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RETURN TO MAIN INDEX
SVM129-A
January 1998
INVERTEC
®
STT
TM
& STT II
TM
For use with machine code numbers: 10151
10152
10153
10381
10382
10383
Safety Depends on You
Lincoln arc welding and cutting equipment is designed and built with safety in mind. However, your overall safety can be increased by proper installation .
. . and thoughtful operation on your part. DO NOT INSTALL,
OPERATE OR REPAIR THIS
EQUIPMENT WITHOUT READ-
ING THIS MANUAL AND THE
SAFETY PRECAUTIONS CON-
TAINED 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
22801 St. Clair Ave. Cleveland, Ohio 44117-1199 U.S.A. Tel. (216) 481-8100
i
SAFETY
WARNING
CALIFORNIA PROPOSITION 65 WARNINGS
Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.
The Above For Diesel Engines
The engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.
The Above For Gasoline Engines
i
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 purchase 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
PERFORMED ONLY BY QUALIFIED INDIVIDUALS.
FOR ENGINE powered equipment.
1.a. Turn the engine off before troubleshooting and maintenance work unless the maintenance work requires it to be running.
____________________________________________________
1.b.Operate engines in open, well-ventilated areas or vent the engine exhaust fumes outdoors.
1.h. To avoid scalding, do not remove the radiator pressure cap when the engine is hot.
ELECTRIC AND
MAGNETIC FIELDS may be dangerous
____________________________________________________
1.c. Do not add the fuel near an open flame welding arc or when the engine is running. Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on contact with hot engine parts and igniting. Do not spill fuel when filling tank. If fuel is spilled, wipe it up and do not start engine until fumes have been eliminated.
____________________________________________________
1.d. Keep all equipment safety guards, covers and devices in position and in good repair.Keep hands, hair, clothing and tools away from V-belts, gears, fans and all other moving parts when starting, operating or repairing equipment.
2.a. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF). Welding current creates EMF fields around welding cables and welding machines
2.b. EMF fields may interfere with some pacemakers, and welders having a pacemaker should consult their physician before welding.
2.c. Exposure to EMF fields in welding may have other health effects which are now not known.
2.d. All welders should use the following procedures in order to minimize exposure to EMF fields from the welding circuit:
____________________________________________________
1.e. In some cases it may be necessary to remove safety guards to perform required maintenance. Remove guards only when necessary and replace them when the maintenance requiring their removal is complete.
Always use the greatest care when working near moving parts.
___________________________________________________
1.f. Do not put your hands near the engine fan. Do not attempt to override the governor or idler by pushing on the throttle control rods while the engine is running.
___________________________________________________
1.g. To prevent accidentally starting gasoline engines while turning the engine or welding generator during maintenance work, disconnect the spark plug wires, distributor cap or magneto wire as appropriate.
2.d.1. Route the electrode and work cables together - Secure them with tape when possible.
2.d.2. Never coil the electrode lead around your body.
2.d.3. Do not place your body between the electrode and work cables. If the electrode cable is on your right side, the work cable should also be on your right side.
2.d.4. Connect the work cable to the workpiece as close as possible to the area being welded.
2.d.5. Do not work next to welding power source.
Mar ‘95
INVERTEC STT
ii
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.
3.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 lying, 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.
3.c. In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or semiautomatic welding gun are also electrically “hot”.
3.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.
3.e. Ground the work or metal to be welded to a good electrical
(earth) ground.
3.f. Maintain the electrode holder, work clamp, welding cable and welding machine in good, safe operating condition. Replace damaged insulation.
3.g. Never dip the electrode in water for cooling.
3.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.
3.i. When working above floor level, use a safety belt to protect yourself from a fall should you get a shock.
3.j. Also see Items 6.c. and 8.
SAFETY
ARC RAYS can burn.
4.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.
4.b. Use suitable clothing made from durable flame-resistant material to protect your skin and that of your helpers from the arc rays.
4.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.
5.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.
5.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.
5.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.
5.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.
5.e. Also see item 1.b.
Mar ‘95 ii
INVERTEC STT
iii
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. Avoid welding near hydraulic lines. Have a fire extinguisher readily available.
6.b. Where compressed gases are to be used at the job site, special precautions should be used to prevent hazardous situations. Refer to “Safety in Welding and Cutting” (ANSI
Standard Z49.1) and the operating information for the equipment being used.
6.c. When not welding, make certain no part of the electrode circuit is touching the work or ground. Accidental contact can cause overheating and create a fire hazard.
6.d. Do not heat, cut or weld tanks, drums or containers until the proper steps have been taken to insure that such procedures will not cause flammable or toxic vapors from substances inside. They can cause an explosion even though they have been “cleaned”. For information, purchase “Recommended
Safe Practices for the Preparation for Welding and Cutting of
Containers and Piping That Have Held Hazardous
Substances”, AWS F4.1 from the American Welding Society
(see address above).
6.e. Vent hollow castings or containers before heating, cutting or welding. They may explode.
6.f. Sparks and spatter are thrown from the welding arc. Wear oil free protective garments such as leather gloves, heavy shirt, cuffless trousers, high shoes and a cap over your hair. Wear ear plugs when welding out of position or in confined places.
Always wear safety glasses with side shields when in a welding area.
6.g. Connect the work cable to the work as close to the welding area as practical. Work cables connected to the building framework or other locations away from the welding area increase the possibility of the welding current passing through lifting chains, crane cables or other alternate circuits.
This can create fire hazards or overheat lifting chains or cables until they fail.
6.h. Also see item 1.c.
SAFETY
CYLINDER may explode if damaged.
7.a. Use only compressed gas cylinders containing the correct shielding gas for the process used and properly operating regulators designed for the gas and pressure used. All hoses, fittings, etc. should be suitable for the application and maintained in good condition.
7.b. Always keep cylinders in an upright position securely chained to an undercarriage or fixed support.
7.c. Cylinders should be located:
• Away from areas where they may be struck or subjected to physical damage.
• A safe distance from arc welding or cutting operations and any other source of heat, sparks, or flame.
7.d. Never allow the electrode, electrode holder or any other electrically “hot” parts to touch a cylinder.
7.e. Keep your head and face away from the cylinder valve outlet when opening the cylinder valve.
7.f. Valve protection caps should always be in place and hand tight except when the cylinder is in use or connected for use.
7.g. Read and follow the instructions on compressed gas cylinders, associated equipment, and CGA publication P-l,
“Precautions for Safe Handling of Compressed Gases in
Cylinders,” available from the Compressed Gas Association
1235 Jefferson Davis Highway, Arlington, VA 22202.
iii
FOR ELECTRICALLY powered equipment.
8.a. Turn off input power using the disconnect switch at the fuse box before working on the equipment.
8.b. Install equipment in accordance with the U.S. National
Electrical Code, all local codes and the manufacturer’s recommendations.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
Mar ‘95
INVERTEC STT
iv
SAFETY zones où l’on pique le laitier.
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 suivantes: iv
6. Eloigner les matériaux inflammables ou les recouvrir afin de prévenir tout risque d’incendie dû aux étincelles.
7. Quand on ne soude pas, poser la pince à une endroit isolé de la masse. Un court-circuit accidental peut provoquer un
échauffement et un risque d’incendie.
Sûreté Pour Soudage A L’Arc
1. Protegez-vous contre la secousse électrique: a. Les circuits à l’électrode et à la piéce sont sous tension quand la machine à souder est en marche. Eviter toujours tout contact entre les parties sous tension et la peau nue ou les vétements mouillés. Porter des gants secs et sans trous pour isoler les mains.
b. Faire trés attention de bien s’isoler de la masse quand on soude dans des endroits humides, ou sur un plancher metallique ou des grilles metalliques, principalement dans les positions assis ou couché pour lesquelles une grande partie du corps peut être en contact avec la masse.
c. Maintenir le porte-électrode, la pince de masse, le câble de soudage et la machine à souder en bon et sûr état defonctionnement.
d.Ne jamais plonger le porte-électrode dans l’eau pour le refroidir.
e. Ne jamais toucher simultanément les parties sous tension des porte-électrodes connectés à deux machines à souder parce que la tension entre les deux pinces peut être le total de la tension à vide des deux machines.
f. Si on utilise la machine à souder comme une source de courant pour soudage semi-automatique, ces precautions pour le porte-électrode s’applicuent aussi au pistolet de soudage.
8. S’assurer que la masse est connectée le plus prés possible de la zone de travail qu’il est pratique de le faire. Si on place la masse sur la charpente de la construction ou d’autres endroits
éloignés de la zone de travail, on augmente le risque de voir passer le courant de soudage par les chaines de levage, câbles de grue, ou autres circuits. Cela peut provoquer des risques d’incendie ou d’echauffement des chaines et des câbles jusqu’à ce qu’ils se rompent.
9. Assurer une ventilation suffisante dans la zone de soudage.
Ceci est particuliérement important pour le soudage de tôles galvanisées plombées, ou cadmiées ou tout autre métal qui produit des fumeés toxiques.
10. Ne pas souder en présence de vapeurs de chlore provenant d’opérations de dégraissage, nettoyage ou pistolage. La chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs du solvant pour produire du phosgéne (gas fortement toxique) ou autres produits irritants.
11. Pour obtenir de plus amples renseignements sur la sûreté, voir le code “Code for safety in welding and cutting” CSA Standard
W 117.2-1974.
2. Dans le cas de travail au dessus du niveau du sol, se protéger contre les chutes dans le cas ou on recoit un choc. Ne jamais enrouler le câble-électrode autour de n’importe quelle partie du corps.
3. Un coup d’arc peut être plus sévère qu’un coup de soliel, donc:
PRÉCAUTIONS DE SÛRETÉ POUR
LES MACHINES À SOUDER À
TRANSFORMATEUR ET À
REDRESSEUR
a. Utiliser un bon masque avec un verre filtrant approprié ainsi qu’un verre blanc afin de se protéger les yeux du rayonnement de l’arc et des projections quand on soude ou quand on regarde l’arc.
b. Porter des vêtements convenables afin de protéger la peau de soudeur et des aides contre le rayonnement de l‘arc.
c. Protéger l’autre personnel travaillant à proximité au soudage à l’aide d’écrans appropriés et non-inflammables.
1. Relier à la terre le chassis du poste conformement au code de l’électricité et aux recommendations du fabricant. Le dispositif de montage ou la piece à souder doit être branché à une bonne mise à la terre.
2. Autant que possible, I’installation et l’entretien du poste seront effectués par un électricien qualifié.
4. Des gouttes de laitier en fusion sont émises de l’arc de soudage. Se protéger avec des vêtements de protection libres de l’huile, tels que les gants en cuir, chemise épaisse, pantalons sans revers, et chaussures montantes.
3. Avant de faires des travaux à l’interieur de poste, la debrancher à l’interrupteur à la boite de fusibles.
4. Garder tous les couvercles et dispositifs de sûreté à leur place.
5. Toujours porter des lunettes de sécurité dans la zone de soudage. Utiliser des lunettes avec écrans lateraux dans les
INVERTEC STT
Mar. ‘93
v
MASTER TABLE OF CONTENTS FOR ALL SECTIONS
RETURN TO MAIN INDEX
Page
Safety .................................................................................................................................................i-iv
Installation.............................................................................................................................Section A
Technical Specifications ..............................................................................................................A-2
Location.......................................................................................................................................A-3
Stacking.......................................................................................................................................A-3
Tilting...........................................................................................................................................A-3
Machine Grounding and High Frequency Interference Protection..............................................A-3
Input Connections .......................................................................................................................A-3
Supply Connections..............................................................................................................A-3
Input Cable Installation and Connection...............................................................................A-4
Ground Connection...............................................................................................................A-4
Input Voltage Reconnect Procedure ...........................................................................................A-5
Output Connections ....................................................................................................................A-5
Wire Feeder Output Connections .........................................................................................A-5
Operation...............................................................................................................................Section B
Safety Instructions.......................................................................................................................B-2
General Description ....................................................................................................................B-3
Recommended Equipment..........................................................................................................B-3
Operating Controls ......................................................................................................................B-3
Design Features ..........................................................................................................................B-3
Welding Capability.......................................................................................................................B-3
Limitations ...................................................................................................................................B-3
Operational Features and Controls .............................................................................................B-4
Welding Operation.......................................................................................................................B-5
Welding Parameters and Guidelines...........................................................................................B-5
Recommended Settings..............................................................................................................B-6
.045" L-50 and L-56 Welding Procedures.............................................................................B-6
.030", .035" L-50 and L-56 Welding Procedures ..................................................................B-7
.035", .045" L-50 and L-56, 75% Ar/25% CO
2
Welding Procedure......................................B-8
.030", .035", .045" Stainless Steel Welding Procedures ......................................................B-9
1.2mm DIN SG2 Welding Procedures ................................................................................B-10
0.8, 1.0mm DIN SG2 Welding Procedures.........................................................................B-11
0.8, 1.0, 1.2mm Stainless Steel Welding Procedures ........................................................B-12
Accessories ..........................................................................................................................Section C
Maintenance ..........................................................................................................................Section D
Theory of Operation .............................................................................................................Section E
Troubleshooting and Repair ................................................................................................Section F
Electrical Diagrams ..............................................................................................................Section G
STT Parts .......................................................................................................................................P257
STT II Parts ....................................................................................................................................P294
v
INVERTEC STT
DEC 97
Section A-1
TABLE OF CONTENTS
- INSTALLATION SECTION -
Installation .............................................................................................................................
Section A
Technical Specifications ..............................................................................................................A-2
Location.......................................................................................................................................A-3
Stacking.......................................................................................................................................A-3
Tilting ...........................................................................................................................................A-3
Machine Grounding and High Frequency Interference Protection..............................................A-3
Input Connections .......................................................................................................................A-3
Supply Connections..............................................................................................................A-3
Input Cable Installation and Connection...............................................................................A-4
Ground Connection...............................................................................................................A-4
Input Voltage Reconnect Procedure ...........................................................................................A-5
Output Connections ....................................................................................................................A-5
Wire Feeder Output Connections .........................................................................................A-5
Section A-1
INVERTEC STT
A-2
INSTALLATION
TECHNICAL SPECIFICATIONS - INVERTEC STT
INPUT - THREE PHASE ONLY
STANDARD VOLTAGE
208/230/460/3/60 HZ
200/220/380/415/440/3/50/60 HZ
INPUT CURRENT AT RATED OUTPUT
32/30/19
33/30/18/17/16
A-2
DUTY CYCLE
60% Duty Cycle
100% Duty Cycle
RATED OUTPUT
AMPS
225
200
VOLTS AT RATED AMPS
29
28
OUTPUT - WELDER AND GENERATOR
CURRENT RANGE
Peak Current 1 0 - 450 Amps
Background 0 - 125 Amps
OPEN CIRCUIT VOLTAGE
85 VDC Maximum
AUXILIARY POWER
115 2 VAC @ 6 Amps
42 VAC @ 6 Amps
RECOMMENDED INPUT WIRE AND FUSE SIZES
INPUT VOLTAGE FUSE(SUPER LAG) INPUT AMPERE
AND FREQUENCY OR BREAKER RATING ON
SIZE NAMEPLATE
208/60
230/60
460/60
200/50/60
220/50/60
380/50/60
415/50/60
440/50/60
40
30
30
30
40
40
30
40
30
18
17
16
32
30
16
33
TYPE 75 C
COPPER
SUPPLY WIRE
IN CONDUIT
AWG (IEC) SIZES
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
TYPE 75 C
COPPER
GROUND WIRE
IN CONDUIT
AWG (IEC) SIZES
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
10 (6 mm 2 )
PHYSICAL DIMENSIONS
HEIGHT
23.2 in.
589 mm
WIDTH
13.2 in.
336 mm
DEPTH
24.4 in.
620 mm
WEIGHT
100 lbs.
46 kg
1 At low input voltages (below 208 VAC) and input voltages of 380 VAC through 415 VAC there may be a 15% reduction in Peak Current.
2 115 VAC not present on European Models.
INVERTEC STT
DEC 97
A-3 A-3
INSTALLATION
Read and understand entire Installation Section before starting installation.
WARNING
ELECTRIC SHOCK can kill.
• Only qualified personnel should perform this installation.
• Turn the input power OFF at the disconnect switch or fuse box before installing this equipment.
• Turn the power switch on the
Invertec STT “OFF” before connecting or disconnecting input power lines, output cables, or control cables.
• Do not touch electrically hot parts.
• Always connect the ground terminal to a good electrical earth ground.
MACHINE GROUNDING AND HIGH
FREQUENCY INTERFERENCE
PROTECTION
The machine may not be suitable for use in an environment where high frequency is present. For example do not place the machine in close proximity to “TIG” or “PLASMA” operations. To minimize high frequency interference:
Locate the STT power source more than 15 feet
(4.5 m) away from high frequency units and more than 25 feet (7.6 m) separation between ground connections or welding arcs or high frequency units.
Provide proper electrical ground to the machine per local and national electrical codes.
INPUT CONNECTIONS
CAUTION
FAILURE TO FOLLOW THESE INSTRUCTIONS CAN
CAUSE IMMEDIATE FAILURE OF COMPONENTS
WITHIN THE WELDER.
Only qualified personnel should install, use, or service this equipment.
Turn the input power off at the disconnect switch before attempting to connect the input power lines.
Connect the green lead of the power cord to ground per local and national electrical codes.
SELECT SUITABLE LOCATION
Locate the machine where there is free circulation of clean air. Place the machine so that air can freely circulate into the sides and out of the rear of the machine.
Dirt and dust that can be drawn into the machine should be kept to a minimum. Failure to observe these precautions can result in excessive operating temperatures and nuisance shut down of the Invertec STT.
This machine carries an enclosure rating of IP 21. It should not be placed in extremely damp or dirty locations. It should not be exposed to rain or snow.
STACKING
The Invertec STT cannot be stacked.
TILTING
Place the machine on a secure, level surface otherwise the unit may topple over.
SUPPLY CONNECTIONS
Be sure the voltage, phase, and frequency of the input supply is as specified on the rating plate. Input power supply line entry is provided on the case back of the machine. See Figure A.1 for location of the rating plate.
The Invertec STT should be connected only by a qualified electrician. Installation should be made in accordance with local and national codes. Refer to the
Technical Specifications at the beginning of this section for proper fuse sizes, ground wire, and input supply power cable sizes.
Some models come from the factory with an input power cord. If you model does not include the input power cord install the proper size input cable and ground cable according to INPUT CABLE INSTALLA-
TION AND CONNECTION.
INVERTEC STT
A-4
INSTALLATION
FIGURE A.1 - CASE BACK
A-4
INPUT CABLE
ENTRY ACCESS
& CABLE STRAIN RELIEF
NAMEPLATE
INPUT CABLE INSTALLATION AND
CONNECTION
A cable strain relief is provided at the supple line entry and is designed to accommodate cable diameters of
.310 - 1.070 in. (7.9 - 27.2 mm). Refer to Technical
Specifications at the beginning of this section for the proper input cable sizes. Refer to Figure A.1 and perform the following steps:
1.
Remove the wraparound cover of the Invertec STT.
2.
Feed the input cable through the input cable entry access hole at the right rear of the machine.
3.
Route the cable through the cable hangers, located along the lower right inside edge of the machine, up to the power switch located on the front panel.
4.
Strip away 102 mm (4 in.) of the outer jacket. Trim fillers and strip conductor jackets to connect to the power switch.
5.
Connect the three phase line conductors to the power switch terminals labeled U, V and W. Tighten the connections to 3.0 Nm. (27 in.-lb.) torque.
6.
Securely tighten the cable strain relief located on the case back of the machine.
GROUND CONNECTION
1.
Connect the ground terminal to earth ground per National Electrical Code.
2.
Replace the wraparound cover of the Invertec STT.
INVERTEC STT
A-5
INSTALLATION
FIGURE A.2 - RECONNECT PANEL
A-5
INPUT VOLTAGE RECONNECT
PROCEDURE
As shipped from the factory, multiple voltage
(208/230/460 VAC) or (200/220/380 - 415/440 VAC) machines are internally configured for the highest input voltage (440 or 460 VAC).
1.
For Connections to 440 or 460 VAC verify the internal configurations to the procedures shown below and refer to Figure A.2.
2.
For Connections to 200, 208, 220, 230, 380 or 415
VAC follow the procedure shown below and refer to Figure A.2.
CAUTION
Turn the main power to the machine OFF before performing the reconnect procedure. Failure to do so will result in damage to the machine. DO NOT switch the reconnect bar with machine power ON.
380 or 415 VAC 1. Open reconnect panel access door on wrap-around.
2. Move input voltage switch to
Voltage = 380 -460V position.
3. Move lead “A” to 380-415
Terminal.
220 or 230 VAC 1. Open reconnect panel access door on wrap-around.
2. Move input voltage switch to
Voltage = 200 -230V position.
3. Move lead “A” to 220-230
Terminal.
200 or 208 VAC 1. Open reconnect panel access door on wrap-around.
2. Move input voltage switch to
Voltage = 200 -230V position.
3. Move lead “A” to 200-208
Terminal.
To Operate at Procedure
460 or 440 VAC 1. Open reconnect panel access door on wrap-around.
2. Move input voltage switch to
Voltage = 380 -460V position.
3. Move lead “A” to 440-460
Terminal.
OUTPUT CONNECTIONS
WIRE FEEDER OUTPUT CONNECTIONS
Refer to the Accessories section of this manual for instructions on connecting a wire feeder to the Invertec
STT.
The LN-742 wire feeder is the recommended feeder for use with the Invertec STT.
INVERTEC STT
Section B-1
TABLE OF CONTENTS
- OPERATION SECTION -
Operation ...............................................................................................................................
Section B
Safety Precautions ......................................................................................................................B-2
General Description ....................................................................................................................B-3
Recommended Equipment..........................................................................................................B-3
Operating Controls ......................................................................................................................B-3
Design Features ..........................................................................................................................B-3
Welding Capability.......................................................................................................................B-3
Limitations ...................................................................................................................................B-3
Operational Features and Controls .............................................................................................B-4
Welding Operation.......................................................................................................................B-5
Welding Parameters and Guidelines...........................................................................................B-5
Recommended Settings for STT.................................................................................................B-6
.045" L-50 and L-56 Welding Procedures.............................................................................B-6
.030", .035" L-50 and L-56 Welding Procedures ..................................................................B-7
.035", .045" L-50 and L-56, 75% Ar/25% CO
2
Welding Procedure......................................B-8
.030", .035", .045" Stainless Steel Welding Procedures ......................................................B-9
1.2mm DIN SG2 Welding Procedures ................................................................................B-10
0.8, 1.0mm DIN SG2 Welding Procedures.........................................................................B-11
0.8, 1.0, 1.2mm Stainless Steel Welding Procedures ........................................................B-12
Recommended Settings for STT II............................................................................................B-13
Section B-1
INVERTEC STT
DEC 97
B-2
OPERATION
OPERATING INSTRUCTIONS
Read and understand this entire section before operating your Invertec STT.
SAFETY INSTRUCTIONS
WARNING
ELECTRIC SHOCK can kill.
• Do not touch electrically live parts or electrode with skin or wet clothing.
ground.
• Always wear dry insulating gloves.
FUMES AND GASES can be dangerous.
• Keep your head out of fumes.
• Use ventilation or exhaust to remove fumes from breathing zone.
WELDING SPARKS can cause fire or explosion.
• Keep flammable material away.
• Do not weld on containers that have held combustibles.
ARC RAYS can burn.
• Wear eye, ear, and body protection.
Observe additional Safety Guidelines detailed in the beginning of this manual.
B-2
INVERTEC STT
B-3 B-3
OPERATION
GENERAL DESCRIPTION
The Invertec STT is a 225-ampere inverter based arc welding power source specifically designed for the STT welding process. It is neither a constant current (CC) nor a constant voltage (CV) machine. It is a power source that delivers current of a desired wave form to reduce spatter and fumes.
The process is optimized for short-circuiting GMAW welding.
RECOMMENDED EQUIPMENT
The LN-742 wire feeder is recommended for use with the STT. The LN-7 GMA, LN-9 GMA, NA-5, and NA-5R can all be used with the STT. These units can only be used to feed wire.
• Thermostat and FET over current protector prevent overheating from overloads, high ambient temperatures, or loss of air flow.
• High temperature Class H insulation.
• Protection circuits and ample safety margins prevent damage to the solid state components from transient voltages and high currents.
• Preset welding current capability.
• The STT II offers improvements over the previous model. Approximately 40% increase in deposition rate capability, and a significant increase in travel speed.
OPERATING CONTROLS
The Invertec STT has the following controls as standard: On/Off switch, Peak Current adjustment,
Background Current adjustment, Hot Start adjustment,
Tailout (STT II only), and 2 toggle switches; one for wire size selection and one for wire type selection.
WELDING CAPABILITY
The Invertec STT is rated at 225 amps, 29 volts, at
60% duty cycle on a ten minute basis. It is capable of higher duty cycles at lower output currents. If the duty cycle(s) are exceeded, a thermal protector will shut off the output until the machine cools to a reasonable operating temperature.
DESIGN FEATURES
• State of the art inverter technology yields high power efficiency, excellent welding performance, lightweight and compact design.
• Twist-Mate output terminals.
• Digital meters for procedure settings are standard.
• Automatic Inductance or Pinch Control.
• Solid state circuitry for extra long component life.
• Current feedback ensures that original procedure settings all remain constant.
• Arc Sense lead assembly (Electrode and Work), connects through a 4-pin case front connector.
• Peak Current and Background Current may be remotely controlled.
LIMITATIONS
• The Invertec STT is not recommended for spray or pulse GMAW, FCAW, arc gouging or other constant voltage processes or SMAW.
• GMAW is the only process supported by the STT.
• May not be suitable for use in an environment with
High Frequency present. (See Machine Grounding
and High Frequency Protection in the Installation
Section of this manual.)
• Suitable for indoor use only (IEC IP21).
INVERTEC STT DEC 97
B-4 B-4
OPERATION
FIGURE B.1 - CASE FRONT CONTROLS
5
7
4 6
3
11
14
8
10
9
2
1
13
15
OPERATIONAL FEATURES AND
CONTROLS
All operator controls are located on the case front of the Invertec STT. Refer to Figure B.1 for locations.
1.
POWER SWITCH: Turns output power ON and OFF. This switch also controls auxiliary power available through the 14-pin
Wire Feeder Receptacle.
V
2A. BACKGROUND CURRENT OUTPUT CONTROL:
The output current is switched to the
Background level at the conclusion of the preceding Peak Current pulse. This knob allows preset adjustment of the amplitude of the background current up to 125 amperes.
2B. BACKGROUND CURRENT DISPLAY METER:
This is a digital meter for displaying the preset Background Current. This meter displays in 1 amp increments.
This
A
meter does not indicate the actual welding current, only the preset current.
3A. PEAK CURRENT OUTPUT CONTROL: The beginning portion of the welding arc is a pulse of current referred to as Peak
Current. This knob allows preset adjustment of the amplitude of the peak current up to 450 amperes.
12
3B. PEAK CURRENT DISPLAY METER:
This is a digital meter for displaying the preset Peak Current. This meter displays in 1 amp increments. This meter
A
does not indicate actual welding current only the preset current.
4.
HOT START CONTROL POTENTIOMETER: ”Hot
Start” provides approximately 25% to
50% more current during the initial start of the weld for improved arc starting and bead appearance. This control adjusts the duration of this “Hot Start” current. The control range is from 0 to 10, where 0 corresponds to the zero or no “Hot Start”, and 10 is maximum for a
“Hot Start” lasting for about four (4) seconds.
