1. Manuals
  2. Brands
  3. Lincoln Electric Manuals
  4. Welding System
  5. SQUARE WAVE SVM141-A
  6. Service manual

Lincoln Electric SQUARE WAVE SVM141-A Service Manual

Lincoln electric welder user manual
Hide thumbs
Table of Contents

Advertisement

Quick Links

RETURN TO MAIN INDEX
SVM141-A
November, 1998

Square Wave TIG 275

For use with machine code numbers: 10523 & 10525
Safety Depends on You
Lincoln arc welding and cutting
equipment is designed and built
with safety in mind. However,
your overall safety can be in-
creased by proper installation . . .
and thoughtful operation on
your part. DO NOT INSTALL,
OPERATE OR REPAIR THIS
EQUIPMENT WITHOUT
READING THIS MANUAL AND
THE SAFETY PRECAUTIONS
CONTAINED THROUGHOUT.
And, most importantly, think
before you act and be careful.
SERVICE MANUAL
World's Leader in Welding and Cutting Products
Premier Manufacturer of Industrial Motors
• Sales and Service through Subsidiaries and Distributors Worldwide •
Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com

Advertisement

Table of Contents
loading

Related Manuals for Lincoln Electric SQUARE WAVE SVM141-A

Summary of Contents for Lincoln Electric SQUARE WAVE SVM141-A

  • Page 1: Square Wave Tig

    RETURN TO MAIN INDEX SVM141-A November, 1998 Square Wave TIG 275 For use with machine code numbers: 10523 & 10525 Safety Depends on You Lincoln arc welding and cutting equipment is designed and built with safety in mind. However, your overall safety can be in- creased by proper installation .

  • Page 2: Safety

    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 PERFORMED ONLY BY QUALIFIED INDIVIDUALS.

  • Page 3: Electric Shock Can Kill

    ELECTRIC SHOCK can kill. 3.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.
  • Page 4 WELDING SPARKS can cause fire or explosion. 6.a. Remove fire hazards from the welding area. If this is not possible, cover them to prevent the welding sparks from starting a fire. Remember that welding sparks and hot materials from welding can easily go through small cracks and openings to adjacent areas.
  • Page 5 PRÉCAUTIONS DE SÛRETÉ Pour votre propre protection lire et observer toutes les instructions et les précautions de sûreté specifiques qui parraissent dans ce manuel aussi bien que les précautions de sûreté générales suiv- antes: Sûreté Pour Soudage A L’Arc 1. Protegez-vous contre la secousse électrique: a.

  • Page 6: Table Of Contents

    MASTER TABLE OF CONTENTS FOR ALL SECTIONS Safety ...i-iv Installation...Section A Technical Specifications ...A-2 Safety Precautions ...A-3 Input Supply Connections ...A-4 Input Reconnect Procedure ...A-5 User Supplied Connectors ...A-6 Output Connections...A-6 Work Cable Connection ...A-6 TIG Torch Connection ...A-7 Twist-Mate Adapter for LA-9 and LA-17 TIG Torch ...A-8 Twist-Mate Adapter for LW-18 and LW-20 TIG Torch...A-8 Stick Electrode Cable Connection...A-9 Operation...Section B...
  • Page 7 Section A-1 - INSTALLATION SECTION - Installation ...Section A Technical Specifications, Square Wave TIG 275 (K1617-1) ...A-2 Safety Precautions...A-3 Select Suitable Location ...A-3 Stacking...A-3 Lifting and Moving...A-3 Tilting ...A-3 Environmental Rating ...A-3 Machine Grounding and High Frequency Interference Protection ...A-3 Input Supply Connections ...A-4 Input Reconnect Procedure...A-5 User Supplied Connectors ...A-6...

  • Page 8: Installation

    TECHNICAL SPECIFICATIONS - Square Wave TIG 275 Input Current at Standard 40% Duty Cycle Voltage 95/86/43 130/120/61 208/230/460/1/60 (K1617-1) 43/35 61/49 460/575/1/60 (K1617-2) RATED OUTPUT & ADDITIONAL OUTPUT CAPACITY Duty Cycle 40% Duty Cycle DC TIG & AC/DC Stick NEMA Class II (40) AC TIG 60% Duty Cycle DC TIG &...

