Lincoln Electric SVM100-A service manual TIG Welding Problems

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F-13

 

TROUBLESHOOTING & REPAIR

 

 

 

TROUBLESHOOTING GUIDE

 

 

 

Observe Safety Guidelines

 

 

 

 

 

 

 

 

 

 

detailed in the beginning of this manual.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PROBLEMS

 

POSSIBLE AREAS OF

RECOMMENDED

 

 

(SYMPTOMS)

 

 

 

MISADJUSTMENT(S)

 

 

COURSE OF ACTION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TIG WELDING PROBLEMS

 

 

 

 

 

 

 

High frequency “Spark” is present

 

 

1.

Torch may be faulty.

 

 

This may be a welding procedure

 

 

 

at tungsten electrode, but operator

 

 

 

 

 

 

problem.

 

 

 

is unable to establish a welding arc.

 

 

2. If an amptrol is not being used,

 

 

 

 

 

 

 

Machine has normal open circuit

 

 

 

then the machine must be in

 

 

Contact The Lincoln Electric

 

 

 

voltage (approximately 53V).

 

 

 

 

the Local Control Mode.

 

 

Service Department (216) 383-

 

 

 

 

 

 

 

 

3. Tungsten electrode may be

 

 

2531 or 1-800-833-9353 (WELD).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

too large for the process.

 

 

 

 

 

 

 

 

 

 

 

 

4. If helium shielding gas is being

 

 

 

 

 

 

 

 

 

 

 

 

 

used, then reduce percentage

 

 

 

 

 

 

 

 

 

 

 

 

 

of helium.

 

 

 

 

 

 

 

 

 

 

 

 

5. If TIG welding in the DC

 

 

 

 

 

 

 

 

 

 

 

 

 

negative mode, then a properly

 

 

 

 

 

 

 

 

 

 

 

 

 

sharpened thoriated tungsten

 

 

 

 

 

 

 

 

 

 

 

 

 

should be used.

 

 

 

 

 

 

 

 

 

 

 

 

6. Check the welding cables and

 

 

 

 

 

 

 

 

 

 

 

 

 

output stud connections.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No high frequency. Machine is

 

 

1.

In order for the high frequency

 

 

1. Check the high voltage trans-

 

 

 

in the TIG Mode and has normal

 

 

 

to operate, the machine must

 

 

 

 

 

 

 

 

 

 

former (T3). The normal resis-

 

 

 

output.

 

 

 

 

be either in the start only

 

 

 

 

 

 

 

 

 

 

 

tance of the secondary winding

 

 

 

 

 

 

 

 

 

Mode or the continuous high

 

 

 

 

 

 

 

 

 

 

 

 

 

of the high voltage transformer

 

 

 

 

 

 

 

 

 

frequency mode.

 

 

 

 

 

 

 

 

 

 

 

 

 

is 12.5k ohms. 115vac is

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. The high frequency spark gap

 

 

applied to the primary of T3. A

 

 

 

 

 

 

 

 

 

 

very high voltage is developed

 

 

 

 

 

 

 

 

 

may be too large or shorted.

 

 

 

 

 

 

 

 

 

 

 

 

 

on the secondary winding. For

 

 

 

 

 

 

 

 

 

Check gap as per

 

 

 

 

 

 

 

 

 

 

 

 

 

assistance call The Lincoln

 

 

 

 

 

 

 

 

 

maintenance instructions.

 

 

 

 

 

 

 

 

 

 

 

 

 

Electric Service Department.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(216) 383-2531 or 1-800-833-

 

 

 

 

 

 

 

 

 

 

 

 

9353 (WELD).

 

 

 

 

 

 

 

 

 

 

 

 

2. Check the values of R3, R4

 

 

 

 

 

 

 

 

 

 

 

 

and C2. Replace if faulty.

 

 

 

 

 

 

 

 

 

 

 

 

3. The Protection/Snubber board

 

 

 

 

 

 

 

 

 

 

 

 

may be faulty. See

 

 

 

 

 

 

 

 

 

 

 

 

Protection/Snubber Board

 

 

 

 

 

 

 

 

 

 

 

 

Continuity Test.

