Lincoln Electric SVM 119-A Right side heat sink See Figure F.14, Disconnection Heat Sink Lead

Page 83

 

 

F-32

TROUBLESHOOTING & REPAIR

F-32

 

 

 

 

TOC

TOC

SCR OUTPUT RECTIFIER REMOVAL & REPLACEMENT (CONTINUED)

 

 

 

 

Section

Master

PROCEDURE

4. Cut the SCR gate leads G1 and G2

 

 

 

 

 

(see wire markers and wiring dia-

 

to

to

1.

Disconnect lead #208 and

gram) using wire cutters.

 

 

 

 

 

 

 

Return

Return

 

Transformer Lead X1 from the heat

leads is from the right side of the

 

 

(facing the front) using a 1/2" socket

 

 

 

 

sink on the left side of the machine

a. The easiest access to these

 

 

 

 

 

 

 

 

 

wrench. See Figure F.12.

machine.

 

 

 

 

 

 

 

 

 

a. Thin lead is always on the out-

b. Cut any necessary cable ties.

 

 

 

 

 

 

 

 

 

board side of the connection.

 

 

 

 

 

5. Remove the four screws holding the

 

 

 

SCR Assembly to the floor of the

 

 

 

machine using a 5/16" nut driver.

TOC

TOC

 

6. Pivot the SCR Assembly counter-

 

clockwise to provide access to the

SectiontoReturn

MastertoReturn

 

right side heat sink.

 

 

 

 

 

 

 

 

 

 

See Figure F.14.

 

 

 

 

FIGURE F.12 - Heat Sink lead discon-

 

 

 

 

 

 

 

 

nection.

 

 

 

 

 

 

 

 

2. Disconnect lead #204 and heavy

 

 

 

 

 

 

TOC

 

lead from the middle heat sink with a

 

 

 

 

 

 

TOC

1/2" socket wrench and 1/2" open

 

 

 

 

 

 

end wrench. See Figure F.13.

 

 

 

 

 

 

Section

Master

negative capacitor band buss bar on

Disconnection

-

Heat

Sink

Lead

 

 

3. Remove the diode lead from the

FIGURE

F.14

 

 

 

 

 

 

 

 

to

to

the right side of the machine using a

7. Remove lead #209 and Transformer

Return

Return

slot head screwdriver and 3/8" open

Lead X4 from the right side heat sink

 

 

 

 

end wrench.

 

 

using a 1/2" socket wrench and 1/2"

 

 

 

 

 

 

open end wrench.

 

 

 

 

 

8. Clear the leads and carefully

 

 

 

remove the SCR Rectifier Assembly.

 

 

 

NOTE: When installing the SCR

 

 

 

Rectifier Assembly, apply a thin coating

TOCSectionto

TOCMasterto

 

of Dow Corning #340 Compound to the

 

electrical connections.

 

 

 

 

 

 

 

Return

Return

FIGURE F.13 - Heat Sink lead discon-

 

 

 

 

 

 

nection.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WIRE-MATIC 255

 

 

 

 

 