  • Page 9: Safety Precautions

    Dirt, dust or any foreign material that can be drawn into the welder should be kept at a minimum. Failure to observe these precautions can result in excessive operating temperatures and nuisance trips.

  • Page 10: Input Supply Connections

    1. Keep the welder power supply lines as short as possible and enclose as much of them as possible in rigid metallic conduit or equivalent shielding for a distance of 50 feet (15.2m). There should be good electrical contact between this conduit and the welder case ground.

  • Page 11: Input Reconnect Procedure

    Failure to follow instructions below can cause immediate failure of components within the welder. 1. Connect the input power leads to the input terminals, L1 (U) and L2 (V), at the right below.

  • Page 12: User Supplied Connectors

    USER SUPPLIED CONNECTORS The Square Wave TIG 275 should be permanently wired into the power system. No plugs or connectors are necessary. OUTPUT CONNECTIONS WARNING To avoid being startled by a high frequency shock, keep the TIG torch and cables in good condition. ELECTRIC SHOCK can kill.

  • Page 13: Tig Torch Connection

    TIG TORCH CONNECTION The Twist-Mate connection allows fast and reliable TIG torch attachment to the electrode terminal of the Square Wave TIG 275 welding power supply. Twist- Mate TIG adapters are made of brass, combining high electrical conductivity with mechanical strength. They are available in several sizes and styles to accommo- date a wide selection of gas and water-cooled TIG torches.
  • Page 14 TWIST-MATE ADAPTER FOR LA-9 and LA-17 TIG TORCH The Twist-Mate connection allows fast and reliable TIG torch connections to the electrode terminal of the Square Wave TIG 275. The Twist-Mate adapter, strain relief boot and retaining compound needed to connect an LA-9 or LA-17 torch (or any equivalent air-cooled TIG torch with a right-hand male 3/8-24 fitting) are included with the Square Wave TIG 275.

  • Page 15: Stick Electrode Cable Connection

    4. Hold the TIG adapter, with cables and hoses installed, firmly in place by securing it into the Twist-Mate recep- tacle on the power source or into a padded vise. Apply a thin film of lubricant to the boot’s lead in chamfer area.
  • Page 16 A-10 A-10 NOTES SQUARE WAVE TIG 275...
  • Page 17 Section B-1 - OPERATION SECTION - Operation...Section B Safety Precautions ...B-2 General Description ...B-3 Recommended Processes and Equipment ...B-3 Design Features and Advantages...B-3 Welding Capability ...B-4 Limitations...B-4 Controls and Settings ...B-5 Welding Operation ...B-6 TIG Welding ...B-6 TIG Welding Guidelines...B-6 TIG Welding Sequence of Operation (2-Step TIG Mode) ...B-7 TIG Welding Sequence of Operation (4-Step TIG Mode) ...B-7 Hand and Foot Amptrol Operation...B-8...

  • Page 18: Operation

    SAFETY PRECAUTIONS Read and understand this entire section before operat- ing the machine. Observe additional Safety Guidelines detailed in the beginning of this manual. OPERATION WARNING ELECTRIC SHOCK can kill. • Do not touch electrically live parts or electrode with skin or wet clothing. •...

  • Page 19: General Description

    This style connector makes the gas and current connections for the TIG torch at the same time. (Adaptor plugs are provided) • DC+/AC/DC- Polarity Switch allows the welder to change polarity without reconnecting leads. SQUARE WAVE TIG 275...

  • Page 20: Welding Capability

    • Provides excellent arc starting and stability through- out the machines wide current range (5 to 315 Amps) to handle the vast majority of TIG welding applica- tions. • Simple output current dial allows the user to preset the peak current within the full output range of the machine.

  • Page 21: Controls And Settings

    CONTROLS AND SETTINGS All operator controls and adjustments are located on the case front of the Square Wave TIG 275. Refer to Figure B.1 and corresponding explanations following. 1. Current Control - This knob is used to set the welding current from 5 to 315 amps. Read the complete Operating Instructions section for more information on Local and Remote setting of cur- rent.