5.
WIRE SIZE SELECT SWITCH: This toggle switch selects between electrode diameters of .035" (1 mm) and smaller or .045" (1.2 mm) and larger. The
0.35" (1 mm) position provides improved performance of smaller diameter wires at higher wire feed speeds.
6.
WIRE TYPE SELECT SWITCH: This toggle switch selects between mild or stainless steel.
In the stainless position, the pulse width of the Peak
Current is changed from 1 to 2 ms for better performance for stainless steel welding.
7. TAILOUT: Alters the current waveform to increase deposit rate and travel speed. The Minimum setting sets STT II to the original STT waveform. As tailout is increased peak and Background current may need to be reduced to maintain optimum performance.
INVERTEC STT
DEC 97
B-5 B-5
OPERATION
8.
THERMAL SHUT-DOWN INDICATOR:
This light will indicate that either the internal thermostat(s) or the FET over current sensor has actuated.
Machine output will return after the internal components have returned to normal operating temperature (if the thermostat(s) “opened”) or after about 3-7 seconds (if the
FET over current sensor activated).
9.
REMOTE RECEPTACLE: This is a 10 pin MS-type connector for remote control of Peak Current and Background
Current. Trigger switch connections are also provided. The presence of the mating connector is automatically sensed, disabling the front panel Peak and Background Current controls.
Refer to “REMOTE CONTROL CONNECTOR” in the ACCESSORIES Section of this manual for more information.
15. ELECTRODE TERMINAL: instructions.
WELDING OPERATION
WELDING PARAMETERS AND
GUIDELINES
This twistmate connection is the positive output terminal for connecting an electrode cable to the wire feeder conductor block.
Refer to the
Accessories section for wire feeder connection
Familiarize yourself with the controls on the Invertec
STT before beginning to weld. Familiarize yourself with the operating manual for the wire feeder and the wire feeder controls before beginning to weld.
Refer to Recommended Settings in this section for initial machine settings for a particular application.
Set the Wire Size and Wire Type selection switches per the appropriate wire. Refer to Operational Features
and Controls in this section for the function of these switches.
10. WIRE FEEDER RECEPTACLE: This is
14 pin MS-type connector for the wire feeder connection.
115 and 42 VAC along with the trigger switch connections are provided.
(Only 42 VAC is available on
European models). There are no provisions for voltage control of the power source by the wire feeder. Refer to the Accessories Section of this manual for wire feeder connection instructions.
11. ARC SENSE RECEPTACLE: This is a four pin
MS-type connector for WORK and ELECTRODE sense leads. The STT requires a WORK sense and ELECTRODE sense lead for proper operation.
The ELECTRODE sense lead is bolted together with power source electrode lead at the wire feeder gun block. The WORK sense lead is furnished with an “alligator” type clip for connection to the work piece. Refer to the LN 742 wire feeder connection instructions in the Accessories section of this manual for proper connection of these leads.
The Invertec STT is neither a constant current (CC) nor a constant voltage (CV) power source. In general, wire diameter will be increased one size compared to conventional (CV) power sources. The larger the wire diameter the higher the deposition rate (Up to 1/16”).
Wire sizes below .035” are unnecessary for most applications. The Invertec STT is a current controlled machine which is capable of changing the electrode current quickly in order to respond to the instantaneous requirements of the arc and optimize performance. By sensing changes in welding current, and hence the electrode state, the power source will supply varying output currents to minimize spatter.
The Peak and
Background currents are two such current outputs that can be adjusted.
12. 42V AUXILIARY POWER CIRCUIT BREAKER:
The 42 VAC supply is protected from excessive current draws with a 6 amp circuit breaker. When the breaker “trips” its button will extend. Depressing this button will reset the breaker.
13. 115V AUXILIARY POWER CIRCUIT BREAKER:
(Not on European Models): The 115 VAC supply is protected from excessive current draws with a 6 amp circuit breaker.
When the breaker “trips” it button will extend.
Depressing this button will reset the breaker.
14. WORK TERMINAL: This twist-mate connection is the negative output terminal for connecting a work cable and clamp to the workpiece.
Wire Feed Speed controls the deposition rate. Peak
Current controls the Arc Length. Background Current controls the Bead Contour. And Tailout (STT II only) increases Power in the Arc.
PEAK CURRENT
The Peak Current control acts similar to an “arc pinch” control. Peak current serves to establish the arc length and promote good fusion. Higher peak current levels will cause the arc to broaden momentarily while increasing the arc length. If set too high, globular type transfer will occur. Setting this level to low will cause instability and wire stubbing. In practice, this current level should be adjusted for minimum spatter and puddle agitation.
INVERTEC STT
DEC 97
B-6
Adjust Arc Length with Peak Current
B-6
OPERATION of the greater heat generated in the 100% CO
2 arc.
(100% CO
2 is 35 volts/cm and 100% Argon is 20 volts/cm. 75% Argon, 25% CO
2 is about 24 volts/cm.
Contact Tip to Work Distance
Note: In 100% CO
2 shielding gas applications the peak current level should be set greater than in a corresponding application using a gas blend with a high percentage of Argon. Longer initial arc lengths with 100%
CO2 are required to reduce spatter.
BACKGROUND CURRENT
The Background Current provides the control for the overall heat input to the weld. Adjusting this level too high will cause a large droplet to form and globular type transfer to occur resulting in increased spatter.
Adjusting this level to low will cause wire stubbing and also poor wetting of the weld metal. This is similar to a low voltage setting on a standard CV machine
Adjust Bead Shape using Background Current
Note: Background Current levels for applications using
100% CO
2 is less than similar procedures involving gas blends with high percentages of Argon. This is a result
HOT START
The Hot Start control can be set to enhance establishing the arc and provide the capability of increasing the heat at the start of the weld to compensate for a cold work piece. Hot start adjusts the time that additional current is applied during the starting of the arc. Refer to
“Operational Features and Controls” in this section for a description of this control.
TAILOUT (STT II Only)
The tail out provides additional heat without the molten droplet becoming too large. Increase as necessary to add “Heat” to the arc without increasing arc length.
(This will allow for faster travel speeds and produce improved wetting). As tailout is increased, the peal and/or background current is usually reduced.
WELDING ARC PERFORMANCE
For optimum spatter reduction, the arc should be concentrated on the puddle.
RECOMMENDED INITIAL SETTINGS For STT only
Refer to the following tables for recommended settings such as wire types, sizes, wire feed speeds, peak current settings, background current settings, and travel speeds.
TABLE B.1 - ALL POSITION WELDING .045" L-50 AND L-56 WITH CARBON DIOXIDE SHIELDING GAS 1
Wire Feed Background Tip to Plate Welding
Speed Peak Current Current Travel Speed Distance (in) Current
Material Size (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)
3/16"
10 ga.
12 ga.
14 ga.
16 ga.
175
150
110
100
65
440
400
390
380
235
1 Shielding gas flow rate of 25 CFH
75
60
40
30
40
10--11
12--13
13--14
11--12
11-12
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
230
200
175
160
125
INVERTEC STT
DEC 97
B-7 B-7
OPERATION
TABLE B.2 - PIPE WELDING 3/8" THICKNESS MAXIMUM .045" L-50 AND L-56 WITH CARBON DIOXIDE
SHIELDING GAS 1
Pass
Hot/Fill
Cap
Root Pass
Vertical
Down
Root Pass
Vertical Up
Fill Pass
Vertical Up
Cap Pass
Vertical Up
Wire Feed
Speed
(in/min.)
120
75
120
120
Background
Peak Current Current
Control Setting Control Setting (in/min.)
370
275
370
370
25
40
50
50
8--9
3--4
3
3
Tip to Plate Welding
Travel Speed Distance (in) Current
1/4
1/4
1/4
1/4
(approx. AMPS)
200
130
210
210
Vertical-up procedures are recommended for top (12 to 2 o’clock) and overhead (4 to 6 o’clock) positions.
1 Shielding gas flow rate of 25 CFH
TABLE B.3 - ALL POSITION WELDING .035" L-50 AND L-56 WITH CARBON DIOXIDE SHIELDING GAS 1
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
3/16"
10 ga.
12 ga.
14 ga.
16 ga.
18 ga.
20 ga.
250
235
220
210
190
90
80
1 Shielding gas flow rate of 25 CFH
420
400
390
380
360
320
295
30
25
25
50
40
35
30
13--14
14--15
16--17
17--18
19--20
11-12
12--13
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4-5/16
1/4-5/16
1/4--5/16
190
185
180
175
170
115
100
TABLE B.4 - ALL POSITION WELDING .030" L-50 AND L-56 WITH CARBON DIOXIDE SHIELDING GAS 1
Wire Feed Background Tip to Plate Welding
Speed Peak Current Current Travel Speed Distance (in) Current
Material Size (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)
12 ga.
14 ga.
16 ga.
18 ga.
20 ga.
250
235
175
150
90
300
290
275
250
220
1 Shielding gas flow rate of 25 CFH
50
45
35
25
30
16--17
16--17
16--17
15--16
11--12
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
140
135
125
110
70
The serviceability of a product or structure utilizing this type of information is and must be the sole responsibility of the builder/user. Many variables beyond the control of The Lincoln Electric Company affect the results obtained in applying this type of information. These variables include, but are not limited to, welding procedure, plate chemistry and temperature, weldment design, fabrication methods and service requirements.
INVERTEC STT
DEC 97
B-8 B-8
OPERATION
TABLE B.5 - ALL POSITION WELDING .045" L-50 AND L-56 WITH 75% ARGON/25% CARBON DIOXIDE
SHIELDING GAS
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
3/16"
10 ga.
12 ga.
14 ga.
175
150
110
100
358
354
326
296
120
90
68
66
10--11
12--13
11-12
11-12
1/4-5/16
1/4--5/16
1/4--5/16
1/4--5/16
200
190
150
140
TABLE B.6 - ALL POSITION WELDING .035" L-50 AND L-56 WITH 75% ARGON /25% CARBON DIOXIDE
SHIELDING GAS
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
3/16"
10 ga.
12 ga.
14 ga.
16 ga.
18 ga.
300
235
220
210
190
90
300
300
285
280
260
200
105
80
80
75
70
39
10--12
14--15
16--17
19--20
17--18
12--13
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
195
185
180
175
160
105
The serviceability of a product or structure utilizing this type of information is and must be the sole responsibility of the builder/user. Many variables beyond the control of The Lincoln Electric Company affect the results obtained in applying this type of information. These variables include, but are not limited to, welding procedure, plate chemistry and temperature, weldment design, fabrication methods and service requirements.
INVERTEC STT
B-9 B-9
OPERATION
TABLE B.7 - ALL POSITION WELDING .045" BLUE MAX MIG 308LSi 1
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
3/16"
10 ga.
12 ga.
14 ga.
16 ga.
160
150
135
120
100
155
140
135
110
105
105
95
90
80
70
9
14
17
17
15
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
150
145
120
105
95
1 Procedures were developed using a shielding gas composition of 90% Helium 7-1/2% Argon 2-1/2% Carbon Dioxide.
Shielding gas flow rate of 25 CFH.
TABLE B.8 - ALL POSITION WELDING .035" BLUE MAX MIG 308LSi 1
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
10 ga.
12 ga.
14 ga.
16 ga.
18 ga.
250
230
210
190
175
160
140
130
120
95
100
90
85
80
70
12
13.5
10
12.5
11
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
130
120
110
100
85
1 Procedures were developed using a shielding gas composition of 90% Helium 7-1/2% Argon 2-1/2% Carbon Dioxide.
Shielding gas flow rate of 25 CFH.
TABLE B.9 - ALL POSITION WELDING .030" BLUE MAX MIG 308LSi 1
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
10 ga.
12 ga.
14 ga.
16 ga.
18 ga.
20 ga.
235
225
200
190
180
170
195
180
180
175
170
160
65
60
60
55
50
45
11.5
14
12.5
13
14
16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
1/4--5/16
105
95
90
85
75
65
1 Procedures were developed using a shielding gas composition of 90% Helium 7-1/2% Argon 2-1/2% Carbon Dioxide.
Shielding gas flow rate of 25 CFH.
INVERTEC STT
B-10 B-10
OPERATION
TABLE B.10 - ALL POSITION WELDING 1.2 mm DIN SG 2 WITH CARBON DIOXIDE SHIELDING GAS 1
Wire Feed
Material Size Speed
(mm) (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
5
3.6
2.8
2
1.6
4.4
3.8
2.8
2.5
1.6
425
400
385
370
235
80
60
45
45
45
28
33
36
30
30
6--8
6--8
6--8
6--8
6--8
220
205
175
160
125
1 Shielding gas flow rate of 12 Liters/minute.
TABLE B.11 - PIPE WELDING 1.0 mm THICKNESS MAXIMUM 1.2 mm DIN SG 2 WITH CARBON DIOXIDE
SHIELDING GAS 1
Pass
Hot/Fill
Cap
Root Pass
Vertical
Down
Root Pass
Vertical Up
Fill Pass
Vertical Up
Cap Pass
Vertical Up
Wire Feed Background Tip to Plate Welding
Speed Peak Current Current Travel Speed Distance (in) Current
(in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)
2.77
370 30 20 6 200
1.78
2.77
2.77
300
380
380
50
65
65
7
7
8
6
6
6
130
210
210
Vertical-up procedures are recommended for top (12 to 2 o’clock) and overhead (4 to 6 o’clock) positions.
1 Shielding gas flow rate of 12 Liters/minute.
INVERTEC STT
B-11 B-11
OPERATION
TABLE B.12 - ALL POSITION WELDING 1.0 mm DIN SG 2 WITH CARBON DIOXIDE SHIELDING GAS 1
Wire Feed Background Tip to Plate Welding
Speed Peak Current Current Travel Speed Distance (in) Current
Material Size (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)
5
3.6
2.8
2
1.6
1.2
5
4.7
4.4
4.2
3.8
2.5
420
400
390
380
360
340
1 Shielding gas flow rate of 12 Liters/minute.
50
40
35
30
30
40
36
38
43
45
51
30
6--8
6--8
6--8
6--8
6--8
6--8
190
180
175
165
160
95
TABLE B.13 - ALL POSITION WELDING 0.8 mm DIN SG 2 WITH CARBON DIOXIDE SHIELDING GAS 1
Wire Feed
Material Size Speed
(mm) (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
2.8
2
1.6
1.2
0.9
6.3
6
4.4
3.8
2.5
300
290
275
250
220
50
45
35
25
30
43
43
43
41
30
6--8
6--8
6--8
6--8
6--8
140
135
125
110
70
1 Shielding gas flow rate of 12 Liters/minute.
The serviceability of a product or structure utilizing this type of information is and must be the sole responsibility of the builder/user. Many variables beyond the control of The Lincoln Electric Company affect the results obtained in applying this type of information. These variables include, but are not limited to, welding procedure, plate chemistry and temperature, weldment design, fabrication methods and service requirements.
INVERTEC STT
B-12 B-12
OPERATION
TABLE B.14 - ALL POSITION WELDING 1.2 mm BLUE MAX MIG 308LSi 1
Wire Feed Background Tip to Plate Welding
Material Size Speed
(mm) (in/min.)
Peak Current
Control Setting
Current
Control Setting
Travel Speed
(in/min.)
Distance (in) Current
(approx. AMPS)
5
3.6
2.8
2
1.6
3.7
3.5
3.1
2.8
2.3
155
140
135
110
105
110
95
95
80
70
23
36
43
43
38
6--8
6--8
6--8
6--8
6--8
155
135
125
110
90
1 Procedures were developed using a shielding gas composition of 90% Helium 7-1/2% Argon 2-1/2% Carbon Dioxide.
Shielding gas flow rate of 12 Liter/minute.
TABLE B.15 - ALL POSITION WELDING 1.0 mm BLUE MAX MIG 308LSi 1
Wire Feed
Material Size Speed
(mm) (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
3.6
2.8
2
1.6
1.2
5
4.6
4.2
3.8
3.5
150
140
130
120
95
90
90
85
80
70
30
35
25
32
28
6--8
6--8
6--8
6--8
6--8
125
120
110
100
90
1 Procedures were developed using a shielding gas composition of 90% Helium 7-1/2% Argon 2-1/2% Carbon Dioxide.
Shielding gas flow rate of 12 Liter/minute.
TABLE B.16 - ALL POSITION WELDING 0.8 mm BLUE MAX MIG 308Si 1
Wire Feed
Speed
Material Size (in/min.)
Background Tip to Plate Welding
Peak Current Current Travel Speed Distance (in) Current
Control Setting Control Setting (in/min.) (approx. AMPS)
3.6
2.8
2
1.6
1.2
0.9
6
5.7
5
4.8
4.6
4.3
200
180
180
175
170
160
77
65
60
55
50
45
29
35
32
33
36
40
6--8
6--8
6--8
6--8
6--8
6--8
105
95
90
85
75
65
1 Procedures were developed using a shielding gas composition of 90% Helium 7-1/2% Argon 2-1/2% Carbon Dioxide.
Shielding gas flow rate of 12 Liter/minute.
The serviceability of a product or structure utilizing this type of information is and must be the sole responsibility of the builder/user. Many variables beyond the control of The Lincoln Electric Company affect the results obtained in applying this type of information. These variables include, but are not limited to, welding procedure, plate chemistry and temperature, weldment design, fabrication methods and service requirements.
INVERTEC STT
B-13
WELDING SETTINGs FOR STT II -
(Steel) Horizontal Fillet (See Table B.17 and B.18)
DIRECTION
OF
TRAVEL
OPERATION
75
°
(Stainless Steel) Horizontal Fillet
(See Table B.19 and B.20)
DIRECTION
OF
TRAVEL
B-13
75
°
45
°
TOP VIEW
DIRECTION
OF
TRAVEL
75
°
45
°
TOP VIEW
DIRECTION
OF
TRAVEL
75
°
END VIEW
100% CO
2
Table B.17
Gas Shield (Set for Steel Mode)
Plate Thickness “ (mm) 20 ga
(0.9)
Electrode size “ (mm) 0.035
(0.9)
WFS “/min (m/min)
Peak Current
Background Current
Tailout setting
Average Amperage
100
(2.5)
220
30
3
60
Travel Speed “/min 12
(m/min) (0.3)
Gas Flow cfh (L/min)
Electrical Stickout “
(mm)
Plate Thickness “ (mm) 20 ga
(0.9)
Electrode size “ (mm) 0.035
(0.9)
WFS “/min (m/min)
Peak Current
Background Current
Tailout setting
Average Amperage
100
(2.5)
225
40
8
70
Travel Speed “/min 12
(m/min) (0.3)
Gas Flow cfh (L/min)
Electrical Stickout “
(mm)
FRONT VIEW
14 ga 10 ga
(2.0) (3.25)
0.045
0.045
(1.1) (1.1)
100
(2.5)
260
40
170
(4.2)
280
65
7
105
12
(0.3)
25 (12)
1/4 - 3/8
(6.4 - 10)
5
120
12
(0.3)
END VIEW FRONT VIEW
Table B.19
90% He, 7.5% Ar, 2.5% CO
2
Gas Shield (Set for Steel Mode)
Plate Thickness “ (mm) 20 ga
(0.9)
Electrode size “ (mm) 0.035
(0.9)
WFS “/min (m/min)
Peak Current
Background Current
Tailout setting
Average Amperage
100
(2.5)
165
35
7
40
Travel Speed “/min 12
(m/min) (0.3)
Gas Flow cfh (L/min)
Electrical Stickout “
(mm)
14 ga 10 ga
(2.0) (3.25)
0.045
0.045
(1.1) (1.1)
130
(3.3)
210
60
7
95
16
(0.4)
25 (12)
1/4 - 3/8
(6.4 - 10)
170
(4.2)
250
85
4
120
16
(0.4)
75% CO
2
Table B.18
- 25% Ar Gas Shield (Set for Steel Mode)
14 ga 10 ga
(2.0) (3.25)
0.045
0.045
(1.1) (1.1)
100
(2.5)
270
65
120
(3.0)
310
70
4
110
12
(0.3)
25 (12)
1/4 - 3/8
(6.4 - 10)
6
130
12
(0.3)
Table B.20
98% Ar, 2% O
2
Gas Shield (Set for Stainless Steel Mode)
Plate Thickness “ (mm) 20 ga
Electrode size “ (mm)
WFS “/min (m/min)
Peak Current
Background Current
Tailout setting
Average Amperage
INVERTEC STT
(0.9)
100
(2.5)
145
45
7
60
Travel Speed “/min 12
(m/min) (0.3)
Gas Flow cfh (L/min)
Electrical Stickout “
(mm)
(0.9)
0.035
14 ga 10 ga
(2.0) (3.25)
0.045
0.045
(1.1) (1.1)
130
(3.3)
190
95
170
(4.2)
280
95
8
120
12
(0.3)
25 (12)
1/4 - 3/8
(6.4 - 10)
7
150
12
(0.3)
DEC 97
Section C-1
TABLE OF CONTENTS
- ACCESSORIES -
Accessories ...........................................................................................................................
Section C
Options/Accessories ...................................................................................................................C-2
LN-742 Wire Feeder Connection Instructions.............................................................................C-3
Section C-1
INVERTEC STT
C-2 C-2
ACCESSORIES
OPTIONS/ACCESSORIES
SENSE LEADS (K940) - These leads are used to accurately sense arc voltage. One set is required for each STT power source. A 10 ft and 25 ft set are provided as standard with the machine. Additional sets are available in 10 ft (K940-10), 25 ft (K940-25) and 50 ft (K940-50) lengths.
REMOTE CONTROL (K942-1) - Allows remote adjustment of Peak and Background Current settings.
REMOTE RECEPTACLE (For optional remote interface or Robotic Control)
1.
The 10 pin MS connector labeled “Remote Control” located on the front panel of the STT is used for remote control of the power source. Control for the
PEAK (PB pot) and BACKGROUND (BG pot) current along with the trigger switch is provided through this connector.
2.
See Figure C.1 below for details about the remote receptacle (J38). Note that pins “J” and “B” are shorted together. This “short circuit” tells the STT control board to accept PEAK and BACKGROUND inputs on this connector rather than from the front panel controls. If this short is removed, the front panel controls will be active. By adding a switch between pins”J” and “B” a LOCAL/REMOTE control switch can be created. (Switch open for “local” and closed for “remote.”)
3.
For robotic control of the PEAK CURRENT, a 0 to
+10 volt DC signal is applied between pins “A” and
“G” with + applied to pin “G”. The BACKGROUND
CURRENT is controlled with a similar signal applied between pins “A” and “C” with + applied to pin “C”. In this application pins “J” and “B” must be shorted as described in 2 above.
NOTE: These analog signals should be isolated from the robot circuitry to prevent interference.
4.
The trigger switch is connected between pins “D” and “F”. These connections are in parallel with the trigger switch from the wire feeder.
5.
The digital meters for PEAK AND BACKGROUND currents will show preset values in both local and remote operation.
FIGURE C.1 – PORTION OF G2773 WIRING DIAGRAM
(Refer to actual diagram pasted inside your machine.)
R E M O T E
P R O T E C T I O N B O A R D
2 2 3
2 1 2 C
4 3 A
3 3 C
3 2 C
2 1 2 B
+ A R C
- A R C
J 3 7
1
2
3
4
4
8
5
3
2
6
1
7
8
J 3 8
1 0
9
1 2
4
1 1
3
2
1
INVERTEC STT
2 9 0
291
J 1 9
3
4
1
2
( + )
( - )
V O L T A G E
S E N S E
C O N N E C T I O N
J 3 8
J
G
A
D
B
C
I
E
F
H
T R I G G E R
G N D
O P T I O N A L
R E M O T E
I N T E R F A C E
B G
1 0 K
P B
1 0 K
C-3 C-3
ACCESSORIES
LN-742 WIRE FEEDER CONNEC-
TION INSTRUCTIONS
The LN-742 is the recommended wire feeder for use with the Invertec STT. Refer to the LN-742 Operator
Manual for Wire Feed Operation. Refer to Figure C.2
and follow the instructions below to connect the LN-
742.
WARNING
ELECTRIC SHOCK can kill.
• Only qualified personnel should perform this installation.
• Turn the input power OFF at the disconnect switch or fuse box before connecting the wire feeder.
1.
Turn the Invertec STT power off.
2.
Connect the ARC SENSE LEAD MS connector to the mating connector on STT front panel.
3.
Connect the electrode lead (Twist-Mate) to (+) output terminal on STT.
4.
Connect the other end of electrode lead (Step #3) and the ARC SENSE LEAD (Lead with ring lug, step #2) together to the gun block on the LN-742.
5.
Connect work lead between STT (-) terminal and the work piece.
6.
Connect the ARC SENSE LEAD (lead with alligator clip) to work piece.
NOTE: For best welding performance, make this connection as close as possible to the welding arc.
7.
Connect the wire feeder control cable between the
LN-742 and the 14-pin Wire Feeder Receptacle on the STT.
FIGURE C.2 – INVERTEC STT/LN-742 WIRE FEEDER CONNECTION
WARNING
ELECTRIC
SHOCK
CAN KILL
Turn off input power to the Welding
Power Source using the disconnect switch at the fuse box before connecting the wire feeder.
Only qualified persons should install, use or service this machine.
CONTROL, ELECTRODE AND ARC SENSE
CABLES SHOULD BE TAPED TOGETHER
REMOTE RECEPTACLE
WIRE FEEDER
LN742
LN7 GMA
LN9 GMA
NA5R
NA5
WORK LEAD
WIRE FEEDER
CONTROL CABLE
ELECTRODE LEAD
ARC SENSE LEAD
"ELECT"
ARC SENSE LEAD "WORK"
(SHOULD BE LOCATED
AS CLOSE AS POSSIBLE
TO THE WELDING ARC.
CONNECT ELECTRODE AND "ELECT"
ARC SENSE LEAD TOGETHER TO ELECTRODE
TERMINAL OF WIRE FEEDER
INVERTEC STT
Section D-1
TABLE OF CONTENTS
-MAINTENANCE-
Maintenance .........................................................................................................................
Section D
Input Filter Capacitor Discharge Procedure................................................................................D-2
Preventive Maintenance .............................................................................................................D-3
Major Component Locations .......................................................................................................D-4
Section D-1
INVERTEC STT
D-2 D-2
MAINTENANCE
WARNING
ELECTRIC SHOCK can kill.
• Failure to follow this capacitor discharge procedure can result in electric shock.
INPUT FILTER CAPACITOR
DISCHARGE PROCEDURE
1.
Turn off input power and disconnect input power lines.
2.
Remove the 5/16" hex head screws from side and top of machine and remove wrap-around machine cover.
3.
Be careful not to make contact with the capacitor terminals that are located in the center of the
Switch Boards.
4.
Obtain a high resistance and high wattage resistor
(25-1000 ohms and 25 watts minimum). This resistor is not supplied with machine. NEVER USE
A SHORTING STRAP FOR THIS PROCEDURE.
5.
Locate the two capacitor terminals (large hex head cap screws) shown in Figure D.1.
6.
Use electrically insulated gloves and insulated pliers. Hold body of the resistor and connect resistor leads across the two capacitor terminals. Hold resistor in place for 10 seconds. DO NOT TOUCH
CAPACITOR TERMINALS WITH YOUR BARE
HANDS.
7.
Repeat discharge procedure for capacitor on other side of machine.
8.
Check voltage across terminals of all capacitors with a DC voltmeter. Polarity of capacitor terminals is marked on PC board above terminals. Voltage should be zero. If any voltage remains, repeat this capacitor discharge procedure.
