Perform the SCR Bridge Test | Lincoln Electric SVM162-B guide

PRECISION TIG 275

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F-8		TROUBLESHOOTING & REPAIR				F-8
	Observe Safety Guidelines			TROUBLESHOOTING GUIDE
	detailed in the beginning of this manual.
	PROBLEMS		POSSIBLE AREAS OF	RECOMMENDED
	(SYMPTOMS)		MISADJUSTMENT(S)	COURSE OF ACTION
			OUTPUT PROBLEMS		Perform the SCR Bridge Test.
	The machine welds at a very high		1. If welding in the TIG mode, the	1.	Perform the SCR Bridge Test.
	output regardless of the current		remote control device may be	2.	Perform the T1 Transformer
	control setting.		defective.	3.	Test.
	NOTE: BEFORE REPLACING A			3.	Check the output current con-
	NOTE: BEFORE REPLACING A				trols for proper	operation.
	CONTROL BOARD				Normal resistance	is 10,000
	If an Advanced Control Panel is			4.	ohms. See the Wiring Diagram.
	installed, remove it and replace			4.	Check leads #221 and #222
	the Jumper in connector J-3. If				between the output shunt and
	the machine functions normally,				the control board.	See the
	the Advanced Process panel or				Wiring Diagram.
	harness is defective.			5. The control board may be faulty

Accessories plugged into the volt 1. Make sure		the accessory plug	1.	The circuit breaker (CB1) may be
receptacle do not work.	and associated leads are in good		2.	faulty.
2.	working condition.			Check the receptacle and asso-
	Make certain the correct input			ciated leads for loose or faulty
	voltage is being applied to the		3.	connections.
	machine.	(The reconnect lead		Perform the T1 Transformer
3.	must be in the correct position.)			Test.
	The circuit breaker CB1 may be
4.	tripped. Reset if necessary.
	Only the top part of the recepta-
	cle is electronically “Hot” all of
	the time.

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CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con- tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.

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Lincoln Electric SVM162-B service manual Perform the SCR Bridge Test