  • Page 22: Welding Operation

    8. Digital Voltmeter - This meter displays welding voltage, as measured on the output studs of the Square Wave TIG 275. After welding is complete, the meter displays the welding voltage corre- sponding to the peak welding current and displays this value for approximately 5 seconds.

  • Page 23: Tig Welding Sequence Of Operation (2-Step Tig Mode

    (4-Step TIG Mode) 1. Connect an Arc Start Switch to the Remote Amphenol. 2. Turn the welder, gas supply and water supply (if so equipped), on. The digital ammeter/voltmeter dis- play will illuminate when the power is on. 3. Select the 4-Step TIG Mode with the 2-Step/4-Step TIG/Stick switch.

  • Page 24: Advanced Tig Welding Features

    11. Hold the Arc Start Switch down until an arc is established. The arc will start at a low current value that is equal to 25% of the preset current established in Step 4. It will remain at this current as long as the Arc Start Switch is closed.

  • Page 25: Stick Welding

    STICK WELDING 1. Turn the welder “on”. The digital ammeter/volt- meter will illuminate when the power is on. 2. Set the Mode Switch to “STICK”. Set the output current using the Output Control Knob. No other functions or adjustments operate in the Stick Mode.
  • Page 26 B-10 B-10 NOTES SQUARE WAVE TIG 275...
  • Page 27 Section C-1 Section C-1 TABLE OF CONTENTS - ACCESSORIES - Accessories...Section C Accessories Included with Machine...C-2 Optional Accessories ...C-2 SQUARE WAVE TIG 275...

  • Page 28: Accessories Included With Machine

    ACCESSORIES INCLUDED WITH MACHINE K852-50 - Twist Mate Cable Plug for #2 to #1 Work Lead. K1622-1 - Twist Mate Adapter Kit for LA9 and LA17 Torches. K1622-2 - Twist Mate Adapter Kit for LW18 and LW20 Torches. OPTIONAL ACCESSORIES Any necessary installation instructions are included for the following accessories: K963-1, -2 - Hand Amptrol...

  • Page 29: Routine And Periodic Maintenance

    Section D-1 - MAINTENANCE SECTION - Maintenance ...Section D Safety Precautions...D-2 Routine and Periodic Maintenance...D-2 Overload Protection ...D-2 Fan As Needed (F.A.N.)...D-2 Service Procedures...D-2 Component Location and Access ...D-3 Control PC Board ...D-3 Display PC Board, Arc Starter/Bypass PC Board ...D-3 Spark Gap Assembly, High Voltage Transformer ...D-3 Main Rectifier...D-3 Spark Gap Adjustment ...D-3...

  • Page 30: Maintenance

    1. Periodically blow out dust and dirt which may accu- mulate within the welder using an air stream. 2. Inspect welder output and control cables for fray- ing, cuts, and bare spots. 3. Inspect the spark gap at regular intervals to main- tain the recommended spacing.

  • Page 31: Component Location And Access

    COMPONENT LOCATION AND ACCESS CONTROL PC BOARD Remove the left case side. Use a 3/8" Nut Driver or other suitable tool. NOTE: The Case side can be removed while roof is in place, as long as the three screws which secure the roof to the case side are removed.
  • Page 32 FIGURE D.2 - MAJOR COMPONENT LOCATIONS 1. CASE FRONT (WITH DISPLAY BOARD) 2. INTERNAL DIVIDER (WITH CONTROL BOARD) 3. CASE SIDES 4. CASE TOP 5. CASE BACK 6. FAN MOTOR ASSEMBLY 7. RECONNECT PANEL 8. BASE 9. HIGH VOLTAGE TRANSFORMER 10.

  • Page 33: Input Power Circuit

    Section E-1 - THEORY OF OPERATION SECTION - Theory of Operation ...Section E General Description ...E-2 Input Power Circuit...E-2 Output Rectification, Control Board and Feedback ...E-3 High Voltage/High Frequency Circuit ...E-4 DC Welding Output ...E-5 AC Welding Output ...E-6 SCR Operation...E-7 Protective Circuits ...E-8 Thermal Protection ...E-8 Overload Protection ...E-8...

