Page 2 - SAFETY; WARNING; ARC WELDING can be hazardous.; Return to Master TOC
i SAFETY SQUARE WAVE TIG 255 PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDRENAWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING. Read and understand the following safety highlights. For additional safety information, it is strongly recommended t...
Page 3 - ii
ii SQUARE WAVE TIG 255 SAFETY FOR ELECTRICALLYpowered equipment. 6.a. Turn off input power using the disconnect switch at the fuse box before working onthe equipment. 6.b. Install equipment in accordance with the U.S. National Electrical Code, all local codes and the manufacturer’srecommendations. 6...
Page 4 - iii
iii SAFETY SQUARE WAVE TIG 255 Mar. ‘93 ELECTRIC AND MAGNETICFIELDSmay be dangerous 8 . a . E l e c t r i c c u r r e n t f l o w i n g t h r o u g h a n y c o n d u c t o r c a u s e s localized Electric and Magnetic Fields (EMF). Welding c u r r e n t c r e a t e s E M F f i e l d s a r o u n d w ...
Page 5 - iv; PRÉCAUTIONS DE SÛRETÉ
iv SAFETY SQUARE WAVE TIG 255 PRÉCAUTIONS DE SÛRETÉ Pour votre propre protection lire et observer toutes les instruc- tions et les précautions de sûreté specifiques qui parraissent d a n s c e m a n u e l a u s s i b i e n q u e l e s p r é c a u t i o n s d e s û r e t é générales suivantes: Sûreté...
Page 6 - MASTER TABLE OF CONTENTS FOR ALL SECTIONS; Page
MASTER TABLE OF CONTENTS FOR ALL SECTIONS Page Safety .........................................................................................................................i-iv Installation ......................................................................................................Secti...
Page 7 - Section A; TABLE OF CONTENTS
Installation .......................................................................................................Section A Technical Specifications ........................................................................................A-1 Input and Output SpecificationsCable and Fuse SizesPhysic...
Page 8 - INSTALLATION; Return to Section TOC; TECHNICAL SPECIFICATIONS – SQUARE WAVE TIG 255; For all Stick, DC TIG, and Balanced AC TIG; AC and DC; INPUT - SINGLE PHASE ONLY
A-1 INSTALLATION SQUARE WAVE TIG 255 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 TECHNICAL SPECIFICATIONS – SQUARE WAVE TIG 255 For all Stick, DC TIG, and Balanced AC TIG W...
Page 9 - SAFETY PRECAUTIONS; STACKING; ELECTRIC SHOCK can kill.
A-2 INSTALLATION SQUARE WAVE TIG 255 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 Read entire installation section before startinginstallation. SAFETY PRECAUTIONS SELECT SUI...
Page 10 - FIGURE A.1 — REAR PANEL; GROUND CONNECTION; INPUT CONNECTIONS
A-3 INSTALLATION SQUARE WAVE TIG 255 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 4. Keep the torch in good repair and all connections tight to reduce high frequency leakage...
Page 11 - RECONNECT PROCEDURE; circuit breakers. Choose an input; OUTPUT CONNECTIONS; TIG TORCH CONNECTION
A-4 INSTALLATION SQUARE WAVE TIG 255 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 RECONNECT PROCEDURE On multiple input voltage welders, be sure the recon-nect panel is conn...
Page 12 - Cable Sizes for Combined Lengths of Copper; STICK ELECTRODE CABLE CONNECTION
A-5 INSTALLATION SQUARE WAVE TIG 255 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 DO NOT operate a water-cooled torch unless water isflowing. Water doesn’t flow until soleno...
Page 13 - Section B
Operation ..........................................................................................................Section B Safety Precautions .................................................................................................B-1 Graphic Symbols .........................................
Page 14 - OPERATION; OPERATING INSTRUCTIONS; GENERAL WARNINGS
B-1 OPERATION SQUARE WAVE TIG 255 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 ELECTRIC SHOCKcan kill. • Do not touch electrically live parts or electrode with skin or wetcl...
Page 15 - HF
B-2 OPERATION SQUARE WAVE TIG 255 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 ON 2 A TIG 2-STEP TIG 4-STEP STICK CURRENT CONTROL OUTPUT LOCAL CUR- RENT CON- TROL REMOTE CUR...
