january 1998 invertec & stt ii

SVM129-AJanuary 1998

Safety Depends on You

Lincoln arc welding and cuttingequipment is designed and builtwith safety in mind. However,your overall safety can beincreased by proper installation .. . and thoughtful operation onyour part. DO NOT INSTALL,OPERATE OR REPAIR THISEQUIPMENT WITHOUT READ-ING THIS MANUAL AND THESAFETY PRECAUTIONS CON-TAINED THROUGHOUT. And,most importantly, think beforeyou 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 Worldwide22801 St. Clair Ave. Cleveland, Ohio 44117-1199 U.S.A. Tel. (216) 481-8100

For use with machine code numbers: 101511015210153103811038210383

INVERTEC ® STT TM & STT II TM

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SAFETYi i

INVERTEC STT

FOR ENGINEpowered equipment.

1.a. Turn the engine off before troubleshooting and maintenancework 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.c. Do not add the fuel near an open flame weld-

ing arc or when the engine is running. Stopthe engine and allow it to cool before refuel-ing to prevent spilled fuel from vaporizing oncontact with hot engine parts and igniting. Donot spill fuel when filling tank. If fuel is spilled,wipe it up and do not start engine until fumeshave been eliminated.

____________________________________________________1.d. Keep all equipment safety guards, covers

and devices in position and in goodrepair.Keep hands, hair, clothing and toolsaway from V-belts, gears, fans and all othermoving parts when starting, operating orrepairing equipment.

____________________________________________________

1.e. In some cases it may be necessary to remove safetyguards to perform required maintenance. Removeguards only when necessary and replace them when themaintenance requiring their removal is complete.Always use the greatest care when working near movingparts.

___________________________________________________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 con-trol rods while the engine is running.

___________________________________________________1.g. To prevent accidentally starting gasoline engines while

turning the engine or welding generator during maintenancework, disconnect the spark plug wires, distributor cap ormagneto wire as appropriate.

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 youpurchase 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 theLincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.

BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES AREPERFORMED ONLY BY QUALIFIED INDIVIDUALS.

WARNING

Mar ‘95

ELECTRIC AND MAGNETIC FIELDSmay be dangerous

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, andwelders having a pacemaker should consult their physicianbefore welding.

2.c. Exposure to EMF fields in welding may have other healtheffects which are now not known.

2.d. All welders should use the following procedures in order tominimize exposure to EMF fields from the welding circuit:

2.d.1. Route the electrode and work cables together - Securethem 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 andwork 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 aspossible to the area being welded.

2.d.5. Do not work next to welding power source.

1.h. To avoid scalding, do not remove theradiator pressure cap when the engine ishot.

CALIFORNIA PROPOSITION 65 WARNINGS

Diesel engine exhaust and some of its constituentsare known to the State of California to cause can-cer, birth defects, and other reproductive harm.

The engine exhaust from this product containschemicals known to the State of California to causecancer, birth defects, or other reproductive harm.

The Above For Diesel Engines The Above For Gasoline Engines

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ii ii

INVERTEC STT

ARC RAYS can burn.4.a. Use a shield with the proper filter and cover

plates to protect your eyes from sparks andthe rays of the arc when welding or observingopen arc welding. Headshield and filter lensshould conform to ANSI Z87. I standards.

4.b. Use suitable clothing made from durable flame-resistantmaterial to protect your skin and that of your helpers fromthe arc rays.

4.c. Protect other nearby personnel with suitable, non-flammablescreening and/or warn them not to watch the arc nor exposethemselves to the arc rays or to hot spatter or metal.

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 bareskin or wet clothing. Wear dry, hole-freegloves to insulate hands.

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

In addition to the normal safety precautions, if weldingmust be performed under electrically hazardousconditions (in damp locations or while wearing wetclothing; on metal structures such as floors, gratings orscaffolds; when in cramped positions such as sitting,kneeling or lying, if there is a high risk of unavoidable oraccidental contact with the workpiece or ground) usethe 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 semiautomaticwelding gun are also electrically “hot”.

3.d. Always be sure the work cable makes a good electricalconnection with the metal being welded. The connectionshould 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 andwelding machine in good, safe operating condition. Replacedamaged insulation.

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

3.h. Never simultaneously touch electrically “hot” parts ofelectrode holders connected to two welders because voltagebetween the two can be the total of the open circuit voltageof both welders.

3.i. When working above floor level, use a safety belt to protectyourself from a fall should you get a shock.

3.j. Also see Items 6.c. and 8.

FUMES AND GASEScan be dangerous.5.a. Welding may produce fumes and gases

hazardous to health. Avoid breathing thesefumes and gases.When welding, keepyour head out of the fume. Use enoughventilation and/or exhaust at the arc to keep

fumes and gases away from the breathing zone. Whenwelding with electrodes which require specialventilation such as stainless or hard facing (seeinstructions on container or MSDS) or on lead orcadmium plated steel and other metals or coatingswhich produce highly toxic fumes, keep exposure aslow as possible and below Threshold Limit Values (TLV)using local exhaust or mechanical ventilation. Inconfined spaces or in some circumstances, outdoors, arespirator may be required. Additional precautions arealso required when welding on galvanized steel.

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

5.c. Shielding gases used for arc welding can displace air andcause 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 thisequipment and the consumables to be used, including thematerial safety data sheet (MSDS) and follow youremployer’s safety practices. MSDS forms are available fromyour welding distributor or from the manufacturer.

5.e. Also see item 1.b. Mar ‘95

SAFETY

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SAFETYiii iii

INVERTEC STT

FOR ELECTRICALLYpowered equipment.

8.a. Turn off input power using the disconnectswitch at the fuse box before working onthe equipment.

8.b. Install equipment in accordance with the U.S. NationalElectrical Code, all local codes and the manufacturer’srecommendations.

8.c. Ground the equipment in accordance with the U.S. NationalElectrical Code and the manufacturer’s recommendations.

CYLINDER may explodeif damaged.7.a. Use only compressed gas cylinders

containing the correct shielding gas for theprocess used and properly operatingregulators designed for the gas and

pressure used. All hoses, fittings, etc. should be suitable forthe application and maintained in good condition.

7.b. Always keep cylinders in an upright position securelychained to an undercarriage or fixed support.

7.c. Cylinders should be located:• Away from areas where they may be struck or subjected tophysical damage.

• A safe distance from arc welding or cutting operations andany other source of heat, sparks, or flame.

7.d. Never allow the electrode, electrode holder or any otherelectrically “hot” parts to touch a cylinder.

7.e. Keep your head and face away from the cylinder valve outletwhen opening the cylinder valve.

7.f. Valve protection caps should always be in place and handtight except when the cylinder is in use or connected foruse.

7.g. Read and follow the instructions on compressed gascylinders, associated equipment, and CGA publication P-l,“Precautions for Safe Handling of Compressed Gases inCylinders,” available from the Compressed Gas Association1235 Jefferson Davis Highway, Arlington, VA 22202.

Mar ‘95

WELDING SPARKS cancause fire or explosion.6.a. Remove fire hazards from the welding area.

If this is not possible, cover them to preventthe welding sparks from starting a fire.Remember that welding sparks and hot

materials from welding can easily go through small cracksand openings to adjacent areas. Avoid welding nearhydraulic 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 hazardoussituations. Refer to “Safety in Welding and Cutting” (ANSIStandard Z49.1) and the operating information for theequipment being used.