Contents

Safety Depends on You Precision TIG For Engine SafetyPowered equipment Mar ʻ95 ARC Rays can burn Fumes and GasesAug ʻ06 Welding Sparks can Cylinder may explode If damagedIii LES Machines À Souder À Précautions DE SûretéPrécautions DE Sûreté Pour Transformateur ET À Master Table of Contents for ALL Sections Table of Contents Installation Section Unbalance 70% Penetration AC TIG 15.4 200 100% 28.0 InstallationUnbalance 70% Penetration AC TIG 16.1 255 60% 29.0 225 Unbalance 70% Penetration AC TIG 14.8 150 Output Current Maximum Open Safety Precautions ProtectionSelect Suitable Location Before working on this equip Turn the input power OFF atDisconnect switch or fuse box Ment Work Cable Connection Figure A.2 Auxiliary Power Connections Figure A.3 Robotic Interface Connection Figure A.4 Return to Section TOC Table of Contents Operation Section Operation Product DescriptionPipe Thawing Recommended Processes Equipment Stick mode the Electrode circuits Controls and SettingsWhen the Power Source is on Both the Stick and TIG torch cables AC Balance Ontrol Maximum Output Control The large knob Operation for Codes Above 11000 only Menu Button and Display Switch CodesTIG Mode Menu Select Advanced Panel Controls Gure B.3 Pulse Frequency Control Time Control PULSE% onPulse Background Current Control Internal SET UP Controls TIG Welding FeaturesStick Welding Features Step Trigger Modes Figure B.4 TIG Weld Cycle Chart Codes below 11000 K1829-1 Setup Guidelines for TIG Welding With AN Amptrol Figure B.6 Smaw Process Making a TIG Weld with AN AmptrolRecommended Electrode Amperage Ranges Precision TIG Gtaw Process Table of Contents Accessories for Codes below Optional EquipmentMagnum PTA and PTW Series Torches Accessories for Codes Above Return to Section TOC Maintenance Component Location and Access Safety Precautions Overload Protection Service Procedures Spark GAP AdjustmentUNDER-COOLER Service Warni Table of Contents Theory of Operation Section Input Power Circuit Theory of OperationGeneral Description Output Rectification Control board also monitors the thermostatsSee SCR Operation High VOLTAGE/HIGH Frequency Circuit Figure E.4 High Voltage / High Frequency Circuit DC Welding Output Figure E.5 DC Welding Output AC Welding Output Figure E.7 AC Welding Output SCR Operation Figure E.9 SCR Operation FAN-AS-NEEDED F.A.N 8THEORY of OPERATIONE-8Protection Circuits Thermal Protection Table of Contents Troubleshooting & Repair Section 2TROUBLESHOOTING & REPAIRF-2 HOW to USE Troubleshooting Guide Troubleshooting & Repair Reconnect Troubleshooting GuideProcedure Test Control Board TransformerSCR Bridge Test Perform the Protection Board Installed, remove it and replaceMachine functions normally T1 Transformer See Note below Protection BoardPerform the T1 Transformer Perform the SCR Bridge Test Perform the SCR Bridge Tests Est Perform the Gas Solenoid Test Maintenance Electric ShockCan Kill Maintenance Section High frequency transformer See the Maintenance Secti Problems Possible AreasSymptoms Misadjustments Course of Action To Technical Specifications Stick Welding Problems Stick electrode blasts-off Welding current may be too high Function Problems Installation Manual Be plugged into J3 Display switch may be faulty Precision TIG Voltmeter/Ohmmeter Nut Driver Wiring Diagram 19TROUBLESHOOTING & REPAIRF-19Meter Calibration Adjustments Description 20TROUBLESHOOTING & REPAIRF-20 Meter Calibration AdjustmentsCalibration Check 21TROUBLESHOOTING & REPAIRF-21 Ammeter Calibration ProcedureControl board. See Figure F1 Return to Section TOC 23TROUBLESHOOTING & REPAIRF-23 High Frequency Circuit Disable ProcedureNut Driver Electrical Insulating Tape 24TROUBLESHOOTING & REPAIRF-24 High Frequency Circuit Disable ProcedureProcedure 25TROUBLESHOOTING & REPAIRF-25 Protection Board TestTest Description Protection Board Test Resistance Between Reading 27TROUBLESHOOTING & REPAIRF-27 T1 Main Transformer Test 28TROUBLESHOOTING & REPAIRF-28 Test ProceduresT1 Main