FIGURE D.1 – LOCATION OF INPUT FILTER CAPACITOR TERMINALS
WARNING
ELECTRIC
SHOCK
CAN KILL
Turn off input power to the Welding
Power Source using the disconnect switch at the fuse box before connecting the wire feeder.
Only qualified persons should install, use or service this machine.
CAPACITOR
TERMINALS
POWER
RESISTOR
INSULATED
PLIERS
INVERTEC STT
D-3
PREVENTIVE MAINTENANCE
See Figure D.2 for the location of components.
1.
Perform the following preventive maintenance procedures at least once every six months. It is good practice to keep a preventive maintenance record; a record tag attached to the machine works best.
2.
Remove the machine wrap-around cover and perform the input filter capacitor discharge procedure
(detailed at the beginning of this chapter).
3.
Clean the inside of the machine with a low pressure airstream. Be sure to clean the following components thoroughly.
• Power Switch, Driver, Protection, and Control printed circuit boards
• Power Switch
• Main Transformer
• Input Rectifier
• Heat Sink Fins
• Input Filter Capacitors
• Output Terminals
• Lower base compartment
D-3
MAINTENANCE
4.
Examine capacitors for leakage or oozing.
Replace if needed.
5.
Examine wrap-around cover for dents or breakage.
Repair as needed. Cover must be kept in good condition to assure high voltage parts are protected and correct spacings are maintained.
6.
Check electrical ground continuity. Using an ohmmeter, measure resistance between either output stud and an unpainted surface of the machine case. Meter reading should be 500,000 ohms or more. If meter reading is less than 500,000 ohms, check for electrical components that are not properly insulated from the case. Correct insulation if needed.
7.
Check arc sensing leads for loose or faulty connections.
8.
Replace machine cover and screws.
INVERTEC STT
D-4
14
7
8
MAINTENANCE
FIGURE D.2 – MAJOR COMPONENT LOCATIONS
12
1. BASE ASSEMBLY
2. REAR NAMEPLATE
3. RESISTORS
4. FAN SHROUD ASSEMBLY
5. PROTECTION PC BOARD
6. DRIVER PC BOARD
7. CONTROL BOX
8. CONTROL PC BOARD
9. BLEEDER RESISTORS
10. RECONNECT PANEL
11. DARLINGTON MODULE
12. WRAPAROUND ASSEMBLY
13. CASE FRONT ASSEMBLY
14. OUTPUT TERMINALS
15. OUTPUT CHOKE ASSEMBLY
16. TRANSFORMER ASSEMBLY
17. OUTPUT RECTIFIER ASSEMBLY
18. AUXILIARY TRANSFORMER
19. FET HEAT SINK ASSEMBLY
D-4
4
9
6
5
10
16
15
17
2
13
18
19
3
1
11
INVERTEC STT
Section E-1
TABLE OF CONTENTS
-THEORY OF OPERATION SECTION-
Theory of Operation .............................................................................................................
Section E
General Description ...............................................................................................................E-2
Input Voltage..........................................................................................................................E-2
Reconnect, Protection Board, Rectification and Precharge ..................................................E-3
Switch Boards........................................................................................................................E-4
Main Transformer, Output Rectification and Choke...............................................................E-5
Control Board, Darlington Drive and Module.........................................................................E-6
Power Board ..........................................................................................................................E-7
Remote Protection Board ......................................................................................................E-7
Field Effect Transistor (FET) Operation.................................................................................E-8
Pulse Width Modulation .........................................................................................................E-9
Minimum Output ..............................................................................................................E-9
Maximum Output .............................................................................................................E-9
Protective Circuits................................................................................................................E-10
Overload Protection.......................................................................................................E-10
Thermal Protection ........................................................................................................E-10
Section E-1
MAIN
TRANSFORMER
T2
T
I
S
W
C
H
FET
CAP
FET
B
O
A
R
D
FAN
LINE
SWITCH
115 VAC
TRANS
T4
INPUT
RECTIFIER
"A"
LEAD
TRANS
T1
115
VAC
CR1
N
E
C
T
R
E
C
O
N
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
CR2
18
VAC P
O
W
E
R
B
O
A
R
D
A
T
S
T
M
O
T
H
E
R
2
4
V
A
C
PWM SIGNAL
15VDC
GUN TRIGGER
S
W
I
T
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PRE -
CHARGE
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CURRENT
TRANS
T3
CURRENT FEEDBACK
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SIZE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
CHOKE
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
D
R
I
V
E
S
I
G
N
A
L C
T
I
O
N
P
R
O
T
E
R
E
M
O
T
E
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
FIGURE E.1 – INVERTEC STT
INVERTEC STT
E-2 E-2
THEORY OF OPERATION
FIGURE E.2 – INPUT VOLTAGE
MAIN
TRANSFORMER
T2
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
FAN
LINE
SWITCH
115 VAC
INPUT
RECTIFIER
"A"
LEAD
TRANS
T1
115
VAC
TRANS
T4
CR1
CR2
T
I
S
W
C
H
N
N
E
C
T
R
E
C
O
FET
CAP
FET
B
O
A
R
D
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
PRE -
CHARGE
A
T
S
T
M
O
T
H
E
R
2
4
V
A
C
18
VAC P
O
W
E
R
B
O
A
R
D
PWM SIGNAL
15VDC
GUN TRIGGER
T
I
S
W
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CURRENT
TRANS
T3
CHOKE
CURRENT FEEDBACK
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SIZE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
S
I
G
N
A
L
D
R
I
V
E
C
T
T
E
P
R
O
I
O
N
R
E
M
O
T
E
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
GENERAL DESCRIPTION
The Invertec STT is a 225 ampere, inverter based, arc welding power supply specifically designed for the
Surface Tension Transfer (STT) welding process. It cannot be classified as either a constant current (CC) or a constant voltage (CV) machine. The STT produces current of a desired waveform to reduce spatter and fumes. The STT process is optimized for short circuit GMAW welding only.
INPUT VOLTAGE
The Invertec STT can be connected for a variety of three-phase voltages. The initial input power is applied to the STT through a line switch located on the front of the machine. The AC input voltage is applied to the input rectifier and the T1 auxiliary transformer. The T1 transformer develops the appropriate AC voltages to operate the cooling fan, the power and control boards.
The T1 transformer also supplies primary voltage to the
T4 auxiliary transformer as well as 42 VAC to an external wire feeder. The T4 transformer supplies power to the Darlington drive board and the control board.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
INVERTEC STT
E-3
THEORY OF OPERATION
FIGURE E.3 – RECONNECT, PROTECTION BOARD, RECTIFICATION AND PRECHARGE
E-3
MAIN
TRANSFORMER
T2
FAN
LINE
SWITCH
115 VAC
INPUT
RECTIFIER
"A"
LEAD
TRANS
T1
115
VAC
TRANS
T4
CR2
M
O
S
T
T
H
E
R
A
T
2
4
V
A
C
18
VAC P
O
W
E
R
B
O
A
R
D
PWM SIGNAL
15VDC
GUN TRIGGER
S
W
T
I
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PRE -
CHARGE
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CR1
S
W
T
I
C
H
FET
CAP
FET
N
N
E
C
T
R
E
C
O
B
O
A
R
D
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
CURRENT
TRANS
T3
CURRENT FEEDBACK
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SIZE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
CHOKE
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
D
R
I
V
E
S
I
G
N
A
L
P
R
O
T
E
C
T
I
O
N
R
E
M
O
T
E
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
RECONNECT, PROTECTION
BOARD, RECTIFICATION AND
PRECHARGE
The reconnect panel allows the user to switch to low or high input voltage to match the input line voltage. The
AC input voltage is rectified and applied to the driver board. The driver board contains precharging circuitry for safe charging of the input filter capacitors. Once the capacitors are precharged, the input relays are energized, connecting full input power to the input filter capacitors. The protection board monitors the capacitors for voltage balance and/or overvoltage and will deenergize the input relays and precharge circuitry if either occurs. The machine output will be disabled.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
INVERTEC STT
E-4 E-4
THEORY OF OPERATION
FIGURE E.4 – SWITCH BOARDS
MAIN
TRANSFORMER
T2
FAN
LINE
SWITCH
115 VAC
TRANS
T1
115
VAC
TRANS
T4
INPUT
RECTIFIER
"A"
LEAD
CR2
18
VAC P
O
W
E
R
B
O
A
R
D
A
T
S
T
M
O
T
H
E
R
V
A
2
4
C
PWM SIGNAL
15VDC
GUN TRIGGER
S
W
I
T
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PRE -
CHARGE
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CR1
T
I
S
W
C
H
N
N
E
C
T
R
E
C
O
FET
CAP
FET
B
O
A
R
D
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
CURRENT
TRANS
T3
CURRENT FEEDBACK
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SIZE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
CHOKE
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
D
R
I
V
E
S
I
G
N
A
L
T
I
E
C
P
R
O
T
O
N
R
E
M
O
T
E
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
SWITCH BOARDS
There are two switch boards in the Invertec STT, each containing an input filter capacitor. The capacitors are connected in parallel when the machine is connected for "low" input voltage. The capacitors are connected in series when the reconnect switch is configured for
"high" input voltage. When the capacitors are fully charged, they act as power supplies for the switch boards. The switch boards contain the Field Effect
Transistors (FETs) which, when switched on, supply the main transformer primary windings with DC current flow. See Field Effect Transistor (FET) Operation discussion and diagrams. See Figure E.4.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
INVERTEC STT
E-5
THEORY OF OPERATION
FIGURE E.5 – MAIN TRANSFORMER, OUTPUT RECTIFICATION AND CHOKE
E-5
MAIN
TRANSFORMER
T2
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
FAN
LINE
SWITCH
115 VAC
TRANS
T4
INPUT
RECTIFIER
"A"
LEAD
TRANS
T1
115
VAC
CR1
CR2
S
W
T
I
C
H
N
N
E
C
R
E
C
O
T
FET
CAP
FET
B
O
A
R
D
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
PRE -
CHARGE
A
T
M
O
S
T
T
H
E
R
V
A
2
4
C
18
VAC P
O
W
E
R
B
O
A
R
D
PWM SIGNAL
15VDC
GUN TRIGGER
T
I
S
W
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CURRENT
TRANS
T3
CHOKE
CURRENT FEEDBACK
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SIZE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
S
I
G
N
A
L
D
R
I
V
E
R
E
M
O
T
E
T
I
E
C
P
R
O
T
O
N
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
MAIN TRANSFORMER, OUTPUT
RECTIFICATION AND CHOKE
Each switch board works as a switch pair. Each board feeds a separate, oppositely wound primary winding of the main transformer. The opposite directions of current flow through the main transformer primary and the offset timing of the switch boards induce an AC square wave output signal at the secondary of the main transformer.
The DC current flow through each primary winding, which is monitored by the current transformer T3, is redirected or "clamped" back to each respective input capacitor when the FETs are turned off. This is needed due to the inductance of the transformer primary windings. The cross coupling of the primaries along with the clamping action of the diode maintain capacitor balance when they are connected in the series (high voltage) input configuration.
The firing of both switch board pairs occurs during halves of 50 microsecond intervals, creating a constant
20 KHZ output.
The AC output from the main transformer secondary is rectified to a DC output and is applied through a stabilizer output choke, current sensor, Darlington module and remote protection board to the output terminals.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
INVERTEC STT
E-6 E-6
THEORY OF OPERATION
FIGURE E.6 – CONTROL BOARD, DARLINGTON DRIVE AND MODULE
MAIN
TRANSFORMER
T2
FAN
LINE
SWITCH
115 VAC
TRANS
T4
INPUT
RECTIFIER
"A"
LEAD
TRANS
T1
115
VAC
CR2
18
VAC P
O
W
E
R
B
O
A
R
D
M
O
S
T
T
H
E
R
A
T
2
4
V
A
C
PWM SIGNAL
15VDC
GUN TRIGGER
S
W
I
T
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PRE -
CHARGE
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CR1
I
T
S
W
C
H
FET
CAP
FET
N
N
E
C
T
R
E
C
O
B
O
A
R
D
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
CURRENT
TRANS
T3
CURRENT FEEDBACK
TAILOUT
CONTROL
(STT II ONLY)
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
CHOKE
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
D
R
I
V
E
S
I
G
N
A
L
P
R
O
T
E
C
T
I
O
N
R
E
M
O
T
E
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
CONTROL BOARD, DARLINGTON
DRIVE AND MODULE
The control board monitors the directives of the various controls and compares these commands to the current and voltage feedback information received from the current sensor and voltage sensing receptacle. This data is processed and the suitable PWM signal is sent to the power board. (See Pulse Width Modulation discussion).
The control board also determines when the Darlington module should be switched OFF to reduce weld spatter and fumes.
The appropriate signal is sent to the
Darlington drive board which then applies, or removes, the base drive signal to the Darlington module. When the Darlington module is in the OFF state, the welding current must pass through the one ohm resistance.
This reduces the current and, subsequently, spatter and fumes.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
INVERTEC STT
DEC 97
E-7 E-7
THEORY OF OPERATION
FIGURE E.7 – POWER BOARD AND REMOTE PROTECTION BOARD
MAIN
TRANSFORMER
T2
POSITIVE
OUTPUT
TERMINAL
1 OHM
CURRENT
SENSOR
DARLINGTON
MODULE
NEGATIVE
OUTPUT
TERMINAL
FAN
LINE
SWITCH
115 VAC
TRANS
T4
INPUT
RECTIFIER
"A"
LEAD
TRANS
T1
115
VAC
CR1
S
W
I
T
C
H
N
N
E
C
R
E
C
O
T
FET
CAP
FET
B
O
A
R
D
E
C
T
I
P
R
O
T
O
N
B
O
A
R
D
PRE -
CHARGE
D
R
I
V
E
R
B
O
A
R
D
CR2
18
VAC P
O
W
E
R
B
O
A
R
D
A
T
M
O
S
T
T
H
E
R
V
A
2
4
C
PWM SIGNAL
15VDC
GUN TRIGGER
I
T
S
W
C
H
FET
CAP
FET
B
O
A
R
D
LESS THAN 1VDC
PRE -
CHARGE
PULSE TRANSFORMER SIGNAL
CONTROL BOARD
36VAC
CURRENT
TRANS
T3
CHOKE
CURRENT FEEDBACK
PEAK
CURRENT
METER
BACK-
GROUND
METER
PEAK
CURRENT
CONTROL
HOT
START
CONTROL
BACK-
GROUND
CONTROL
WIRE
SIZE
SWITCH
WIRE
TYPE
SWITCH
10VAC AND 6VAC
DARLINGTON
DRIVER
BOARD
VOLTAGE FEEDBACK
S
I
G
N
A
L
D
R
I
V
E
R
E
M
O
T
E
T
I
E
C
P
R
O
T
O
N
R
D
B
O
A
42VAC
VOLTAGE
SENSING
RECEPTACLE
REMOTE
CONTROL
RECEPTACLE
WIRE
FEEDER
RECEPTACLE
POWER BOARD
The power board creates a pulse transformer drive signal, which is derived from the PWM signal received from the control board. See Pulse Width Modulation discussion. This drive signal is applied to the primary winding of the pulse transformer, which is located on the driver board. The pulse transformer secondary windings generate the proper gate pulse for the switch board FETs. See Field Effect Transistor (FET)
Operation.
The power board supplies a 15VDC supply voltage for the control board and also powers the input relays
(CR1 and CR2).
REMOTE PROTECTION BOARD
The remote protection board provides noise suppression and by-pass filtering to protect the internal circuitry of the STT machine.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
INVERTEC STT
E-8
THEORY OF OPERATIONS
FIGURE E-8 – FIELD EFFECT TRANSISTOR OPERATION
SOURCE
TERMINAL
GATE
TERMINAL
(0 VOLTS)
DRAIN
TERMINAL
DRAIN (N)
SOURCE (N)
E-8
SUBSTRATE (P)
A. PASSIVE
N CHANNEL
GATE
TERMINAL
(+ 6 VOLTS)
SOURCE (N) DRAIN (N)
ELECTRONS
B. ACTIVE
FIELD EFFECT TRANSISTOR (FET)
OPERATION
An FET is a type of transistor. FETs are semiconductors well suited for high-frequency switching.
Drawing A above shows an FET in a passive mode.
There is no gate signal, zero volts relative to the source and, therefore, no current flow. The drain terminal of the FET may be connected to a voltage supply; but since there is no conduction, the circuit will not supply current to downstream components connected to the source. The circuit is turned off like a light switch in the
OFF position.
Drawing B above shows the FET in an active mode.
When the gate signal, a positive DC voltage relative to the source, is applied to the gate terminal of the FET, it is capable of conducting current. A voltage supply connected to the drain terminal will allow the FET to conduct and henceforth supply current to downstream components. Current will flow through the conducting
FET to downstream components as long as the gate signal is present. This is similar to turning on a light switch.
INVERTEC STT
E-9 sec
THEORY OF OPERATION
FIGURE E-9 – TYPICAL FET OUTPUTS
48
50 sec sec
MINIMUM OUTPUT
E-9 sec
24 sec
2 sec
50 sec
MAXIMUM OUTPUT
24 sec
PULSE WIDTH MODULATION
The term PULSE WIDTH MODULATION is used to describe how much time is devoted to conduction in the positive and negative portions of the cycle.
Changing the pulse width is known as MODULATION.
Pulse Width Modulation (PWM) is the varying of the pulse width over the allowed range of a cycle to affect the output of the machine.
MINIMUM OUTPUT
By controlling the duration of the gate signal, the FET is turned on and off for different durations during a cycle. The top drawing above shows the minimum output signal possible over a 50-microsecond time period.
The positive portion of the signal represents one FET group 1 conducting for 1 microsecond. The negative portion is the other FET group 1 . The dwell time (off time) is 48 microseconds (both FET groups off). Since only 2 microseconds of the 50-microsecond time period is devoted to conducting, the output power is minimized.
MAXIMUM OUTPUT
By holding the gate signals on for 24 microseconds each and allowing only 2 microseconds of dwell time
(off time) during the 50-microsecond cycle, the output is maximized. The darkened area under the top curve can be compared to the area under the bottom curve.
The more dark area under the curve, the more power is present.
1 A FET group consists of the sets of FET modules grouped onto one switch board.
INVERTEC STT
E-10 E-10
THEORY OF OPERATION
PROTECTIVE CIRCUITS
Protective circuits are designed into the Invertec machine to sense trouble and shut down the machine before the trouble damages the internal machine components. Both overload and thermal protection circuits are included.
OVERLOAD PROTECTION
The machine is electrically protected from producing abnormally high output currents due to short electrode
“stick-out” or the nozzle shorting to the work. Should the output current exceed 500 amps, an electronic protection circuit will reduce the current to zero amps.
Five seconds after the “short” is removed the Invertec
STT will produce normal output.
A protection circuit is included to monitor the voltage across input filter capacitors. In the event that the capacitor voltage is too high, the protection circuit will prevent output. The protection circuit may prevent output, if any of these circumstances occur:
1. Capacitor conditioning is required
(Required if machine has been off for prolonged periods of time.)
2. Line surges over 500 VAC
3. Internal Component damage
4. Improper connections
THERMAL PROTECTION
Thermostats protect the machine from excessive operating temperatures. Excessive temperatures may be caused by a lack of cooling air or operating the machine beyond the duty cycle and output rating. If excessive operating temperature should occur, the thermostat will prevent output voltage or current. The meter will remain on during this time. (In addition, the yellow thermo LED will light.)
Thermostats are self-resetting once the machine cools sufficiently. If the thermostat shutdown was caused by excessive output or duty cycle and the fan is operating normally, the Power Switch may be left on and the reset should occur within a 15-minute period. If the fan is not turning or the air intake louvers were obstructed, then the power must be switched off for 15 minutes in order to reset. The fan problem or air obstruction must also be corrected.
INVERTEC STT
Section F-1
TABLE OF CONTENTS
TROUBLESHOOTING & REPAIR SECTION
Troubleshooting & Repair Section ................................................................................Section F
How to Use Troubleshooting Guide .......................................................................................F-2
PC Board Troubleshooting Procedures .................................................................................F-3
Troubleshooting Guide .................................................................................................F4 - F-12
Test Procedures ...................................................................................................................F-13
T1 Auxiliary Transformer Test........................................................................................F-13
T4 Auxiliary Transformer Test........................................................................................F-18
Input Rectifier Test.........................................................................................................F-24
Capacitor Balance Test .................................................................................................F-27
Switch Board Test..........................................................................................................F-30
Snubber Resistors Test .................................................................................................F-34
Power Board Test ..........................................................................................................F-37
Protection Board Test ....................................................................................................F-41
Trigger Circuit Test ........................................................................................................F-44
Replacement Procedures ....................................................................................................F-48
Darlington Module Removal and Replacement.............................................................F-48
Switch Board Replacement ...........................................................................................F-53
Capacitor Removal and Replacement Procedure .........................................................F-58
Output Rectifier Removal and Replacement.................................................................F-66
Retest After Repair...............................................................................................................F-70
Input Filter Capacitor Conditioning ......................................................................................F-71
Environmental Protection.....................................................................................................F-71
Section F-1
INVERTEC STT
F-2
TROUBLESHOOTING & REPAIR
HOW TO USE TROUBLESHOOTING GUIDE
WARNING
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.
This Troubleshooting Guide is provided to help you locate and repair possible machine malfunctions. Simply follow the three-step procedure listed below.
Step 1. LOCATE PROBLEM (SYMPTOM). Look under the column labeled “PROBLEM (SYMP-
TOMS). This column describes possible symptoms that the machine may exhibit. Find the listing that best describes the symptom that the machine is exhibiting. Symptoms are grouped into two main categories: Output Problems, and
Welding Problems.
Step 2. PERFORM EXTERNAL TESTS.
The second column, labeled “POSSIBLE AREAS OF
MISADJUSTMENT(S)”, lists the obvious external possibilities that may contribute to the machine symptom. Perform these tests/checks in the order listed. In general, these tests can be conducted without removing the case wrap-around cover.
Step 3. PERFORM COMPONENT TESTS. The last column, labeled “Recommended Course of
Action” lists the most likely components that may have failed in your machine. It also specifies the appropriate test procedure to verify that the subject component is either good or bad. If there are a number of possible components, check the components in the order listed to eliminate one possibility at a time until you locate the cause of your problem.
All of the referenced test procedures referred to in the Troubleshooting Guide are described in detail at the end of this chapter. Refer to the
Troubleshooting and Repair Table of Contents to locate each specific Test Procedure. All of the referred to test points, components, terminal strips, etc., can be found on the referenced electrical wiring diagrams and schematics. Refer to the Electrical Diagrams Section Table of
Contents to locate the appropriate diagram.
F-2
OSCILLOSCOPE WARNING
WARNING
Do not use oscilloscopes and other test equipment which are powered by 115 VAC. This equipment should not be used with inverter-type machines, such as Invertec STT. There are high voltages present, which are “floating” off case ground (floating ground). Connecting the ground lead of a test probe
(which may be connected to the case of the test equipment) to a high voltage potential presents a shock hazard as well as the possibility of damage to the equipment in question.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.
INVERTEC STT
F-3 F-3
TROUBLESHOOTING & REPAIR
PC BOARD TROUBLESHOOTING PROCEDURES
WARNING
ELECTRIC SHOCK can kill.
Have an electrician install and service this equipment. Turn the machine OFF before working on equipment. Do not touch electrically hot parts.
Sometimes machine failures appear to be due to PC board failures. These problems can sometimes be traced to poor electrical connections. To avoid problems when troubleshooting and replacing PC boards, please use the following procedure:
1.
Determine to the best of your technical ability that the PC board is the most likely component causing the failure symptom.
2.
Check for loose connections at the PC board to assure that the PC board is properly connected.
3.
If the problem persists, replace the suspect PC board using standard practices to avoid static electrical damage and electrical shock. Read the warning inside the static resistant bag and perform the following procedures:
PC Board can be damaged by static electricity.
ATTENTION
Static-Sensitive
Devices
Handle only at
Static-Safe
Workstations
Reusable
Container
Do Not Destroy
• Remove your body’s static charge before opening the static-shielding bag. Wear an anti-static wrist strap. For safety, use a 1 Meg ohm resistive cord connected to a grounded part of the equipment frame.
• If you don’t have a wrist strap, touch an unpainted, grounded, part of the equipment frame. Keep touching the frame to prevent static build-up. Be sure not to touch any electrically live parts at the same time.
• Tools which come in contact with the PC Board must be either conductive, anti-static or static-dissipative.
• Remove the PC Board from the static-shielding bag and place it directly into the equipment. Don’t set the
PC Board on or near paper, plastic or cloth which could have a static charge. If the PC Board can’t be installed immediately, put it back in the static-shielding bag.
• 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 proper failure analysis.
4.
Test the machine to determine if the failure symptom has been corrected by the replacement PC board.
NOTE: Allow the machine to heat up so that all electrical components can reach their operating temperature.
5.
Remove the replacement PC board and substitute it with the original PC board to recreate the original problem.
a. If the original problem does not reappear by substituting the original board, then the
PC board was not the problem. Continue to look for bad connections in the control wiring harness, junction blocks, and terminal strips.
b. If the original problem is recreated by the substitution of the original board, then the
PC board was the problem. Reinstall the replacement PC board and test the machine.
6.
Always indicate that this procedure was followed when warranty reports are to be submitted.
NOTE: Following this procedure and writing on the warranty report, “INSTALLED AND
SWITCHED PC BOARDS TO VERIFY PROB-
LEM,” will help avoid denial of legitimate PC board warranty claims.
INVERTEC STT
F-4
Observe Safety Guidelines detailed in the beginning of this manual.
F-4
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
Major physical or electrical damage is evident.
1. Contact your local Lincoln
Authorized Field Service
Facility.
RECOMMENDED
COURSE OF ACTION
1. Contact the Lincoln Electric
Service Department, 216-383-
2531 or 1-800-833-9353 (WELD).
Machine has no open circuit voltage. Wire feeds OK.
between the feeder and the
STT unit. Make sure the #2 and
#4 leads are intact.
2. Put a jumper wire between Pins
"C" and "D" on the 14 pin amphenol. If normal open circuit voltage (85VDC) is restored, the problem is in the feeder control cable or the wire feeder.
3. Make sure the reconnect switch
S7 is in the correct position for the three-phase input voltage being applied.
CAUTION
Do not switch reconnect switch with input power applied to machine.
1. Perform the T1 Auxiliary
Transformer Test.
2. Perform the T4 Auxiliary
Transformer Test.
3. Perform the Power Board Test.
4. Perform the Trigger Circuit
Test.
5. Perform Capacitor Balance
Test.
6. Perform the Protection Board
Test.
7. Perform the Switch Board
Test.
8. Check for loose or broken connections on the heavy current carrying conductors (i.e., main transformer, choke, output diodes, Darlington module and output terminals).
9. The control PC board may be faulty. Replace.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
INVERTEC STT
F-5
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
F-5
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Machine has no welding output (no open circuit voltage), and the wire feeder does not feed wire when the gun trigger is pulled.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. The 42VAC circuit breaker CB1 may be tripped. Reset if necessary.
2. Check the 4 amp slow blow fuse located on the reconnect panel.
Replace if faulty.
3. Put a jumper between pins "A" and "C" on the 5 pin amphenol located on the LN-742 wire feeder. If wire feeds, check the gun trigger. Repair or replace if necessary.
4. Check for the presence of
42VAC at pins "K" and "I" on the
14 pin amphenol. If the 42VAC is present and the feeder does not work, the problem is in the feeder control cable or the wire feeder.
