Troubleshooting & Repair | Lincoln Electric SVM 122-A specs

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

F-39

F-39

TROUBLESHOOTING & REPAIR

ABNORMAL OPEN CIRCUIT VOLTAGE WAVEFORM

CONSTANT VOLTAGE SUBARC

ONE OUTPUT SCR NOT FUNCTIONING

CH1

0 volts

20 volts

5 ms

This is NOT the typical DC output voltage waveform. One output SCR is not functioning. Note the “gap” in the waveform. One SCR gate is dis- connected to simulate an open or non-functioning output SCR. Each vertical division represents 20 volts and each horizontal division repre- sents 5 milliseconds in time.

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 83

Lincoln Electric SVM 122-A service manual Troubleshooting & Repair

Contents

Idealarc TMDC-400 Safety Depends on You California Proposition 65 Warnings Safety Electric 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 Installation Tilting Safety PrecautionsSelect Suitable Location Lifting Electric Shock can kill Input ConnectionsGround Connection Input Supply Connections Figure A.3 Input Power Supply Connections Input Wire and Fuse Size Input Supply Connection Diagram Reconnect Procedure Figure A.6 Output Terminal Connections Output Connections Cycle Wire Feeder ConnectionsCycle 500 Amp 50% Duty Operation Section Operating Instructions Safety InstructionsOPERATIONB-2 General Description Operation Figure B.1 Case Front Controls Controls and Settings Operation Operating Steps Remote ControlWelding Procedure Recommendations Welding Operation ARC Striking with the NA-3 Start Board NA-3 Automatic Wire Feeder LN-8 Semiautomatic Wire Feeder NA-5 Automative Wire Feeder Overload Protection Auxiliary Power Table of Contents Accessories Diode Option OPTIONS/ACCESSORIESFactory Installed Option Field Installed Options Connections Multiprocess Switch Operation Amptrol Adapter Cable K843 Remote Control Adapter Cable K864K843 Amptrol Adapter Installation Instructions Remote Output Control K857 with K864 Adapter Plug or K775 Amptrol and Hi-Freq. Kit The Amptrol will start K843 Amptrol Adapter Installation Instructions HI-FREQ KIT K799 for Codes 8634 and Above only Automatic Wire FeedersConnecting the NA-3 to the Idealarc DC-400 Terminal Strip Capacitor Discharge Circuit K828-1 Connecting 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-400 Connecting the LN-7 to the Idealarc DC-400 14-PIN Amphenol Semiautomatic Wire Feeders Connecting 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 Transformer Theory of OperationInput Line Voltage Contactor and Main Output Mode and CONTROL, Rectification and Feedback Protective Devices and Circuits Figure E.4 SCR Operation SCR Operation Table of Contents Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & Repair PC Board can be damaged by static electricity PC Board Troubleshooting Procedures Output Problems Troubleshooting Guide Perform 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 Toxic. Avoid contact with any Portion of your body. CleanTrolyte in these capacitors is Make sure welding process is Materials Needed Input Contactor TestDescription Input Contactor Test Test Procedure Figure F.2 Input Contactor Test Connections Test for Contact Continuity Control Transformer T2 Voltage Test Figure F.3 Control Transformer and Lead Locations Control Transformer T2 Voltage Test Troubleshooting & 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 Voltages Static SCR/DIODE Rectifier Bridge Test Figure F.9 Control Board and Snubber Board Plug Locations Static SCR/DIODE Rectifier Bridge Test SCR Test Active SCR Test P1 and P3 Locations Plug P5 Location Active SCR Test Figure F.15 Heat Sink Test Points Figure F.16 SCR Tester Circuit and SCR Connections CH1 Scope Settings Maximum Output Setting no Load Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair 2V/Div Troubleshooting & Repair Input Contactor CR1 CLEANING/REPLACEMENT Contactor Replacement Procedure Input Contactor CR1 CLEANING/REPLACEMENTCleaning Procedure FAN Motor and Blade Removal and Replacement Procedure FAN Motor and Blade Removal and Replacement SCR/DIODE Rectifier Assembly Removal and Replacement Removal and Replacement SCR/DIODE Rectificer Assembly SCR Removal and Replacement Special Instructions SCR Removal and Replacement Figure F.21 1/2 Wide Leaf Spring Procedure for the 1/2 Inch Wide Spring Clamping Procedure For 1/4-20 CAP Screws Clamping Procedure For 1/4-28 CAP Screws Inch Wide Spring Procedure for After Replacing the SCRs Mounting of Stud Type Diodes to Aluminum Heat Sinks Diode Stud Foot Inch Size Pounds Mounting of Stud Type Diodes to AluminumHeat Sinks Main Transformer Removal and Replacement Removal of Lift Bail Main Transformer Removal & Replacement Figure F.26 Choke Removal Removal of Choke and TOP Iron Assembly Figure F.27 Epoxy MIX Application Areas Reassembly of Transformer Coils Figure F.28 Coil Lead Placement Figure F.30 Primary Thermostat Location Reassemble the Lift Bail Reassembling the Main Transformer Into the Machine Input Idle Amps and Watts Input volts/Phase/Hertz Maximum Idle Amps Maximum Idle KWMode Input Hertz Open Circuit Volts Retest After Repair Retest After Repair Maximum Acceptable Output Voltage AT Minimum Ouput SettingsMode Control Settings Load Table of Contents Electrical Diagrams Section Idealarc DC400 LOW Voltage Wiring Diagram Codes 9847 Only. It may not be accurate for all Wiring Diagram Code Control DC400 Control PC Board G2588 Layout TP2 Starting PC Board M14520 Layout Snubber PC Board M15370 Layout 2586 Control PC Board G2588 Schematic General Information Starting PC Board M14520 Schematic General Information Snubber PC Board M15370 Schematic