Page 17 - GENERAL DESCRIPTION
B-4 OPERATION SQUARE WAVE TIG 255 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 • Welding current limit can be preset from 5 to 315 amps and is displayed on the Ammeter when ...
Page 18 - WELDING CAPABILITY
B-5 OPERATION SQUARE WAVE TIG 255 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 • Strain relief holes in base for welding cables, gas and water hoses and control cables. • Ea...
Page 19 - CONTROL PANEL KEYS; CONTROLS AND SETTINGS
B-6 OPERATION SQUARE WAVE TIG 255 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 4. AC WAVE BALANCE: These keys are active inthe AC TIG mode only. They are used to set theamou...
Page 20 - CASE FRONT CONTROLS
B-7 OPERATION SQUARE WAVE TIG 255 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 A. AC/DC INDICATOR: This symbol represents the output polarity of the 255 . . . either AC or D...
Page 21 - RECOMMENDED POLARITY SETTINGS FOR; WELDING OPERATION; TIG WELDING; HAND AND FOOT AMPTROL; ACCESSORY OPERATION
B-8 OPERATION SQUARE WAVE TIG 255 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 TABLE B.1 RECOMMENDED POLARITY SETTINGS FOR TIG WELDING Type of Welding Electrode Polarity Hig...
Page 22 - TYPICAL CURRENT RANGES
B-9 OPERATION SQUARE WAVE TIG 255 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 5. Select Continuous High Frequency if welding withA C p o l a r i t y , o r S t a r t O n l y...
Page 24 - AUXILIARY POWER; ALL MACHINES; AC WAVE BALANCE AND AUTO BALANCETM; BALANCED (0): T h e a m o u n t s o f p o s i t i v e a n d; TIG PULSER; CAUTION
B-11 OPERATION SQUARE WAVE TIG 255 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 Up/Down. Adjustment of the pulses per second (pulsefrequency), allows for control of the heat...
Page 25 - OVERLOAD PROTECTION
B-12 OPERATION SQUARE WAVE TIG 255 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 Note that some types of equipment, especially pumpsand motors, have starting currents which a...
Page 26 - NOTES
B-13 NOTES SQUARE WAVE TIG 255 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
Page 27 - Section C
SQUARE WAVE TIG 255 Accessories ......................................................................................................Section C Available Option and Accessories .........................................................................C-1Undercarriage Function ...........................
Page 28 - ACCESSORIES; OPTIONS / ACCESSORIES; • Magnum Cooler Horizontal TIG Mounting Bracket; UNDERCARRIAGE FUNCTION
C-1 ACCESSORIES SQUARE WAVE TIG 255 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 OPTIONS / ACCESSORIES • Hand Amptrol (K812) • Foot Amptrol (K870) • Arc Start Switch (K814) ...
Page 29 - Section D
Maintenance .....................................................................................................Section D Safety Precautions .................................................................................................D-1Routine and Periodic Maintenance ............................
Page 30 - Keep TIG torch and cables in good condition.; MAINTENANCE
D-1 MAINTENANCE SQUARE WAVE TIG 255 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 ELECTRIC SHOCK can kill. • Only qualified personnel should perform this maintenance. • Turn ...
Page 31 - FIGURE D.1 - GENERAL ASSEMBLY EXPLODED VIEW
D-2 MAINTENANCE SQUARE WAVE TIG 255 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 FIGURE D.1 - GENERAL ASSEMBLY EXPLODED VIEW 1, MAIN TRANSFORMER 5. CONTROL BOX ASSEMBLY 2. O...
Page 33 - Section E; POWER SUPPLY BLOCK LOGIC DIAGRAM; portions of the circuit are shaded.
Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC SQUARE WAVE TIG 255 Theory of Operation Section ...........................................................................Section E Power Supply Operation ...............................................................
Page 34 - THEORY OF OPERATION; INPUT LINE VOLTAGE AND MAIN TRANSFORMER
SQUARE WAVE TIG 255 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 E-1 THEORY OF OPERATION INPUT LINE VOLTAGE AND MAIN TRANSFORMER LINE SWITCH RECON N EC T MAIN TRANSFORMER X2...