RECOMMENDED
COURSE OF ACTION
1. If 42VAC is NOT present at pins
"K" and "I" on the 14 pin amphenol, perform the T1 Auxiliary
Transformer Test.
2. Check leads #43 and #212C for loose or faulty connections between the T1 auxiliary transformer and the remote protection board. See the Wiring
Diagram. Also check the continuity through the remote protection board to the 14 pin amphenol. See the Remote Protection
Board Schematic.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-
383-2531 or 1-800-833-9353.
INVERTEC STT
F-6
Observe Safety Guidelines detailed in the beginning of this manual.
F-6
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
RECOMMENDED
COURSE OF ACTION
Machine is dead - no output - no fan - no display.
1. The power switch must be in the
"ON" position.
2. Check the input voltage. Make sure all three phases are applied to the machine.
3. With input power removed, check that the input voltage setup switch and jumper "A" (the reconnect auxiliary jumper) are in the proper position for the input voltage being used.
4. With input power removed, check the continuity of the 4 amp slow blow fuse located on the reconnect panel.
1. The input power switch (S1) may be faulty. Check or replace.
2. Perform the T1 Auxiliary
Transformer Test.
No output or reduced output the first time power is applied to the machine.
1. Check input voltages, fuses and input voltage reconnect procedures. See the Installation section.
2. If high input voltage (380VAC or higher) is applied, the capacitors may need conditioning. Let the "unloaded" machine idle for
30 minutes.
1. Contact the Lincoln Electric
Service Department. 1-216-
383-2581 or 1-800-833-WELD
(9353).
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
INVERTEC STT
F-7
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
F-7
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
RECOMMENDED
COURSE OF ACTION
No output. Main fuses are open, indicating excessive current draw.
1. With the input power removed, inspect input leads for possible shorts or grounds or misconnections.
2. Install new fuses and reapply power. If fuses open again, contact your local Lincoln
Authorized Field Service
Facility.
1. Check the input power switch
(S1) and the reconnect switch for "shorted" or "grounded" wires or connections.
2. Perform the Input Rectifier
Test.
3. Perform the Switch Board
Test.
Machine loses output when gun trigger is pulled or arc is struck.
Machine output returns after a few seconds and trigger is pulled again.
The thermal indicator light is lit.
1. The overcurrent sensor is activated, indicating that too much output current is being drawn from the machine. Reduce welding current demands or remove the "fault" in welding cables.
2. Make sure that the gun tip is not
"shorted" to the work surface and that the proper welding procedures are being used.
1. The current sensor may be faulty.
2. The control PC board may be faulty.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-
383-2531 or 1-800-833-9353.
INVERTEC STT
F-8
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
F-8
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
RECOMMENDED
COURSE OF ACTION
Machine loses output while welding. The thermal indicator light is lit. Normal welding output returns after about 10 minutes.
1. Check to make sure the fan is running and operating correctly.
1. The Darlington heat sink thermostat or fan thermostat may be defective. Check or replace.
exceed recommended duty cycle.
3. Dirt and dust may have clogged the cooling channels. Blow out the unit with clean, dry compressed air.
4. Air intake and exhaust louvers may be blocked due to inadequate clearance around the machine.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-
383-2531 or 1-800-833-9353.
INVERTEC STT
F-9
Observe Safety Guidelines detailed in the beginning of this manual.
F-9
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
Porosity in the weld.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
RECOMMENDED
COURSE OF ACTION
1. Make sure the gas type and flow rate is correct for the procedure being used. Shield the work from excessive outside air currents.
2. Check the gun and nozzle for leaks or obstructions.
3. Make certain the machine and wire feed settings are correct for the process.
1. Contact the Lincoln Electric
Service Department. 1-216-
383-2581 or 1-800-833-WELD
(9353).
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
INVERTEC STT
F-10
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
F-10
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Weld bead appears "cold."
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
1. One or more of the machine settings may be wrong. Check the Background, Peak Current,
Tailout (STT II Only), and Wire
Speed controls for proper settings. Adjust for optimum welding performance.
2. Make sure the Wire Type and
Wire Size switches are in the correct position for the electrode wire being used.
RECOMMENDED
COURSE OF ACTION
1. Check for the correct open circuit voltage (approximately
85VDC). If the correct open circuit voltage IS present, the
Background control (R12) or the
Peak Current (R11) and associated wiring may be faulty. See the Wiring Diagram. The control
PC board may be faulty. Also check for loose or faulty connections on the heavy current carrying conductors (i.e., main transformer, choke, output diodes, Darlington module and output terminals).
2. If the correct open circuit voltage is NOT present, perform the
Switch Board Test.
3. The output diodes may be faulty. Check or replace if necessary.
4. The driver PC board and or control PC board may be faulty.
5. The Darlington module may be faulty. Check or replace.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-
383-2531 or 1-800-833-9353.
INVERTEC STT
DEC 97
F-11
Observe Safety Guidelines detailed in the beginning of this manual.
F-11
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
RECOMMENDED
COURSE OF ACTION
Molten weld puddle appears excessively "violent."
1. The Wire Type switch may be in the wrong position for the electrode wire being used.
2. The Peak Current or Background Setting may be too high.
Adjust for optimum welding performance.
3. The Tailout may not be set correctly for the process. (STT II
Only)
1. The Darlington module may be faulty. Check or replace.
2. The Darlington driver PC board may be faulty.
3. The control PC board may be faulty.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
INVERTEC STT
DEC 97
F-12
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
F-12
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
RECOMMENDED
COURSE OF ACTION
Excessive weld spatter. Arc sounds and looks like a standard
MIG process.
1. Check the Arc Sense leads for loose or faulty connections.
2. Make sure the Arc Sense
"WORK" lead is as close as possible to the welding arc.
3. Make sure the machine and wire feed settings are correct for the process and wire being used.
1. The Darlington module may be faulty. Check or replace.
2. The Darlington driver PC board may be faulty.
3. The control PC board may be faulty.
Poor welding, weld settings drift, or output power is low.
1. Make sure the machine settings are correct for the welding process being used.
2. Check the welding cables for loose or faulty connections.
3. Make sure the reconnect switch
S7 is in the correct position for the three-phase input voltage being applied.
1. The current sensor may be faulty. Check associated leads for loose or faulty connections.
2. The control PC board may be faulty.
CAUTION
Do not switch reconnect switch with input power applied to machine.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
INVERTEC STT
F-13
TROUBLESHOOTING & REPAIR
T1 AUXILIARY TRANSFORMER TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.
Call 216-383-2531 or 1-800-833-9353
(WELD).
TEST DESCRIPTION
This test will determine if the correct voltages are being: a. applied to the primary of the T1 auxiliary transformer.
b. induced upon the secondary windings of the T1 auxiliary transformer.
MATERIALS NEEDED
Volt/Ohmmeter (Multimeter)
Invertec STT wiring diagrams
5/16" Nut driver
3/8" Wrench
Slot head screw driver
Note: Component locations and disassembly procedures may vary slightly on STT II models
F-13
INVERTEC STT
DEC 97
F-14
TROUBLESHOOTING & REPAIR
T1 AUXILIARY TRANSFORMER TEST (continued)
FIGURE F.1 – T1 AUXILIARY TRANSFORMER AND J30/J31 LOCATION
F-14
PLUG
J30
PLUG
J31
T1 AUXILIARY
TRANSFORMER
TEST PROCEDURE
1. Turn off Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the
Maintenance section.
4. Locate the T1 auxiliary transformer and secondary lead molex plugs (J30 and J31) on the left side, just in front of the main transformer assembly. Check for broken or loose wires. See Figure F.1.
WARNING
ELECTRIC SHOCK can kill.
the test procedure, perform the capacitor discharge procedure to avoid electric shock.
INVERTEC STT
F-15
TROUBLESHOOTING & REPAIR
T1 AUXILIARY TRANSFORMER TEST (continued)
FIGURE F.2 – PRIMARY LEAD PLUG J21 LOCATION
PLUG J21
LOCATION BEHIND
RECONNECT PANEL
F-15
RECONNECT
PANEL
5. Locate the primary lead molex plug (J21) just behind the reconnect panel assembly on the right side of the machine. Check for broken or loose wires. See Figure F.2.
6. Disconnect plugs J30 and J31 from the wiring harness.
7. Apply the correct input power to the machine and test for the correct secondary voltages at plugs J30 and J31. (Make sure the reconnect panel is configured properly for the input voltage being applied.) See Table F.1.
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
INVERTEC STT
F-16 F-16
TROUBLESHOOTING & REPAIR
T1 AUXILIARY TRANSFORMER TEST (continued)
8. If the correct secondary voltages are present
(according to Table F.1), the T1 transformer is functioning properly.
9. If the secondary voltages are missing or incorrect, the primary voltages must be checked.
10. Remove input power to the STT machine.
11. Perform the Input Filter Capacitor
Discharge Procedure.
12. Reconnect Plugs J30 & J31.
13. Gain access to the primary lead plug J21 by removing the reconnect panel assembly from the upper support panel using the 3/8" wrench and slot head screwdriver. This will allow the reconnect panel assembly to be moved out of the way. Be careful NOT to stress the leads connected to the reconnect panel. See Figure F.2.
14. Before applying input power make certain the reconnect panel assembly is insulated and supported for safe operation.
WARNING
ELECTRIC SHOCK can kill.
the test procedure, perform the capacitor discharge procedure to avoid electric shock.
TABLE F.1 – T1 AUXILIARY TRANSFORMER VOLTAGES
TEST POINTS NORMAL VOLTAGE
PLUG J30 PINS 1 TO 2
(LEADS 32 TO 33)
PLUG J31 PINS 1 TO 4
(LEADS 501 TO 504)
PLUG J31 PINS 2 TO 3
(LEADS 212 TO 503)
PLUG J31 PINS 2 TO 5
(LEADS 212 TO 43A)
PLUG J21 PINS 1 TO 4
(LEADS H1 TO H2)
PLUG J21 PINS 1 TO 2
(LEADS H1 TO H3)
PLUG J21 PINS 1 TO 3
(LEADS H1 TO H4)
PLUG J21 PINS 1 TO 6
(LEADS H1 TO H5) (H6)
115VAC
18VAC
24VAC
42VAC
200/208VAC
220/230VAC
380/415VAC
440/460VAC
NOTE: If the main AC input supply voltage varies, the auxiliary transformer voltages will vary by the same percentages.
INVERTEC STT
F-17 F-17
TROUBLESHOOTING & REPAIR
T1 AUXILIARY TRANSFORMER TEST (continued)
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
15. Apply the correct input power and carefully test for the correct primary voltages at plug
J21. See Table F.1.
16. If the correct AC input voltages are applied to the primary windings and any or all of the secondary voltages are missing or not correct, the T1 auxiliary transformer may be faulty.
17. After all tests are complete, reconnect plugs
J30 and J31.
18. Install the case wraparound cover.
INVERTEC STT
F-18
TROUBLESHOOTING & REPAIR
T4 AUXILIARY TRANSFORMER TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
TEST DESCRIPTION
This test will determine if the correct voltages are being: a. applied to the primary of the T4 auxiliary transformer.
b. induced on the secondary windings of the T4 auxiliary transformer.
F-18
MATERIALS NEEDED
Volt/Ohmmeter (Multimeter)
Invertec STT Wiring Diagrams
Isolated 115VAC supply
5/16" Nut driver
7/16" Wrench
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-19
TROUBLESHOOTING & REPAIR
T4 AUXILIARY TRANSFORMER TEST (continued)
FIGURE F.3 – OUTPUT CHOKE/DARLINGTON MODULE SPLICED CONNECTION
F-19
LOWER
TRAY
AREA
OUTPUT CHOKE/
DARLINGTON MODULE
SPLICED CONNECTION
TEST PROCEDURE
1. Turn off the Invertec STT and disconnect main AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure.
See the
Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Locate the lead connection splice from the output choke to the Darlington module.
Remove the insulating sleeve. Cut any necessary cable ties. Using the 7/16" wrench, disconnect the lead splice. Thread the lower lead down into the lower tray assembly area. See Figure F.3.
INVERTEC STT
F-20
TROUBLESHOOTING & REPAIR
T4 AUXILIARY TRANSFORMER TEST (continued)
FIGURE F.4 – PLUG J1 LOCATION
F-20
J1 CURRENT
SENSING PLUG
LOWER
TRAY
AREA
5. Disconnect the current sensing Plug J1 from the control PC board. Carefully remove Plug
J1 and associated leads from control board compartment. See Figure F.4.
FIGURE F.5 – PLUG J22 LOCATION
OUTPUT CHOKE/
DARLINGTON MODULE
SPLICED CONNECTION
PLUG J22
6. Locate and disconnect plug J22 from the wiring harness. See Figure F.5.
INVERTEC STT
F-21
TROUBLESHOOTING & REPAIR
T4 AUXILIARY TRANSFORMER TEST (continued)
FIGURE F.6 – STT ON ITS RIGHT SIDE
F-21
MOUNTING
BOLTS (5)
7. Carefully lift and tilt the Invertec STT machine onto its right side. See Figure F.6.
8. Using the 7/16" wrench, remove the five bolts holding the lower tray assembly to the case bottom.
9. Carefully slide out and support the lower tray assembly for testing purposes.
10. Locate and remove plug J13 from the
Darlington drive board. See Figure F.7.
DARLINGTON
DRIVE BOARD
PLUG J13
T4 AUXILIARY
TRANSFORMER
STT
FIGURE F.7 – PLUG J13 LOCATION
DARLINGTON
DRIVE BOARD
PLUG J13
T4 AUXILIARY
TRANSFORMER
STT II
INVERTEC STT
DEC 97
F-22
TROUBLESHOOTING & REPAIR
T4 AUXILIARY TRANSFORMER TEST (continued)
FIGURE F.8 – T4 TRANSFORMER LEAD CONNECTIONS
F-22
LEADS
32A, 32B, 33A, 33B
T4 AUXILIARY
TRANSFORMER
LEADS
32A, 32B, 33A, 33B
STT
T4 AUXILIARY
TRANSFORMER
STT II
11. Locate and remove leads #32A, #32B and
#33A, #33B from the T4 transformer tabs.
See Figure F.8.
WARNING
12. Carefully apply the 115VAC isolated supply to the T4 transformer at the #32 and #33 tabs.
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
INVERTEC STT
DEC 97
F-23 F-23
TROUBLESHOOTING & REPAIR
T4 AUXILIARY TRANSFORMER TEST (continued)
TABLE F.2 – T4 AUXILIARY TRANSFORMER VOLTAGES
TEST POINTS
NORMAL VOLTAGES
PLUG J13 PINS 5 TO 6
PLUG J13 PINS 2 TO 3
PLUG J22 PINS 1 TO 2
(LEADS 240 TO 241)
PLUG J22 PINS 2 TO 9
(LEADS 241 TO 242)
PLUG J22 PINS 3 TO 4
(LEADS 243 TO 244)
PLUG J22 PINS 12 TO 13
(LEADS 245 TO 246)
6VAC
10VAC
18VAC
18VAC
18VAC
18VAC
13. Check the secondary AC voltages according to Table F.2.
14. With the correct 115VAC applied to the primary winding (#32 to #33), if any or all of the secondary voltages are missing or low, the T4 auxiliary transformer may be faulty.
Replace the T4 auxiliary transformer.
15. After all tests are completed, reconnect the following:
Leads #32A, #32B, #33A, #33B to the
T4 transformer tabs
Plug J13 to the Darlington drive board
Plug J22 to the wiring harness
Reinstall lower tray assembly using
7/16” wrench and 5 bolts
Plug J1 to the control PC board
Reconnect lead splice from the output choke to the Darlington module.
Reposition insulating sleeve.
16. Install the case wraparound cover.
INVERTEC STT
F-24
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
F-24
TEST DESCRIPTION
This test will help determine if the input rectifier and associated components are functioning properly.
MATERIALS NEEDED
5/16" Nut driver
Analog Voltmeter/ohmmeter (Multimeter)
Inverter STT Wiring Diagrams
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-25
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER TEST (continued)
FIGURE F.9 - INPUT RECTIFIER LOCATION
A B C
INPUT
RECTIFIER
9
12
F-25
TEST PROCEDURE
1.
Turn off the Invertec STT and disconnect main AC input power to the machine.
2.
Using the 5/16" nut driver, remove the case wraparound cover.
3.
Perform the Input Filter Capacitor
Discharge procedure.
See the
4.
Locate the input rectifier. See Figure F.9.
5.
Locate the leads needed to perform the tests. See Figure F.9.
6.
Use an ANALOG ohmmeter to perform the tests shown in Table F.3.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
INVERTEC STT
F-26 F-26
TROUBLESHOOTING & REPAIR
INPUT RECTIFIER TEST (continued)
TABLE F.3 – INPUT RECTIFIER TEST
TEST POINTS
+PROBE -PROBE
A
B
C
12
12
12
A
B
C
9
9
9
12
12
12
A
B
C
9
9
9
A
B
C
ACCEPTABLE METER READING
Greater than 100K ohms
Greater than 100K ohms
Greater than 100K ohms
Less than 100 ohms
Less than 100 ohms
Less than 100 ohms
Less than 100 ohms
Less than 100 ohms
Less than 100 ohms
Greater than 100K ohms
Greater than 100K ohms
Greater than 100K ohms
6.
Replace the input rectifier when any of the tests are NOT OK.
NOTE: When installing a new input rectifier, torque the mounting nuts (in a cross-tightening pattern) to 6 inch-pounds (.7 Nm). Torque terminals to 26 inch-pounds (3 Nm). PROCEED
TO STEP 7 TO CHECK RELATED COMPO-
NENTS.
7.
Inspect main power switch S1 and replace if faulty. Go to step 8.
8.
Test capacitors C1 and C2 and replace both capacitors if either is faulty.
NOTE: Faulty capacitors could be the reason for input rectifier failure.
Visually inspect the capacitors for leakage, damage, etc., and use appropriate test equipment to determine component integrity.
9.
Perform the Switch Board Test.
10. After all tests are completed, install the case wraparound cover.
INVERTEC STT
F-27
TROUBLESHOOTING & REPAIR
CAPACITOR BALANCE TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
TEST DESCRIPTION
This test will help determine if the capacitors, bleeder resistors and switch boards are functioning properly.
MATERIALS NEEDED
5/16" Nut driver
Analog Volt/ohmmeter (Multimeter)
F-27
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-28
TROUBLESHOOTING & REPAIR
CAPACITOR BALANCE TEST (continued)
FIGURE F.10 – SWITCH BOARD TEST POINTS
9 12
F-28
L8441 SWITCH
TEST PROCEDURE
1. Turn off the Invertec STT and disconnect main AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
3. Carefully apply the correct input power to the machine.
NOTE: This test should only be conducted when the machine reconnect switch and jumper are set for high voltage (above
380VAC) and the proper line voltage is applied.
4. Test for VDC across terminals #9 and #12 of one switch board and repeat the test for the other switch board. See Table F.4 in this procedure for expected voltage readings.
See Figure F.10.
A. If less than 25VDC difference is measured between each switch board, the capacitive balance is OK. This indicates that capacitors C1, C2, and resistors R1 and R9 are functioning properly. Proceed to Step #5.
B. If more than 25VDC difference is measured between each switch board, test each of the following components:
Capacitors C1, C2 and resistors R1 and R9. See the Invertec STT Wiring
Diagram.
INVERTEC STT
F-29 F-29
TROUBLESHOOTING & REPAIR
CAPACITOR BALANCE TEST (continued)
TABLE F.4 – EXPECTED VOLTAGE READINGS
If VAC Input is:
460 VAC
440 VAC
415 VAC
380 VAC
5. Adjust the Peak and Background controls to the minimum settings (controls on case front).
6. Jumper together pins "C" and "D" on the 14 pin amphenol. This will energize the output terminals.
7. Test for VDC across terminals #9 and #12 of one switch board and repeat the test for the other switch board. See Table F.4 in this procedure for expected voltage readings.
See Figure F.10.
A. If less than 15VDC difference is measured between each switch board, the test is OK.
B. If more than 15VDC difference is measured between each switch board, the switch board(s) and or power PC board may be faulty. Perform the Switch
Board Test. Perform the Power Board
Test.
VDC at terminals #9 (+) and #12 (-) should be approximately:
325VDC
311VDC
293VDC
269VDC
8. After all tests are completed, remove the jumper between pins C and D on the 14-pin amphenol.
9. Install the case wraparound cover.
INVERTEC STT
F-30
TROUBLESHOOTING & REPAIR
SWITCH BOARD TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
TEST DESCRIPTION
The Switch Board Test determines if the switch boards are operating properly. This resistance test is preferable to a voltage test with the machine energized because these boards can be damaged easily. In addition, it is dangerous to work on these boards with machine power ON.
MATERIALS NEEDED
Analog Volt/ohmmeter (Multimeter)
5/16" Nut driver
F-30
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-31
TROUBLESHOOTING & REPAIR
SWITCH BOARD TEST (continued)
FIGURE F.11 - SWITCH BOARD RESISTANCE TEST
F-31
TEST PROCEDURE
NOTE: There are two switch boards. One is located on each side of the machine.
NOTE: The switch boards are designed to receive gate (turn-on) signals from the driver board (pulse transformer secondaries). The internal board circuitry processes the signals and outputs them to the FETs. The switch board circuitry contains snubber circuitry to protect the
FETs. This protection is supplemented by offboard resistors. The switch board design accommodates the connection point(s) for the capacitor(s), main transformer primary windings, input rectifier, and reconnect switches.
1. Turn off Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the
Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4.
Disconnect all wiring harness leads
(401/403, 1/8, 9, 12, 4/5, 402/404) from the switch board.
5. Fold the leads up so they do not interfere with the exposed terminals. See Figure F.11.
6. Using an analog ohmmeter, perform the resistance tests detailed in Table F.5 and shown in
Figure F.11. If any test fails, replace both switch boards. See the Switch Board
Removal and Replacement procedure.
7. If the switch boards appear to be burned or overheated, or if the machine was supplied by a 380 VAC or higher voltage supply when the failure occurred, replace the capacitors and the switch boards.
INVERTEC STT
F-32
TROUBLESHOOTING & REPAIR
SWITCH BOARD TEST (continued)
TABLE F.5 – SWITCH BOARD RESISTANCE TEST
Apply Positive Apply Negative
Test Probe to Test Probe to
Terminal Terminal
1/8 12
Test Result Conclusion Repair Action Next Procedure Notes
Greater than
1K ohm
OK None Continue
Less than
100 ohms
Shorted Replace both Snubber Test switch boards
12 1/8 None Continue
9
4/5
1/8
4/5
9
9
Less than
100 ohms
OK
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than
100 ohms
Shorted
Less than
100 ohms
OK
Greater than Open
1K ohm
Replace both switch boards
None
Replace both switch boards
None
Replace both switch boards
None
Snubber Test
Continue
Snubber Test
Continue
Snubber Test
Continue
9
12
1/8
4/5
Less than
100 ohms
OK
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than
100 ohms
Shorted
Replace both switch boards
None
Replace both switch boards
None
Snubber Test
Continue
Snubber Test
Continue
4/5 12
Less than
100 ohms
OK
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than
100 ohms
Shorted
Replace both switch boards
None
Replace both switch boards
Snubber Test
Continue
Snubber Test
Continued . . .
NOTE: K ohm = ohm reading multiplied by 1000.
NOTE: Always make sure that switch boards are changed in matched pairs. Never mix an old style (different part number) switch board with a new switch board (new part number).
INVERTEC STT
F-32
F-33
TROUBLESHOOTING & REPAIR
SWITCH BOARD TEST (continued)
TABLE F.5 – SWITCH BOARD RESISTANCE TEST (continued)
Apply Positive Apply Negative
Test Probe to Test Probe to
Terminal Terminal
12 401/403
Test Result Conclusion Repair Action Next Procedure Notes
Greater than
1K ohm
OK None Continue
Less than
100 ohms
Shorted Replace both Snubber Test switch boards
401/403 12 None Continue
9
402/404
402/404
9
Less than
100 ohms
OK
Greater than Open
1K ohm
Less than
100 ohms
OK
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than
100 ohms
Shorted
Replace both switch boards
None
Replace both switch boards
None
Replace both switch boards
Snubber Test
Continue
Snubber Test
Continue
Snubber Test
NOTE: K ohm = ohm reading multiplied by 1000.
NOTE: Always make sure that switch boards are changed in matched pairs. Never mix an old style (different part number) switch board with a new switch board (new part number).
8. Reconnect all wiring harness leads (401/403,
1/8, 9, 12, 4/5, 402/404) to the switch board.
9. Install the case wraparound cover.
F-33
INVERTEC STT
F-34
TROUBLESHOOTING & REPAIR
SNUBBER RESISTORS TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
DESCRIPTION
This test will determine if the snubber resistors (R4, R5, R6, R7) are functioning properly.
MATERIALS NEEDED
Analog Volt/ohmmeter (Multimeter)
STT Wiring Diagrams
5/16” Nut driver
F-34
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-35
TROUBLESHOOTING & REPAIR
SNUBBER RESISTORS TEST (continued)
FIGURE F.12 - REMOVING LEADS
F-35
TEST PROCEDURE
1. Turn off Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the
Maintenance section.
4. Locate and gain access to the switch board.
5. Remove leads from terminals 401/403,
402/404 on the switch board. See Figure
F.12.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
INVERTEC STT
F-36
TROUBLESHOOTING & REPAIR
SNUBBER RESISTORS TEST (continued)
FIGURE F.13 - SWITCH BOARD TEST POINTS
401/403
9
12
402/404
F-36
L8441 SWITCH
6. Test for 25 ohms resistance from lead terminal 401 to terminal 12 on the switch board.
See Figure F.13.
a. If 25 ohms is measured, resistor R4 is OK.
b. If 30 ohms or more is measured, resistor
R4 is faulty and must be replaced.
c. If 20 ohms or less is measured, resistor
R4 is faulty and must be replaced.
7. Repeat the same procedures to test R5, R6, and R7 according to Table F.6.
8. Reconnect leads 401/403 and 402/404 to the switch board.
9. Install the case wraparound cover.
Check
Lead 401 to
Terminal 12
Lead 402 to
Terminal 9
Lead 403 to
Terminal 12
Lead 404 to
Terminal 9
TABLE F.6 – SNUBBER RESISTORS TEST
Test Result
25 ohms
>30 ohms
<20 ohms
25 ohms
>30 ohms
<20 ohms
25 ohms
>30 ohms
<20 ohms
25 ohms
>30 ohms
<20 ohms
Conclusion
OK
R4 open
R4 faulty
OK
R5 open
R5 faulty
OK
R6 open
R6 faulty
OK
R7 open
R7 faulty
Next Test Step
Continue
Continue
Continue
Continue
> = GREATER THAN < = LESS THAN
INVERTEC STT
Repair Action
Replace R4
Replace R5
Replace R6
Replace R7
F-37
TROUBLESHOOTING & REPAIR
POWER BOARD TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
TEST DESCRIPTION
This test will help determine if the power PC board is receiving the correct AC voltages and also if the correct DC voltages are being generated on the power PC board.
MATERIALS NEEDED
5/16" Nut driver
Volt/ohmmeter (Multimeter)
Wiring diagram
F-37
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-38
TROUBLESHOOTING & REPAIR
POWER BOARD TEST (continued)
FIGURE F.14 – REMOVING THE FRONT PANEL ASSEMBLY
POWER
PC BOARD
(Located on Back of
Case Front)
F-38
QUICK CHECK PROCEDURE
1. Turn off the Invertec STT and disconnect main AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Locate relays CR1 and CR2 just to the front of the fan motor.