Image 83
Contents Safety Depends on You WIRE-MATICFumes and Gases can be dangerous SafetyElectric Shock can kill ARC Rays can burnWelding Sparks can cause fire or explosion Cylinder may explode if damagedIii Electric and MAG- Netic FieldsMay be dangerous Sûreté Pour Soudage a L’Arc Précautions DE SûretéWIRE-MATIC Table of Contents Table of Contents Table of Contents Installation Section InstallationTechnical Specifications Wire-Matic-255 Stacking Safety PrecautionsSelect Proper Location Input ConnectionsFuse and Wire Sizes Connect Shielding GAS Figure A.4 Input Gas Supply Connections Reconnect ProcedureFigure A.5 Reconnect Diagram For 208/230/1/60 Machines Connections Connect Output ComponentsGUN and Cable Installation Wire Size Conversion PartsWIRE-MATIC Operation Table of Contents Operation SectionWELDING, Cutting Safety InstructionsGeneral Description Recommended Processes and Equipment Design Features AdvantagesDuty Cycle Amps Volts Machine CapabilityLimitations Figure B.1 Operator Controls Controls and SettingsFigure B.2 Wire Reel Loading Using the Wire Drive RollFeeding Electrode Operating Steps Setting Idle Roll PressureMaking a Weld WIRE-MATIC Table of Contents Accessories Section AccessoriesK672-1 Spool GUN Adapter KIT OPTIONS/ACCESSORIESMagnum GUN Connection KIT Optional K466-6 Making a Weld with the Spool GUN Adapter K672-1 Installed Timer KIT Installation Optional K585-1 Timer KIT K585-1K363P READI-REEL Adapter Drive Roll Kits64 1.2mm Aluminum Feeding KIT K673-1 K468 8 Spool AdapterDual Cylinder Mounting KIT K671-1 Table of Contents Maintenance Section MaintenancePerform the following daily Routine and Periodic MaintenanceMaintenance GUN Tubes and Nozzles Cable CleaningContact TIP and GAS Nozzle Installation Drive Rolls and Guide TubesFigure D.2 Liner maintenance Liner Removal ReplacementTo open up the handle GUN Handle DisassemblyDescription English Size Metric Size WIRE-MATIC Theory of Operation Table of Contents Theory of Operation SectionTransformer Input Line Voltage and MainFeedback Control Output RectificationFigure E.4 Constant Voltage Output Constant Voltage OutputFeedback Wire Drive MotorThermal Protection Figure E.6 SCR Operation SCR OperationWIRE-MATIC Table of Contents Troubleshooting & Repair Section Troubleshooting & RepairRecommended Course of Action HOW to USE Troubleshooting GuideBoard can be dam- aged by static electricity PC Board Troubleshooting ProceduresElectric Shock can kill Main Transformer Rectifier Assembly Test To Section TOC SCR Rectifier Perform the Wire Drive Motor Trolyte in these capacitors is Liquid elecPerform the Output Rectifier Materials Needed Main Transformer TestTest Description ON/OFF Power Switch will be hot during these tests Main Transformer Test Test ProcedureLead Plug Location Static SCR Rectifier Assembly Test Leads Figure F.4 SCR 1 Test Points Active SCR Rectifier Assembly Test Leads SCR connections Figure F.7 SCR Tester CircuitWire Drive Motor and Tachometer Feedback Test Wire Drive Motor and Tachometer Feedback Test Test Procedure Test for Feedback Voltage to the Control Board Test for Supply Voltage to TachometerNormal Open Circuit Voltage Waveform Scope SettingsTypical Output Voltage Waveform Machine Loaded Machine Loaded to 250 Amps AT 26 VDC Scope SettingsMachine Loaded to 220 Amps AT 22 VDC Scope Settings Troubleshooting & Repair Typical SCR Gate Voltage Waveform Removal and Replacement Procedure Control PC Board Removal and ReplacementRemoval and REPLACE- Ment Procedure Wire Drive Assembly Removal and Replacement Figure F.11 Wire Drive Assembly Removal ProcedureSCR Output Rectifier Removal & Replacement Disconnection Heat Sink Lead Right side heat sink See Figure F.14Capacitor Bank Removal and Replacement Components Bank Removal ReplacementMain Transformer Removal and Replacement Power Switch FAN Motor and FAN Removal and Replacement Figure F.16 Fan Motor and Fan Removal Components FAN Motor and FAN Removal and Replacement ProcedureTroubleshooting & Repair 230/60 375 Wire Speed RangeOpen Circuit Voltage Input Volts/HertzWIRE-MATIC Table of Contents Electrical Diagrams Section WIRE-MATIC Wiring Diagram 208/230 Code Electrical DiagramsWiring Diagram 230/460/575 Code Wire Matic 255 230 / 460Control PC Board G2803 Schematic Control PC Board G2803 Layout Wirematic 255 Control