6.c. When not welding, make certain no part of the electrodecircuit is touching the work or ground. Accidental contact cancause overheating and create a fire hazard.

6.d. Do not heat, cut or weld tanks, drums or containers until theproper steps have been taken to insure that such procedureswill not cause flammable or toxic vapors from substancesinside. They can cause an explosion even though they havebeen “cleaned”. For information, purchase “RecommendedSafe Practices for the Preparation for Welding and Cutting ofContainers and Piping That Have Held HazardousSubstances”, AWS F4.1 from the American Welding Society(see address above).

6.e. Vent hollow castings or containers before heating, cutting orwelding. They may explode.

6.f. Sparks and spatter are thrown from the welding arc. Wear oilfree protective garments such as leather gloves, heavy shirt,cuffless trousers, high shoes and a cap over your hair. Wearear plugs when welding out of position or in confined places.Always wear safety glasses with side shields when in awelding area.

6.g. Connect the work cable to the work as close to the weldingarea as practical. Work cables connected to the buildingframework or other locations away from the welding areaincrease the possibility of the welding current passingthrough lifting chains, crane cables or other alternate circuits.This can create fire hazards or overheat lifting chains orcables until they fail.

6.h. Also see item 1.c.

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SAFETYiv iv

INVERTEC STT

PRÉCAUTIONS DE SÛRETÉPour votre propre protection lire et observer toutes les instructionset les précautions de sûreté specifiques qui parraissent dans cemanuel aussi bien que les précautions de sûreté générales suiv-antes:

Sûreté Pour Soudage A L’Arc1. Protegez-vous contre la secousse électrique:

a. Les circuits à l’électrode et à la piéce sont sous tensionquand la machine à souder est en marche. Eviter toujourstout contact entre les parties sous tension et la peau nueou les vétements mouillés. Porter des gants secs et sanstrous pour isoler les mains.

b. Faire trés attention de bien s’isoler de la masse quand onsoude dans des endroits humides, ou sur un plancher met-allique ou des grilles metalliques, principalement dans les positions assis ou couché pour lesquelles une grandepartie du corps peut être en contact avec la masse.

c. Maintenir le porte-électrode, la pince de masse, le câble desoudage et la machine à souder en bon et sûr état defonc-tionnement.

d.Ne jamais plonger le porte-électrode dans l’eau pour lerefroidir.

e. Ne jamais toucher simultanément les parties sous tensiondes porte-électrodes connectés à deux machines à soud-er parce que la tension entre les deux pinces peut être letotal de la tension à vide des deux machines.

f. Si on utilise la machine à souder comme une source decourant pour soudage semi-automatique, ces precautionspour le porte-électrode s’applicuent aussi au pistolet desoudage.

2. Dans le cas de travail au dessus du niveau du sol, se protégercontre les chutes dans le cas ou on recoit un choc. Ne jamaisenrouler le câble-électrode autour de n’importe quelle partiedu corps.

3. Un coup d’arc peut être plus sévère qu’un coup de soliel,donc:

a. Utiliser un bon masque avec un verre filtrant appropriéainsi qu’un verre blanc afin de se protéger les yeux du ray-onnement de l’arc et des projections quand on soude ouquand on regarde l’arc.

b. Porter des vêtements convenables afin de protéger lapeau de soudeur et des aides contre le rayonnement del‘arc.

c. Protéger l’autre personnel travaillant à proximité ausoudage à l’aide d’écrans appropriés et non-inflammables.

4. Des gouttes de laitier en fusion sont émises de l’arc desoudage. Se protéger avec des vêtements de protection libresde l’huile, tels que les gants en cuir, chemise épaisse, pan-talons sans revers, et chaussures montantes.

5. Toujours porter des lunettes de sécurité dans la zone desoudage. Utiliser des lunettes avec écrans lateraux dans les

zones où l’on pique le laitier.

6. Eloigner les matériaux inflammables ou les recouvrir afin deprévenir tout risque d’incendie dû aux étincelles.

7. Quand on ne soude pas, poser la pince à une endroit isolé dela masse. Un court-circuit accidental peut provoquer unéchauffement et un risque d’incendie.

8. S’assurer que la masse est connectée le plus prés possible dela zone de travail qu’il est pratique de le faire. Si on place lamasse sur la charpente de la construction ou d’autres endroitséloignés de la zone de travail, on augmente le risque de voirpasser le courant de soudage par les chaines de levage,câbles de grue, ou autres circuits. Cela peut provoquer desrisques d’incendie ou d’echauffement des chaines et descâbles 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 tôlesgalvanisées plombées, ou cadmiées ou tout autre métal quiproduit des fumeés toxiques.

10. Ne pas souder en présence de vapeurs de chlore provenantd’opérations de dégraissage, nettoyage ou pistolage. Lachaleur ou les rayons de l’arc peuvent réagir avec les vapeursdu solvant pour produire du phosgéne (gas fortement toxique)ou autres produits irritants.

11. Pour obtenir de plus amples renseignements sur la sûreté, voirle code “Code for safety in welding and cutting” CSA StandardW 117.2-1974.

PRÉCAUTIONS DE SÛRETÉ POURLES MACHINES À SOUDER ÀTRANSFORMATEUR ET ÀREDRESSEUR

1. Relier à la terre le chassis du poste conformement au code del’électricité et aux recommendations du fabricant. Le dispositifde montage ou la piece à souder doit être branché à unebonne mise à la terre.

2. Autant que possible, I’installation et l’entretien du poste seronteffectués par un électricien qualifié.

3. Avant de faires des travaux à l’interieur de poste, la debranch-er à l’interrupteur à la boite de fusibles.

4. Garder tous les couvercles et dispositifs de sûreté à leurplace.

Mar. ‘93

MASTER TABLE OF CONTENTS FOR ALL SECTIONSv v

INVERTEC STT

PageSafety .................................................................................................................................................i-iv

Installation.............................................................................................................................Section ATechnical Specifications ..............................................................................................................A-2Location.......................................................................................................................................A-3Stacking.......................................................................................................................................A-3Tilting...........................................................................................................................................A-3Machine Grounding and High Frequency Interference Protection..............................................A-3Input Connections .......................................................................................................................A-3

Supply Connections..............................................................................................................A-3Input Cable Installation and Connection...............................................................................A-4Ground Connection...............................................................................................................A-4

Input Voltage Reconnect Procedure ...........................................................................................A-5Output Connections ....................................................................................................................A-5

Wire Feeder Output Connections .........................................................................................A-5

Operation...............................................................................................................................Section BSafety Instructions.......................................................................................................................B-2General Description ....................................................................................................................B-3Recommended Equipment..........................................................................................................B-3Operating Controls ......................................................................................................................B-3Design Features ..........................................................................................................................B-3Welding Capability.......................................................................................................................B-3Limitations ...................................................................................................................................B-3Operational Features and Controls .............................................................................................B-4Welding Operation.......................................................................................................................B-5Welding Parameters and Guidelines...........................................................................................B-5Recommended 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% CO2 Welding Procedure......................................B-8