OK. If the relays are NOT being activated, the power PC board could be faulty. Continue with the voltage tests.
VOLTAGE TEST PROCEDURE
1. Remove input power to the Invertec STT.
2. Perform the Input Filter Capacitor Discharge
Procedure. See the Maintenance section.
WARNING
WARNING
ELECTRIC SHOCK can kill. there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Apply the correct input power and turn ON the
Invertec STT machine.
5. After about a 5 second delay the relays should activate. This can be determined by an audible click which can be heard when the relays are activated. If the relays are being activated, the power PC board is most likely
INVERTEC STT
3. Using the 5/16" nut driver, loosen the front control panel by removing the four sheet metal screws from the top and bottom of the front panel. Carefully move the front panel assembly to the right to gain access to the power PC board. See Figure F.14.
F-39
309 310
F-39
TROUBLESHOOTING & REPAIR
POWER BOARD TEST (continued)
FIGURE F.15 – POWER PC BOARD TEST POINTS
POWER BOARD
212A
301
302
L8033
501
504
J7
313
J14
311
211A
J6
305
275
4. Secure and insulate the front panel assembly for POWER ON testing.
WARNING
ELECTRIC SHOCK can kill. there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
5. Apply the correct input power and turn ON the machine.
6. Carefully test for 18VAC input from the T1
Auxiliary Transformer between plug J7 pin 5
(lead#501) and plug J7 pin 6 (lead #504) at the power PC board. See Figure F. 15.
NOTE: If the 18VAC is NOT present, perform the T1 Auxiliary Transformer Test. Also check associated wiring. See the Wiring Diagram.
INVERTEC STT
F-40
TROUBLESHOOTING & REPAIR
POWER BOARD TEST (continued)
FIGURE F.16 – SIMPLIFIED TRIGGER CIRCUIT
FROM PROTECTION
BOARD OVERVOLTAGE
POWER BOARD CONTROL BOARD
7J6
#301
11J4
2J6
#305
3J4
PWM
OUTPUTS
TO POWER
BOARD
P
W
M
STT II Only
T1 AUXILIARY
TRANSFORMER
2
4
V
A
C
3J31
#503A
2J31
#212
6J22
#224
TO
POWER
BOARD
#379
#210
6J4
5J4
12J4 6J34
REMOTE
PROTECTION
BOARD
9J4
#223
8J33
3.5 ohms
14 AMPHENOL
13J36
#413
C
3.5 ohms
5J36
#405
D
F-40
#212C
7. Carefully test for 15VDC output from the power PC board at plug J6 pin1 (lead #275)
(-) and plug J6 pin 6 (lead #302)(+).
See
Figure F.15.
NOTE: If the 18VAC is present but the 15VDC is
NOT, the power PC board may be faulty.
8. Carefully test for 24VAC input from the T1
Auxiliary Transformer between plug J6 pin 4
(lead#211A) and plug J6 pin 9 (lead#212A).
See Figure F.15.
NOTE: If the 24VAC is NOT present, perform the
T1 Auxiliary Transformer Test. Also check the associated wiring. See the Wiring Diagram. The control PC board or thermostats may be faulty.
See Figure F.16, the Simplified Trigger Circuit diagram.
9. Carefully test for 24VDC at the power PC board at plug J7 pin 2 (lead #309)(+) to plug
J6 pin1 (lead #275)(-). See Figure F.15.
NOTE: If the 24VAC is present but the 24VDC is
NOT, the power PC board may be faulty.
10. Carefully test for approximately 24VDC at plug J7 pin 2 (lead#309)(+) to plug J7 pin 4
(lead#310)(-). If the 24VDC is NOT present, test for approximately 1VDC at plug J14 pin1
(lead#311)(+) to plug J14 pin 2 (lead#313)(-).
See Figure F.15.
NOTE: If more than 1VDC is measured, perform the Protection Board Test.
NOTE: If approximately 1VDC IS present and the 24VDC is NOT present at leads #309 to
#310, the power PC board may be faulty.
11. After all tests are completed, install the front panel assembly.
12. Install the case wraparound cover.
INVERTEC STT
DEC 97
F-41
TROUBLESHOOTING & REPAIR
PROTECTION BOARD TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
TEST DESCRIPTION
This test will help determine if the protection PC board is functioning properly.
MATERIALS NEEDED
5/16" Nut driver
Volt/ohmmeter (Multimeter)
Wiring Diagrams
F-41
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-42
TROUBLESHOOTING & REPAIR
PROTECTION BOARD TEST (continued)
FIGURE F.17 – PROTECTION PC BOARD TEST POINTS
L7915-[ ]
PROTECTION
F-42
313
315
314
J8 317
J15
316
311
TEST PROCEDURE
1. Turn off the Invertec STT and disconnect main AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor Discharge
Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Locate the protection PC board just in front of the input rectifier and relay mountings.
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
5. Apply the correct input power and turn the machine ON.
6. Test for approximately 1VDC from plug J8 pin 1 (lead #311)(+) to plug J8 pin 3 (lead
#313) (-). See Figure F.17.
A. If approximately 1VDC is present, the protection PC board is functioning properly.
B. If more than 5 VDC is measured, perform the Capacitor Balance Test.
INVERTEC STT
F-43
309A
TROUBLESHOOTING & REPAIR
PROTECTION BOARD TEST (continued)
FIGURE F.18 - LEADS #309, #309A AT CR1, CR2 RELAYS
CR2 CR1
309
F-43
7. If the Capacitor Balance Test is OK and more than 5VDC is present at leads #311 to
#313 (Step 6), the protection PC board may be faulty.
NOTE: The above voltage checks pertain only to the over voltage signal from the protection
PC board to the power PC board. The capacitor precharge circuits are also incorporated within the protection PC board. If the problem has not been identified, carefully proceed with the following steps.
8. Remove input power to the Invertec STT machine.
9. Perform the Input Filter Capacitor Discharge
Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
10. Locate and remove leads #309 and #309A from CR1 and CR2 relays. See Figure
F.18.
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
11. Apply correct input power and turn ON the machine.
12. Check for approximately 12VDC from plug
J15 pin 1 (lead #314)(+) to plug J15 pin 4
(lead#315) (-). See Figure F.17.
13. Check for approximately 12VDC from plug
J15 pin 3 (lead #316)(+) to plug J15 pin 6
(lead#317) (-). See Figure F.17.
14. If a low voltage is present in either steps 12 or 13 (approximately 1VDC), perform the
Capacitor Balance Test.
15. If the Capacitor Balance Test is OK, the protection PC board may be faulty.
16. Be certain to replace leads #309 and #309A onto the CR1 and CR2 relays.
17. After all tests are completed, install the case wraparound cover.
INVERTEC STT
F-44
TROUBLESHOOTING & REPAIR
TRIGGER CIRCUIT TEST
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
TEST DESCRIPTION
This test includes a few quick checks to troubleshoot the machine trigger circuit.
The
Simplified Trigger Circuit Diagram will enable the technician to view the trigger circuit in an abbreviated, uncomplicated format.
MATERIALS NEEDED
5/16" Nut driver
Volt/ohmmeter (Multimeter)
Wiring Diagram and board Schematics
F-44
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-45
TROUBLESHOOTING & REPAIR
TRIGGER CIRCUIT TEST (continued)
FIGURE F.19 – PLUG J31 LOCATION
F-45
PLUG
J31
TEST PROCEDURE
1. Turn off the Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Locate plug J31 at the left side of the machine. See Figure F.19.
INVERTEC STT
F-46
TROUBLESHOOTING & REPAIR
TRIGGER CIRCUIT TEST (continued)
FIGURE F.20 – 14 PIN AMPHENOL AND PLUG J31 PIN ASSIGNMENTS
E
D
M
C
L
B
K
F
G
N
H
A
J
212
PLUG J31
F-46
5. Using the ohmmeter check for approximately
3.5 ohms resistance from pin "D" of the 14 pin amphenol to plug J31 pin 2 (lead #212). See
Figure F.20, and Figure F.22, Simplified
Trigger Circuit Diagram.
FIGURE F.21 – CONTROL PC BOARD MOLEX PLUG
J5 J17 J27 J28 J2 J3 J1 J4
223
6. Using the ohmmeter, check for approximately
3.5 ohms resistance from pin "C" of the 14 pin amphenol (see Figure F.20) to plug J4 pin 9
INVERTEC STT
210
(lead#223) at the control PC board. See
Figure F.21 and Figure F.22, Simplified
Trigger Circuit Diagram.
F-47
TROUBLESHOOTING & REPAIR
TRIGGER CIRCUIT TEST (continued)
FIGURE F.22 – SIMPLIFIED TRIGGER CIRCUIT DIAGRAM
FROM PROTECTION
BOARD OVERVOLTAGE
POWER BOARD CONTROL BOARD
7J6
#301
11J4
2J6
#305
3J4
PWM
OUTPUTS
TO POWER
BOARD
STT II Only
P
W
M
T1 AUXILIARY
TRANSFORMER
2
4
V
A
C
3J31
#503A
2J31
#212
6J22
#224
TO
POWER
BOARD
#379
#210
6J4
5J4
12J4
REMOTE
PROTECTION
BOARD
9J4
#223
8J33
3.5 ohms
14 AMPHENOL
13J36
#413
C
6J34
3.5 ohms
5J36
#405
D
F-47
#212C
7. Using the ohmmeter check for continuity (zero ohms) from plug J31 pin 3 (lead#503A) to plug
J4 pin 6 (lead#210).
See Figure F.22,
Simplified Trigger Circuit Diagram.
8. If any of the resistance checks are abnormally high in steps 5, 6 or 7, check for broken or loose wires, connections or "open" thermostats.
Also check the small inductors on the Remote Protection Board.
See Figure
F.22, Simplified Trigger Circuit Diagram.
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages inside the machine. Do not reach into the machine or touch any internal part.
9. Apply the correct input power to the machine and turn ON.
10. Locate plug J6 on the power PC board. See
Figure F. 15. in the Power Board Test.
11. Carefully check for approximately 1VDC from plug J6 pin 2 (lead #305)(+) to plug J6 pin 7
(lead #301) (-). If the approximately 1VDC is present the power PC board and protection
PC board are functioning properly for the trigger circuit to operate. If the correct DC voltage is NOT present, perform the Protection
Board Test and the Power Board Test.
12. Test to make sure the T1 auxiliary transformer is producing 24VAC.
See Figure F.22,
Simplified Trigger Circuit Diagram.
13. If the above tests do not reveal the problem, the control PC board or associated wiring may be faulty.
See Figure F.22, Simplified
Trigger Circuit Diagram.
INVERTEC STT
DEC 97
F-48
TROUBLESHOOTING & REPAIR
DARLINGTON MODULE
REMOVAL AND REPLACEMENT
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
F-48
DESCRIPTION
The following procedure will aid the technician in the removal and replacement of the
Darlington module located in the lower tray assembly.
MATERIALS NEEDED
5/16" Nut driver
Phillips head screw driver
7/16" wrench
Needle nose pliers
1/2" Wrench
10mm Wrench
3/16" Allen type wrench
Dow Corning 340 Heat Sink Compound (Lincoln E1868).
Silicone Rubber RTV Coating (Lincoln E2861 or Dow 3140)
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-49
TROUBLESHOOTING & REPAIR
DARLINGTON MODULE REMOVAL
AND REPLACEMENT (continued)
FIGURE F.23 – OUTPUT CHOKE LEAD DISCONNECTION
F-49
LOWER
TRAY
AREA
OUTPUT CHOKE/
DARLINGTON MODULE
SPLICED CONNECTION
PROCEDURE
1. Turn off the Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the Maintenance section.
4. Locate the lead connection splice from the output choke to the Darlington module.
Remove the insulating sleeve. Using the
7/16" wrench disconnect the lead splice.
Thread the lower lead down into the lower tray assembly area. See Figure F.23.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
INVERTEC STT
F-50
TROUBLESHOOTING & REPAIR
DARLINGTON MODULE REMOVAL
AND REPLACEMENT (continued)
FIGURE F.24 – PLUG J1 DISCONNECTION
F-50
J1 CURRENT
SENSING PLUG
LOWER
TRAY
AREA
OUTPUT CHOKE/
DARLINGTON MODULE
SPLICED CONNECTION
5. Disconnect the current sensing plug J1 from the control PC board. Carefully remove plug
J1 and associated leads from the control PC board compartment. See Figure F.24.
FIGURE F.25 – PLUG J22 DISCONNECTION
PLUG J22
6. Locate and disconnect plug J22 from the wiring harness. See Figure F.25.
INVERTEC STT
F-51
TROUBLESHOOTING & REPAIR
DARLINGTON MODULE REMOVAL
AND REPLACEMENT (continued)
FIGURE F.26 – STT PLACED ON ITS RIGHT SIDE
F-51
MOUNTING
BOLTS (5)
7. Carefully lift and tilt the Invertec STT machine onto its right side. See Figure F.26.
8. Using the 7/16" wrench, remove the five bolts holding the lower tray assembly to the case bottom.
9. Carefully slide out and support the lower tray assembly.
10. Using the needle nose pliers, remove the strain relief holding the J22 lead harness to the case bottom.
Darlington cable from the negative output terminal.
12. Carefully remove the lower tray assembly clear from the machine.
13. Remove the rubber RTV coating from the
Darlington module.
INVERTEC STT
F-52 F-52
TROUBLESHOOTING & REPAIR
DARLINGTON MODULE REMOVAL
AND REPLACEMENT (continued)
FIGURE F.27 – DARLINGTON MODULE CONNECTIONS
E
DARLINGTON
MODULE
C
E
B
For steps 14-18, see Figure F.27.
14. Using the phillips head screw driver, remove the small leads from the small "E" and "B" terminals. Note lead placement for reassembly.
15. Using the 10mm wrench, remove the large lead and the #289 lead from the large "E" terminal. Note lead placement for reassembly.
16. Using the 10mm wrench, remove the large lead and the #287 lead from the large "C" terminal. Note lead placement for reassembly.
17. Using the 3/16" Allen type wrench, remove the four socket head cap screws that mount the module to the heat sink.
18. Carefully remove the Darlington module.
19. Upon reassembly, use Dow Corning 340
Heat Sink Compound (Lincoln E1868) between the module and the heat sink.
20. Mount the new module using the socket head cap screws and torque to 26 inch pounds.
Note: The torque should be rechecked after three hours.
21. Using the 10mm wrench, assemble the large
STT II
STT
lead and the smaller #289 lead to the large
"E" terminal. Torque to 26 inch pounds.
22. Using the 10mm wrench, assemble the large lead and the smaller #287 lead to the large
"C" terminal. Torque to 26 inch pounds.
23. Using the phillips head screw driver, reassemble the small leads to the small "E" and "B" terminals. Torque to 12 inch pounds.
24. Apply the Silicone Rubber RTV Coating
(Lincoln E2861 or Dow 3140) to the terminals and lead connections as was previously removed.
25. Replace the lower tray assembly.
26. Connect plug J22 to the wiring harness and plug J1 to the control PC board.
27. Connect the lead splice between the output choke and the Darlington module.
28. Install the case wraparound cover.
INVERTEC STT
DEC 97
F-53
TROUBLESHOOTING & REPAIR
SWITCH BOARD
REPLACEMENT
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
DESCRIPTION
This procedure will aid the technician in the removal and replacement of the switch boards.
MATERIALS NEEDED
5/16" Nut driver
7/16" Wrench
3/16" Allen type wrench
3/16" Socket wrench
Dow Corning 340 Heat Sink Compound (Lincoln E1868)
ANALOG Ohmmeter
F-53
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-54
TROUBLESHOOTING & REPAIR
SWITCH BOARD REPLACEMENT (continued)
FIGURE F.28 – SWITCH BOARD REMOVAL
F-54
SOCKET
HEAD
SCREWS
PROCEDURE
NOTE: If a test indicates that a switch board is defective, both switch boards must be replaced at the same time. In addition to replacing the switch boards, replace capacitors C1 and C2 if the following conditions exist: a. The machine was operating from 380 VAC or higher when the failure occurred.
b. Burned areas are visible on the switch boards.
1. Turn off the Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor Discharge
Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Carefully disconnect the leads at the top of the switch board.
5. Using the 3/16" socket wrench, remove the four cap screws from the switch board. See
Figure F.28.
INVERTEC STT
F-55 F-55
TROUBLESHOOTING & REPAIR
SWITCH BOARD REPLACEMENT (continued)
6. Using the 7/16" wrench, remove the two hex head capacitor screws located in the center of the switch board. Hold the board firmly as you remove the screws.
7. Carefully remove the switch board.
8. Clean the heat sink surfaces thoroughly to remove all the heat sink compound. (During machine operation, this compound helps conduct heat from the switch board to the heat sinks.
9. Apply a thin layer (.002") of Dow Corning
340 Heat Sink Compound (Lincoln E1868) to the mounting surfaces of the new switch board and to the capacitor terminals. DO
NOT allow the compound to enter the mounting screw holes. It can distort the torque values.
10. Prepare to mount the new switch board on the heat sink by first lining up the mounting holes. Then press the switch board into place.
11. Insert each of the four socket head screws into the mounting holes. Thread them finger tight. The threads are soft -- be careful no to cross-thread them.
12. Insert each of the two hex head screws into the capacitor terminal holes. Thread them finger tight. Be careful not to cross-thread the screws.
13. Torque both sets of screws in 10 inch-pound increments. Use a diagonal tightening sequence. Torque the four socket head screws to 44 inch-pounds (5 Nm). Torque the two hex head screws to 55 inch-pounds (6
Nm).
CAUTION
Failure to connect the switch board leads correctly can result in damage to the Invertec STT machine when power is applied.
14. Reconnect all the leads to the switch board.
Be sure each lead is connected to the correct terminal.
15. Perform the Test after Repair of Switch
Boards and/or Capacitors.
NOTE: Always make sure that the switch boards are changed in matched pairs. Never mix an old style switch board (different part number) with new style (new part number).
INVERTEC STT
F-56 F-56
TROUBLESHOOTING & REPAIR
SWITCH BOARD REPLACEMENT (continued)
TEST AFTER REPAIR OF SWITCH
BOARDS AND/OR CAPACITORS
The following test must be performed after the switch boards and/or the capacitors have been replaced.
NOTE: Always make sure that switch boards are changed in matched pairs. Never mix an old style
(different part number) switch board with a new style (new part number).
TEST PROCEDURE
1. Turn main power OFF.
2. Perform Input Filter Capacitor Discharge
Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
3. Connect a shorting conductor across terminals 14 and 53 of the protection PC board.
See Figure F.29.
4. Set an ANALOG ohmmeter to X1000 range and place the probes on terminals 9 (+) and
12 (–) of one switch board. The meter will show the capacitors charging up and may take a minute or so to stabilize. The final meter reading should not exceed 8600 ohms
(8.6 on the scale).
5. Test the other switch board the same way.
NOTE: Repeat the Input Filter Capacitor
Discharge Procedure.
6. Remove the shorting conductor set up in step
3.
7. Replace 20 amp fuses with 5-amp fuses in the input supply fuse holders.
NOTE: These fuses should be installed to protect against excessive current flow caused by a short circuit during the procedure.
FIGURE F.29 — SHORTING TERMINALS 14 AND 53 OF PROTECTION BOARD
L7915-[ ] PROTECTION
53 14
INVERTEC STT
JUMPER TERMINALS
F-57 F-57
TROUBLESHOOTING & REPAIR
SWITCH BOARD REPLACEMENT (continued)
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there are high voltages in the machine. Do not reach into the machine or touch any internal part.
9. With the output free of a load, check open circuit voltages of the output. Voltage should be
85 VDC maximum.
10. Remove input power. Then remove the
5-amp fuses from the input supply fuse holders.
11. Install 20-amp fuses and test under load.
NOTE: A resistive-type grid load bank is recommended.
14. Perform Retest After Repair.
8. With the machine connected for 440/460 volt operation and the proper input voltage applied, turn on input power to the machine.
INVERTEC STT
F-58
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND
REPLACEMENT PROCEDURE
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
F-58
DESCRIPTION
This procedure will aid the technician in the removal and replacement of the input filter capacitors C1 and C2.
MATERIALS NEEDED
5/16" Nut driver
Slot head screw driver
7/16" Wrench
Needle nose pliers
1/2" Wrench
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-59 F-59
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.30 – OUTPUT CHOKE LEAD DISCONNECTION
LOWER
TRAY
AREA
OUTPUT CHOKE/
DARLINGTON MODULE
SPLICED CONNECTION
PROCEDURE
1. Turn off Invertec STT and disconnect main AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Locate the lead connection splice from the output choke to the Darlington module.
Remove the insulating sleeve. Using the
7/16" wrench disconnect the lead splice.
Thread the lower lead down into the lower tray assembly area. See Figure F.30.
INVERTEC STT
F-60 F-60
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.31 – PLUG J1 DISCONNECTION
J1 CURRENT
SENSING PLUG
LOWER
TRAY
AREA
5. Disconnect the current sensing plug J1 from the control PC board. Carefully remove plug
J1 and associated leads from the control PC board compartment.
FIGURE F.32 – PLUG J22 DISCONNECTION
OUTPUT CHOKE/
DARLINGTON MODULE
SPLICED CONNECTION
PLUG J22
6. Locate and disconnect plug J22 from the wiring harness. See Figure F.32.
INVERTEC STT
F-61 F-61
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.33 – STT PLACED ON ITS RIGHT SIDE
MOUNTING
BOLTS (5)
7. Carefully lift and tilt the Invertec STT machine onto its right side. See Figure F.33.
8. Using the 7/16" wrench, remove the five bolts holding the lower tray assembly to the case bottom.
9. Carefully slide out and support the lower tray assembly.
10. Using the needle nose pliers, remove the strain relief holding the J22 lead harness to the case bottom.
Darlington cable from the negative output terminal.
12. Carefully remove the lower tray assembly clear from the machine and set aside.
13. Carefully disconnect the leads at the top of the switch board.
INVERTEC STT
F-62 F-62
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.34 – REMOVING HEX HEAD NUTS OF THROUGH-BOLTS
HEX NUT
CAPACITOR REPLACEMENT
NOTE: Capacitors must always be replaced in matched sets (C1 and C2 as a set)).
When replacing Capacitors, remove the entire
FET heat sink assembly, including the capacitors and switch board, as a unit.
Disassemble and reassemble only one unit at a time. Use the other unit as a model during reassembly so that all parts are reinstalled properly.
14. Remove the two 3/8” hex head nuts from the top of the through-bolts. The hex nuts are located on top of the fan shroud. See Figure
F.34.
INVERTEC STT
F-63 F-63
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.35 – REMOVING THROUGH-BOLTS
PLASTIC RETAINING
INSULATORS
15. Place the machine on its side as shown in
Figure F.35. Slide the plastic retaining insulators that go through the base of the machine to one side. Pull the through-bolts out of the machine, being careful to save all the insulation and standoff material. Set aside for reassembly.
16. Remove the switch board and capacitor assembly from the machine.
INVERTEC STT
F-64 F-64
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.36 – REMOVING CAPACITOR NUTS
17. Remove the two 7/16” hex bolts that hold the capacitor to the switch board. See Figure
F.36.
18. Loosen the set screw of the capacitor clamp ring and remove the capacitor from the clamp ring. See Figure F.37.
FIGURE F.37 – LOOSENING THE CLAMP RING SET SCREW
17. Remove the two 7/16” hex bolts that hold the capacitor to the switch board. See Figure
F.36.
18. Loosen the set screw of the capacitor clamp ring and remove the capacitor from the clamp ring. See Figure F.37.
INVERTEC STT
F-65 F-65
TROUBLESHOOTING & REPAIR
CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)
FIGURE F.38 – COMPLETE SWITCH BOARD ASSEMBLY READY FOR INSTALLATION
INSULATOR
19. Install the new capacitor and tighten the two
7/16” hex bolts to a torque of 55 inch-pounds
(6 Nm). Tighten these bolts in increments of
10 inch-pounds, alternating between the two bolts. Capacitor installation is complete. See
Figure F.38.
CAUTION
Proper capacitor polarity must be noted when attaching the capacitor to the switch board assembly.
20. Install the switch board and capacitor assembly into the machine. Take special care that ALL insulators and sleevings are in their proper positions. See Figure F.38.
21. Install the lower tray assembly and all previously disconnected loads and plugs.
22. Perform the Test After Repair of Switch
Boards and/or Capacitors.
NOTE: Always make sure that the switch boards are changed in matched pairs. Never mix an old style switch board (different part number) with new style (new part number).
INPUT FILTER CAPACITOR CONDITIONING
If the machine will not produce output when turned on and the following two conditions exist:
The machine is connected to operate at an input voltage of 380 VAC or higher and
Power has not been applied to the machine for a long period of time (many months). Then. . .
The Input Filter Capacitor Protection Circuit could have been activated and prevented output. This means the Input Filter Capacitors must be conditioned.
The Input Filter Capacitor Protection Circuit monitors the voltage across input filter capacitors C1 and C2. When it senses an overvoltage condition, the protection circuit will prevent the machine from operating.
To condition the Input Filter Capacitors:
1. Turn main power OFF.
2. Remove any load and do not load machine until conditioning procedure is complete.
3. Turn main power ON.
4. Let the unloaded machine sit for 30 minutes.
5. Turn main power OFF.
6. Turn main power ON.
NOTE: The machine should be ready to operate, and the protection circuit should have automatically reset once the capacitors have been conditioned and capacitor voltage has reached the acceptable operating level.
INVERTEC STT
F-66
TROUBLESHOOTING & REPAIR
OUTPUT RECTIFIER
REMOVAL AND REPLACEMENT
WARNING
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.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).
DESCRIPTION
This procedure will aid the technician in the removal and replacement of the output diode heat sink assembly.
MATERIALS NEEDED
5/16" Nut driver
3/8" Nut driver
7/16" Wrench
Slot head screw driver
Dow Corning 340 Heat Sink Compound (Lincoln E1868)
F-66
Note: Component locations and disassembly procedures may vary slightly on STT II models
INVERTEC STT
DEC 97
F-67
TROUBLESHOOTING & REPAIR
OUTPUT RECTIFIER REMOVAL AND REPLACEMENT (continued)
FIGURE F.39 – CHOKE LEAD/HEAT SINK CONNECTION
F-67
HEAT SINK TAB
CHOKE LEAD
PROCEDURE
1. Turn off Invertec STT and disconnect main
AC input power to the machine.
2. Using the 5/16" nut driver, remove the case wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure. See the Maintenance section.
WARNING
ELECTRIC SHOCK can kill.
• Before continuing with the test procedure, perform the capacitor discharge procedure to avoid electric shock.
4. Using the slot head screw driver, loosen the input cable strain relief.
5. Using the 5/16" nut driver, remove the four screws securing the case back to the internal horizontal baffles.
6. Carefully pull the case back away from the output rectifier assembly.
NOTE: The case back will NOT detach from the case bottom.
7. Using the 7/16" wrench, remove the four bolts and washers mounting the fan motor bracket to the top horizontal baffle.
Carefully set the fan and motor assembly aside. Note insulation placement for reassembly.
NOTE: The fan motor leads do NOT have to be cut.
8. Using the 7/16" wrench, remove the choke lead from the heat sink tab. See Figure F.39.
INVERTEC STT
F-68
TROUBLESHOOTING & REPAIR
OUTPUT RECTIFIER REMOVAL AND REPLACEMENT (continued)
FIGURE F.40 – MAIN TRANSFORMER DIODE CONNECTIONS
F-68
MAIN
TRANSFORMER
SECONDARY
LEADS
9. Remove the two sleevings from the diode connections at the main transformer. See
Figure F.40.
