Lincoln Electric SVM157-A service manual Control BOARD, GUN Trigger and Wire Drive Motor

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E-4

THEORY OF OPERATION

E-4

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FIGURE E.4 – OPTIONAL 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

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CONTROL BOARD, GUN

TRIGGER AND WIRE DRIVE

MOTOR

When the control board receives an activation command from the trigger circuit the control board activates the gas solenoid, output contactor, and the wire drive motor. The control board monitors the motor’s tach feedback signals and compares these to the wire speed control setting. The proper armature voltage is then applied to the wire drive motor. The drive motor speed is thus controlled which in turn regulates the electrode wire feed speed through the gun.

Two thermostats are included in the trigger circuitry. If either of these thermostats would “open”, the trigger circuit would be interrupted and the machine’s output would be disabled.

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

POWER MIG 200

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Contents Power MIG Safety Depends on YouSafety California Proposition 65 WarningsElectric Shock can kill ARC Rays can burnCylinder may explode if damaged IiiPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcMaster Table of Contents for ALL Sections Table of Contents Installation SectionInstallation Technical Specifications Power MIG3INSTALLATIONA-3 Figure A.1 Dual Voltage Machine Input Connections Output Polarity Connections Figure A.2 Triple Voltage Machine Input ConnectionsCylinder may explode if damaged GUN and Cable InstallationShielding GAS Operation Section Operation Section BOperation Wear eye, ear and body protec- tionWire Drive Roll Wire Size Conversion PartsProduct Description Recommended Processes and EquipmentTo Start the Welder Procedure for Changing Drive and Idle Roll SetsWire Reel Loading READI-REELS, Spools or Coils Feeding Wire Electrode Making a Weld Idle Roll Pressure SettingAvoiding Wire Feeding Problems Wire Feed Overload ProtectionFAN Control Input Line Voltage VariationsAccessories Section Accessories Drive Roll KitsK363P READI-REEL Adapter Dual Cylinder Mounting KIT K1702-1Installed Adapter KIT and Spool GUNPower MIG Maintenance Section Maintenance Cause poor wire feeding Liner Removal and REPLACE- MentThis screw should only be gently tightened Overtightening will split or collapse the linerGUN Handle Disassembly English Metric Description SizeMaintenance Power MIG Line Switch Theory of Operation SectionTheory of Operation Output Rectification Contactor and Control Board Motor Control BoardControl BOARD, GUN Trigger and Wire Drive Motor Figure E.4 Optional CircuitsWirefeed Overload Protection Thermal and Overload ProtectionPower MIG Troubleshooting and Repair Section Troubleshooting and Repair Section FTroubleshooting and Repair How To Use Troubleshooting GuidePC Board Troubleshooting Procedures Perform the Main Transformer Perform the Output Contactor Your body These capacitors is toxicAvoid contact with any portion Function Problems Tachometer Feedback Test Welding Problems Weld bead is narrow or ropy Make sure the welding proce Materials Needed Main Transformer TestTest Description ON/OFF Power Switch will be hot during these tests Main Transformer TestX10 Table F.1. Test Points Input Voltage Test PointsWire Drive Motor and Tachometer Feedback Test Test Procedure Figure F.4. Plug J4Disconnect the main AC input power to the machine Test for Supply Voltage to TachometerTest for Feedback Voltage to Control Board VDCOutput Bridge Rectifier Test Test Procedure Output Bridge Rectifier TestContactor Test Contactor Test Figure F.7. Contactor Terminals and LeadsVolts 10.0 Typical Output Voltage Waveform Machine Loaded MAX TAP GVolts 20.0 Normal Open Circuit Voltage Waveform MAX TAP GMachine Loaded to 180 Amps AT 16 VDC Scope Settings Volts 20.0 Control Board Replacement DescriptionControl Board Replacement ProcedureWire Drive Motor Assembly Replacement Wire Drive Motor Assembly Replacement Wire DriveBolt Gas Hose TOC Output Diode Bridge Rectifier Replacement Output Diode Bridge Rectifier Mounting Bracket Mounting Bolts Rectifier Power MIG Output Capacitors Replacement Output Capacitors Replacement Figure F.14. Capacitor Bank LocationLead Mounting Bolts Nuts & Lock washers Places Power MIG 41TROUBLESHOOTING and REPAIRF-41 Main Transformer ReplacementMain Transformer Replacement See Figure F.17Replacement Figure F.17. Leads X9, X10, 104B,104C, & H1BX2 X3 X4 X5 X6 X7 Lead Power MIG FAN BLADE/MOTOR Replacement FAN BLADE/MOTOR Replacement Perform the Output Capacitor Bank Removal ProcedureOutput Contactor Replacement Output Contactor Replacement Figure F.24Mounting Bolts Retest After Repair Electrical Diagrams Table of Contents Electrical Diagrams SectionPower MIG 200 208/230V Wiring DiagramSchematic Control PC Board PC Board ASSEMBLY-CONTROL G3851-1SVM Error Reporting Form
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