.030", .035", .045" Stainless Steel Welding Procedures ......................................................B-91.2mm DIN SG2 Welding Procedures................................................................................B-100.8, 1.0mm DIN SG2 Welding Procedures.........................................................................B-110.8, 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 .......................................................................................................................................P257STT II Parts ....................................................................................................................................P294

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DEC 97

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TABLE OF CONTENTS- INSTALLATION SECTION -

Section A-1 Section A-1

INVERTEC STT

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

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INSTALLATIONA-2 A-2

INVERTEC STT

TECHNICAL SPECIFICATIONS - INVERTEC STT

INPUT - THREE PHASE ONLY

STANDARD VOLTAGE INPUT CURRENT AT RATED OUTPUT

208/230/460/3/60 HZ 32/30/19

200/220/380/415/440/3/50/60 HZ 33/30/18/17/16

RATED OUTPUT

DUTY CYCLE AMPS VOLTS AT RATED AMPS

60% Duty Cycle 225 29100% Duty Cycle 200 28

OUTPUT - WELDER AND GENERATOR

CURRENT RANGE OPEN CIRCUIT VOLTAGE AUXILIARY POWER

Peak Current 1 0 - 450 Amps 85 VDC Maximum 115 2 VAC @ 6 AmpsBackground 0 - 125 Amps 42 VAC @ 6 Amps

RECOMMENDED INPUT WIRE AND FUSE SIZES

INPUT VOLTAGE FUSE(SUPER LAG) INPUT AMPERE TYPE 75 C TYPE 75 CAND FREQUENCY OR BREAKER RATING ON COPPER COPPER

SIZE NAMEPLATE SUPPLY WIRE GROUND WIREIN CONDUIT IN CONDUIT

AWG (IEC) SIZES AWG (IEC) SIZES

208/60 40 32 10 (6 mm2) 10 (6 mm2)230/60 40 30 10 (6 mm2) 10 (6 mm2)460/60 30 16 10 (6 mm2) 10 (6 mm2)200/50/60 40 33 10 (6 mm2) 10 (6 mm2)220/50/60 40 30 10 (6 mm2) 10 (6 mm2)380/50/60 30 18 10 (6 mm2) 10 (6 mm2)415/50/60 30 17 10 (6 mm2) 10 (6 mm2)440/50/60 30 16 10 (6 mm2) 10 (6 mm2)

PHYSICAL DIMENSIONS

HEIGHT WIDTH DEPTH WEIGHT

23.2 in. 13.2 in. 24.4 in. 100 lbs.589 mm 336 mm 620 mm 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.

DEC 97

Read and understand entire Installation Sectionbefore starting installation.

ELECTRIC SHOCK can kill.

• Only qualified personnel shouldperform this installation.

• Turn the input power OFF at thedisconnect switch or fuse boxbefore installing this equipment.

• Turn the power switch on theInvertec STT “OFF” before con-necting or disconnecting inputpower lines, output cables, orcontrol cables.

• Do not touch electrically hotparts.

• Always connect the ground ter-minal to a good electrical earthground.

Only qualified personnel should install, use, or ser-vice this equipment.

SELECT SUITABLE LOCATIONLocate the machine where there is free circulation ofclean air. Place the machine so that air can freely cir-culate into the sides and out of the rear of the machine.Dirt and dust that can be drawn into the machineshould be kept to a minimum. Failure to observe theseprecautions can result in excessive operating tempera-tures and nuisance shut down of the Invertec STT.This machine carries an enclosure rating of IP 21. Itshould not be placed in extremely damp or dirty loca-tions. It should not be exposed to rain or snow.

STACKINGThe Invertec STT cannot be stacked.

TILTINGPlace the machine on a secure, level surface otherwisethe unit may topple over.

MACHINE GROUNDING AND HIGHFREQUENCY INTERFERENCE PROTECTIONThe machine may not be suitable for use in an envi-ronment where high frequency is present. For exam-ple do not place the machine in close proximity to “TIG”or “PLASMA” operations. To minimize high frequencyinterference:

Locate the STT power source more than 15 feet(4.5 m) away from high frequency units and morethan 25 feet (7.6 m) separation between groundconnections or welding arcs or high frequencyunits.

Provide proper electrical ground to the machineper local and national electrical codes.

INPUT CONNECTIONS

FAILURE TO FOLLOW THESE INSTRUCTIONS CANCAUSE IMMEDIATE FAILURE OF COMPONENTSWITHIN THE WELDER.

Turn the input power off at the disconnect switch beforeattempting to connect the input power lines.

Connect the green lead of the power cord to groundper local and national electrical codes.

SUPPLY CONNECTIONS

Be sure the voltage, phase, and frequency of the inputsupply is as specified on the rating plate. Input powersupply line entry is provided on the case back of themachine. See Figure A.1 for location of the ratingplate.

The Invertec STT should be connected only by a qual-ified electrician. Installation should be made in accor-dance with local and national codes. Refer to theTechnical Specifications at the beginning of this sec-tion for proper fuse sizes, ground wire, and input sup-ply power cable sizes.

Some models come from the factory with an inputpower cord. If you model does not include the inputpower cord install the proper size input cable andground cable according to INPUT CABLE INSTALLA-TION AND CONNECTION.

INSTALLATIONA-3 A-3

INVERTEC STTRet

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WARNING

CAUTION

INPUT CABLE INSTALLATION AND CONNECTION

A cable strain relief is provided at the supple line entryand is designed to accommodate cable diameters of.310 - 1.070 in. (7.9 - 27.2 mm). Refer to TechnicalSpecifications at the beginning of this section for theproper input cable sizes. Refer to Figure A.1 and per-form the following steps:

1. Remove the wraparound cover of the Invertec STT.

2. Feed the input cable through the input cable entryaccess hole at the right rear of the machine.

3. Route the cable through the cable hangers, locat-ed along the lower right inside edge of themachine, up to the power switch located on thefront panel.

4. Strip away 102 mm (4 in.) of the outer jacket. Trimfillers and strip conductor jackets to connect to thepower switch.

5. Connect the three phase line con-ductors to the power switch termi-nals labeled U, V and W. Tightenthe connections to 3.0 Nm. (27 in.-lb.) torque.

6. Securely tighten the cable strain relief located onthe case back of the machine.

GROUND CONNECTION

1. Connect the ground terminal to earthground per National Electrical Code.

2. Replace the wraparound cover of the Invertec STT.

INSTALLATIONA-4 A-4

INVERTEC STTRet

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INPUT CABLEENTRY ACCESS& CABLE STRAIN RELIEF

NAMEPLATE

INPUT VOLTAGE RECONNECTPROCEDUREAs shipped from the factory, multiple voltage(208/230/460 VAC) or (200/220/380 - 415/440 VAC)machines are internally configured for the highest inputvoltage (440 or 460 VAC).

1. For Connections to 440 or 460 VAC verify theinternal configurations to the procedures shownbelow and refer to Figure A.2.

2. For Connections to 200, 208, 220, 230, 380 or 415VAC follow the procedure shown below and referto Figure A.2.

Turn the main power to the machine OFF before per-forming the reconnect procedure. Failure to do so willresult in damage to the machine. DO NOT switch thereconnect bar with machine power ON.

To Operate at Procedure

460 or 440 VAC 1. Open reconnect panel accessdoor on wrap-around.