10. Using the 7/16" wrench, remove the diode leads from the main transformer secondary leads. Note washer and lead placement for reassembly.
INVERTEC STT
F-69
TROUBLESHOOTING & REPAIR
OUTPUT RECTIFIER REMOVAL AND REPLACEMENT (continued)
FIGURE F.41 – SWITCH BOARD/CAPACITOR ASSEMBLY THROUGH-BOLTS
F-69
THROUGH-BOLTS
11. Using the 3/8" nut driver, remove the rear nuts and washers from the switch board/capacitor assembly through-bolts.
See Figure F.41.
12. Using the 3/8" nut driver, loosen the front nuts from the switch board/capacitor assembly through-bolts.
13. Carefully lift the horizontal baffle away from the upper tabs of the output rectifier heat sink assembly.
14. Slide the heat sink assembly to the right
(facing the back of the machine) to disengage the bottom tabs from the lower horizontal baffle.
15. Carefully remove the output rectifier heat sink assembly and leads from the STT machine.
16. Remove the nut that secures each diode that is to be replaced.
NOTE: The output diodes must be replaced in matched sets.
INVERTEC STT
17. Before mounting the new diode sets, clean and brighten the mounting surfaces of both the diode sets and the heat sink with fine steel wool.
18. Apply an even coating of DOW Corning
340 Heat Sink Compound to the mounting surfaces of the diodes that contact the heat sink. This compound layer should be less than .001 inch thick. DO NOT apply the compound to the diode studs or mounting nut threads.
19. Insert the diode sets into the mounting hole and tighten the diode mounting nuts to a torque of 25 inch-pounds (3 Nm).
20. Replace the rectifier heat sink assembly, leads and connections that were previously removed. Install the fan and motor assembly (note insulation placement).
Install the case back and the case wraparound cover.
F-70 F-70
TROUBLESHOOTING & REPAIR
RETEST AFTER REPAIR
Retest the INVERTEC STT:
• If it fails any test and the test requires removing or replacing any mechanical part that could affect the machine's electrical characteristics.
OR
• If you repair or replace any electrical components.
MAXIMUM INPUT IDLE AMPS AND IDLE WATTS
INPUT CURRENT @ IDLE 3.5 AMPS
INPUT POWER @ IDLE 800 WATTS
MINIMUM ACCEPTABLE OUTPUT (AT MAXIMUM BACKGROUND SETTING)
[STATIC GRID LOAD]
CONTROL MODE
BACKGROUND
AMPS
140
VOLTS
20
OPEN CIRCUIT VOLTAGE RANGE
73 TO 85 VDC
INVERTEC STT
F-71 F-71
TROUBLESHOOTING & REPAIR
INPUT FILTER CAPACITOR
CONDITIONING
If the machine will not produce output when turned on and the following two conditions exist:
The machine is connected to operate at an input voltage of 380 VAC or higher and
Power has not been applied to the machine for a long period of time (many months). Then. . .
The Input Filter Capacitor Protection Circuit could have been activated and prevented output. This means the
Input Filter Capacitors must be conditioned.
The Input Filter Capacitor Protection Circuit monitors the voltage across input filter capacitors C1 and C2.
When it senses an overvoltage condition, the protection circuit will prevent the machine from operating.
To condition the Input Filter Capacitors:
1. Turn main power OFF.
2. Remove any load and do not load machine until conditioning procedure is complete.
3. Turn main power ON.
4. Let the unloaded machine sit for 30 minutes.
5. Turn main power OFF.
6. Turn main power ON.
NOTE: The machine should be ready to operate, and the protection circuit should have automatically reset once the capacitors have been conditioned and capacitor voltage has reached the acceptable operating level.
ENVIRONMENTAL PROTECTION
High voltage connections are covered with an RTV sealant to prevent malfunction in severe environments.
Sealant must be applied to connections which have been opened or otherwise lost their protection. A noncorrosive, electronic grade sealant such as Dow
Corning 3140, 3145, or 738; Columbus Adhesives
0172; or GE RTV-162 is recommended. Sealant may also be purchased from Lincoln Electric (order E2519
Silicone Rubber RTV Coating). Apply sealant after machine is repaired and tested. All five terminals of the input rectifier require this type of sealant.
INVERTEC STT
G-1
ELECTRICAL DIAGRAMS
TABLE OF CONTENTS
ELECTRICAL DIAGRAMS SECTION
Electrical Diagrams Section...........................................................................................Section G
Wiring Diagram......................................................................................................................G-2
Control PC Board (G2782) Schematic 1 of 2........................................................................G-3
Control PC Board (G2782) Schematic 2 of 2.......................................................................G-4
Control PC Board (G2782) Layout ........................................................................................G-5
Power Board (L8033) Schematic ..........................................................................................G-6
Power Board (L8033) Layout.................................................................................................G-7
Darlington Drive Board (G2778) Schematic..........................................................................G-8
Darlington Drive Board (G2778) Layout ................................................................................G-9
Switch Board (L8441) Schematic........................................................................................G-10
Switch Board (L8441) Layout ..............................................................................................G-11
Driver Board (L9134) Schematic .........................................................................................G-12
Driver Board (L9134) Layout ...............................................................................................G-13
Protection Board (L7915) Schematic ..................................................................................G-14
Protection Board (L7915) Layout ........................................................................................G-15
Current Sense Board (M17591) Schematic ........................................................................G-16
Current Sense Board (M17591) Layout ..............................................................................G-17
Remote Protection Board Schematic ..................................................................................G-18
Wiring Diagram STT II.........................................................................................................G-19
G-1
INVERTEC STT
DEC 97
NOTES
INVERTEC STT
G-2
Wiring Diagram
ELECTRICAL DIAGRAMS
WIRING DIAGRAM - INVERTEC STT
N.L.
C
J4, J17
B
LOAD
POWER LINE
FILTER
ASSEMBLY
LINE
C
B
A
A
J1, J8,
J11, J12, J14
J18, J37
J3, J9,
J10, J13,
J15, J35
9A
9A
9A
9A
N.F.
52
7500
25W
R1
53
N.G.
9A
9A
R7
25
25W C2 +
25
25W
R6
2200 F
450V
12A
12A
9
+
402, 404
SWITCH
BOARD
(LEFT) -
401, 403
R
12
W R
4, 5
W
1, 8
4
1
C
B
A
INPUT
RECTIFIER
D13
H1
H1
C D
+
TP1
9D 9D
9C
B
A
A
TP3
TP2
F
-
12C
12D
12D
N.K.
H1 H3
FAN
MOTOR
A
B
S1
POWER
ON OFF
U
W
V
R
C
W
B
G
INPUT
PER
N.A.
CR1
9D
310
310A
14 53
53
J8
1
3
2
4
311
313
309
310
S7
RECONNECT
9C
12C
9B
9B
12A
12A
9B
N.H.
12D
CR2 309A
12B
12B
310A
12B
12B
N.F.
BOARD
H5 51
J15
2
5
1
4
3
6
51
52
52
314
315
316
317
9B
7500
25W
12B
51
12B
N.G.
9B
9B
R5
25
25W
25
25W
R4
2200 F
450V
C1 +
12B
12B
9D
12D
12B
52
9
+
402, 404
-
401, 403
12
6
8
12
J16
2
1
7
3
14
13
307 308
3 2 5 1
J10
4
DRIVER
BOARD
J9
1 2 3 4
J11
3 6 2 5 4 1
W R W
4,5
R
SWITCH
BOARD
(RIGHT)
1, 8
4 AMP
SLOW
BLOW
A
440-
A
380-
415V
N.D.
H3
H6
H4
H3
H2
H1
J21
6
3
H5
H4
R
115V
1
J30
32
R
2 33
42V
U
24V
N
3
5
J31
43A
503
2
4
1
H3
H2
H1
0V
W
2
Y
18V
4
Y
1
T1
AUXILIARY
TRANSFORMER
212
504
501
5
T3
CURRENT
TRANSFORMER
I
Y Y
I
8
32C
J22
15
16
33C
7
8
32A
32B
33A
33B
115V
371
374
J22
10
11
R
18V
1
W
18V
R
2
9
3
B
18V
B
4
371A
374A
240
241
242
243
244
N
10V
N
O
6V
O
245
U
18V
12
U
13
T4
AUXILIARY
TRANSFORMER
246
T2
MAIN
TRANSFORMER
TOP
4
F
OUTSIDE
S
BOTTOM
INSIDE
1
F
F
BOTTOM
S
10
2W
.001/400
R3
C4
D11
D10
D9
D8
D7
5
F
BOTTOM
OUTSIDE
S
TOP
S
INSIDE
8
F
S
TOP
F
N.E.
10
2W
N.E.
D1
D2
D3
D4
D5
C3
R2
.001/400
503A
224
503A
W
J22
14
W
6
503B
DARLINGTON
HEATSINK
THERMOSTAT
224A
FAN
THERMOSTAT
224
210A
212B
150 5W
212A 210
J5, J7,
J34
J16, J28
J6, J27, J33
J2, J36
P.C. BOARD CONNECTOR CAVITY NUMBERING SEQUENCE
(VIEWED FROM COMPONENT SIDE OF BOARD)
J38
J39
J19
P30
PINOUT OF FRONT PANEL CONNECTORS (REAR VIEW)
J30 P29, P31
J29. J31 P21
P22 J22
J21
J24
J26
J23
J25
METER PINOUT (VIEWED FROM BACK OF METER)
ELECTRICAL SYMBOLS PER E1537
COLOR CODE:
B = BLACK
G = GREEN
N = BROWN
O = ORANGE
R = RED
W = WHITE
Y = YELLOW
U = BLUE
NOTES:
N.A.
1. FOR MACHINES SUPPLIED WITH INPUT CABLE
FOR SINGLE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.
CONNECT BLACK & WHITE LEADS TO SUPPLY CIRCUIT.
WRAP RED LEAD WITH TAPE TO PROVIDE 600V. INSULATION.
FOR THREE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.
CONNECT BLACK, RED & WHITE LEADS TO SUPPLY CIRCUIT.
2. FOR MACHINES NOT SUPPLIED WITH INPUT CABLE
FOR SINGLE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.
CONNECT TERMINALS U & W TO SUPPLY CIRCUIT.
FOR THREE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.
CONNECT TERMINALS U, V & W TO SUPPLY CIRCUIT.
N.B. SINCE COMPONENTS OR CIRCUITRY OF A PRINTED CIRCUIT BOARD MAY CHANGE WITHOUT AFFECTING
THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY NOT SHOW THE EXACT
COMPONENTS OR CIRCUITRY HAVING A COMMON CODE NUMBER.
N.D. PLACE "A" LEAD ON APPROPRIATE CONNECTION FOR INPUT VOLTAGE.
CONNECTION SHOWN IS FOR 440-460V OPERATION.
N.E. D1 THRU D5 OUTPUT DIODES ARE A MATCHED SET.
D7 THRU D11 OUTPUT DIODES ARE A MATCHED SET.
N.F. R1, R9 BLEEDER RESISTORS ARE A MATCHED SET.
N.G. C1, C2 CAPACITORS ARE A MATCHED SET.
N.H. PLACE SWITCH IN APPROPRIATE POSITION FOR INPUT VOLTAGE.
CONNECTION SHOWN IS FOR 380-460V OPERATION.
N.I. DENOTES A TWISTED WIRE PAIR OR GROUP.
N.J. NOT PRESENT ON EUROPEAN VERSIONS.
N.K. NOT PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.
N.L. PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.
307
308
309
310
501
504
311
313
L3
CHOKE
J12
1
2
3
4
371
374
N
N
O
O
3
5
6
1
4
2
J13
DARLINGTON
DRIVE BOARD
W
B
6
1
4
5
3
7
8
2
J7
3
4
2
1
J14
POWER
BOARD
J6
8
1
10
2
7
9
4
5
3
6
303
302
304
275
212
305
301
212A
211A
CURRENT
SENSE
BOARD
J18
3
4
1
2
R
B
W
Y
Y
301
305
245
223
211A
212C
210
246
502
240
241
242
W
B
R
B
371A
374A
243
244
303
302
304
275
R
B
W 2
3
1
4
2
8
11
3
1
7
6
9
5
12
4
10
J1
J27
5
6
4
7
2
1
8
9
3
10
2
4
5
6
8
3
7
1
J5
3
11
10
6
4
8
1
7
14
2
5
9
12
13
J17
J28
7
8
5
6
3
4
1
2
9
10
11
12
J2
J4
4
15
16
10
7
14
3
5
11
9
6
12
8
2
1
13
J3
2
6
5
1
4
3
N.L.
TOROIDAL
CORE
289B
C8 20/400
R14
2 300W
289A
289
R13
2 300W
E
288B
288A
288
C
287
D7
B
W
E
B
DARLINGTON
MODULE
358
359
360
361
362
363
350
351
352
353
354
355
356
357
370
371
372
374
376
364
365
366
367
368
369
REMOTE
PROTECTION BOARD
223
212C
43A
33C
32C
212B
B
R
W
B
370
371
372
374
376
+ ARC
- ARC
J37
3
2
8
5
7
6
1
4
J34
7
1
6
2
3
8
9
10
5
4
J33
J36
3
2
1
10
9
12
4
11
14
6
5
13
16
8
15
7
J35
1
2
3
4
3
6
2
5
1
4
290
291
J19
3
4
1
2
(+)
(-)
VOLTAGE
SENSE
CONNECTION
403
402
401
410
409
412
404
411
J38
J
B
D
F
H
C
G
A
E
I
TRIGGER
GND
OPTIONAL
REMOTE
INTERFACE
414
406
405
413
416
408
415
407
H
L
N
B
M
D
C
K
I
A
J
E
F
G
J39
WIRE
FEEDER
32
31
77
76
75
81
4
2
42
41
SPARE
GND
21
82
TRIGGER
42
VAC
115
VAC
BG
10K
PB
10K
N.J.
43B
42
CB1
6AMP
42
VAC
33D
31A
CB2
6AMP
115
VAC
353
352
351
350
357
356
355
354
358
359
360
361
362
363
CW (MAX)
10K
2W
R11
CW (MAX)
10K
2W
R12
J24
3
4
1
2
5
6
3
4
1
2
5
6
J23
J26
1
4
5
2
3
6
1
4
5
2
3
6
J25
PEAK
CURRENT
CONTROL
PEAK
CURRENT
METER
BACKGROUND
METER
BACKGROUND
CONTROL
CONTROL
BOARD
364
365
366
367
367A
.045
368
367A
STAINLESS
369
502
CW (MAX)
10K
2W
R13
S2
.035
503
503A
S3
MILD
(-)
Y
(+)
HOT START
CONTROL
WIRE SIZE
WIRE TYPE
THERMAL
OVERLOAD
INDICATOR
INLINE CONNECTOR CAVITY NUMBERING SEQUENCE
(VIEWED FROM WIRE SIDE OF CONNECTOR)
R
9-13-96
CLEVELAND, OHIO U.S.A.
G2773
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.
G-2
INVERTEC STT
G-3
Control PC Board (G2782) Schematic 1 of 2
ELECTRICAL DIAGRAMS G-3
< .035 DIA WIRE
-
J3
WIRE TYPE SELECT
4
> .045 DIA WIRE
-
SS_WIRE
3SEC
OFF
CW
10K
ARC_START
2781-A
WIRE SIZE SELECT
1
2
1
G
X25
PWM
SG3846
12
J27
+15V POWER SUPPLY FOR
DIGITAL, TRIGGER & ANALOG SECTIONS
SENSE
BOARD
18 VAC
CURRENT
CURRENT FEEDBACK
1V/100A
MILD
1
J3
STAINLESS
3
9
J27
2
10
CW
10K
X18
NAND
A
2
3
4
J27
J27
13
2
5
6
7
1
J1
J3
C460
1.0
35V
J3
3
J3
J3
+15V
14
C439
0.1
50V
C440
4.7
35V
X19
DUAL FF
MC14013B
7
J28
14
J28
CFB
J1
J1
J1
1
R467
+ t
.25
2
R526
+ t
56
D306
1N4007
C310
.0047
1400V
D308
1N4007
+15V
REMOTE_POTS
2.67K
R546
100
R489
R478
10.0K
R485
33.2K
DZ18
12V
1W
D412
1N914
R466
10.0
C412
1.0
35V
CW
10K
2.67K
R545
Q6
2N4401
C461
+15V
+15V
16
C441
0.1
50V
X20
COUNTER
MC14040
D307
1N4007
C312
D309
1N4007
47.5K
R519
68.1K
R513
+15V
C423
1.0
35V
3V
5V
LOCAL_POTS
15
2.67K
R543
75.0
R504
2.67K
R544
R481
100
J2
16
J2
J2
10
1.0
C446
35V
2.67K
R406
C447
1.0
35V
+15V
D406
DZ20
R403
10.0K
R404
100
10V
1W
2
.33
X35
1014
A
3
+15V
200V
1
C469
39
20V
6
5
2.67K
R542
IN
8
C311
35V
1000
C400
1.0
35V
16
C442
0.1
50V
X32
COUNTER
MC14040
CURRENT
INTEGRATOR
X36
NAND
B
D407
DZ15
12V
1W
POWER PLANE
GROUND PLANE
2.67K
R541
D310
8
X8 lm350 s18395-23
ADJ
R337
243
OUT
C464
C401
+15V
C404
1.0
35V
4
1
X33
TL431
6
8
REF
C402
1.0
35V
500
C313
100
20V
CW
10V
1W
C449
DZ9
6
X35
B
1014
5
R522
332K
10.0K
R510
DZ11
12V
1W
7
DZ10
12V
1W
+15V
+15V
POWER PLANE
GROUND PLANE
Q8
2N4401
2.5V
12
X29
LM224
D
13
C456
0.1
50V
X9
TIMER
MC14538B
C314
2.67K
R508
C443
0.1
50V
X10
TIMER
MC14538B
+15V
OVERCURRENT TRIP
+15V
R405
100
16
8
10 VDC
CONTROL
POTS
R525
100
POWER
+15V
D400
C403
D409
C405
X31 B
X31 C
ARC_START
HOT START
TIMING
GENERATOR
3
8
LOCAL
14
D408
5
6
D411
1
2
X36
NAND A
+15V
4
9
6
5
X29
LM224
B
13
12
X34
LM224
D
C445
0.1
50V
X34
OP AMP
LM224
6
5
X34
LM224
B
+5.1V
2
3
X34
LM224
A
C463
R524
150K
10
9
X35
1014
C
8
"ANALOG LOGIC"
REMOTE
HOT_START
R536
10.0K
D413
C462
1.0
35V
D410
C465
39
20V
C409
1.0
35V
16
8
H= .045
L= .035
/HOT_START
7
R527
10.0K
R528
10.0K
DZ19
12V
1W
OVERCURRENT
TRIP TIMING
14
DZ12
15V
1W
15.0K
R407
C406
4
11
3
OVERCURRENT
OUTPUT DISABLE
R509
10.0K
D416
1N4936
+5.1V
7
1
C466
0.1
50V
X35
OP AMP
LT1014
LOCAL
REMOTE
C448
1.0
35V
4
11
ARC/SHORT DETECT
FROM FE (SHEET 2)
+15V
X26
1
TL431
6
8
REF
2N4403
Q7
TO TRIGGER CIRCUIT
OVERCURRENT FAULT
( SHEET 2 )
CR1
12Vdc
10K
CW
FUSE
9
10
X34
LM224
C
10K
CW
7
14
3
5
6
7
8
J2
J2
J2
8
4
3
13
12
Unused Devices
J28
J28
J28
9
5
4
2
J27
J27
J27
4
5
J28
J28
J28
X22
3
C467
0.1
50V
X11
NAND
4093B
100K
R559
+15V
R434
10.0
R435
10.0K
R491
100
J27
J27
J27
R492
10.0
R549
2.67K
R493
100
C475
2700p
50V
D424
1N914
500K
8
14
7
2.5V
HP2231
SLOW RAMP
R409
47.5K
+15V
375us
50K
R301
CW
R550
15.0K
13
D
X23
2901
10
500A MAX
PINCH LIMIT
R530
8.25K
11 PINCH COMMAND
PB_SCALED
CW
SHORT OR 500K POT
METER_1
R483
10.0
R484
10.0
R532
1.00K
LOCAL_POTS
REMOTE_POTS
R548
2.67K
+5 VOLT
METER
POWER
PINCH SLOW RAMP
PINCH KNEE
PINCH FAST RAMP
BACKGND
14
C432
0.1
50V
X12
NAND
4093B
OCI2 A
X22 B
6
+5.1V
+15V
+15V
9
11
10
7
R414
10K
5
TAIL OUT
J2
J2
11
R412
10K
R413
200
7
METER_2
+15V +15V
ARC
10.0K
R540
C433
0.1
50V
+15V
14
X13
NAND
4093B
7
GROUND PLANE
4.75K
R302
C300
332K
R562
ARC
X28
2901
D
13
150us FUSE ENTRY
ARC KILLER PULSE
D423
1N914
100A/ms
R410
15.0K
FAST RAMP
1000A/ms
R411
6.81K
BALL
KEEP_ALIVE LEVEL
9
/PINCH
6
B X21
C407
.0047
50V
9
X24
1014
C
8
.294V
10
R443
82.5K
R547
2.67K
B.PT
14
8
C
X23
2901
9
/HOT_START
R471
100K
R415
47.5K
PINCH RAIL
COMMAND SIGNAL
1
C434
0.1
50V
X14
NAND
4093B
PINCH KILLER Varc
ADJUST FE (SHEET 2)
8
4
5
1 2
A
T1
B
X9
A
T2
Q
/Q
RST
3
6
7
10
R495
2.67K
BALL
/RESET
X31 D
13
X30 A
2
R490
267K
P_BOOST
RAMP
FUSE
KEEP_ALIVE LEVEL
ARC
+15V
POWER PLANE
14
7
/BALL
13
12
PB_START SIGNAL
TO FE (SHEET 2)
FOR ENERGY
CONTROL OPTION
12
11
PINCH
11
TAILOUT
RAMP
PINCH
12
B X21
R416
100K
C452
1.0
35V
10
+15V
4.75K
R340
OCI1
4
B
5.62K
R303
X11
NAND
A
Q10
2N4401
CFB
47.5K
R419
COMMAND
1
P BOOST
INCREASE TAILOUT
DURING HOT START
BACKGND
14
C435
0.1
50V
X15
NAND
4093B
HP2231
Q3
2N4401
1
OCI6
A
HP2231
2
D414
DZ16
12V
1W
11
13
3
7
BALL_OR_FUSE 9
/KILLER
750us
8
/ARC
4.75K
R334
X22 A
+15V
2
C451
1.0
35V
2
PINCH
13
A
X21
R420
47.5K
R421
475K
2
3
X24
A
1014
R424
100K
1
CURRENT
ERROR AMP
C454
R333
10.0K
D300
+15V
D415
1
47p
5
14
C436
0.1
50V
X16
NAND
4093B
7
DV/DT KILLER
DV/DT LEVEL DETECT
FROM FE (SHEET 2)
X11
NAND
D
/KILLER
/BALL_RC
C301
100p
100V
1
2
PB_START
R422
150K
C410
100V
10.0K
R444
C417
2700p
50V
10.0K
R445
+15V
8
DZ17
12V
1W
C455
10
PINCH
R305
4.75K
X11
C
NAND
3
X13
NAND
D
10
KILL_START
C302
4 /KILLER
X11
NAND
B
13
3
/BALL_DELAYED
12
( SHEET 2 )
PWM_EN
15.0K
R453
C450
0.1
50V
C437
0.1
50V
1
2
KILLER
11
P_BOOST COMMAND
6
5
X24
1014
B
7
D402
13
X24
1014
12
D
14
C444
0.1
50V
X18
NAND
4093B
HP2231
/RESET
X12
NAND
A
BALL_DELAYED
11
1
/ARC
2
X12
NAND
B 3
6
5
/(BALL & SHORT)
X12
NAND
C
RESET
PULSE
Q4
2N4401
D401
3us MAX DEADTIME
1N4936
+15V
R425
CW
10K
3.32K
R426
X30 C
6
LOCAL
X30 D
12
REMOTE
9
11
14
X17
NAND
4093B
7
/RESET
12
/ARC
13
NAND
X13
A
CW
500
OCI2
B
11
14
7
2
3
X29
LM224
A
6
DV/DT
D
X16
NAND
12
13
1us MIN PULSEWIDTH
BACKGROUND COMMAND
D403
1.00M
C303
330p
100V
( SHEET 2 )
PRI_FB
C473
1.00K
R427
1.00K
R428
SAWTOOTH
WAVEFORM
GENERATOR
C438
0.1
50V
X36
NAND
4093B
R306
4.75K
+15V
D305
11
C472
100p
100V
Verror
COMMAND
C471
330p
100V
/RAMP
ARC
9
8
14
7
C418
.018
50V
9
8
D302
1N4936
X36
NAND C
13
12
R537
4.75K
X36
NAND
D
R498
20.0K
1
R497
150K
11% BACKGROUND INCREASE
DURING HOT START
3
HOT_START
NOTES :
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE
NUMBER.
C419
1.8
20V
4
C468
0.1
50V
X17 D
NAND
X13
NAND
B
+5.1V
11
B X21
X30 B
5
4
C453
10
X22
100K
C426
0.1
50V
X31
SWITCH
4066B
1V
AMPS>100
8
NAND C
X17
10
13
X35
1014
D
14
12
9
ARC
Ch'ge.Sht.No.
5-19-95
5-24-96E
B
4
OCI5
3
6
Analog Logic I/O to Control Panel
4
C428
0.1
50V
X29
OP AMP
LM224
C458
0.1
50V
Vcc
8
OCI2
HP2231
GND
5
HP2231
GND
5
EQUIP.