Transformer Test Test Points Acceptable Voltages Primary Windings Return to Section TOC 31TROUBLESHOOTING & REPAIRF-31 GAS Water Solenoid Test GAS Water Solenoid Test Test ProcedureDisable Procedure Perform the High Frequency Circuit 33TROUBLESHOOTING & REPAIRF-33 Static SCR Test Assembly. See SCR Bridge Assembly 34TROUBLESHOOTING & REPAIRF-34Removal and Replacement Static SCR Test Service and repair Active SCR Test 36TROUBLESHOOTING & REPAIRF-36 Active SCR Test Active SCR Test Figure F.9 SCR Gate Locations Scope Settings 39TROUBLESHOOTING & REPAIRF-39DC TIG Mode Typical Output Voltage Waveform Machine Loaded to 2 Amps Milliseconds in time. The machine 40TROUBLESHOOTING & REPAIRF-40AC TIG Mode Was loaded with a resistance grid bank This is the typical DC + output voltage 41TROUBLESHOOTING & REPAIRF-41Typical AC Voltage Waveform Machine Loaded to 50 Amps Horizontal Sweep Ms/Div 42TROUBLESHOOTING & REPAIRF-42 Typical AC Voltage Waveform Machine Loaded to 2 AmpsAC Balance Control in Auto Output Control AT Minimum 43TROUBLESHOOTING & REPAIRF-43 Return to Section TOC 45TROUBLESHOOTING & REPAIRF-45 High Voltage Transformer Removal and ReplacementNut Driver Phillips Head Screwdriver Off-set Wire Cutters Removal Procedure 46TROUBLESHOOTING & REPAIRF-46Removal and Replacement Replacement Procedure 47TROUBLESHOOTING & REPAIRF-47 Figure F.11 3/8 Screw & Leads S and F Locations Return to Section TOC 49TROUBLESHOOTING & REPAIRF-49 Control Board Removal and ReplacementNut Driver Phillips Head Screwdriver Wire Cutters 50TROUBLESHOOTING & REPAIRF-50 Control Board Removal and Replacement 51TROUBLESHOOTING & REPAIRF-51 J10 J11 J12 Return to Section TOC 53TROUBLESHOOTING & REPAIRF-53 SCR Bridge Assembly Removal and ReplacementNut Driver Pliers Crimp Wire Cutters 54TROUBLESHOOTING & REPAIRF-54 SCR Bridge Assembly Removal and ReplacementSee Figure F.14 SCR Bridge Removal and Replacement Mounting of Stud Type Diodes to Aluminum Heat Sinks CONT’D Diode Stud Foot Inch Size Pounds25-27 300-324 10±.5 125+0/-5 22-25 57TROUBLESHOOTING & REPAIRF-57 Polarity Switch Removal and Replacement 58TROUBLESHOOTING & REPAIRF-58 Polarity Switch Removal and Replacement 59TROUBLESHOOTING & REPAIRF-59 SCR Removal and Replacement 60TROUBLESHOOTING & REPAIRF-60 SCR Removal and ReplacementSpecial Instructions Open Circuit Voltages Retest After RepairInput Idle Amps Recommended Meters for Machine Output Tests Return to Section TOC Electrical Diagrams Section Section G Control P.C. Board Schematic Electrical Diagrams Wiring Diagram Entire Machine Code 10806 G4031 Wiring Diagram Entire Machine Code 10807 G4031-1 SCR2 Precision TIG 275 Wiring Diagram Wiring Diagram Entire Machine Code 10893 G4031-2 Wiring Diagram Entire Machine Code 11158 G5692 Precision TIG 275 Wiring DiagramSchéma DE Câblage Diagramas DE Cableado Wiring Diagram Entire Machine Code 11159 G5692-1 Robotic Interface Connection Connexion Interface Robotique Schematic Entire Machine below Code 11000 G4075 Return to Section Schematic Entire Machine Above Code 11000 G5691 Change Detail Released from X A.02 Schematic Control PC Board below Code 11000 G3908 Electrical Diagrams Electrical Diagrams PC Board ASSEMBLY-CONTROL below Code 11000 G3909-2 G3909 Schematic Control PC Board Above Code 11000 G4762 Electrical Diagrams Electrical Diagrams Electrical Diagrams Electrical Diagrams PC Board ASSEMBLY-CONTROL Above Code 11000 G4763-1 G4763 SCHEMATIC-PROTECTION P.C. Board M16115 16115 M PC Board ASSEMBLY-PROTECTION M16062-1 Reqd Identification SCHEMATIC-BYPASS / Stabilizer P.C. Board S22530-1 Code 10806 PC Board ASSEMBLY-BYPASS / Stabilizer L10121-1 Code 10806 L10121-1 SCHEMATIC-BYPASS and CE P. C. Board S24206 Code Frame Ground PC Board ASSEMBLY-BYPASS and CE L10882-1 Code Bottom View Schematic TIG Option P.C. Board below Code 11000 G4039 Electrical Diagrams Return to Section TOC To Section TOC Schematic TIG Option P.C. Board Above Code 11000 G4760 Electrical Diagrams Electrical Diagrams MAK E Detail SVM Error Reporting Form