Page 35 - OUTPUT RECTIFICATION AND FEEDBACK CONTROL
SQUARE WAVE TIG 255 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 E-2 THEORY OF OPERATION OUTPUT RECTIFICATION AND FEEDBACK CONTROL LINE SWITCH RECON N EC T MAIN TRANSFORMER ...
Page 36 - HIGH VOLTAGE / HIGH FREQUENCY CIRCUIT
SQUARE WAVE TIG 255 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 E-3 THEORY OF OPERATION HIGH VOLTAGE / HIGH FREQUENCY CIRCUIT LINE SWITCH RECON N EC T MAIN TRANSFORMER X2 X...
Page 37 - DC WELDING OUTPUT; CHOKE; DC WELDING CIRCUIT
SQUARE WAVE TIG 255 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 E-4 THEORY OF OPERATION LINE SWITCH RECON N EC T MAIN TRANSFORMER X2 X1 POWER FACTOR CAPACITORS FAN 115VAC P...
Page 38 - AC WELDING OUTPUT; AC WELDING CIRCUIT
SQUARE WAVE TIG 255 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 E-5 THEORY OF OPERATION LINE SWITCH RECON N EC T MAIN TRANSFORMER X2 X1 POWER FACTOR CAPACITORS FAN 115VAC P...
Page 39 - SCR OPERATION
SQUARE WAVE TIG 255 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 E-6 THEORY OF OPERATION A silicon controlled rectifier (SCR) is a three terminaldevice used to control rathe...
Page 40 - THERMAL PROTECTION
SQUARE WAVE TIG 255 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 E-7 THEORY OF OPERATION A thermostat protects the machine from excessiveoperating temperatures. Excessive op...
Page 41 - Section F
Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC SQUARE WAVE TIG 255 Troubleshooting & Repair Section ................................................................Section F Safety Precautions .....................................................................
Page 42 - TROUBLESHOOTING & REPAIR; HOW TO USE TROUBLESHOOTING GUIDE; HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment.
SQUARE WAVE TIG 255 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-1 TROUBLESHOOTING & REPAIR This Troubleshooting Guide is provided tohelp you locate and repair possibl...
Page 43 - PC BOARD TROUBLESHOOTING PROCEDURES
SQUARE WAVE TIG 255 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-2 TROUBLESHOOTING & REPAIR CAUTION: Sometimes machine failuresa p p e a r t o b e d u e t o P C b o a ...
Page 44 - TROUBLESHOOTING GUIDE; OUTPUT PROBLEMS
SQUARE WAVE TIG 255 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-3 TROUBLESHOOTING & REPAIR TROUBLESHOOTING GUIDE Observe Safety Guidelines detailed in the beginning o...
Page 46 - Check for proper fan operation.
SQUARE WAVE TIG 255 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-5 TROUBLESHOOTING & REPAIR TROUBLESHOOTING GUIDE Observe Safety Guidelines detailed in the beginning o...
Page 48 - FUNCTION PROBLEMS
SQUARE WAVE TIG 255 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-7 TROUBLESHOOTING & REPAIR TROUBLESHOOTING GUIDE Observe Safety Guidelines detailed in the beginning o...
Page 49 - None
SQUARE WAVE TIG 255 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-8 TROUBLESHOOTING & REPAIR Observe Safety Guidelinesdetailed in the beginning of this manual. TROUBLES...
Page 51 - Arc “Flutters” when TIG welding.; TIG MODE PROBLEMS
SQUARE WAVE TIG 255 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-10 TROUBLESHOOTING & REPAIR Observe Safety Guidelinesdetailed in the beginning of this manual. TROUBLE...
Page 52 - Black areas along weld bead.
SQUARE WAVE TIG 255 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-11 TROUBLESHOOTING & REPAIR TROUBLESHOOTING GUIDE Observe Safety Guidelines detailed in the beginning ...
Page 54 - TIG WELDING PROBLEMS
SQUARE WAVE TIG 255 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-13 TROUBLESHOOTING & REPAIR TROUBLESHOOTING GUIDE Observe Safety Guidelines detailed in the beginning ...