2. Move input voltage switch toVoltage = 380 -460V position.

3. Move lead “A” to 440-460Terminal.










OUTPUT CONNECTIONS

WIRE FEEDER OUTPUT CONNECTIONS

Refer to the Accessories section of this manual forinstructions on connecting a wire feeder to the InvertecSTT.

The LN-742 wire feeder is the recommended feeder foruse with the Invertec STT.

INSTALLATIONA-5 A-5

INVERTEC STTRet

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CAUTION

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Section B-1 Section B-1

INVERTEC STT

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% CO2 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

DEC 97

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OPERATIONB-2 B-2

INVERTEC STT

OPERATING INSTRUCTIONSRead and understand this entire section beforeoperating your Invertec STT.

SAFETY INSTRUCTIONS


• Do not touch electrically live parts orelectrode with skin or wet clothing.

• Insulate yourself from work andground.

• Always wear dry insulating gloves.

FUMES AND GASES can bedangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust to removefumes from breathing zone.

WELDING SPARKS can causefire or explosion.

• Keep flammable material away.

• Do not weld on containers that haveheld combustibles.

ARC RAYS can burn.

• Wear eye, ear, and body protection.

WARNING

Observe additional Safety Guidelines detailed in the beginning of this manual.

GENERAL DESCRIPTIONThe Invertec STT is a 225-ampere inverter based arcwelding power source specifically designed for the STTwelding process. It is neither a constant current (CC)nor a constant voltage (CV) machine. It is a powersource that delivers current of a desired wave form toreduce spatter and fumes. The process is optimized for short-circuiting GMAW welding.

RECOMMENDED EQUIPMENTThe LN-742 wire feeder is recommended for use withthe STT. The LN-7 GMA, LN-9 GMA, NA-5, and NA-5Rcan all be used with the STT. These units can only beused to feed wire.

OPERATING CONTROLSThe Invertec STT has the following controls as stan-dard: On/Off switch, Peak Current adjustment,Background Current adjustment, Hot Start adjustment,Tailout (STT II only), and 2 toggle switches; one for wiresize selection and one for wire type selection.

DESIGN FEATURES• State of the art inverter technology yields high power

efficiency, excellent welding performance, lightweightand 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 proceduresettings all remain constant.

• Arc Sense lead assembly (Electrode and Work), con-nects through a 4-pin case front connector.

• Peak Current and Background Current may beremotely controlled.

• Thermostat and FET over current protector preventoverheating from overloads, high ambient tempera-tures, or loss of air flow.

• High temperature Class H insulation.

• Protection circuits and ample safety margins preventdamage to the solid state components from transientvoltages and high currents.

• Preset welding current capability.

• The STT II offers improvements over the previousmodel. Approximately 40% increase in depositionrate capability, and a significant increase in travelspeed.

WELDING CAPABILITYThe Invertec STT is rated at 225 amps, 29 volts, at60% duty cycle on a ten minute basis. It is capable ofhigher duty cycles at lower output currents. If the dutycycle(s) are exceeded, a thermal protector will shut offthe output until the machine cools to a reasonableoperating temperature.

LIMITATIONS• The Invertec STT is not recommended for spray or

pulse GMAW, FCAW, arc gouging or other constantvoltage processes or SMAW.

• GMAW is the only process supported by the STT.

• May not be suitable for use in an environment withHigh Frequency present. (See Machine Groundingand High Frequency Protection in the InstallationSection of this manual.)

• Suitable for indoor use only (IEC IP21).

OPERATIONB-3 B-3

INVERTEC STTRet

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DEC 97

OPERATIONAL FEATURES ANDCONTROLSAll operator controls are located on the case front ofthe Invertec STT. Refer to Figure B.1 for locations.

1. POWER SWITCH: Turns outputpower ON and OFF. This switchalso controls auxiliary poweravailable through the 14-pinWire Feeder Receptacle.

2A. BACKGROUND CURRENT OUTPUT CONTROL:The output current is switched to theBackground level at the conclusion ofthe preceding Peak Current pulse. Thisknob allows preset adjustment of the amplitude ofthe background current up to 125 amperes.

2B. BACKGROUND CURRENT DISPLAY METER:This is a digital meter for displaying thepreset Background Current. This meterdisplays in 1 amp increments. Thismeter does not indicate the actual welding current,only the preset current.

3A. PEAK CURRENT OUTPUT CONTROL: Thebeginning portion of the welding arc is apulse of current referred to as PeakCurrent. This knob allows preset adjust-ment of the amplitude of the peak current up to 450amperes.

3B. PEAK CURRENT DISPLAY METER:This is a digital meter for displaying thepreset Peak Current. This meter dis-plays in 1 amp increments. This meterdoes not indicate actual welding current only thepreset current.

4. HOT START CONTROL POTENTIOMETER: ”HotStart” provides approximately 25% to50% more current during the initial startof the weld for improved arc starting andbead appearance. This control adjuststhe duration of this “Hot Start” current. The controlrange is from 0 to 10, where 0 corresponds to thezero 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 switchselects between electrode diameters of .035" (1mm) and smaller or .045" (1.2 mm) and larger. The0.35" (1 mm) position provides improved perfor-mance of smaller diameter wires at higher wirefeed speeds.

6. WIRE TYPE SELECT SWITCH: This toggle switchselects between mild or stainless steel. In thestainless position, the pulse width of the PeakCurrent is changed from 1 to 2 ms for better per-formance for stainless steel welding.

7. TAILOUT: Alters the current waveform to increasedeposit rate and travel speed. The Minimum settingsets STT II to the original STT waveform. As tailoutis increased peak and Background current mayneed to be reduced to maintain optimum perfor-mance.

OPERATIONB-4 B-4

INVERTEC STTRet

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FIGURE B.1 - CASE FRONT CONTROLS

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DEC 97

8. THERMAL SHUT-DOWN INDICATOR:This light will indicate that either the internalthermostat(s) or the FET over current sen-sor has actuated. Machine output willreturn after the internal components have returnedto normal operating temperature (if the thermo-stat(s) “opened”) or after about 3-7 seconds (if theFET over current sensor activated).

9. REMOTE RECEPTACLE: This is a 10pin MS-type connector for remote con-trol of Peak Current and BackgroundCurrent. Trigger switch connections arealso provided. The presence of the mating con-nector is automatically sensed, disabling the frontpanel Peak and Background Current controls.Refer to “REMOTE CONTROL CONNECTOR” inthe ACCESSORIES Section of this manual formore information.

10. WIRE FEEDER RECEPTACLE: This is14 pin MS-type connector for the wirefeeder connection. 115 and 42 VACalong with the trigger switch connectionsare provided. (Only 42 VAC is available onEuropean models). There are no provisions forvoltage control of the power source by the wirefeeder. Refer to the Accessories Section of thismanual for wire feeder connection instructions.

11. ARC SENSE RECEPTACLE: This is a four pinMS-type connector for WORK and ELECTRODEsense leads. The STT requires a WORK senseand ELECTRODE sense lead for proper operation.The ELECTRODE sense lead is bolted togetherwith power source electrode lead at the wire feed-er gun block. The WORK sense lead is furnishedwith an “alligator” type clip for connection to thework piece. Refer to the LN 742 wire feeder con-nection instructions in the Accessories section ofthis manual for proper connection of these leads.