  • Page 34: Theory Of Operation

    THEORY OF OPERATION FIGURE E.2 – MAIN TRANSFORMER AND INPUT POWER TRANSFORMER INPUT RECONNECT POWER PANEL SWITCH "A" 115VAC RECEPTACLE REMOTE RECEPTACLE GENERAL DESCRIPTION The Square Wave TIG 275 machine is a constant cur- rent, single range square wave AC/DC TIG (GTAW) arc welding power source with built-in high frequency sta- bilization.

  • Page 35: Output Rectification, Control Board And Feedback

    THEORY OF OPERATION FIGURE E.3 – OUTPUT RECTIFICATION, CONTROL BOARD AND FEEDBACK TRANSFORMER INPUT RECONNECT POWER PANEL SWITCH "A" 115VAC RECEPTACLE REMOTE RECEPTACLE OUTPUT RECTIFICATION, CONTROL BOARD AND FEEDBACK The AC output from the main transformer secondary is rectified and controlled through the SCR bridge. Output current is sensed at the shunt as a low voltage signal and fed back to the control board.

  • Page 36: High Voltage / High Frequency Circuit

    THEORY OF OPERATION FIGURE E.4 – HIGH VOLTAGE / HIGH FREQUENCY CIRCUIT TRANSFORMER INPUT RECONNECT POWER PANEL SWITCH "A" 115VAC RECEPTACLE REMOTE RECEPTACLE HIGH VOLTAGE / HIGH FREQUENCY CIRCUIT The control board passes the 115 VAC voltage to the primary of the high voltage transformer. The secondary of the high voltage transformer is coupled to a spark gap generator and also to the high frequency trans- former.

  • Page 37: Dc Welding Output

    THEORY OF OPERATION INPUT RECONNECT POWER PANEL SWITCH "A" 115VAC RECEPTACLE REMOTE RECEPTACLE DC WELDING OUTPUT When the polarity switch is placed in either DC position, the AC voltage from the main transformer secondary is applied to the SCR bridge. The SCR bridge and choke circuits are connected in a conventional full wave bridge and filter configuration, resulting in a controlled DC output.

  • Page 38: Ac Welding Output

    THEORY OF OPERATION TRANSFORMER INPUT RECONNECT POWER PANEL SWITCH "A" 115VAC RECEPTACLE REMOTE RECEPTACLE AC WELDING OUTPUT Rotating the polarity switch to the AC position changes the welding power circuit. One lead (X1) of the main transformer secondary is connected to the machine’s output work terminal.

  • Page 39: Scr Operation

    THEORY OF OPERATION INPUT CATHODE OUTPUT ANODE GATE GATE SCR OPERATION A silicon controlled rectifier (SCR) is a three-terminal device used to control rather large currents to a load. An SCR acts very much like a switch. When a gate sig- nal is applied to the SCR, it is turned ON and there is current flow from anode to cathode.

  • Page 40: Protective Circuits

    THEORY OF OPERATION PROTECTIVE CIRCUITS Protective circuits are designed into the Square Wave TIG 275 to sense trouble and shut down the machine before the trouble damages the internal machine com- ponents. Both thermal protection and current overload are included. THERMAL PROTECTION Thermostats protect the machine from excessive oper- ating temperatures.
  • Page 41 Section F-1 - TROUBLESHOOTING & REPAIR SECTION - Troubleshooting & Repair Section...Section F How to Use Troubleshooting Guide ...F-2 PC Board Troubleshooting Procedures...F-3 Troubleshooting Guide ...F-4 Test Procedures High Frequency Circuit Disable Procedure ...F-18 T1 Main Transformer Test...F-20 Gas (Water) Solenoid Test...F-24 Static SCR Test...F-26 Active SCR Test ...F-29 Oscilloscope Waveforms...

  • Page 42: Troubleshooting And Repair

    TROUBLESHOOTING & REPAIR HOW TO USE TROUBLESHOOTING GUIDE Service and repair should be performed by only Lincoln Electric Factory Trained Personnel. Unauthorized repairs performed on this equipment may result in danger to the technician and machine operator and will invalidate your factory warranty. For your safety and to avoid Electrical Shock, please observe all safety notes and precautions detailed throughout this manual.

