Lincoln Electric SVM100-A Safety, Electric Shock can kill, ARC Rays can burn, Square Wave TIG

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SAFETY

 

 

 

WARNING

 

ARC WELDING can be hazardous.

PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.

Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you pur- chase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1” from the American Welding Society, P.O. Box 351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety” booklet E205 is available from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.

BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE PER- FORMED ONLY BY QUALIFIED INDIVIDUALS.

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ELECTRIC SHOCK can kill.

1.a. The electrode and work (or ground) circuits are electrically “hot” when the welder is on. Do not touch these “hot” parts with your bare skin or wet clothing. Wear dry, hole-free gloves to insulate hands.

1.b. Insulate yourself from work and ground using dry insulation. Make certain the insulation is large enough to cover your full area of physical contact with work and ground.

In addition to the normal safety precautions, if welding must be performed under electrically hazardous conditions (in damp locations or while wearing wet clothing; on metal structures such as floors, gratings or scaffolds; when in cramped positions such as sitting, kneeling or Iying, if there is a high risk of unavoidable or accidental contact with the workpiece or ground) use the following equipment:

Semiautomatic DC Constant Voltage (Wire) Welder.

DC Manual (Stick) Welder.

AC Welder with Reduced Voltage Control.

1.c. In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or semiautomatic welding gun are also electrically “hot”.

1.d. Always be sure the work cable makes a good electrical connection with the metal being welded. The connection should be as close as possible to the area being welded.

1.e. Ground the work or metal to be welded to a good electrical (earth) ground.

1.f. Maintain the electrode holder, work clamp, welding cable and welding machine in good, safe operating condition. Replace damaged insulation.

1.g. Never dip the electrode in water for cooling.

1.h. Never simultaneously touch electrically “hot” parts of electrode holders connected to two welders because voltage between the two can be the total of the open circuit voltage of both welders.

1.i. When working above floor level, use a safety belt to protect yourself from a fall should you get a shock.

1.j. Also see Items 4.c. and 6.

ARC RAYS can burn.

2.a. Use a shield with the proper filter and cover plates to protect your eyes from sparks and the rays of the arc when welding or observing open arc welding. Headshield and filter lens should conform to ANSI Z87. I standards.

2.b. Use suitable clothing made from durable flame-resistant material to protect your skin and that of your helpers from the arc rays.

2.c. Protect other nearby personnel with suitable, non-flammable screening and/or warn them not to watch the arc nor expose themselves to the arc rays or to hot spatter or metal.

FUMES AND GASES can be dangerous.

3.a. Welding may produce fumes and gases hazardous to health. Avoid breathing these fumes and gases.When welding, keep your head out of the fume. Use enough ventilation and/or exhaust at the arc to keep

fumes and gases away from the breathing zone. When

welding with electrodes which require special ventilation such as stainless or hard facing (see instructions on container or MSDS) or on lead or cadmium plated steel and other metals or coatings which produce highly toxic fumes, keep exposure as low as possible and below Threshold Limit Values (TLV) using local exhaust or mechanical ventilation. In confined spaces or in some circumstances, outdoors, a respirator may be required. Additional precautions are also required when welding on galvanized steel.

3.b. Do not weld in locations near chlorinated hydrocarbon vapors coming from degreasing, cleaning or spraying operations. The heat and rays of the arc can react with solvent vapors to form phosgene, a highly toxic gas, and other irritating products.

3.c. Shielding gases used for arc welding can displace air and cause injury or death. Always use enough ventilation, especially in confined areas, to insure breathing air is safe.

3.d. Read and understand the manufacturer’s instructions for this equipment and the consumables to be used, including the material safety data sheet (MSDS) and follow your employer’s safety practices. MSDS forms are available from your welding distributor or from the manufacturer.

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3.e. Also see item 7b.

Apr. ‘93

SQUARE WAVE TIG 255

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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 Supply Connections Input ConnectionsGround Connection TIG Torch Connection Reconnect ProcedureOutput Connections 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 GuidelinesSquare Wave TIG 255 12/95 TIG Welding Sequence Operation 2-STEP ModeTable B.2 Typical Current Ranges 1 for Tungsten Electrodes 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 Recommended Course of Action Problems SymptomsPossible Areas of Misadjustments 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 ConnectorsMaterials Needed Control Transformer T2 Voltage TestTest Description 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 VDCMachine Loaded to 200 Amps AT 46 VAC AC TIG Mode Auto Balance onMachine Loaded to 50 Amps AT 26VAC 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 Recommended Meters for Machine Output Tests Retest After RepairInput Idle Amps 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