12. 42V AUXILIARY POWER CIRCUIT BREAKER:The 42 VAC supply is protected fromexcessive current draws with a 6 ampcircuit breaker. When the breaker “trips”its button will extend. Depressing this button willreset the breaker.

13. 115V AUXILIARY POWER CIRCUIT BREAKER:(Not on European Models): The 115 VACsupply is protected from excessive cur-rent 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-mateconnection is the negative output termi-nal for connecting a work cable andclamp to the workpiece.

15. ELECTRODE TERMINAL: This twist-mate connection is the positive output ter-minal for connecting an electrode cable tothe wire feeder conductor block. Refer to theAccessories section for wire feeder connectioninstructions.

WELDING OPERATION

Familiarize yourself with the controls on the InvertecSTT before beginning to weld. Familiarize yourself withthe operating manual for the wire feeder and the wirefeeder controls before beginning to weld.

Refer to Recommended Settings in this section forinitial machine settings for a particular application.Set the Wire Size and Wire Type selection switches perthe appropriate wire. Refer to Operational Featuresand Controls in this section for the function of theseswitches.

WELDING PARAMETERS ANDGUIDELINES

The Invertec STT is neither a constant current (CC) nora constant voltage (CV) power source. In general, wirediameter will be increased one size compared to con-ventional (CV) power sources. The larger the wirediameter the higher the deposition rate (Up to 1/16”).Wire sizes below .035” are unnecessary for most appli-cations. The Invertec STT is a current controlledmachine which is capable of changing the electrodecurrent quickly in order to respond to the instantaneousrequirements of the arc and optimize performance. Bysensing changes in welding current, and hence theelectrode state, the power source will supply varyingoutput currents to minimize spatter. The Peak andBackground currents are two such current outputs thatcan be adjusted.

Wire Feed Speed controls the deposition rate. PeakCurrent controls the Arc Length. Background Currentcontrols the Bead Contour. And Tailout (STT II only)increases Power in the Arc.

PEAK CURRENTThe Peak Current control acts similar to an “arc pinch”control. Peak current serves to establish the arc lengthand promote good fusion. Higher peak current levelswill cause the arc to broaden momentarily whileincreasing the arc length. If set too high, globular typetransfer will occur. Setting this level to low will causeinstability and wire stubbing. In practice, this currentlevel should be adjusted for minimum spatter and pud-dle agitation.

OPERATIONB-5 B-5

INVERTEC STTRet

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DEC 97

RECOMMENDED INITIAL SETTINGS For STT onlyRefer to the following tables for recommended settings such as wire types, sizes, wire feed speeds, peak currentsettings, background current settings, and travel speeds.

OPERATIONB-6 B-6

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TABLE B.1 - ALL POSITION WELDING .045" L-50 AND L-56 WITH CARBON DIOXIDE SHIELDING GAS1

Wire Feed Background Tip to Plate WeldingSpeed Peak Current Current Travel Speed Distance (in) Current

Material Size (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)

3/16" 175 440 75 10--11 1/4--5/16 230

10 ga. 150 400 60 12--13 1/4--5/16 200

12 ga. 110 390 40 13--14 1/4--5/16 175

14 ga. 100 380 30 11--12 1/4--5/16 160

16 ga. 65 235 40 11-12 1/4--5/16 125

1 Shielding gas flow rate of 25 CFH

DEC 97

Adjust Arc Length with Peak Current

Note: In 100% CO2 shielding gas applications the peakcurrent level should be set greater than in a corre-sponding application using a gas blend with a high per-centage of Argon. Longer initial arc lengths with 100%CO2 are required to reduce spatter.

BACKGROUND CURRENTThe Background Current provides the control for theoverall heat input to the weld. Adjusting this level toohigh will cause a large droplet to form and globular typetransfer to occur resulting in increased spatter.Adjusting this level to low will cause wire stubbing andalso poor wetting of the weld metal. This is similar to alow voltage setting on a standard CV machine

Adjust Bead Shape using Background Current

Note: Background Current levels for applications using100% CO2 is less than similar procedures involving gasblends with high percentages of Argon. This is a result

of the greater heat generated in the 100% CO2 arc.(100% CO2 is 35 volts/cm and 100% Argon is 20volts/cm. 75% Argon, 25% CO2 is about 24 volts/cm.

Contact Tip to Work Distance

HOT STARTThe Hot Start control can be set to enhance establish-ing the arc and provide the capability of increasing theheat at the start of the weld to compensate for a coldwork piece. Hot start adjusts the time that additionalcurrent is applied during the starting of the arc. Refer to“Operational Features and Controls” in this section fora description of this control.

TAILOUT (STT II Only)The tail out provides additional heat without the moltendroplet becoming too large. Increase as necessary toadd “Heat” to the arc without increasing arc length.(This will allow for faster travel speeds and produceimproved wetting). As tailout is increased, the pealand/or background current is usually reduced.

WELDING ARC PERFORMANCEFor optimum spatter reduction, the arc should be con-centrated on the puddle.

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OPERATIONB-7 B-7

INVERTEC STT

TABLE B.3 - ALL POSITION WELDING .035" L-50 AND L-56 WITH CARBON DIOXIDE SHIELDING GAS 1



3/16" 250 420 50 13--14 1/4--5/16 190

10 ga. 235 400 40 14--15 1/4--5/16 185

12 ga. 220 390 35 16--17 1/4--5/16 180

14 ga. 210 380 30 17--18 1/4--5/16 175

16 ga. 190 360 30 19--20 1/4-5/16 170

18 ga. 90 320 25 11-12 1/4-5/16 115

20 ga. 80 295 25 12--13 1/4--5/16 100


TABLE B.4 - ALL POSITION WELDING .030" L-50 AND L-56 WITH CARBON DIOXIDE SHIELDING GAS1



12 ga. 250 300 50 16--17 1/4--5/16 140

14 ga. 235 290 45 16--17 1/4--5/16 135

16 ga. 175 275 35 16--17 1/4--5/16 125

18 ga. 150 250 25 15--16 1/4--5/16 110

20 ga. 90 220 30 11--12 1/4--5/16 70


The serviceability of a product or structure utilizing this type of information is and must be the sole responsibilityof the builder/user. Many variables beyond the control of The Lincoln Electric Company affect the results obtainedin applying this type of information. These variables include, but are not limited to, welding procedure, plate chem-istry and temperature, weldment design, fabrication methods and service requirements.

TABLE B.2 - PIPE WELDING 3/8" THICKNESS MAXIMUM .045" L-50 AND L-56 WITH CARBON DIOXIDESHIELDING GAS 1

Pass Wire Feed Background Tip to Plate WeldingHot/Fill Speed Peak Current Current Travel Speed Distance (in) CurrentCap (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)

Root Pass 120 370 25 8--9 1/4 200VerticalDown

Root Pass 75 275 40 3--4 1/4 130Vertical Up

Fill Pass 120 370 50 3 1/4 210Vertical Up

Cap Pass 120 370 50 3 1/4 210Vertical Up

Vertical-up procedures are recommended for top (12 to 2 o’clock) and overhead (4 to 6 o’clock) positions.