  • Page 43: Pc Board Troubleshooting Procedures

    • If the PC Board uses protective shorting jumpers, don’t remove them until installation is complete. • If you return a PC Board to The Lincoln Electric Company for credit, it must be in the static-shielding bag. This will prevent further damage and allow prop- er failure analysis.

  • Page 44: Troubleshooting Guide

    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 216-383-2531 or 1-800-833-9353. POSSIBLE AREAS OF...

  • Page 45: Troubleshooting Guide

    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 216- 383-2531 or 1-800-833-9353.
  • Page 46 The thermal light is not lit. 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 216-383-2531 or 1-800-833-9353.
  • Page 47 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 216- 383-2531 or 1-800-833-9353.
  • Page 48 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 216-383-2531 or 1-800-833-9353. POSSIBLE AREAS OF...
  • Page 49 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 216-383-2531 or 1-800-833-9353. detailed in the beginning of this manual.
  • Page 50 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 216-383-2531 or 1-800-833-9353.
  • Page 51 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 216-383-2531 or 1-800-833-9353. detailed in the beginning of this manual.
  • Page 52 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 216-383-2531 or 1-800-833-9353.
  • Page 53 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 216-383-2531 or 1-800-833-9353.
  • Page 54 Stick mode. 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 216-383-2531 or 1-800-833-9353.
  • Page 55 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 216-383-2531 or 1-800-833-9353.
  • Page 56 One of the display meters is blank. 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 216-383-2531 or 1-800-833-9353.
  • Page 57 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 216-383-2531 or 1-800-833-9353.

  • Page 58: High Frequency Circuit Disable Procedure

    TROUBLESHOOTING & REPAIR HIGH FREQUENCY CIRCUIT DISABLE PROCEDURE Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 59 F-19 TROUBLESHOOTING & REPAIR HIGH FREQUENCY CIRCUIT DISABLE PROCEDURE (continued) PROCEDURE 1. Remove the input power to the TIG 275 machine. 2. Using the 3/8” nut driver, remove the right side case cover. 3. Locate the Spark Gap Assembly at the lower right side of the machine.

  • Page 60: T1 Main Transformer Test

    TROUBLESHOOTING & REPAIR T1 MAIN TRANSFORMER TEST Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.

  • Page 61: Test Procedures

    F-21 TROUBLESHOOTING & REPAIR T1 MAIN TRANSFORMER TEST (continued) FIGURE F.2 – PLUG J8 LOCATION ON CONTROL BOARD PIN 13 (LEAD #211A) PIN 14 (LEAD #212) PIN 6 (LEAD #201) PIN 4 (LEAD #204) TEST PROCEDURE 1. Remove main supply power to the machine. 2.
  • Page 62 F-22 TROUBLESHOOTING & REPAIR T1 MAIN TRANSFORMER TEST (continued) 6. If all of the secondary voltages are correct, the T1 transformer is functioning properly. a. If all of the secondary voltages are missing or incorrect, make certain that the correct input voltage is being applied to the correct primary leads.
  • Page 63 F-23 TROUBLESHOOTING & REPAIR T1 MAIN TRANSFORMER TEST (continued) TEST POINTS SECONDARY WINDINGS PLUG J8 PIN 1 (LEAD #210) PLUG J8 PIN 9 (LEAD #209) PLUG J8 PIN 6 (LEAD #201) PLUG J8 PIN 4 (LEAD #204) PLUG J8 PIN 2 (LEAD #231) PLUG J8 PIN 12 (LEAD #232A) PLUG J8 PIN 13 (LEAD #211A) PLUG J8 PIN 14 (LEAD #212)

  • Page 64: Gas (Water) Solenoid Test

    TROUBLESHOOTING & REPAIR GAS (WATER) SOLENOID TEST Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 65 F-25 TROUBLESHOOTING & REPAIR GAS (WATER) SOLENOID TEST (continued) FIGURE F.3 – GAS SOLENOID LOCATION SOLENOID CASE BACK TEST PROCEDURE 1. Remove input power to the TIG 275 machine. 2. Remove the left case side. 3. Perform the High Frequency Circuit Disable Procedure.