 

 

 

 

 

 

 

 

 

 

 

 

4. The Control board may be

 

 

 

 

 

 

 

 

 

 

 

 

faulty. Replace.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

SQUARE WAVE TIG 255

Image 54
Contents Square Wave TIG ARC Rays can burn SafetyElectric Shock can kill Fumes and Gases can be dangerousCylinder may explode if damaged Welding Sparks can cause fire or explosionElectric and Magnetic Fields May be dangerousPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcMaster Table of Contents for ALL Sections Table of Contents Installation SectionInstallation Technical Specifications Square Wave TIGSelect Suitable Location Safety PrecautionsHigh Frequency Interference Protection StackingInput Connections Ground ConnectionInput Supply Connections Reconnect Procedure Output ConnectionsTIG Torch Connection Table A.1 Stick Electrode Cable ConnectionOperation Section General Warnings OperationOperating Instructions Fumes and GasesSection TOC Work Connec Polarity Do not Switch AC & DC Recti Fier Power SourceWhile Weld ING TIG Gtaw Single Phase Coolant Tion OutputGeneral Description Design Features AdvantagesOperational Features and Controls Recommended Processes and EquipmentWelding Capability LimitationsControls and Settings Control Panel KeysCase Front Controls LoadHand and Foot Amptrol Welding Operation Accessory Operation TIG WeldingTable B.1 Recommended Polarity Settings for TIG Welding TIG Welding GuidelinesTIG Welding Sequence Operation 2-STEP Mode Table B.2 Typical Current Ranges 1 for Tungsten ElectrodesSquare Wave TIG 255 12/95 TIG Welding Sequence Operation 4-STEP Mode ALL Machines Auxiliary PowerAdvanced TIG Welding Features AC Wave Balance and Auto BalanceOverload Protection Square Wave TIG Accessories Section Installation of Field Installed Options AccessoriesOptions / Accessories Undercarriage FunctionMaintenance Section Routine and Periodic Maintenance MaintenanceMaintenance Safety PrecautionsFigure D.1 General Assembly Exploded View Square Wave TIG Power Supply Block Logic Diagram Theory of Operation SectionTheory of Operation Input Line Voltage and Main TransformerOutput Rectification and Feedback Control High Voltage / High Frequency Circuit DC Welding Output DC Welding CircuitAC Welding Output AC Welding CircuitSCR Operation SCR Operation Square Wave TIGThermal Protection Troubleshooting & Repair Section 1TROUBLESHOOTING & Repair HOW to USE Troubleshooting GuideTroubleshooting & Repair PC Board Troubleshooting ProceduresTroubleshooting Guide Output Problems12/95 Square Wave TIG Troubleshooting & Repair Problems Symptoms Possible Areas of MisadjustmentsRecommended Course of Action Function Problems Troubleshooting Guide Troubleshooting & Repair TIG Mode Problems Troubleshooting & Repair Troubleshooting Guide TIG Welding Problems Troubleshooting & Repair Stick Welding Problems PC Board Connector Locations Figure F.1 Control Board ConnectorsControl Transformer T2 Voltage Test Test DescriptionMaterials Needed Test Procedure Control BOXControl Transformer T2 Voltage Test Figure F.4 Control Board and TransformerPROTECTION/SNUBBER Board Continuity Test PROTECTION/SNUBBER Board Continuity Test Figure F.6 PROTECTION/SNUBBER Board Test Points Table F.6 Square Wave TIGARC Start Trigger Circuit Test ARC Start Trigger Circuit Test Figure F.9 PROTECTION/SNUBBER Board Test Points Static SCR Test Static SCR Test Figure F.11 Protection Board Plug LocationsActive SCR Test Active SCR Test Figure F.13 PROTECTION/SNUBBER Board Plug LocationsBattery Test Silicon Controlled Rectifier TestNormal Open Circuit Voltage Waveform DC Stick Mode Scope SettingsNormal Open Circuit Voltage Waveform AC Stick Mode Normal Open Circuit Voltage Waveform DC TIG Mode Normal Open Circuit Voltage Waveform AC TIG Mode Typical Output Voltage Waveform Machine Loaded DC TIG Mode Machine Loaded to 200 Amps AT 50 VDCAC TIG Mode Auto Balance on Machine Loaded to 50 Amps AT 26VACMachine Loaded to 200 Amps AT 46 VAC Volts 5ms Typical SCR Gate Voltage WaveformVolts 2ms Troubleshooting & Repair FAN Motor and Blade Removal Tools RequiredFAN Motor and Blade Removal SCR Heat Sink Assembly Removal Materials RequiredSCR Heat Sink Assembly Removal Retest After Repair Input Idle AmpsRecommended Meters for Machine Output Tests Retest After Repair cont’d Figure F.16 Transformer Lead Test PointsElectrical Diagrams Electrical Diagrams Control Board G2150 PTC1,PTC2 THERMISTOR-PTC,56 OHMS,90MAControl Board G2150 cont’d Square Wave TIG PROTECTION/SNUBBER Board L9255 CAPACITOR-CEMO,4700P,50V,10% Square Wave TIG Wiring Diagram Square Wave TIG Machine Schematic Square Wave TIG 6 a 0 a 7 a 8 a 3 CG2150 A C C TControl Board Schematic Square Wave TIG 255 cont’d G2150 Y P a DPROTECTION/SNUBBER Board Schematic Square Wave TIG 255 L9255 Keypad LED Board Square Wave TIG 255 L9212