DEC 97

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OPERATIONB-8 B-8

INVERTEC STT

TABLE B.5 - ALL POSITION WELDING .045" L-50 AND L-56 WITH 75% ARGON/25% CARBON DIOXIDESHIELDING GAS



3/16" 175 358 120 10--11 1/4-5/16 200

10 ga. 150 354 90 12--13 1/4--5/16 190

12 ga. 110 326 68 11-12 1/4--5/16 150

14 ga. 100 296 66 11-12 1/4--5/16 140

TABLE B.6 - ALL POSITION WELDING .035" L-50 AND L-56 WITH 75% ARGON /25% CARBON DIOXIDESHIELDING GAS



3/16" 300 300 105 10--12 1/4--5/16 195

10 ga. 235 300 80 14--15 1/4--5/16 185

12 ga. 220 285 80 16--17 1/4--5/16 180

14 ga. 210 280 75 19--20 1/4--5/16 175

16 ga. 190 260 70 17--18 1/4--5/16 160

18 ga. 90 200 39 12--13 1/4--5/16 105


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OPERATIONB-9 B-9

INVERTEC STT

TABLE B.7 - ALL POSITION WELDING .045" BLUE MAX MIG 308LSi1



3/16" 160 155 105 9 1/4--5/16 150

10 ga. 150 140 95 14 1/4--5/16 145

12 ga. 135 135 90 17 1/4--5/16 120

14 ga. 120 110 80 17 1/4--5/16 105

16 ga. 100 105 70 15 1/4--5/16 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.




10 ga. 250 160 100 12 1/4--5/16 130

12 ga. 230 140 90 13.5 1/4--5/16 120

14 ga. 210 130 85 10 1/4--5/16 110

16 ga. 190 120 80 12.5 1/4--5/16 100

18 ga. 175 95 70 11 1/4--5/16 85





10 ga. 235 195 65 11.5 1/4--5/16 105

12 ga. 225 180 60 14 1/4--5/16 95

14 ga. 200 180 60 12.5 1/4--5/16 90

16 ga. 190 175 55 13 1/4--5/16 85

18 ga. 180 170 50 14 1/4--5/16 75

20 ga. 170 160 45 16 1/4--5/16 65


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OPERATIONB-10 B-10

INVERTEC STT

TABLE B.10 - ALL POSITION WELDING 1.2 mm DIN SG 2 WITH CARBON DIOXIDE SHIELDING GAS1

Wire Feed Background Tip to Plate WeldingMaterial Size Speed Peak Current Current Travel Speed Distance (in) Current

(mm) (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)

5 4.4 425 80 28 6--8 220

3.6 3.8 400 60 33 6--8 205

2.8 2.8 385 45 36 6--8 175

2 2.5 370 45 30 6--8 160

1.6 1.6 235 45 30 6--8 125

1 Shielding gas flow rate of 12 Liters/minute.

Pass Wire Feed Background Tip to Plate WeldingHot/Fill Speed Peak Current Current Travel Speed Distance (in) CurrentCap (in/min.) Control Setting Control Setting (in/min.) (approx. AMPS)

Root Pass 2.77 370 30 20 6 200VerticalDown

Root Pass 1.78 300 50 7 6 130Vertical Up

Fill Pass 2.77 380 65 7 6 210Vertical Up

Cap Pass 2.77 380 65 8 6 210Vertical Up

Vertical-up procedures are recommended for top (12 to 2 o’clock) and overhead (4 to 6 o’clock) positions.


TABLE B.11 - PIPE WELDING 1.0 mm THICKNESS MAXIMUM 1.2 mm DIN SG 2 WITH CARBON DIOXIDESHIELDING GAS1

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OPERATIONB-11 B-11

INVERTEC STT




5 5 420 50 36 6--8 190

3.6 4.7 400 40 38 6--8 180

2.8 4.4 390 35 43 6--8 175

2 4.2 380 30 45 6--8 165

1.6 3.8 360 30 51 6--8 160

1.2 2.5 340 40 30 6--8 95





2.8 6.3 300 50 43 6--8 140

2 6 290 45 43 6--8 135

1.6 4.4 275 35 43 6--8 125

1.2 3.8 250 25 41 6--8 110

0.9 2.5 220 30 30 6--8 70



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OPERATIONB-12 B-12

INVERTEC STT


TABLE B.14 - ALL POSITION WELDING 1.2 mm BLUE MAX MIG 308LSi1



5 3.7 155 110 23 6--8 155

3.6 3.5 140 95 36 6--8 135

2.8 3.1 135 95 43 6--8 125

2 2.8 110 80 43 6--8 110

1.6 2.3 105 70 38 6--8 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 308LSi1



3.6 5 150 90 30 6--8 125

2.8 4.6 140 90 35 6--8 120

2 4.2 130 85 25 6--8 110

1.6 3.8 120 80 32 6--8 100

1.2 3.5 95 70 28 6--8 90


TABLE B.16 - ALL POSITION WELDING 0.8 mm BLUE MAX MIG 308Si1



3.6 6 200 77 29 6--8 105

2.8 5.7 180 65 35 6--8 95

2 5 180 60 32 6--8 90

1.6 4.8 175 55 33 6--8 85

1.2 4.6 170 50 36 6--8 75

0.9 4.3 160 45 40 6--8 65


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OPERATIONB-13 B-13

INVERTEC STT

DEC 97

WELDING SETTINGs FOR STT II -(Steel) Horizontal Fillet (See Table B.17 and B.18)

Table B.17 100% CO2 Gas Shield (Set for Steel Mode)

Table B.18 75% CO2 - 25% Ar Gas Shield (Set for Steel Mode)

(Stainless Steel) Horizontal Fillet(See Table B.19 and B.20)

Table B.19 90% He, 7.5% Ar, 2.5% CO2

Gas Shield (Set for Steel Mode)

Table B.20 98% Ar, 2% O2

Gas Shield (Set for Stainless Steel Mode)

45°

END VIEW

75°

FRONT VIEW

DIRECTIONOF

TRAVEL

75°

TOP VIEW

DIRECTIONOF

TRAVEL

Plate Thickness “ (mm) 20 ga 14 ga 10 ga(0.9) (2.0) (3.25)

Electrode size “ (mm) 0.035 0.045 0.045(0.9) (1.1) (1.1)

WFS “/min (m/min) 100 100 170(2.5) (2.5) (4.2)

Peak Current 220 260 280Background Current 30 40 65Tailout setting 3 7 5Average Amperage 60 105 120Travel Speed “/min 12 12 12

(m/min) (0.3) (0.3) (0.3)Gas Flow cfh (L/min) 25 (12)Electrical Stickout “ 1/4 - 3/8

(mm) (6.4 - 10)



WFS “/min (m/min) 100 100 120(2.5) (2.5) (3.0)



(mm) (6.4 - 10)

45°

END VIEW

75°

FRONT VIEW

DIRECTIONOF

TRAVEL

75°

TOP VIEW

DIRECTIONOF

TRAVEL



WFS “/min (m/min) 100 130 170(2.5) (3.3) (4.2)



(mm) (6.4 - 10)



WFS “/min (m/min) 100 130 170(2.5) (3.3) (4.2)



(mm) (6.4 - 10)

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OC TABLE OF CONTENTS

- ACCESSORIES -Accessories...........................................................................................................................Section C

Options/Accessories ...................................................................................................................C-2

LN-742 Wire Feeder Connection Instructions.............................................................................C-3

Section C-1 Section C-1

INVERTEC STT

OPTIONS/ACCESSORIES

SENSE LEADS (K940) - These leads are used toaccurately sense arc voltage. One set is required foreach STT power source. A 10 ft and 25 ft set are pro-vided as standard with the machine. Additional setsare available in 10 ft (K940-10), 25 ft (K940-25) and 50ft (K940-50) lengths.

