

 

TACH

 

28VAC

CONTACTOR CONTROL

FEEDBACK

THERMOSTAT

THERMOSTAT

LINE

GUN TRIGGER

 

 

SWITCH

TAP SELECTOR

 

 

 

 

 

 

 

SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

OUTPUT DIODE

 

 

 

 

 

BRIDGE

 

 

 

 

 

+

+

 

 

 

 

OUTPUT

POSITIVE

 

 

 

CHOKE

 

 

 

TERMINAL

 

 

 

 

 

 

CONTACTOR

OUTPUT

 

 

 

 

 

CAPACITORS

 

 

RECONNECT

 

 

-

-

 

MAIN

 

 

NEGATIVE

PANEL

TRANSFORMER

 

 

 

 

TERMINAL

 

 

 

 

GUN

ASSEMBLY

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

OUTPUT RECTIFICATION,

CONTACTOR AND CONTROL

BOARD

The AC voltage developed on the secondary winding is applied, through the selector switch and output contactor, to the output rectifier bridge. This DC welding voltage is filtered by the output capacitors and applied to the output terminals and welding gun. Since the output choke is in series with the positive leg of the output rectifier and also in series with the gun and welding load, a filtered constant voltage output is applied to the output terminals of the machine.

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

POWER MIG 200

Page 30 Page 32
Image 31
Page 30 Page 32
Contents Safety Depends on You Power MIGCalifornia Proposition 65 Warnings SafetyARC Rays can burn Electric Shock can killIii Cylinder may explode if damagedSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Installation Section Table of ContentsTechnical Specifications Power MIG Installation3INSTALLATIONA-3 Figure A.1 Dual Voltage Machine Input Connections Figure A.2 Triple Voltage Machine Input Connections Output Polarity ConnectionsShielding GAS GUN and Cable InstallationCylinder may explode if damaged Operation Section B Operation SectionWear eye, ear and body protec- tion OperationRecommended Processes and Equipment Wire Drive RollWire Size Conversion Parts Product DescriptionWire Reel Loading READI-REELS, Spools or Coils Procedure for Changing Drive and Idle Roll SetsTo Start the Welder Idle Roll Pressure Setting Feeding Wire Electrode Making a WeldInput Line Voltage Variations Avoiding Wire Feeding ProblemsWire Feed Overload Protection FAN ControlAccessories Section Dual Cylinder Mounting KIT K1702-1 AccessoriesDrive Roll Kits K363P READI-REEL AdapterAdapter KIT and Spool GUN InstalledPower MIG Maintenance Section Maintenance Overtightening will split or collapse the liner Cause poor wire feedingLiner Removal and REPLACE- Ment This screw should only be gently tightenedEnglish Metric Description Size GUN Handle DisassemblyMaintenance Power MIG Theory of Operation Section Line SwitchTheory of Operation Motor Control Board Output Rectification Contactor and Control BoardFigure E.4 Optional Circuits Control BOARD, GUN Trigger and Wire Drive MotorThermal and Overload Protection Wirefeed Overload ProtectionPower MIG Troubleshooting and Repair Section F Troubleshooting and Repair SectionHow To Use Troubleshooting Guide Troubleshooting and RepairPC Board Troubleshooting Procedures Perform the Main Transformer Perform the Output Contactor Avoid contact with any portion These capacitors is toxicYour body Function Problems Tachometer Feedback Test Welding Problems Weld bead is narrow or ropy Make sure the welding proce Test Description Main Transformer TestMaterials Needed Main Transformer Test ON/OFF Power Switch will be hot during these testsX10 Input Voltage Test Points Table F.1. Test PointsWire Drive Motor and Tachometer Feedback Test Figure F.4. Plug J4 Test ProcedureTest for Supply Voltage to Tachometer Disconnect the main AC input power to the machineVDC Test for Feedback Voltage to Control BoardOutput Bridge Rectifier Test Output Bridge Rectifier Test Test ProcedureContactor Test Figure F.7. Contactor Terminals and Leads Contactor TestTypical Output Voltage Waveform Machine Loaded MAX TAP G Volts 10.0Normal Open Circuit Voltage Waveform MAX TAP G Volts 20.0Machine Loaded to 180 Amps AT 16 VDC Scope Settings Volts 20.0 Description Control Board ReplacementProcedure Control Board ReplacementWire Drive Motor Assembly Replacement Wire Drive Wire Drive Motor Assembly ReplacementBolt Gas Hose TOC Output Diode Bridge Rectifier Replacement Output Diode Bridge Rectifier Mounting Bracket Mounting Bolts Rectifier Power MIG Output Capacitors Replacement Figure F.14. Capacitor Bank Location Output Capacitors ReplacementLead Mounting Bolts Nuts & Lock washers Places Power MIG Main Transformer Replacement 41TROUBLESHOOTING and REPAIRF-41See Figure F.17 Main Transformer ReplacementFigure F.17. Leads X9, X10, 104B,104C, & H1B ReplacementX2 X3 X4 X5 X6 X7 Lead Power MIG FAN BLADE/MOTOR Replacement Perform the Output Capacitor Bank Removal Procedure FAN BLADE/MOTOR ReplacementOutput Contactor Replacement Figure F.24 Output Contactor ReplacementMounting Bolts Retest After Repair Table of Contents Electrical Diagrams Section Electrical DiagramsWiring Diagram Power MIG 200 208/230VSchematic Control PC Board G3851-1 PC Board ASSEMBLY-CONTROLSVM Error Reporting Form
Top Page Image Contents