Page 56 - STICK WELDING PROBLEMS
SQUARE WAVE TIG 255 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-15 TROUBLESHOOTING & REPAIR TROUBLESHOOTING GUIDE Observe Safety Guidelines detailed in the beginning ...
Page 57 - PC BOARD CONNECTOR LOCATIONS
SQUARE WAVE TIG 255 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-16 TROUBLESHOOTING & REPAIR SQUARE WAVE 255 CONTROL G2150 J1 J2 J3 J4 J5 J6 J7 J8 1J3 2J3 12J6 13J6 5J...
Page 58 - TEST DESCRIPTION
SQUARE WAVE TIG 255 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-17 TROUBLESHOOTING & REPAIR CONTROL TRANSFORMER (T2) VOLTAGE TEST WARNING CAUTION Service and repair s...
Page 59 - CONTROL BOX; TEST PROCEDURE; Remove main supply power to machine; FIGURE F.3 - LOCATION OF CONTROL BOARD AND CONTROL TRANSFORMER.; I f a v e r y l o w o r z e r o v o l t a g e i s
SQUARE WAVE TIG 255 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-18 TROUBLESHOOTING & REPAIR CONTROL TRANSFORMER (T2) VOLTAGE TEST (continued) CONTROL BOX CONTROL BOAR...
Page 60 - VIEWED FROM END; PLUG P8; A. If zero ohms resistance is shown; Secondary
SQUARE WAVE TIG 255 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-19 TROUBLESHOOTING & REPAIR CONTROL TRANSFORMER (T2) VOLTAGE TEST (continued) SQUARE WAVE 255 CONTROL ...
Page 61 - PROTECTION/SNUBBER BOARD CONTINUITY TEST
SQUARE WAVE TIG 255 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-20 TROUBLESHOOTING & REPAIR PROTECTION/SNUBBER BOARD CONTINUITY TEST TEST DESCRIPTION Many circuits pa...
Page 62 - Remove main supply power to machine.
SQUARE WAVE TIG 255 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-21 TROUBLESHOOTING & REPAIR PROTECTION/SNUBBER BOARD CONTINUITY TEST (continued) CONTROL BOX PROTECTIO...
Page 63 - Check Points
SQUARE WAVE TIG 255 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-22 TROUBLESHOOTING & REPAIR PROTECTION/SNUBBER BOARD CONTINUITY TEST (continued) Check Points Componen...
Page 64 - ARC START TRIGGER CIRCUIT TEST
SQUARE WAVE TIG 255 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-23 TROUBLESHOOTING & REPAIR ARC START TRIGGER CIRCUIT TEST TEST DESCRIPTION The Arc Start Trigger Test...
Page 67 - STATIC SCR TEST
SQUARE WAVE TIG 255 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 STATIC SCR TEST TEST DESCRIPTION The Static SCR Test is a quick check to d...
Page 68 - FIGURE F.11 - PROTECTION BOARD PLUG LOCATIONS; A. If a low resistance is indicated in
SQUARE WAVE TIG 255 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-27 TROUBLESHOOTING & REPAIR STATIC SCR TEST (continued) PROTECTION/SNUBBER L9255 J10 J11 J12 J13 J14 J...
Page 69 - ACTIVE SCR TEST
SQUARE WAVE TIG 255 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-28 TROUBLESHOOTING & REPAIR ACTIVE SCR TEST TEST DESCRIPTION The Active SCR Test will determine if the...
Page 71 - BATTERY TEST
SQUARE WAVE TIG 255 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-30 TROUBLESHOOTING & REPAIR ACTIVE SCR TEST (continued) SW1 R2 SW2 R1 A G C V SCRundertest R1= 4 ohms ...
Page 72 - NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM; volts; SCOPE SETTINGS
SQUARE WAVE TIG 255 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-31 TROUBLESHOOTING & REPAIR NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM DC STICK MODE CAUTION HIGH VOLTAGE / ...
Page 74 - CH1
SQUARE WAVE TIG 255 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-33 TROUBLESHOOTING & REPAIR NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM DC TIG MODE CAUTION HIGH VOLTAGE / HI...