REMOTE CONTROL (K942-1) - Allows remote adjust-ment of Peak and Background Current settings.

REMOTE RECEPTACLE (For optional remote inter-face or Robotic Control)

1. The 10 pin MS connector labeled “Remote Control”located on the front panel of the STT is used forremote control of the power source. Control for thePEAK (PB pot) and BACKGROUND (BG pot) cur-rent along with the trigger switch is providedthrough this connector.

2. See Figure C.1 below for details about the remotereceptacle (J38). Note that pins “J” and “B” areshorted together. This “short circuit” tells the STT

control board to accept PEAK and BACKGROUNDinputs on this connector rather than from the frontpanel controls. If this short is removed, the frontpanel controls will be active. By adding a switchbetween pins”J” and “B” a LOCAL/REMOTE con-trol 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 BACKGROUNDCURRENT is controlled with a similar signalapplied between pins “A” and “C” with + applied topin “C”. In this application pins “J” and “B” must beshorted as described in 2 above.

NOTE: These analog signals should be isolatedfrom the robot circuitry to prevent interference.

4. The trigger switch is connected between pins “D”and “F”. These connections are in parallel with thetrigger switch from the wire feeder.

5. The digital meters for PEAK AND BACKGROUNDcurrents will show preset values in both local andremote operation.

ACCESSORIESC-2 C-2

INVERTEC STTRet

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+ ARC

- ARC

1234

VOLTAGESENSECONNECT ION

J19

290

291

(+ )

( - )

JBCGADFHEI

TR IGGER

GND

BG

PB

10K

10K

OPT IONALREMOTEINTERFACE223

7

J38

33C

1234

J37

8

61

584

32

212C43A

212B32C

3

12

10912411

J38

REMOTEPROTECT ION BOARD

FIGURE C.1 – PORTION OF G2773 WIRING DIAGRAM(Refer to actual diagram pasted inside your machine.)

LN-742 WIRE FEEDER CONNEC-TION INSTRUCTIONSThe LN-742 is the recommended wire feeder for usewith the Invertec STT. Refer to the LN-742 OperatorManual for Wire Feed Operation. Refer to Figure C.2and follow the instructions below to connect the LN-742.


• Only qualified personnel shouldperform this installation.

• Turn the input power OFF at thedisconnect switch or fuse boxbefore connecting the wire feeder.

1. Turn the Invertec STT power off.

2. Connect the ARC SENSE LEAD MS connector tothe mating connector on STT front panel.

3. Connect the electrode lead (Twist-Mate) to (+) out-put 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 andthe work piece.

6. Connect the ARC SENSE LEAD (lead with alliga-tor clip) to work piece.

NOTE: For best welding performance, make thisconnection as close as possible to the welding arc.

7. Connect the wire feeder control cable between theLN-742 and the 14-pin Wire Feeder Receptacle onthe STT.

ACCESSORIESC-3 C-3

INVERTEC STTRet

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WARNING

CONNECT ELECTRODE AND "ELECT" ARC SENSE LEAD TOGETHER TO ELECTRODE TERMINAL OF WIRE FEEDERARC SENSE LEAD "WORK"

(SHOULD BE LOCATED AS CLOSE AS POSSIBLE TO THE WELDING ARC.

ARC SENSE LEAD "ELECT"

ELECTRODE LEAD

WIRE FEEDER CONTROL CABLE

CONTROL, ELECTRODE AND ARC SENSE CABLES SHOULD BE TAPED TOGETHER WIRE FEEDER

LN742 LN7 GMA LN9 GMA NA5R NA5

REMOTE RECEPTACLE

WORK LEAD

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.

FIGURE C.2 – INVERTEC STT/LN-742 WIRE FEEDER CONNECTION

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Section D-1 Section D-1

INVERTEC STT

TABLE OF CONTENTS-MAINTENANCE-

Maintenance .........................................................................................................................Section D

Input Filter Capacitor Discharge Procedure................................................................................D-2

Preventive Maintenance .............................................................................................................D-3

Major Component Locations.......................................................................................................D-4


• Failure to follow this capacitor dis-charge procedure can result inelectric shock.

INPUT FILTER CAPACITOR DISCHARGE PROCEDURE1. Turn off input power and disconnect input power

lines.

2. Remove the 5/16" hex head screws from side andtop of machine and remove wrap-around machinecover.

3. Be careful not to make contact with the capacitorterminals that are located in the center of theSwitch Boards.

4. Obtain a high resistance and high wattage resistor(25-1000 ohms and 25 watts minimum). Thisresistor is not supplied with machine. NEVER USEA SHORTING STRAP FOR THIS PROCEDURE.

5. Locate the two capacitor terminals (large hex headcap screws) shown in Figure D.1.

6. Use electrically insulated gloves and insulated pli-ers. Hold body of the resistor and connect resistorleads across the two capacitor terminals. Holdresistor in place for 10 seconds. DO NOT TOUCHCAPACITOR TERMINALS WITH YOUR BAREHANDS.

7. Repeat discharge procedure for capacitor on otherside of machine.

8. Check voltage across terminals of all capacitorswith a DC voltmeter. Polarity of capacitor terminalsis marked on PC board above terminals. Voltageshould be zero. If any voltage remains, repeat thiscapacitor discharge procedure.

MAINTENANCED-2 D-2

INVERTEC STTRet

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WARNING

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.

CAPACITORTERMINALS

POWER RESISTOR

INSULATEDPLIERS

PREVENTIVE MAINTENANCESee Figure D.2 for the location of components.

1. Perform the following preventive maintenance pro-cedures at least once every six months. It is goodpractice to keep a preventive maintenance record;a record tag attached to the machine works best.

2. Remove the machine wrap-around cover and per-form the input filter capacitor discharge procedure(detailed at the beginning of this chapter).

3. Clean the inside of the machine with a low pres-sure airstream. Be sure to clean the followingcomponents thoroughly.

• Power Switch, Driver, Protection, and Controlprinted circuit boards

• Power Switch

• Main Transformer

• Input Rectifier

• Heat Sink Fins

• Input Filter Capacitors

• Output Terminals

• Lower base compartment

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 goodcondition to assure high voltage parts are protect-ed and correct spacings are maintained.

6. Check electrical ground continuity. Using an ohm-meter, measure resistance between either outputstud and an unpainted surface of the machinecase. Meter reading should be 500,000 ohms ormore. If meter reading is less than 500,000 ohms,check for electrical components that are not prop-erly insulated from the case. Correct insulation ifneeded.

