Lincoln Electric SVM 122-A service manual Troubleshooting & Repair

Page 81

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F-37

F-37

TROUBLESHOOTING & REPAIR

TYPICAL OUTPUT VOLTAGE WAVEFORM – MACHINE LOADED

CONSTANT VOLTAGE SUBARC MODE

CH1

0 volts

20 volts

5 ms

This is the typical DC open circuit voltage waveform generated from a properly operating machine. Note that each vertical division represents 20 volts and that each horizontal divi- sion represents 5 milliseconds in time. The machine was loaded with a resistance grid bank. The DC-400 meters read 400 amps at 36 VDC.

Note: Scope probes connected at

machine output terminals: (+) probe to positive terminal, (-) probe to neg- ative terminal.

SCOPE SETTINGS

Volts/Div

20V/Div.

Horizontal Sweep

5 ms/Div.

Coupling

DC

Trigger

Internal

 

 

IDEALARC DC-400

LINCOLN ®

ELECTRIC

Image 81
Contents Idealarc TMDC-400 Safety Depends on YouCalifornia Proposition 65 Warnings SafetyElectric Shock can kill Cylinder may explode if damaged Précautions DE Sûreté Master Table of Contents for ALL Sections Table of Contents Installation Section Technical Specifications Idealarc DC-400 InstallationSelect Suitable Location Safety PrecautionsLifting TiltingGround Connection Input ConnectionsInput Supply Connections Electric Shock can killFigure A.3 Input Power Supply Connections Input Wire and Fuse SizeInput Supply Connection Diagram Reconnect ProcedureFigure A.6 Output Terminal Connections Output ConnectionsWire Feeder Connections Cycle 500 Amp 50% DutyCycle Operation Section Safety Instructions OPERATIONB-2Operating Instructions General Description OperationFigure B.1 Case Front Controls Controls and SettingsOperation Welding Procedure Recommendations Remote ControlWelding Operation Operating StepsARC Striking with the NA-3 Start Board NA-3 Automatic Wire FeederLN-8 Semiautomatic Wire Feeder NA-5 Automative Wire FeederOverload Protection Auxiliary PowerTable of Contents Accessories Factory Installed Option OPTIONS/ACCESSORIESField Installed Options Diode OptionConnections Multiprocess Switch OperationK843 Amptrol Adapter Installation Instructions Remote Control Adapter Cable K864Remote Output Control K857 with K864 Adapter Plug or K775 Amptrol Adapter Cable K843Amptrol and Hi-Freq. Kit The Amptrol will start K843 Amptrol Adapter Installation InstructionsConnecting the NA-3 to the Idealarc DC-400 Terminal Strip Automatic Wire FeedersCapacitor Discharge Circuit K828-1 HI-FREQ KIT K799 for Codes 8634 and Above onlyConnecting the NA-5 to the Idealarc DC-400 Terminal Strip To NA-3 or NA-5 Input Cable Plug K597-XX Input Cable Assembly Idealarc DC-400Connecting the LN-7 to the Idealarc DC-400 14-PIN Amphenol Semiautomatic Wire FeedersConnecting the LN-7 to the Idealarc DC-400 Terminal Strip Accessories Accessories Figure C.11 Idealarc DC-400/LN-742 Connection Diagram Table of Contents Maintenance Routine and Periodic Maintenance Figure D.1 General Component Locations Table of Contents Theory of Operation Section Input Line Voltage Theory of OperationContactor and Main TransformerOutput Mode and CONTROL, Rectification and Feedback Protective Devices and Circuits Figure E.4 SCR Operation SCR OperationTable of Contents Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & RepairPC Board can be damaged by static electricity PC Board Troubleshooting ProceduresOutput Problems Troubleshooting GuidePerform the Main Transformer Rectifier Bridge Test Tifier Bridge Test Output Problems Test Perform the SCR/Diode Rec Tifier Bridge Test Function Problems Form the SCR/Diode Rectifier Welding Problems Portion of your body. Clean Trolyte in these capacitors isToxic. Avoid contact with any Make sure welding process is Input Contactor Test DescriptionMaterials Needed Input Contactor Test Test ProcedureFigure F.2 Input Contactor Test Connections Test for Contact ContinuityControl Transformer T2 Voltage Test Figure F.3 Control Transformer and Lead Locations Control Transformer T2 Voltage TestTroubleshooting & Repair Main Transformer T1 Voltage Test Main Transformer T1 Voltage Test Figure F.6 Main Secondary Lead Test Points Troubleshooting & Repair Figure F.8 Control Board Plug P1 Location Plug P1 Phase Angle Winding VoltagesStatic SCR/DIODE Rectifier Bridge Test Figure F.9 Control Board and Snubber Board Plug Locations Static SCR/DIODE Rectifier Bridge TestSCR Test Active SCR Test P1 and P3 Locations Plug P5 Location Active SCR TestFigure F.15 Heat Sink Test Points Figure F.16 SCR Tester Circuit and SCR Connections CH1 Scope SettingsMaximum Output Setting no Load Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair 2V/Div Troubleshooting & Repair Input Contactor CR1 CLEANING/REPLACEMENT Input Contactor CR1 CLEANING/REPLACEMENT Cleaning ProcedureContactor Replacement Procedure FAN Motor and Blade Removal and Replacement Procedure FAN Motor and Blade Removal and ReplacementSCR/DIODE Rectifier Assembly Removal and Replacement Removal and Replacement SCR/DIODE Rectificer AssemblySCR Removal and Replacement Special Instructions SCR Removal and ReplacementFigure F.21 1/2 Wide Leaf Spring Procedure for the 1/2 Inch Wide SpringClamping Procedure For 1/4-20 CAP Screws Clamping Procedure For 1/4-28 CAP ScrewsInch Wide Spring Procedure forAfter Replacing the SCRs Mounting of Stud Type Diodes to Aluminum Heat Sinks Mounting of Stud Type Diodes to Aluminum Heat SinksDiode Stud Foot Inch Size Pounds Main Transformer Removal and Replacement Removal of Lift Bail Main Transformer Removal & ReplacementFigure F.26 Choke Removal Removal of Choke and TOP Iron AssemblyFigure F.27 Epoxy MIX Application Areas Reassembly of Transformer CoilsFigure F.28 Coil Lead Placement Figure F.30 Primary Thermostat Location Reassemble the Lift Bail Reassembling the Main Transformer Into the MachineMode Input Hertz Open Circuit Volts Input volts/Phase/Hertz Maximum Idle Amps Maximum Idle KWRetest After Repair Input Idle Amps and WattsMaximum Acceptable Output Voltage AT Minimum Ouput Settings Mode Control Settings LoadRetest After Repair Table of Contents Electrical Diagrams Section Idealarc DC400 LOW Voltage Wiring Diagram Codes 9847Only. It may not be accurate for all Wiring Diagram CodeControl DC400 Control PC Board G2588 LayoutTP2 Starting PC Board M14520 LayoutSnubber PC Board M15370 Layout 2586 Control PC Board G2588 SchematicGeneral Information Starting PC Board M14520 SchematicGeneral Information Snubber PC Board M15370 Schematic