TYPE
SUBJECT
C429
0.1
50V
Vcc
8
OCI3
HP2231
GND
5 7 12
GROUND PLANE
11 11
"DIGITAL LOGIC"
/ARC
PINCH SIGNAL
TO FE (SHEET 2)
FOR ENERGY
CONTROL OPTION
/PINCH
OCI1
1
A
4.75K
R319
+15V
HP2231
2
Q9
2N4401
PINCH
BALL_OR_FUSE
D301
DON_MIN
1
2
Q12
Q6
3
Q5
4
5
Q7
Q4
6
Q3
7
Q2
8
VSS
X20
150us MIN
DARLINGTON
ON TIME
COUNTER
MC14040
VDD
Q11
Q10
Q8
13
12
Q9
R 11
/C
Q1
10
9
16
15
14
6
5
13
12
X15
NAND
B
X15
NAND
D
4
/DON_MIN
8
9
NAND
C
X15
11
PWM_SYNC
10
+15V
8
J28
D304
J28
1
OPTO
ISOLATOR
ON
DARL. DRIVE
BOARD
C306
330p
100V
1
2
X14
NAND
A 3
9
8
12
13
NAND
X14
D
X14
NAND
C
11
10
10K
R320
/PB_LOCAL
/PWM_SYNC
2
D420
1
1N4936
NAND
X15
A
3
/PB_OPTION
R325
10.0K
Q2
2N4401
SS_WIRE
C305
330p
100V
D303
1N4936
1N4936
P_BOOST ONLY AFTER
PINCH LATCH
R318
4.75K
C308
0.1
50V
1
13
X31 A
6
5
4
5
6
7
1
2
3
Q1
/Q1
X19
CLOCK 1
RESET 1
D1
SET 1
VSS
/Q2
CLOCK 2
RESET 2
D2
MC14013B
SET 2
ARC_START
VDD
14
Q2 13
12
11
10
9
8
H = A>100
V=ARC
6
5
X16
NAND
B 4
8
9
NAND
X16
C
/PWM_SYNC
10
1
KEEP IN P_BOOST
UNTIL ARC STARTS
START_RESET
2
X17
NAND
B
4
OCI3
A
NAND
X16
A
+15V
PB_START
3
15
12 A
T1
11 B
B
T2
Q
X10
/Q
C307
14
0.1
10
9
R557
4.75K
RST
13
R322
4.75K
7
H= OPTION ENABLED
L= NO OPTION
ENERGY CONTROL OPTION
ENABLE (SHEET 2)
HP2231
+15V
ARC_START
DISABLE OPTION TO START
/HOT_START
2
R345
1.00K
H = STAINLESS
L = MILD
1.3 msec PLASMA
BOOST TIME LIMIT
R328
CW 10K
50V
R323
4.75K
+15V
/PB_LOCAL
+15V
10.0K
R324
D421
1N4936
5
6
+5.1V
C309
1.0
35V
X18
B
/PB_OPTION
L=DISABLE LOCAL PB TIME
4
5
X23
2901
4
2
9
8
DZ8
15V
1W
X18 C
P BOOST
10
ENERGY CONTROL OPTION
P_BOOST TIME (SHEET 2)
5
6
3
10
V+
V-
I-
SYNC
4
8
7
I+
CT
COMP
9 RT
X25
PWM
SG3846
Vref
CLIM
Vin
Vc
GND
OUTA
OUTB
SHUT
13
12
11
14
16
2
1
15
+15V
OUTA OUTB
7
10K
R455
6
X23
2901
B
1
+5.1V
/PWM_SYNC
PWM_EN
(SHEET 2)
R529
10.0K
R539
10.0K
3.92K
R457
+15V
START_RESET
D405
10
5
13
12
1
2
Q12
Q6
3 Q5
6
7
4
5
Q7
Q4
Q3
Q2
8
VSS
X32
COUNTER
VDD
Q11
16
15
Q10
Q8
Q9
14
13
12
R
/C
Q1
11
10
9
ARC
PINCH
+15V
MC14040
FUSE
DV/DT
9
8
4
X21
SWITCH
4066B
10
R496
100K
3
14
7
X12
NAND
D
10
12
11
FUSE
START
A
T1
15
B
B
X9
/Q
14
T2
Q
RST
13
10
9
/BALL
FUSE_RESET
/RESET
6
5
CFB
1V=100A
D418
14
C425
0.1
50V
X22
SWITCH
4066B
REPETITIOUS
PINCH LIMITER
FUSE GEN.
RESET
X13
NAND
C 4
+5.1V
10K
R316
/ARC
12
D
R310
10.0K
D419
11
7
15.0K
R554
RAMP
C470
330p
100V
D404
9
10
X29
LM224
C
1ms
/PINCH
+15V
8
+15V
8
1
SCALED_BGND
1
6
3.1V
D417
J28
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
1
2
14
7
FORCES THIRD CONSECUTIVE
PINCH TO BREAK INTO ARC
CW
C304
J27
5
6
NAND
X14
B
4
X17
NAND
A
R314
10K
C414
.0047
50V
PINCH
3
C416
820p
50V
+15V
5
10
Remote
Control
C459
0.1
50V
X23
COMPARATOR
LM2901
RAMP /RAMP
7
14
Darlington
Drive- Output
Vac In
14
C457
0.1
50V
X30
SWITCH
4066B
+1.42V
P BOOST
C415
4
5
A
T1
B
1
A
X10
RST
/Q
2
T2
Q
"KEEP ALIVE"
CURRENT LEVEL
3
R468
4.75K
6
7
C422
.0047
50V
120us
P BOOST
RAMP IN
+15V
1
9
+15V
1
4
1
3
POWER PLANE
3
4
HP2231
+15V
B
3
OCI4
HP2231
3
OUTA
J2
J3
J1
2
4
1
HP2231
A
2
OCI4
A
1
OCI5
HP2231
2
OUTB
Input- Current
Feedback
4
C427
0.1
50V
X24
OP AMP
LT1014
8
16
Analog Logic I/O to Control Panel
DR.
OCI3
B
HP2231
OCI4
HP2231
OCI4 B
HP2231
A
6
7
6
ISOLATED
CIRCUIT
PWM OUTPUT
( SHEET 2 )
H= OPTION PB TIME
L= LOCAL PB TIME
TO FRONT END
PB_SCALED
+15V_REM
W4
0.01
METER_2
R437
15.0K
METER_1
10.0K
R431
GENERAL INFORMATION
FILE: G2781_1D1
ELECTRICAL SYMBOLS PER E1537
CAPACITORS =
RESISTORS = Ohms (
DIODES = 1A, 400V
MFD ( .022/50V UNLESS OTHERWISE SPECIFIED)
1/4W UNLESS OTHERWISE SPECIFIED)
(UNLESS OTHERWISE SPECIFIED)
REFERENCE DESIGNATOR SERIES DEFINITIONS
100 SERIES- ARC SENSE CIRCUIT
200 SERIES- TRIGGER CIRCUIT
300 SERIES- DIGITAL LOGIC CIRCUIT
400 SERIES- ANALOG LOGIC CIRCUIT
(SHEET 2)
(SHEET 2)
(SHEET 1)
(SHEET 1)
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
MLD
SCALE
DATE
NONE
04/12/94
332
R430
CHK.
D422
1N4936
J28
J28
J28
J28
Vcc
8
OCI4
C413
0.1
50V
C411
0.1
50V
L=DISABLE OPTION PB TIME
H= OPTION PB TIME
3
PHB OUTPUT
11
+15V
10
PHA OUTPUT
COMM
6
REM
+15V_REM
C430
0.1
50V
REM
100
R433
100
R470
SUP'S'D'G.
J2
J2
J2
J2
J2
J2
J2
J2
13
12
2
13
4
1
9
12
8
6
+15V
C424
0.1
50V
X18
D
B OCI6
3
WIRE TYPE POSITION
TO FE (SHEET 2)
FOR ENERGY CONTROL
OPTION
TO
POWER
BOARD
+PWR
+VIN
-VIN
-PWR
+PWR
+VIN
-VIN
-PWR
LABELS
LAST NO. USED
R-
C-
D-
165, 242, 345, 564
129, 211, 314, 475
117, 211, 310, 424
SUPPLY VOLTAGE NET
POWER SUPPLY SOURCE POINT
COMMON CONNECTION
DZ20
OCI7
X36
Q10
W4
FRAME CONNECTION
EARTH GROUND CONNECTION
STT CONTROL
SCHEMATIC (Sheet 1 of 2)
SHT.
NO.
11
4
HP2231
G
2781-A
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-4
Control PC Board (G2782) Schematic 2 of 2
ELECTRICAL DIAGRAMS
2781-B
G
- STUD
INPUT FROM
VOLTAGE
SENSE PANEL
+ STUD
PHASE A
FROM
PWM
PHASE B
FROM
PWM
FRONT END
6
J5
7
3
J5
J5
5
J5
1
J5
Varc FILTERED
TO ENERGY
CONTROL OPTION
10
J17
FE
100p
100V
R115
13.7K
R117
13.7K
R119
13.7K
R121
13.7K
C100
.0047
3000V
OCI5
HP2231
OCI5
A
B
R116
13.7K
R118
13.7K
R120
13.7K
R122
13.7K
6
7
47.5K
R109
ARC VOLT FILTER
C101
.001
400V
D100
1N4007
+12VFE
47.5K
R112
+12VFE
DZ2
12V
1W
DZ1
12V
1W
FE
FE
2
X4
A
OP470
3
C103
100p
100V
C102
R110
47.5K
+12VFE
FE
1
2
FE
X6 A 3
DT
13
12
X6 B
DT
11
47.5K
R133
D103
1N914
DT_RC
R135
267K
7
6
X5
2901
C
R134
1.00K
C106
330p
100V
FE
1
D102
1N914
1
4.75K
R159
9
8
+12VFE
.0047
1.00M
DT_DELAYED
3.92K
R163
C104
50V
R124
4.75K
R128
D115
FE
D101
1N914
+12VFE
VARC_SCALED
X5
2901
D
3.92K
14
DV/DT SAMPLE PULSE
R164
1N914
9
8
C105
100p
100V
NEG_CLAMP
X6 D
FE
10
DV/DT Varc
SAMPLE
X3 A
DV/DT
3
6
2
SMP04
+12VFE
C109
820p
50V
FE
NEG_CLAMP
D117
1N914
5
7
NEW DV/DT
Varc SAMPLE
X3
B
SMP04
1
X3 C
11
9
SMP04
OLD DV/DT
Varc SAMPLE
15
FE
SHORT DETECT
Varc SAMPLE
R142
10K
FE
R145
10K
X3 D
12
10
SMP04
14
R148
10K
C108
1.8
20V
C110
820p
50V
FE
1.89V NORMAL
2.3V PINCH START
TRUNCATES DT_DELAYED
HP2231
ARC DETECTOR
ADJUSTMENT
FOR INITIAL
PINCH PULSE
+12VFE
+12VFE
D104
1N914
1V REF
CW
10K
10
TURN
.400V
C107
0.1
50V
FE
5
6
X4 B
OP470
100K
R144
7
DV/DT 10X
AMPLIFIER
4
X5
2901
A
5
2
Q1
2N4401
15V
1W dv/dt
11
10
X5
2901
B
ARC
DETECTOR
DZ3
3.92K
R153
+12VFE
4
J17
ARC
2
6
B
OCI1
HP2231
+12VFE
B
4
OCI2 DV/DT LEVEL DETECT
TO DIGITAL LOGIC
( SHEET 1 )
HP2231
3
13
DV/DT
2
H=LOW DV/DT
L=HIGH DV/DT
+12VFE
H=SHORT
L=ARC
A
1
OCI2
HP2231
2
ARC/SHORT DETECT
TO DIGITAL LOGIC
( SHEET 1 )
PINCH KILLER
Varc ADJUST
( SHEET 1 )
DT
8
J17
R154
1.50K
ENERGY CONTROL
OPTION ENABLE
9
J17
R155
1.50K
ENERGY CONTROL
OPTION P BOOST
TIME
2
7
J17
R160
1.50K
J17
R161
1.50K
D105
1N4936
D106
1N4936
FE
DIODE ON = OPTION ENABLED
DIODE OFF = OPTION DISABLED
DIODE ON = OPTION P_BOOST TIME
DIODE OFF = LOCAL P_BOOST TIME
OR NOT OPTION
P_BOOST TIME
A
1
OCI3
HP2231
2
B
4
OCI3
HP2231
3
ENERGY CONTROL
OPTION ENABLE
( SHEET 1 )
ENERGY CONTROL
OPTION P BOOST
TIME ( SHEET 1 )
1
J17
H = PINCH
L = NOT PINCH
7
A
OCI1
HP2231
PINCH SIGNAL FOR
ENERGY CONTROL OPTION
( SHEET 1 )
5
J17
H = START PLASMA BOOST TIMING
L = NOT PLASMA BOOST
7
A OCI6
HP2231
PB_START SIGNAL FOR
ENERGY CONTROL OPTION
( SHEET 1 )
+12V OUT
36 VAC
XFMR
18 VAC
CT
18 VAC
12
J17
3
J17
8
J5
2
J5
4
J5
ENERGY
CONTROL
OPTION
-15V OUT
COMMON OUT
J17
11
6
J17
D108
1N4007
C113
.0047
1400V
C114
.0047
1400V
D110
1N4007
D109
1N4007
C111
35V
1000
C115
47
35V
D111
1N4007
+12VFE
D107
C112
IN
1.82K
R156
LM350 s15128-15k1
ADJ
500
R157
243
OUT
CW
X1
C117
27
35V
C118 D113
C116
IN
GND
X2
7915 s15128-12
D112
OUT
C119
27
35V
C120
D114
-15VFE
POWER SUPPLY FOR "FRONT END"
FE
H = STAINLESS
L = MILD STEEL
6
B
OCI6
HP2231
C121
0.1
50V
ISOLATED CIRCUIT
+12VFE
FE
14
X6
NAND
4093B
7
POS FE POWER PLANE
16
Vdd
X3
SMP04
Dgnd Vss
C122
8 13
FE GROUND PLANE
0.1
50V
Vcc
8
OCI5
HP2231
GND
5
+12VFE
C123
0.1
50V
Vcc
OCI1
8
HP2231
GND
5
FE
C128
0.1
50V
Vcc
8
OCI6
HP2231
GND
5
C129
0.1
50V
+12VFE
C124
0.1
50V
FE
C125
0.1
50V
-15VFE
V+
POS FE POWER PLANE
4 3
X4
OP AMP
OP470
V-
11
X5
COMPARATOR
LM2901
NEG FE POWER NET
12
-15VFE
C126
0.1
50V
C127
0.1
50V
FE
UNUSED GATES
+12VFE
6
5
X6 C
NAND
4
10
9
X4
C
OP470
8
12
13
X4
OP470
D
FE
14
WIRE TYPE POSITION
ENERGY CONTROL OPTION
( SHEET 1 )
1
5
J5
4
8
Front End
Vac and Varc
1
7
J17
6
12
Energy
Control
Option
1
7
J4
6
12
Trigger Circuit
I/O and Vac
T1 AUX XFMR
24 VAC
TO POWER
BOARD
PRIMARY CURRENT
FEEDBACK 125:1 RATIO
Y
Y
8
2
J4
J4
CURRENT
TRANS.
TRIGGER
OPTOCOUPLER
ON POWER
BOARD
OVERVOLTAGE
OPTOCOUPLERS
ON PROTECTION
BOARD
Y
OVERHEAT INDICATOR
CHOKE
TSTAT
FAN
TSTAT
C
TRIGGER
D
3
J4
R210
22.1K
UNUSED
J4
4
J4
1
7
J4
NOTES :
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE
NUMBER.
26.7
R207
C200
.33
200V
26.7
R208
+15V
C203
R214
10K
R211
47.5K
D201
1N4936
D202
1N4936
D203
1N4936
D204
1N4936
+15V
3.6V
C202
6
X28
B
2901
7
8.95V
D205
1
1N4936
C204
0.1
50V
J4
11
10
OVERCURRENT FAULT
FROM SHEET 1
J4
D206
R216
2.21K
CR 1
J4
4
6
CR1
6
8
R239
.13
+ t
60V 13
CR1
9
( UNUSED
CONTACT )
11
DZ4
43V
1W
12
9
J4
J4 TO POWER BOARD 5
J4
R238
56
+ t
DZ5
43V
1W
R217
1.30K
R219
1.30K
R221
1.30K
R223
1.30K
3
X28
COMPARATOR
LM2901
12
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
+15V
TRIGGER CIRCUIT
1.00K
R200
D200
PRI_FB
1N4936
C201
( SHEET 1 )
+15V
R218
1.30K
R220
1.30K
R222
1.30K
R224
1.30K
C211
0.1
50V
X28 "D" COMPARITOR
ON SHEET 1
Ch'ge.Sht.No.
5-19-95
5-24-96E
R225
1.50K
R226
1.50K
R227
1.50K
R228
1.50K
1.7V = 150A PRIMARY
C206
C205
330p
100V
5
4
X28
2901
A
2
H=PWM ON
L=PWM OFF
D207 D208
D209 D210
R234
332K
+15V
C207
20
50V
DZ6
3.3V
1W
ISOLATED CIRCUIT
+15V
9
8
X28
2901
C
14
H=PWM OFF
L=PWM ON
267
R229
D211
DR.
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
SCALE
NONE
MLD
DATE
04/04/94
TRIGGER
INTERFACE
CNY17-3
1 OCI7 5
ON=TRIGGER ON
OFF=TRIGGER OFF
2 6 4
CHK.
( SHEET 1 )
PWM_EN
FILE: G2781_1D1
GENERAL INFORMATION
ELECTRICAL SYMBOLS PER E1537
CAPACITORS = MFD .022/50V
RESISTORS = Ohms (
DIODES = 1A, 400V
1/4W
UNLESS OTHERWISE SPECIFIED)
UNLESS OTHERWISE SPECIFIED)
(UNLESS OTHERWISE SPECIFIED)
REFERENCE DESIGNATOR SERIES DEFINITIONS
100 SERIES- ARC SENSE CIRCUIT (SHEET 2)
200 SERIES- TRIGGER CIRCUIT (SHEET 2)
300 SERIES- DIGITAL LOGIC CIRCUIT (SHEET 1)
400 SERIES- ANALOG LOGIC CIRCUIT (SHEET 1)
PWM ENABLE
TO ANALOG LOGIC
( SHEET 1 )
LABELS
LAST NO. USED
R-
C-
D-
165, 242, 345, 564
129, 211, 314, 475
117, 211, 310, 424
SUPPLY VOLTAGE NET
POWER SUPPLY SOURCE POINT
DZ20
OCI7
X36
Q10
W4
COMMON CONNECTION
FRAME CONNECTION
EARTH GROUND CONNECTION
FV
EQUIP.
TYPE
SUBJECT
STT CONTROL
SCHEMATIC (Sheet 2 of 2)
SUP'S'D'G.
SHT.
NO.
G
2781-B
G-4
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-5
Control PC Board (G2782) Layout
2782-1
G
ELECTRICAL DIAGRAMS
ITEM REQ'D PART NO IDENTIFICATION ITEM REQ'D PART NO IDENTIFICATION
G-5
D108
D109
D110
D111
R157
C100
D114
D113
C120
C118
R139
C107
R138
D100
R100
R101
R102
R103
R104
R105
R106
R107
R159
R156
D112
R158
C114
C113
J5
R115
R117
R119
R121
R116
R118
R120
R122
R108
R162
R111
C104
R144
C110
D107
R148
C122
C105
R133
C106
R134
R163
D103
R136
R127
C121
C101
C125
C102
R109
R110
J17
R150
C108
R463
C461
DZ18
C460
R313
J27
C304
R312
R545
R334
R544
R461
Q9
R340
R303
C301
C432 C435
R306
R321
D302
C303
R307
C300
R302
W2
R408
W3
Q3
R547
R548
R541
R508
D305
C433
R305
R317 C306
R331
C462
C404
X33
D309
C312
D307
D306
D308
W4
W1
C466
X8
D310
C470
R448
R499
R556
R345
R503
R532
C457
R528
D413
R527
C463
D400
C403
DZ19
DZ10
C402
R415
R533
R416
C308
R344
DZ8
C309
R343
R430
R403
C451
DZ17
R520
D415
C455
C459
C452
C453
R436
R432
R437
D419
D418
D417
D404
C415
R442
R446
R447
R538
J28
R304
J2
C426
C417
R497
R485
R498
R494
Q6
R479
R490
R496
R475
R474
R473
C427
D422
D421
R409
R410
R414
R551
R411
C407
C469
R539
R536
R445
C416
R481
R440
D406
R480
D408
C410
R422
R421
R444
R487
R486
R488
R472
R482
J3
C446
R455
C473
R552
C472
C447
R424
R420
R423
C450
R412
R449
D402
R554
R458
C419
D407
C449
DZ15
C409
R564
R452
R451
D401
R419
R428
R427
R425
C437
R323
R322
C307
R314
R453
R310
C441
R426
J1
R557
C445
C444
D211
R514
C465
R231
R230
R239
OCI7
D209
C414
R468
R325
R439
R441
D410
R525
R523
D411
R510
Q8
C471
D420
D301
C436
R561
R237
J4
C475
D424
R560
C211
R236
C205
D200
D205
R235
C201
R200
R205
R204
R241
R242
C203
R213
C206
R232
R233
C202
R202
R201
R203
R209
R208
R214
C204
R211
R215
R210
R212
CAPACITORS = MFD/VOLTS
RESISTORS = OHMS
THIS SHEET CONTAINS PROPRIETARY INFORMATION
OWNED BY THE LINCOLN ELECTRIC CO.
AND IS
NOT TO BE REPRODUCED, DISCLOSED OR USED
WITHOUT THE EXPRESS PERMISSION OF
THE LINCOLN ELECTRIC CO.
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLE SIZES PER E2056
5-19-95
ON 2 PLACE DECIMALS IS .02
ON 3 PLACE DECIMALS IS .002
ON ALL ANGLES IS .5 OF A DEGREE
MATERIAL TOLERANCE (" ") TO AGREE
WITH PUBLISHED STANDARDS.
7-28-95C
5-24-96E
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
EQUIP.
TYPE
STT INVERTER WELDER
DR F.V.
SCALE FULL
DATE 6-8-94 CHK FV REF.
L8441-3 SUP'S'D'G
SHT.
NO.
G
2782-1
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-6
Power Board (L8033) Schematic
16018 M
P7 J7
5
18Vac
FROM AUXILIARY
TRANSFORMER
P7 J7
6
TP1
50V
15J
D1 D3
1.0
R1
5W
R44
+ t
.25
D2 D4
C1
3300
50V
D5
IN
C2
X1
LM350
ADJ
R3
243
OUT
+15V
ELECTRICAL DIAGRAMS
267
R7
267
R8
DZ5
12V
1W
R69
.24
+ t
Vin + Vc
OUT
X67 GND
INV IN
N.I. IN
C8
0.1
50V
D15
1.0A
30V
F
D16
1.0A
30V
TO PULSE
TRANSFORMER
J7 P7
8
J7 P7
7
G-6
C3
150
50V
DZ4
12V
1W
Vin + Vc
X68
OUT
GND
INV IN
N.I. IN
C9
0.1
50V
D7
1.0A
30V
E
D6
1.0A
30V
+24V
J7
3
P7
TO
PILOT
LIGHT
(+)
J6 J6 J6 J6 J7
6 8 3 1 1
P6
TO
CONTROL
BOARD
(+15V)
P6
PWM
SIGNAL
P6
PWM
SIGNAL
P6
TO
CONTROL
BOARD
(COM)
P7
TO
PILOT
LIGHT
(-)
J14
1
FROM PROTECTION BD.
J14
2
3
4
J14
J14
24Vac
P6
5
P6
4
J6
J6
P6
P6
9
10
J6
J6
1
J14
2 1
3
D8
TP2
50V
15J
DZ6
6.2V
1W
100
R43
D9
C14
4 5
D10
D11
J7
C10
500
50V
4 1
8 6
IN
C11
Q40
600mA
40V
D12
COM
ADJ
X5
LM350
R24
267
OUT
J6
5
10
C5
39
20V
R42
100
+24V
A
C
COM
10K
R11
+24V
33.2K
R13
15.0K
COM
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
5
6
X4
475K
R12
7
B
C7
33.2K
R15
+24V
4
X4
LM224
11
COM
DZ1
15V
1W
D14
1N4936
G
+24V
J7
D
Q5
J7
S
IRF513
2
P7
RELAY COILS
4
P7
33.2K
R17
26.7K
COM
D13
C6
1.8
20V
10K
R19
COM
10
9
X4
267K
R20
8
D
2.21K
R21
1
2
COM
NOTES :
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS
DIAGRAM MAY NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS
HAVING A COMMON CODE NUMBER.
6
J6
2
P6
5
OCI1
CNY17-3
CONTROL
TRIGGER
4
100K
J6
7
P6
3
2
X4
1
12
13
X4
UNUSED
14
COM
GENERAL INFORMATION
ELECTRICAL SYMBOLS PER E1537
CAPACITORS =
RESISTORS = Ohms (
MFD .022/50V
1/4W
UNLESS OTHERWISE SPECIFIED)
UNLESS OTHERWISE SPECIFIED)
DIODES = 1A, 400V (UNLESS OTHERWISE SPECIFIED)
FILENAME: M16018_6JA
LAST NO. USED
R-
C-
D-
69
14
16 LABELS DZ- 6
SUPPLY VOLTAGE NET
POWER SUPPLY SOURCE POINT
COMMON CONNECTION
FRAME CONNECTION
EARTH GROUND CONNECTION
Ch'ge.Sht.No.
3-22-91
9-11-92B
6-25-93A
9-24-93D
4-13-95C
3-29-96L
9-27-96F
10-25-96
DR.
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
SCALE
NONE
MJH DATE
11/10/92 CHK.
EQUIP.
TYPE
SUBJECT
SUP'S'D'G.
INVERTEC
POWER BD SCHEMATIC
SHT.
NO.
16018
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-7
Power Board (L8033) Layout
ELECTRICAL DIAGRAMS
ITEM REQ'D PART NO.
IDENTIFICATION
D1
D3
TP1
C1
J7
D15
F
D16
E
C9
R5
R6
R8
DZ4
D7
D6
C8
X5
D14
D12
X68 X67
C3
R1
R44
R41
J14
C10
Q5
R43
D9
D11
D8
D10
Q40
DZ1
C
R16
R15
D13
R19
R20
D
X4
R24
R23
B
C5
TP2
J6
X1
D5
G-7
CAPACITORS = MFD/VOLTS
INDUCTANCE = HENRYS
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-8
Darlington Drive Board (G2778) Schematic
M 17581
AUXILLARY
TRANSFORMER
WINDING
10VAC
R
D4
8A
400V
J13
2
J13
3
D3
8A
400V
6
J13
6VAC
5
J13
R
D1
8A
400V
.5
R1
5W
C12
3300
50V
D2
8A
400V
C15
3300
50V
+V
GND
C16
POWER
SUPPLY
ELECTRICAL DIAGRAMS
10.0
R6
DZ1
18V
1W
+V
C17
500p
1000V
1
3
Q1
6A
100V
2
2 AMP
BASE
DRIVE
G-8
NEGATIVE BIAS for
DARLINGTON
HOLD - OFF
D10
1N5402
D6
1N5402
D12
1N5402 D7
1N5402
D11
1N5402
D8
1N5402
D13
1N5402
D9
1N5402
20
R8
5W
10.0
R7
DZ3
18V
1W
C10
.33
200V
2.7
R13
10W
2.7
R14
10W
C9
3300
50V
1
J12
BLUE
DARLINGTON
MODULE
TWISTED
PAIR
B
J12
J12
3
4
2
J12
BLACK
C
E
STT CONTROL BOARD
+15V
1K
1
J13
R2
1.50K
D5
2
3
OCI1
HP2201
7
267
R5
DZ2
12V
1W
+V
C5
0.1
50V
1
2
3
4
V
S
IN
NC
X2
GND
4429
V
S
8
7
OUT
OUT 6
GND 5
G
C8
500p
1000V
D
Q2
4A
100V
S
GND
ON = Darlington ON
OFF = Darlington OFF
4
J13
R3
1.50K
C6
0.1
50V
GND
C14
0.1
50V
+V
Vcc
8
OCI1
HP2201
GND
5
GND
1
J13
3
4 6
1
J12
2
3 4
NOTES :
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE
NUMBER.
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
Ch'ge.Sht.No.
5-19-95
3-29-96L
GENERAL INFORMATION
ELECTRICAL SYMBOLS PER E1537
CAPACITORS =
RESISTORS = Ohms (
MFD
DIODES = 1A, 400V
.022/50V
1/4W
UNLESS OTHERWISE SPECIFIED)
UNLESS OTHERWISE SPECIFIED)
(UNLESS OTHERWISE SPECIFIED)
FILE: M17581_1AB
DR.
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
SCALE
NONE
MLD DATE 03/23/94 CHK.
