Typical SCR Gate Voltage Waveform | Lincoln Electric SVM 117-A

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-26	TROUBLESHOOTING & REPAIR	F-26
	TROUBLESHOOTING & REPAIR

TYPICAL SCR GATE VOLTAGE WAVEFORM

SCOPE SETTINGS

This is a typical SCR gate pulse voltage
waveform. The machine was in an open cir-	Volts/Div	. .2 V/Div.
cuit condition (no load) and operating prop-
erly. Note that each vertical division repre-	Horizontal Sweep	.5 ms/Div.
sents 2 volts and each horizontal division
represents 5 milliseconds in time.	Coupling	. . . . .DC.
Note: Scope probes connected at Plug J3	Trigger	. .Internal.
on the control board. The (+) probe to lead
G2, and the (-) probe to lead 204.

WIRE-MATIC 250

Image 79

Lincoln Electric SVM 117-A service manual Typical SCR Gate Voltage Waveform

Contents

Safety Depends on You WIRE-MATIC ARC Welding can be hazardous Safety Cylinder may explode if damaged Iii Electric and MAG- Netic Fields Sûreté Pour Soudage a L’Arc Précautions DE Sûreté WIRE-MATIC Table of Contents Table of Contents Installation Type 750C Copper Duty Cycle Amps Volts at Rated AmpsCurrent Range Fuse Superlag Stacking Safety PrecautionsSelect Proper Location Input Connections Input Power Connections and Ground Connections Fuse and Wire Sizes Connect Shielding GAS Figure A.4 Input Air Supply Connections Reconnect Procedure Figure A.5 Reconnect Diagram For 208/230/1/60 Machines Output Polarity Connection InstallationInstall the Work Clamp Connect Output Components GUN Liner and Contact GUN and Cable Installation Wire Size Conversion Parts WIRE-MATIC Operation General Description Safety InstructionsWELDING, Cutting Recommended Processes and Equipment Design Features AdvantagesUnit Features Power Source Features Duty Cycle Amps Volts Wire Feeder FeaturesMachine Capability Limitations Figure B.1 Operator Controls Controls and Settings Procedure for Changing Drive Roll Using the Wire Drive RollLoading the Wire Reel Feeding Electrode Proper Wire FeedingTo mount 10 to 30 lb. spools 8 and 12 diameter Operating Steps Setting Idle Roll PressureStarting the Welder Making a Weld WIRE-MATIC Accessories Installing the K607-1 Spool GUN Adapter KIT OPTIONS/ACCESSORIESK607-1 Spool GUN Adapter KIT Spool GUN Module Board Installation Return Return to Section TOC Spool GUN Connection BOX Installation Spool GUN Preparation Spool GUN Connection Making the Weld Making a Weld with the Spool GUN Adapter K607-1 Installed Timer KIT K585-1 To Make Spot Plug Welds Steel Wire Sizes Part NumberAluminum Wire Sizes Drive Roll Kits Maintenance Perform the following daily Routine and Periodic Maintenance Maintenance DROP-IN Reel Spindle and Clips Contact TIP and GAS Nozzle InstallationCable Cleaning Drive Rolls and Guide Tubes GUN Tubes and Nozzles Figure D.2 Liner maintenance Liner Removal Replacement To open up the handle GUN Handle Disassembly Description English Size Metric Size WIRE-MATIC Theory of Operation Transformer Input Line Voltage and Main Feedback Control Output Rectification Figure E.4 Constant Voltage Output Constant Voltage Output Feedback Wire Drive Motor Thermal Protection Figure E.6 SCR Operation SCR Operation WIRE-MATIC Troubleshooting & Repair Recommended Course of Action HOW to USE Troubleshooting Guide Electric Shock can kill PC Board Troubleshooting ProceduresBoard can be dam- aged by static electricity Main Transformer Rectifier Assembly Test To Section TOC Perform the SCR Rectifier Perform the Wire Drive Motor Trolyte in these capacitors is Liquid elec Perform the Output Rectifier Test Description Main Transformer TestMaterials Needed ON/OFF Power Switch will be hot during these tests Main Transformer Test Test Procedure Main Transformer Test 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 Circuit Wire 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 Tachometer Normal Open Circuit Voltage Waveform Scope Settings Typical Output Voltage Waveform Machine Loaded Machine Loaded to 250 Amps AT 26 VDC Scope Settings Machine 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 ReplacementMaterials Needed Removal and REPLACE- Ment Procedure Wire Drive Assembly Removal and Replacement Figure F.11 Wire Drive Assembly Removal Wire Drive Assembly Removal and Replacement Procedure SCR Output Rectifier Removal & Replacement Disconnection Heat Sink Lead Right side heat sink See Figure F.14 Capacitor Bank Removal and Replacement Components Bank Removal Replacement Main 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 Procedure Troubleshooting & Repair 230/60 375 Wire Speed RangeOpen Circuit Voltage Input Volts/Hertz WIRE-MATIC Table of Contents Electrical Diagrams Section WIRE-MATIC Electrical Diagrams Spool GUN Option Wiring Diagram 208/230 Code To Section Available from Lincoln Control PC Board G2332 Layout