Page 76 - TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED; MACHINE LOADED TO 200 AMPS AT 50 VDC
SQUARE WAVE TIG 255 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-35 TROUBLESHOOTING & REPAIR TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED DC TIG MODE CAUTION HIGH ...
Page 78 - TYPICAL SCR GATE VOLTAGE WAVEFORM; volts
SQUARE WAVE TIG 255 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-37 TROUBLESHOOTING & REPAIR TYPICAL SCR GATE VOLTAGE WAVEFORM CAUTION HIGH VOLTAGE / HIGH FREQUENCY ca...
Page 79 - ABNORMAL OPEN CIRCUIT VOLTAGE - DC STICK MODE
SQUARE WAVE TIG 255 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-38 TROUBLESHOOTING & REPAIR ABNORMAL OPEN CIRCUIT VOLTAGE - DC STICK MODE ONE OUTPUT SCR NOT FUNCTIONI...
Page 80 - ABNORMAL OPEN CIRCUIT VOLTAGE - AC STICK MODE
SQUARE WAVE TIG 255 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-39 TROUBLESHOOTING & REPAIR ABNORMAL OPEN CIRCUIT VOLTAGE - AC STICK MODE ONE OUTPUT SCR NOT FUNCTIONI...
Page 81 - FAN MOTOR AND BLADE REMOVAL
SQUARE WAVE TIG 255 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-40 TROUBLESHOOTING & REPAIR FAN MOTOR AND BLADE REMOVAL TEST DESCRIPTION The following procedure will ...
Page 83 - SCR HEAT SINK ASSEMBLY REMOVAL
SQUARE WAVE TIG 255 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-42 TROUBLESHOOTING & REPAIR SCR HEAT SINK ASSEMBLY REMOVAL TEST DESCRIPTION The following procedure wi...
Page 84 - Remove main power supply to machine.
SQUARE WAVE TIG 255 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-43 TROUBLESHOOTING & REPAIR SCR HEAT SINK ASSEMBLY REMOVAL (continued) TEST PROCEDURE 1. Remove main p...
Page 85 - RETEST AFTER REPAIR; Maximum Idle Amps
11 / 94 SQUARE WAVE TIG 255 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-44 TROUBLESHOOTING & REPAIR RETEST AFTER REPAIR Should a machine under test be rejected forany...
Page 86 - Test Points
SQUARE WAVE TIG 255 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-45 TROUBLESHOOTING & REPAIR Test Points Voltages X1 – X2 73 – 78 VAC X3 – X4 (230 – 232) 116 – 122 VAC...
Page 87 - Section G
Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC SQUARE WAVE TIG 255 Electrical Diagrams .........................................................................................Section G Control PC Board (G2150) Components ............................................
Page 88 - ELECTRICAL DIAGRAMS
G-2 ELECTRICAL DIAGRAMS SQUARE WAVE TIG 255 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 NOTE: Lincoln Electric assumes no responsibility for liabilities resulting from boar...
Page 95 - WIRING DIAGRAM - SQUARE WAVE TIG 255
G-9 ELECTRICAL DIAGRAMS SQUARE WAVE TIG 255 2 3 1 T O G R O U N D P E R N A T I O N A L E L E C T R I C C O D E 2 2 9 P I E Z O B U Z Z E R ( + ) ( - ) C 1 ( 1 , 3 ) ( 1 , 2 ) ( 1 , 1 ) ( 2 , 2 ) ( 2 , 1 ) ( 3 , 1 ) ( 4 , 1 ) ( 4 , 2 ) ( 5 , 1 ) ( 5 , 2 ) T O K E Y P A D M A T R I X X 1 2 4 0 2 3 0 ...
Page 96 - MACHINE SCHEMATIC — SQUARE WAVE TIG 255
Retur n to Section TOC Retur n to Section TOC Retur n to Section TOC Retur n to Section TOC Retur n to Master TOC Retur n to Master TOC Retur n to Master TOC Retur n to Master TOC G-10 ELECTRICAL DIAGRAMS SQUARE WAVE TIG 255 MACHINE SCHEMATIC — SQUARE WAVE TIG 255 S C R 2 G A T E S C R 3 G A T E S C...