  • Page 66: Static Scr Test

    F-26 TROUBLESHOOTING & REPAIR Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 67 F-27 TROUBLESHOOTING & REPAIR STATIC SCR TEST (continued) FIGURE F.4 – PLUG J1 LOCATION ON CONTROL BOARD TEST PROCEDURE 1. Remove main supply power to the TIG 275 and remove the case top and left side. 2. Locate and remove plug J1 from the control board.
  • Page 68 F-28 TROUBLESHOOTING & REPAIR STATIC SCR TEST (continued) SCR4 CATHODE SCR3 / SCR4 ANODE SCR1 / SCR2 CATHODE 3. Using an analog ohmmeter, test the resis- tance from anode to cathode of SCR1. Reverse the meter leads and check from cathode to anode of SCR1.

  • Page 69: Active Scr Test

    F-29 TROUBLESHOOTING & REPAIR Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 70 F-30 TROUBLESHOOTING & REPAIR ACTIVE SCR TEST (continued) FIGURE F.6 – PLUG J1 LOCATION ON CONTROL BOARD TEST PROCEDURE 1. Remove main supply power to the TIG 275 machine. 2. Locate and remove plug J1 from the control board. See Figure F.6. 3.
  • Page 71 F-31 TROUBLESHOOTING & REPAIR ACTIVE SCR TEST (continued) FIGURE F.7 – ACTIVE SCR TEST SETUP 6volt Lantern Battery under test R1 = 4 ohms / 10 watts R2 = 3 ohms / 10 watts Resistor valves are ± 10% SQUARE WAVE TIG 275 F-31...
  • Page 72 F-32 F-32 TROUBLESHOOTING & REPAIR TROUBLESHOOTING & REPAIR ACTIVE SCR TEST (continued) SCR4 CATHODE SCR3 / SCR4 ANODE SCR1 / SCR2 CATHODE 6. Connect SCR into the test circuit as shown in Figure F.7 : (A) lead to anode (C) lead to cath- ode and (G) lead to the gate.

  • Page 73: Normal Open Circuit Voltage Waveform

    F-33 TROUBLESHOOTING & REPAIR NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. 50 V AC TIG MODE CAUTION 2 ms This is the typical AC output voltage...
  • Page 74 F-34 TROUBLESHOOTING & REPAIR NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. DC TIG MODE CAUTION 50 V This is the typical DC (+) output volt- age waveform generated from a prop-...
  • Page 75 F-35 TROUBLESHOOTING & REPAIR NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. 50 V AC STICK MODE CAUTION 2 ms This is the typical AC output voltage...
  • Page 76 F-36 TROUBLESHOOTING & REPAIR NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. 50 V DC STICK MODE CAUTION 2 ms This is the typical DC (+) output volt-...
  • Page 77 F-37 TROUBLESHOOTING & REPAIR TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. 20 V AC TIG MODE CAUTION 2 ms...
  • Page 78 F-38 TROUBLESHOOTING & REPAIR TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. DC TIG MODE CAUTION 20 V MACHINE LOADED TO 275 AMPS...
  • Page 79 F-39 TROUBLESHOOTING & REPAIR TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. AC STICK MODE CAUTION 20 V MACHINE LOADED TO 275 AMPS...
  • Page 80 F-40 TROUBLESHOOTING & REPAIR TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. DC STICK MODE CAUTION 20 V MACHINE LOADED TO 275 AMPS...

  • Page 81: Abnormal Open Circuit Voltage-Dc Tig Mode-One Output Scr Not Functioning

    F-41 TROUBLESHOOTING & REPAIR ABNORMAL OPEN CIRCUIT VOLTAGE - DC TIG MODE ONE OUTPUT SCR NOT FUNCTIONING HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment. • Perform all voltage and waveform checks with high frequency circuit OFF. • Perform High Frequency Disable Procedure. CAUTION 50 V This is NOT the typical DC (+) output...

  • Page 82: High Voltage Transformer Removal And Replacement

    TROUBLESHOOTING & REPAIR HIGH VOLTAGE TRANSFORMER REMOVAL Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 83 F-43 TROUBLESHOOTING & REPAIR HIGH VOLTAGE TRANSFORMER REMOVAL AND REPLACEMENT (continued) FIGURE F.9 – SECONDARY LEADS AT HIGH FREQUENCY STARTER BOARD REMOVAL PROCEDURE 1. Remove input power to the TIG 275 machine. 2. Using the 3/8” nut driver, remove the case sides.