LAST NO. USED
R-
C-
D-
18
17
13
DZ3
LABELS
SUPPLY VOLTAGE NET
POWER SUPPLY SOURCE POINT
COMMON CONNECTION
FRAME CONNECTION
EARTH GROUND CONNECTION
EQUIP.
TYPE
SUBJECT
BS
INVERTER WELDERS
SCHEMATIC, DARLINGTON DRIVE
SUP'S'D'G.
SHT.
NO.
M17581
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-9
Darlington Drive Board (G2778) Layout
ELECTRICAL DIAGRAMS G-9
ITEM REQ'D PART NO.
IDENTIFICATION
XXX
XXX
J13
C15
X
XX
X
X
X
X
X
X
C12
X
X
X
X
X X X
X
X
D5
OCI1
D10
D12
STT DARLINGTON DRIVE
G2778-[ ]
D6 D7
R8
D11
D13
X
X
X
X
C9
C14
C10
D8
D9
X2
R6
R7
R11
R18
R17
R14
J12
R15
R16
R13
R10
R12
R9
CAPACITORS = MFD/VOLTS
RESISTORS = OHMS
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-10
Switch Board (L8441) Schematic
ELECTRICAL DIAGRAMS
W
D2
1N4936
C1
D4
1N4936
100
22.1K
R16
1.00K
DZ5
3.3V
1W
D5
1N4936
1.00K
221
Q2
1A
100V
IRFD110
Q7
600mA
40V
2N4403
6.2V
DZ6
1W
Q3
1A
100V
IRFD110
20
Q4
600mA
40V
2N4401
DZ3
10V 1W
100
1
1/2W
1
1/2W
1.50K
D3
1N4936
1N4936
DZ1
10V
1W
15.0K
C2
D9
2700p
50V
47.5
Q5
600mA
40V
2N4403
Q6
600mA
40V
2N4403
B
DZ4
15V
1W
475 475
C7
R6
10.0
R9
10.0
R33
10.0
R8
10.0
R17
10.0
R
W
D6
1N4936
C5
D1
1N4936
100
22.1K
R23
1.00K
DZ8
3.3V
1W
D8
1N4936
1.00K
221
Q1
1A
100V
IRFD110
Q11
600mA
40V
2N4403
6.2V
DZ9
1W
Q10
1A
100V
IRFD110
1
1/2W
20
Q12
600mA
40V
2N4401
DZ12
10V 1W
1
1/2W
D7
1N4936
D10
1N4936
DZ2
10V
1W
15.0K
C8
2700p
50V
100
1.50K
47.5
Q8
600mA
40V
2N4403
Q9
600mA
40V
2N4403
A
DZ7
15V
1W
475 475
C6
R19
10.0
R26
10.0
R25
10.0
R27
10.0
R34
10.0
R
G1
D1
G2
D2 D3 D4 D5
G3
G4
G5
S1 S2 S3 S4 S5
A2
IRFP460
C2
A2
A2
BYT30P600
A1
C1
A2
BYT12P600
9
POSITIVE
INPUT
SNUBBER
RESISTOR
402
404
C3
.047
1200V
-
4
5
TRANSFORMER
PRIMARY
R38
39.2K
R41
39.2K
R39
39.2K
R40
39.2K
INPUT
FILTER
CAPACITOR
C2
A2
A1
BYT30P600
G1
D1 D2 D3 D4 D5
G2
G3
G4
G5
S1 S2 S3 S4
S5
A1
IRFP460
-
1
8
TRANSFORMER
PRIMARY
C4
.047
1200V
401
403
A1
C1
A1
BYT12P600
SNUBBER
RESISTOR
12
NEGATIVE
INPUT
G-10
FRANCE CANADA AUSTRALIA
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-11
Switch Board (L8441) Layout
ELECTRICAL DIAGRAMS
B12 B11 B9 B10 B3 B7
B5
B6 B2 B1
Q3 Q2
B8 B4
L8441-[ ] SWITCH
Q1 Q10
G-11
ITEM
C1, C5, C6, C7
C2, C8
C3, C4
D1, D2, D3, D4, D5, D6,
D7, D8, D9, D10
DZ1, DZ2, DZ3, DZ12
DZ4, DZ7
DZ6, DZ9
DZ5, DZ8
Q1, Q2, Q3, Q10
Q4, Q12
Q5, Q6, Q7, Q8, Q9, Q11
R1, R3, R5, R24
R2, R4
R6, R8, R9, R17, R19, R25
R26, R27, R33, R34
R7, R30
R10, R32
R11, R15, R22, R28
R12, R14, R20, R21
R13, R31
R16, R23
R18, R29, R37, R42
R35, R36
R38, R39, R40, R41
6
4
2
4
2
4
2
2
2
REQ'D
4
2
2
10
PART NO.
S16668-5
S16668-4
S13490-112
T12705-34
IDENTIFICATION
.022/50
2700pF/50
.047/1200
1N4936
T12702-27
T12702-29
1N4740
1N4744A
T12702-40
T12702-53
T12704-73
1N4735
3.3V 1W
IC PKG MOSFET
T12704-68
T12704-69
S19400-1000
2N4401
2N4403
100 1/4W
S19400-2210 221 1/4W
10
4
4
2
2
2
2
4
2
4
S19400-10R0 10 1/4W
S19400-1501 1.5K 1/4W
S19400-1502 15K 1/4W
T14231-20
S19400-1001
1 1/2W
1K 1/4W
S19400-20R0 20 1/4W
S19400-2212 22.1K 1/4W
S19400-4750 475 1/4W
S19400-47R5 47.5 1/4W
S19400-3922 39.2K 1/4W
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-12
Driver Board (L9134) Schematic
ELECTRICAL DIAGRAMS
20799 S
8
J16
3
J11 T1
1
J11
DRIVE
12
TO POWER
BOARD
1
3
10
4
GATE
9
5
GATE
8
6
GATE
7
GATE
J9
J9
J9
J9
J10
4
1
3
6
1
G1
S1
G2 TO
S2
S3
SWITCH
BOARD
250
20W
R2
250
20W
Q1
4A
900V
R3
150K
R4
150K
150K
150K
J10
J10
J10
4
6
3
G3
S4
G4
R7
100
DZ1
12V
1W
J16
1
2
FROM
PROTECTION
BD.
J16
Power Switch Drive Transformer Capacitor Pre-charging Circuits 3
J16
7
R8
150K
R9
150K
1 2 1 3
1 7
250
20W
R14
250
20W
Q2
4A
900V
3 4
J11
4
J9,J10
6
8
J16
14
R12
100
DZ2
12V
1W
NOTES :
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE
NUMBER.
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
Ch'ge.Sht.No.
6-25-93C
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
SCALE
NONE
DR.
LC DATE 11-4-92 CHK.
BS
J16
150K
150K
14
J16 FROM
PROTECTION
BD.
13
J16
12
J16
EQUIP.
TYPE
SUBJECT
FILE: S20799-1AA
INVERTER WELDERS
SCHEMATIC, DRIVER BOARD
SUP'S'D'G.
SHT.
NO.
S 20799
G-12
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-13
Driver Board (L9134) Layout
ELECTRICAL DIAGRAMS
XXXX XXXX XXXX XXXX
DRIVER L9134-[ ]
Q1
R2
R1
R13 R14
T1
Q2
XXXX XXXX
R12 DZ2
XXXX XXXX
J16
J10
J9
XXXX
J11
ITEM REQ'D PART NO.
IDENTIFICATION
RESISTORS = OHMS/WATTS
CAPACITORS = MFD/VOLTS
INDUCTANCE = HENRYS
G-13
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-14
Protection Board (L7915) Schematic
16097 M
ELECTRICAL DIAGRAMS G-14
+5V
FROM (+) UPPER CAPACITOR
B52
+5V
56.2K
150K
56.2K
150K
56.2K
15.0K
D1
5
6
X1
R14
100K
7
10K
10K
3.32K
10
9
X1
8
R15
475
1
C6
2 6 4
5
OCI2
CNY17-3V
681K
J8
1
J8
3
TO POWER BD.
(Over Voltage)
D5
FROM BLEEDER RESISTOR
B14
1.82K
IN
DZ1
10V
1W
D7
X2
GND
OUT
C2
27
35V
+5V
56.2K
56.2K
1.82K
CW
5K
10K
R37
332
1
2
C3
.022
50V
6 4
5
OCI3
CNY17-3V
267K
J15
1
TO DRIVER BD.
(Over Voltage)
J15
4
B53
FROM (-) UPPER CAPACITOR
FROM (-) LOWER CAPACITOR
B51
R12
150K
R11
150K
+5V
1.82K
R28
10K
CW
5K
15.0K
3
2
X1
R22
332K
1
D6
R35
332
1
2
C4
.022
50V
6 4
5
OCI4
CNY17-3V
267K
J15
3
TO DRIVER BD.
(Over Voltage)
J15
6
D4
+5V
FROM CENTER LEG OF INPUT
H5
R30
15.0K
R31
15.0K
4
C1
X1
LM224
11
12
13
X1
14
R29
15.0K
R25
15.0K
R24
15.0K
R23
15.0K
D8
1N4007
D3
1
C5
2
5
6 4
681K
OCI1
CNY17-3V
J8
4
TO CONTROL BD.
(Single Phase)
J8
2
NOTES :
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE
NUMBER.
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
Ch'ge.Sht.No.
1-25-91
9-11-92B
12-10-93A
GENERAL INFORMATION
ELECTRICAL SYMBOLS PER E1537
CAPACITORS =
RESISTORS = Ohms (
DIODES = 1A, 400V
MFD .022/50V
1/4W
UNLESS OTHERWISE SPECIFIED)
UNLESS OTHERWISE SPECIFIED)
(UNLESS OTHERWISE SPECIFIED)
FILE: M 16097-2F1
LABELS
SUPPLY
R-
C-
D-
LAST NO. USED
_
_
_
VOLTAGE NET
POWER SUPPLY SOURCE POINT
COMMON CONNECTION
FRAME CONNECTION
EARTH GROUND CONNECTION
DR.
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
SCALE NONE
BS/DB
DATE
9-7-89
CHK.
TJP
EQUIP.
TYPE
SUBJECT
SUP'S'D'G.
INVERTEC V300
PROTECTION
SHT.
NO.
16097
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-15
Protection Board (L7915) Layout
B51
B5
B53
B14
J15
R1
C5
OCI1
D3
D8
R24
R23
R29
R25
R30
R31
R2
C6
OCI2
R5
R8
R27
R6
OCI3
R34
C3
R12
R4
R26
R21
R20
R14
X1
R35
R37
C2
D6
R32
R19
R18
DZ1
R16
D7
X2
R22
R28
OCI4
R36
C4
ELECTRICAL DIAGRAMS G-15
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-16
Current Sense Board (M17591) Schematic
21410 S
ELECTRICAL DIAGRAMS G-16
+15V
EXCITATION CURRENT
SOURCE
MIN OFF SET
ADJUSTMENT
681K
R11
CURRENT CAL
3.8V = 38 mA
CW
VREF
3
2
X1
1014
1.6V = 16 mA
C1
1
R4
1.00K
Q1
3A
100V
CW
100
20K
R10
13.7K
R9
13.7K
6
X1
1014
5
681K
7
100A/V CURRENT OUT
J18
1
C2
150p
50V
HALL EFFECT
SENSOR
+IC
4
-VH
3
+VH
2
X2
-IC
1
6.81K
+15V
10
9
X1
1014
8
2
J18
10.0
R15
X3
1
TL431
6
8
REF
1.50K
4
X1
LT1014
11
12
13
X1
1014
14
2.94K
C4
0.1
50V
3
4
J18
J18
C3
50
50V
C5
1
J18
2
3 4
THIS SHEET CONTAINS PROPRIETARY INFORMATION OWNED BY
NOTES :
N.A.
SINCE COMPONENTS OR CIRCUITRY ON
CIRCUIT BOARD MAY CHANGE
A PRINTED
WITHOUT AFFECTING
THE INTERCHANGEABILITY
THIS DIAGRAM MAY NOT
OR CIRCUITRY OF
OF A COMPLETE
CONTROLS HAVING A COMMON
BOARD.
SHOW THE EXACT COMPONENTS
CODE NUMBER.
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
Ch'ge.Sht.No.
5-19-95
9-27-96F
11-15-96E
THE LINCOLN ELECTRIC CO.
AND IS NOT TO BE REPRODUCED, DISCLOSED OR USED WITHOUT THE EXPRESS PERMISSION OF THE LINCOLN ELECTRIC CO.
GENERAL INFORMATION
ELECTRICAL SYMBOLS PER E1537
CAPACITORS = MFD
RESISTORS = Ohms (
( .022/50V
1/4W
UNLESS OTHERWISE SPECIFIED)
UNLESS OTHERWISE SPECIFIED)
DIODES = 1A, 400V (UNLESS OTHERWISE SPECIFIED)
LABELS
SUPPLY VOLTAGE NET
POWER SUPPLY SOURCE POINT
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
DR.
MLD
SCALE
DATE
NONE
03/21/94
CHK.
COMMON CONNECTION
EQUIP.
TYPE
FV
SUBJECT
SUP'S'D'G.
FILE: S21410_1BA
FRAME CONNECTION
EARTH GROUND CONNECTION
STT-CURRENT SENSE
SCHEMATIC
SHT.
NO.
S 21410
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-17
Current Sense Board (M17591) Layout
ELECTRICAL DIAGRAMS
ITEM REQ'D PART NO.
DESCRIPTION
XX
XX
XX
XX
XX
XX
XXX
X
XXX
X
X X X
X2
XXX
X
X
X X X
XXX
X XX
XXXX
R7
X X
STT CURRENT SENSE
C3
R14
Q1
X3
R15
R3
R13
R1
R16
C5
R6
C2
R4
R12
C1
R8
R9
R10
R11
R5
X1
R2
J18
CAPACITORS = MFD/VOLTS
G-17
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-18
Remote Protection Board Schematic
ELECTRICAL DIAGRAMS G-18
7
3
2
2
4
J34
J34
J34
J37
J37
M 17609
1
J33
6
J33
2
J33
7
J33
3
J33
8
J33
C1
.0047
3KV
C2
.0047
3KV
C3
.0047
3KV
C4
.0047
3KV
C5
.0047
3KV
L1
.39mH
L2
.39mH
L3
.39mH
L4
.39mH
L5
.39mH
L6
.39mH
C6
.0047
3KV
C7
.0047
3000V
J34
6
5
J34
1
J34
4
J34
C8
.0047
3000V
L7
.39mH
C9
.0047
3000V
5
8
J34
J33
4
J33
C15
.05
600V
10
J33
9
J33
C13
.0047
3000V
CHASSIS
C10
.0047
3000V
TP3
150V
80J 160J
320V
TP1
C16
.05
600V
C14
.0047
3000V
CHASSIS
TP2
160J
320V
R1
1200
5W
R2
1200
5W
B1
B2
(+) STUD
(-) STUD
R3
332
R6
332
VOLTAGE SENSE
R4
332
R5
332
J37
1 1
R7
332
NOTES :
R8
332
J37
3
3
N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE
WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY
NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE
NUMBER.
CHASSIS
UNLESS OTHERWISE SPECIFIED TOLERANCE
ON HOLES SIZES PER E-2056
ON 2 PLACE DECIMALS IS + .O2
ON 3 PLACE DECIMALS IS + .OO2
ON ALL ANGLES IS + .5 OF A DEGREE
MATERIAL TOLERANCE ("t") TO AGREE
WITH PUBLISHED STANDARDS
Ch'ge.Sht.No.
5-19-95
10 PIN REMOTE
AMPHENOL
I
E
J
OPTIONAL REMOTE
INTERFACE
J36
3
J36
2
B
J36
1
J36
10
J36
9
C
G
A
BG
POT
PB
POT
12
J36
J36
J36
4
11
D
F
H
TRIGGER
GND
C11
.0047
3000V
DR.
J36
J36
14
13
5
B
C
D
GND
2
4
TRIGGER
J36
8
I 41
J36
42 VAC
3
6
J35
J36
16
K 42
J35
1
4
J35
7
J 31
J35 J36
115 VAC
C12
.0047
3000V
J35
2
FILE: M17609_1BA
5
J35
J36
J36
GENERAL INFORMATION
ELECTRICAL SYMBOLS PER E1537
CAPACITORS =
RESISTORS = Ohms (
DIODES = 1A, 400V
MFD .022/50V
1/4W
UNLESS OTHERWISE SPECIFIED)
UNLESS OTHERWISE SPECIFIED)
(UNLESS OTHERWISE SPECIFIED)
15
6
F
G
L
A
E
32
M
N
H 21
14 PIN WIRE
FEEDER AMPHENOL
LABELS
SUPPLY
LAST NO. USED
R-
C- 16
D-
8
0
L-
TP-
7
3
VOLTAGE NET
POWER SUPPLY SOURCE POINT
COMMON CONNECTION
FRAME CONNECTION
EARTH GROUND CONNECTION
THE LINCOLN ELECTRIC CO.
CLEVELAND, OHIO U.S.A.
SCALE
NONE
MLD
DATE
04/20/94 CHK.
EQUIP.
TYPE
SUBJECT
F.V.
STT REMOTE PROTECTION BOARD
SCHEMATIC
SUP'S'D'G.
SHT.
NO.
17609
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. Improper PC board repairs could result in damage to the machine.
INVERTEC STT
G-19
Wiring Diagram
ELECTRICAL DIAGRAMS G-19
WIRING DIAGRAM - INVERTEC STT II
N.L.
1
3
P30
2
4
C
LOAD
B
A
POWER
LINE
FILTER
ASSEMBLY
LINE
C
B
J1, J8,
J11, J12, J14
J18, J37
A
J4, J17
C
B
A
INPUT
RECTIFIER
D13
H1
H1
9D 9D
9C
C D +
TP1
B
A
N.K.
A
TP3
TP2
F
-
12D
12C
12D
H1 H3
TOP
FAN
MOTOR
H1 H3
A
H1
LEFT
FAN
MOTOR
S1
POWER
ON
OFF
U
W
H3
B
V
R
C
W
B
G
H1
RIGHT
FAN
MOTOR
INPUT
PER
N.A.
H3
J3, J9,
J10, J13,
J15, J35
J5, J7,
J34
J16, J28
9A
9A
9A
4 AMP
SLOW
BLOW
J6, J27, J33
J2, J36
P.C. BOARD CONNECTOR CAVITY NUMBERING SEQUENCE
(VIEWED FROM COMPONENT SIDE OF BOARD)
J19
J38 J39
PINOUT OF FRONT PANEL CONNECTORS (REAR VIEW)
9A
N.F.
A
52
2
4
J30
3
1
P29, P31
1
4
2
5
3
6
J29. J31
3
6
2
5
1
4
1
4
P21
2
5
3
6
9
1 2
10
P22
3
11
4
12
5
13
6 7
14 15
8
16
8
16
7
15
6
14
J22
5
13
4
12
3 2
11 10 9
1
INLINE CONNECTOR CAVITY NUMBERING SEQUENCE
(VIEWED FROM WIRE SIDE OF CONNECTOR)
3
6
J21
2
5 4
1
7500
25W
R1
53
R7
25
25W
25
25W
R6
N.G.
9A
9A
C2
2200 F
450V
+
12A
12A
9
+
402, 404
-
401, 403
R
12
SWITCH
BOARD
(LEFT)
W R
4, 5
W
1, 8
CR1
9D
309
309A
S7
RECONNECT
9B
9C 9B
12C
12A
12A
9B
N.H.
12D
CR2
309A
310A
12B
12B
14 53
53
J8
BOARD
52
PROTECTION
2
J15
5
1
4
H5 51 3
6
2
4
1
3
51
N.F.
311
313
52
52
314
315
316
317
309
310
9B
7500
25W
12B
51
12B
N.G.
9B
9B
R5
25
25W
25
25W
R4
2200 F
450V
C1 +
12B
12B
9D
12D
12B
52
9
+
402, 404
-
401, 403
12
307 308
8
12
J16
7
3
1
2
14
13
6 3 2 5
1
J10
4
DRIVER
BOARD
3
J9
6 2
5 4
1 2 3 4
J11
1
W R W
4,5
R
SWITCH
BOARD
(RIGHT)
1, 8
4
1
5
T3
CURRENT
TRANSFORMER
I
Y Y
I
8
T2
MAIN
TRANSFORMER
TOP
4
F
OUTSIDE
S
INSIDE
1
S
BOTTOM
F
F
BOTTOM
S
10
2W
.001/400
R3
C4
D11
D10
D9
D8
D7
5
F
BOTTOM
OUTSIDE
S
S
TOP
INSIDE
8
F
S
TOP
F
N.E.
10
2W
N.E.
D1
D2
D3
D4
D5
C3
R2
.001/400
371
374
N
N
O
O
440-
460V
A
380-
415V
220-
230V
200-
208V
H3
N.D.
H6
H4
H3
H2
H1
J21
6
3
H5
H4
R
115V
R
2
1
J30
32
33
42V
U
5
J31
43A
24V
N
3 503
2
4
1
H3
H2
H1
0V
W
2
Y
18V
4
Y
1
T1
AUXILIARY
TRANSFORMER
212
504
501
371
374
J22
10
11
371A
374A
32C
J22
15
16
33C
7
8
32A
32B
33A
33B
115V
R
18V
1
W
18V
R
2
9
3
B
18V
B
4
240
241
242
243
244
N
10V
N
O
6V
U
12
18V
U
13
T4
AUXILIARY
TRANSFORMER
O
245
246
503A
224
503A
503B
DARLINGTON
HEATSINK
THERMOSTAT
W
J22
14
W
6
FAN
THERMOSTAT
224
224A
379
CHOKE
THERMOSTAT
212B
150 5W
212A 210
210A
J24
J26
J23
J25
ELECTRICAL SYMBOLS PER E1537
COLOR CODE:
B = BLACK
G = GREEN
N = BROWN
O = ORANGE
R = RED
W = WHITE
Y = YELLOW
U = BLUE
METER PINOUT (VIEWED FROM BACK OF METER)
N.A.
NOTES:
N.M.
1. FOR MACHINES SUPPLIED WITH INPUT CABLE
FOR SINGLE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.
CONNECT BLACK & WHITE LEADS TO SUPPLY CIRCUIT.
WRAP RED LEAD WITH TAPE TO PROVIDE 600V. INSULATION.
FOR THREE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.
CONNECT BLACK, RED & WHITE LEADS TO SUPPLY CIRCUIT.
2. FOR MACHINES NOT SUPPLIED WITH INPUT CABLE
FOR SINGLE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.
CONNECT TERMINALS U & W TO SUPPLY CIRCUIT.
FOR THREE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.
CONNECT TERMINALS U, V & W TO SUPPLY CIRCUIT.
N.B. SINCE COMPONENTS OR CIRCUITRY OF A PRINTED CIRCUIT BOARD MAY CHANGE WITHOUT AFFECTING
THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY NOT SHOW THE EXACT
COMPONENTS OR CIRCUITRY HAVING A COMMON CODE NUMBER.
N.D. PLACE "A" LEAD ON APPROPRIATE CONNECTION FOR INPUT VOLTAGE.
CONNECTION SHOWN IS FOR 440-460V OPERATION.
N.E. D1 THRU D5 OUTPUT DIODES ARE A MATCHED SET.
D7 THRU D11 OUTPUT DIODES ARE A MATCHED SET.
N.F. R1, R9 BLEEDER RESISTORS ARE A MATCHED SET.
N.G. C1, C2 CAPACITORS ARE A MATCHED SET.
N.H. PLACE SWITCH IN APPROPRIATE POSITION FOR INPUT VOLTAGE.
CONNECTION SHOWN IS FOR 380-460V OPERATION.
N.I. DENOTES A TWISTED WIRE PAIR OR GROUP.
N.J. NOT PRESENT ON EUROPEAN VERSION.
N.K. NOT PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.
N.L. PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.
N.M. PRESENT ON EUROPEAN VERSIONS, CODE 10383 AND HIGHER.
307
308
309
310
501
504
311
313
CASE
FRONT
CASE
BOTTOM
TRAY
L3
CHOKE
J12
3
4
1
2
2
3
1
4
5
6
J13
DARLINGTON
DRIVE BOARD
7
8
2
4
5
6
1
3
J7
1
3
4
2 J14
POWER
BOARD
J6
5
6
3
8
1
10
2
7
9
4
FAN
SHROUD
W
B
CASE
BACK
PLATFORM CASE
BACK
CURRENT
SENSE
BOARD
303
302
304
275
212
305
301
212A
211A
J18
3
4
1
2
R
B
W
B
240
241
242
W
B
R
371A
374A
243
244
303
302
304
275
Y
Y
301
305
245
223
211A
212C
210
246
502
R
B
W
4
2
3
1
J1
J27
9
5
12
6
2
8
11
3
1
7
4
10
J4
2
4
6
8
7
5
3
1
J5
3
11
10
6
8
1
7
14
4
2
5
9
12
13
J17
J28
9
10
11
12
7
8
6
1
2
3
4
5
J2
13
4
15
8
2
1
16
10
7
9
6
12
14
3
5
11
5
6
7
2
1
4
8
3
9
10
289
289B
C8
289A
20/400
288B
R16
2 300W
288A
R15
2 300W
E C
B
W
E
B
DARLINGTON
MODULE
370
371
372
374
376
N.L.
REMOTE
PROTECTION BOARD
288
287
D12
TOROIDAL
CORE
223
B
R
W
B
370
371
372
374
376
212C
43A
33C
32C
212B
+ ARC
- ARC
J37
4
8
3
5
2
7
6
1
J34
5
4
6
2
3
7
1
8
9
10
J33
J36
10
9
12
4
11
3
2
1
14
6
8
15
7
5
13
16
J35
1
2
3
4
3
6
2
5
1
4
290
291
J19
2
1
3
4
(+)
(-)
VOLTAGE
SENSE
CONNECTION
414
406
405
413
416
408
415
407
M
D
C
K
H
L
N
B
I
A
J
E
F
G
403
402
401
410
409
412
404
411
J38
J
B
C
G
A
D
F
H
I
E
TRIGGER
GND
OPTIONAL
REMOTE
INTERFACE 290A
J39
WIRE
FEEDER
77
76
75
42
41
32
31
81
4
2
ELECTRODE SENSE LEAD
GND
21
82
TRIGGER
42
VAC
115
VAC
BG
10K
N.J.
PB
10K
43B
42
CB1
6AMP
42
VAC
33D
31A
CB2
6AMP
115
VAC
J3
4
1
3
2
5
6
CONTROL
BOARD
350
351
352
353
354
355
356
357
358
359
360
361
362
363
377
378
364
365
366
367
368
369
353
352
J24
1
2
3
4
5
6
4
5
6
2
3
1
J23
PEAK
CURRENT
METER
351
350
357
356
J26
5
6
3
4
1
2
5
6
3
4
2
1
J25
BACKGROUND
METER
355
354
358
359
360
361
362
363
CW (MAX)
10K R11
2W
PEAK
CURRENT
CONTROL
364
365
366
367
367A
.045
368
367A
STAINLESS
369
502
503
503A
CW (MAX)
10K
2W
R12
377
378
BACKGROUND
CONTROL
CW
CW (MAX)
10K
2W
R13
HOT START
CONTROL
S2
.035
S3
MILD
Y
(-)
(+)
WIRE SIZE
WIRE TYPE
THERMAL
OVERLOAD
INDICATOR
TAILOUT
CONTROL
500K
2W
R14
D-RW
G3136
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.
DEC 97
INVERTEC STT
Public link updated
The public link to your chat has been updated.
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