  • Page 84: Replacement Procedures

    F-44 TROUBLESHOOTING & REPAIR HIGH VOLTAGE TRANSFORMER REMOVAL AND REPLACEMENT (continued) FIGURE F.10 – HIGH VOLTAGE TRANSFORMER MOUNTING INSULATORS FRONT MOUNTING INSULATOR REPLACEMENT PROCEDURE 1. Carefully position the new high voltage trans- former in place in the two rear mounting insu- lators.

  • Page 85: Scr Bridge Assembly Removal And Replacement

    TROUBLESHOOTING & REPAIR SCR BRIDGE ASSEMBLY REMOVAL AND REPLACEMENT Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 86 F-46 TROUBLESHOOTING & REPAIR SCR BRIDGE ASSEMBLY REMOVAL AND REPLACEMENT (continued) FIGURE F.11 – RECEPTACLE/CIRCUIT BREAKER LEADS CASE BACK SCREW CASE BACK CIRCUIT BREAKER RECEPTACLE PROCEDURE NOTE: “Left” and “right” are from the rear of the machine looking in. 1. Remove input power to the TIG 275 machine. FIGURE F.12 –...
  • Page 87 F-47 TROUBLESHOOTING & REPAIR SCR BRIDGE ASSEMBLY REMOVAL AND REPLACEMENT (continued) FIGURE F.13 – SCR BRIDGE CONNECTIONS For Steps 7-13, see Figure F.13. 7. Using the 7/16” wrench, label and remove the “POS” lead from the left side heat sink assem- bly.
  • Page 88 F-48 TROUBLESHOOTING & REPAIR SCR BRIDGE ASSEMBLY REMOVAL AND REPLACEMENT (continued) REPLACEMENT PROCEDURE Refer to Figures F.11 - F.13. 1. Carefully place the new SCR bridge assembly in position in the TIG 275. 2. Using the 3/8” wrench, install the four mount- ing screws.

  • Page 89: Polarity Switch Removal And Replacement

    TROUBLESHOOTING & REPAIR POLARITY SWITCH REMOVAL AND REPLACEMENT Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 90 F-50 TROUBLESHOOTING & REPAIR POLARITY SWITCH REMOVAL AND REPLACEMENT (continued) NAMEPLATE OUTPUT CONTROL KNOB ALLEN SCREW CONTROL KNOBS SCREW POLARITY SWITCH HANDLE PROCEDURE 1. Remove the input power to the TIG 275 machine. 2. Using the 3/8” nut driver, remove the case sides and top.
  • Page 91 F-51 TROUBLESHOOTING & REPAIR POLARITY SWITCH REMOVAL AND REPLACEMENT (continued) FIGURE F.15 – POLARITY SWITCH CONNECTIONS SQUARE WAVE TIG 275 F-51 CHOKE MICRO SWITCH LEADS...
  • Page 92 F-52 TROUBLESHOOTING & REPAIR POLARITY SWITCH REMOVAL AND REPLACEMENT (continued) FIGURE F.16 – POLARITY SWITCH WIRING DIAGRAM 232A 211A W 221 R 222 SCR1 SCR2 SCR3 220A SCR4 SPARK 115VAC ARC STARTER AS'BLY 211B 115VAC 232C FRONT GANG POLARITY SWITCH BYPASS / STABILIZER PC BOARD...
  • Page 93 F-53 TROUBLESHOOTING & REPAIR POLARITY SWITCH REMOVAL AND REPLACEMENT (continued) For Steps 9--17, see Figure F.15 and F.16. 9. With the 1/2” wrench, remove the “POS” flex lead from the polarity switch. See the Wiring Diagram. Label lead and connection point for reassembly.

  • Page 94: Main Transformer And Output Choke Assembly Removal And Replacement

    MAIN TRANSFORMER AND OUTPUT CHOKE ASSEMBLY REMOVAL AND REPLACEMENT Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty. For your safety and to avoid elec- trical shock, please observe all safety notes and precautions detailed throughout this manual.
  • Page 95 F-55 TROUBLESHOOTING & REPAIR MAIN TRANSFORMER AND OUTPUT CHOKE ASSEMBLY REMOVAL AND REPLACEMENT (continued) FIGURE F.17 – PLUG J8 LOCATION ON CONTROL BOARD PIN 13 (LEAD #211A) PIN 14 (LEAD #212) PIN 6 (LEAD #201) PIN 4 (LEAD #204) PROCEDURE 1.
  • Page 96 F-56 TROUBLESHOOTING & REPAIR MAIN TRANSFORMER AND OUTPUT CHOKE ASSEMBLY REMOVAL AND REPLACEMENT (continued) FIGURE F.18 – TRANSFORMER CONNECTIONS CHOKE LEAD LEFT SIDE INTERNAL PANEL 10. Using the 7/16” wrench, disconnect the transformer primary leads from the recon- nect studs. See the Wiring Diagram and Figure F.18.
  • Page 97 F-57 TROUBLESHOOTING & REPAIR MAIN TRANSFORMER AND OUTPUT CHOKE ASSEMBLY REMOVAL AND REPLACEMENT (continued) FIGURE F.19 – POLARITY SWITCH CONNECTIONS 20. Using the 3/8” wrench, remove the two screws holding the left side panel to the base of the machine. See Figure F.18. 21.
  • Page 98 F-58 TROUBLESHOOTING & REPAIR MAIN TRANSFORMER AND OUTPUT CHOKE ASSEMBLY REMOVAL AND REPLACEMENT (continued) Reassembly Procedure Refer to Figures F.17 - F.19. 1. Set the transformer onto the four mounting studs on the base. Attach the four nuts. 2. Connect the lead splices to the three ther- mostats: •...

  • Page 99: Retest After Repair

    F-59 TROUBLESHOOTING & REPAIR Should a machine under test be rejected for any reason requiring the removal of any mechanical part that could affect the machine’s electrical characteristics, or if any electrical components are repaired or replaced, the machine must be retested. Input Volts/Hertz 208/60 230/60...
  • Page 100 F-60 F-60 NOTES SQUARE WAVE TIG 275...
  • Page 101 ELECTRICAL DIAGRAMS TABLE OF CONTENTS ELECTRICAL DIAGRAMS SECTION Electrical Diagrams Section ...Section G Wiring Diagram (L10747)...G-2 Wiring Diagram (L10747-2) ...G-3 Control Board Schmatic (G3358-1) ...G-4 Control Board Schmatic (G3358-2) ...G-5 Display Board Schematic (L10768) ...G-6 Bypass Board Schematic (S22530)...G-7 Display Board Layout (L10770-1) ...G-8 Control Board Layout (G3360-1) ...G-9 Bypass Board Layout (L10121-1) ...G-10 SQUARE WAVE TIG 275...

  • Page 102: Wiring Diagram (L10747

    ELECTRICAL DIAGRAMS Wiring Diagram (L10747) NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine. 275C 277A SQUARE WAVE TIG 275...

  • Page 103: Wiring Diagram (L10747-2

    ELECTRICAL DIAGRAMS Wiring Diagram (L10747-2) NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine. 275C 277A SQUARE WAVE TIG 275...
  • Page 104 NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician.
  • Page 105 NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician.

  • Page 106: Display Board Schematic (L10768

    NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician.

  • Page 107: Bypass Board Schematic (S22530

    ELECTRICAL DIAGRAMS Bypass Board Schematic (S22530) SQUARE WAVE TIG 275 S22530 7-12-96...

  • Page 108: Display Board Layout (L10770-1

    ELECTRICAL DIAGRAMS Display Board Layout (L10770-1) ITEM ITEM L10770-1 DISPLAY PART NO. PART NO. DESCRIPTION DESCRIPTION REQ'D REQ'D SQUARE WAVE TIG 275 L10770-1 7-24-98...
  • Page 109 NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician.

  • Page 110: Electrical Diagrams

    Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the machine.
  • Page 111 G-11 G-11 Notes SQUARE WAVE TIG 275...

This manual is also suitable for:

Square wave tig 275

Table of Contents