7. Check arc sensing leads for loose or faulty connections.

8. Replace machine cover and screws.

MAINTENANCED-3 D-3

INVERTEC STTRet

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MAINTENANCED-4 D-4

INVERTEC STT

12

4

17

5

69

8

7

10

16

15

1318

14

19

11

1

3

2

FIGURE D.2 – MAJOR COMPONENT LOCATIONS

1. BASE ASSEMBLY2. REAR NAMEPLATE3. RESISTORS4. FAN SHROUD ASSEMBLY5. PROTECTION PC BOARD6. DRIVER PC BOARD7. CONTROL BOX8. CONTROL PC BOARD9. BLEEDER RESISTORS

10. RECONNECT PANEL11. DARLINGTON MODULE12. WRAPAROUND ASSEMBLY13. CASE FRONT ASSEMBLY14. OUTPUT TERMINALS15. OUTPUT CHOKE ASSEMBLY16. TRANSFORMER ASSEMBLY17. OUTPUT RECTIFIER ASSEMBLY18. AUXILIARY TRANSFORMER19. FET HEAT SINK ASSEMBLY

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Section E-1 Section E-1

INVERTEC STT

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

TABLE OF CONTENTS-THEORY OF OPERATION SECTION-

POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE

CONTROL BOARDDARLINGTON

DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL

PULSE TRANSFORMER SIGNAL

GROUND GROUND

FET

FET

FET

FET

CAP

CAP

FIGURE E.1 – INVERTEC STT

GENERAL DESCRIPTIONThe Invertec STT is a 225 ampere, inverter based, arcwelding power supply specifically designed for theSurface Tension Transfer (STT) welding process. Itcannot be classified as either a constant current (CC)or a constant voltage (CV) machine. The STT pro-duces current of a desired waveform to reduce spatterand fumes. The STT process is optimized for short -circuit GMAW welding only.

INPUT VOLTAGEThe Invertec STT can be connected for a variety ofthree-phase voltages. The initial input power is appliedto the STT through a line switch located on the front ofthe machine. The AC input voltage is applied to theinput rectifier and the T1 auxiliary transformer. The T1transformer develops the appropriate AC voltages tooperate the cooling fan, the power and control boards.The T1 transformer also supplies primary voltage to theT4 auxiliary transformer as well as 42 VAC to an exter-nal wire feeder. The T4 transformer supplies power tothe Darlington drive board and the control board.

THEORY OF OPERATIONE-2 E-2

INVERTEC STTRet

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OC FIGURE E.2 – INPUT VOLTAGE

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE


DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL


GROUND GROUND

FET

FET

FET

FET

CAP

CAP

RECONNECT, PROTECTIONBOARD, RECTIFICATION ANDPRECHARGEThe reconnect panel allows the user to switch to low orhigh input voltage to match the input line voltage. TheAC input voltage is rectified and applied to the driverboard. The driver board contains precharging circuitryfor safe charging of the input filter capacitors. Once thecapacitors are precharged, the input relays are ener-gized, connecting full input power to the input filtercapacitors. The protection board monitors the capaci-tors for voltage balance and/or overvoltage and will de-energize the input relays and precharge circuitry ifeither occurs. The machine output will be disabled.


INVERTEC STTRet

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FIGURE E.3 – RECONNECT, PROTECTION BOARD, RECTIFICATION AND PRECHARGE

POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE


DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL


GROUND GROUND

FET

FET

FET

FET

CAP

CAP

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INVERTEC STT


FIGURE E.4 – SWITCH BOARDS

SWITCH BOARDSThere are two switch boards in the Invertec STT, eachcontaining an input filter capacitor. The capacitors areconnected in parallel when the machine is connectedfor "low" input voltage. The capacitors are connectedin series when the reconnect switch is configured for"high" input voltage. When the capacitors are fullycharged, they act as power supplies for the switchboards. The switch boards contain the Field EffectTransistors (FETs) which, when switched on, supplythe main transformer primary windings with DC currentflow. See Field Effect Transistor (FET) Operationdiscussion and diagrams. See Figure E.4.

POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE


DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL


GROUND GROUND

FET

FET

FET

FET

CAP

CAP

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INVERTEC STT

FIGURE E.5 – MAIN TRANSFORMER, OUTPUT RECTIFICATION AND CHOKE

MAIN TRANSFORMER, OUTPUTRECTIFICATION AND CHOKEEach switch board works as a switch pair. Each boardfeeds a separate, oppositely wound primary winding ofthe main transformer. The opposite directions of cur-rent flow through the main transformer primary and theoffset timing of the switch boards induce an AC squarewave output signal at the secondary of the main trans-former.

The DC current flow through each primary winding,which is monitored by the current transformer T3, isredirected or "clamped" back to each respective inputcapacitor when the FETs are turned off. This is need-ed due to the inductance of the transformer primarywindings. The cross coupling of the primaries alongwith the clamping action of the diode maintain capaci-tor balance when they are connected in the series (highvoltage) input configuration.

The firing of both switch board pairs occurs duringhalves of 50 microsecond intervals, creating a constant20 KHZ output.

The AC output from the main transformer secondary isrectified to a DC output and is applied through a stabi-lizer output choke, current sensor, Darlington moduleand remote protection board to the output terminals.


POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE


DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL


GROUND GROUND

FET

FET

FET

FET

CAP

CAP

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INVERTEC STT

FIGURE E.6 – CONTROL BOARD, DARLINGTON DRIVE AND MODULE

CONTROL BOARD, DARLINGTONDRIVE AND MODULEThe control board monitors the directives of the variouscontrols and compares these commands to the currentand voltage feedback information received from thecurrent sensor and voltage sensing receptacle. Thisdata is processed and the suitable PWM signal is sentto the power board. (See Pulse Width Modulationdiscussion).

The control board also determines when the Darlingtonmodule should be switched OFF to reduce weld spatterand fumes. The appropriate signal is sent to theDarlington drive board which then applies, or removes,the base drive signal to the Darlington module. Whenthe Darlington module is in the OFF state, the weldingcurrent must pass through the one ohm resistance.This reduces the current and, subsequently, spatterand fumes.


POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE


DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL


GROUND GROUND

FET

FET

FET

FET

CAP

CAP

TAILOUTCONTROL

(STT II ONLY)

DEC 97

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INVERTEC STT

FIGURE E.7 – POWER BOARD AND REMOTE PROTECTION BOARD

POWER BOARDThe power board creates a pulse transformer drive sig-nal, which is derived from the PWM signal receivedfrom the control board. See Pulse Width Modulationdiscussion. This drive signal is applied to the primarywinding of the pulse transformer, which is located onthe driver board. The pulse transformer secondarywindings generate the proper gate pulse for the switchboard FETs. See Field Effect Transistor (FET)Operation.

The power board supplies a 15VDC supply voltage forthe control board and also powers the input relays(CR1 and CR2).

REMOTE PROTECTION BOARDThe remote protection board provides noise suppres-sion and by-pass filtering to protect the internal circuit-ry of the STT machine.


POSITIVEOUTPUT

TERMINAL

TERMINALOUTPUT

NEGATIVE


DRIVERBOARD

POWER

BOARD

FAN TRANST1

TRANST4

SWITCH

BOARD

SWITCH

BOARD

RECONNECT

PROTECTION

INPUTRECTIFIER

LINESWITCH

CR1

CR2

BOARD

DRI

VER

BOARD

PRE - CHARGE

PRE - CHARGE

CHOKE

CURRENTSENSOR

DARLINGTONMODULE

1 OHM

PEAKCURRENT

METER

BACK-

METERPEAK

CURRENTCONTROL

BACK-

CONTROL

HOT START

CONTROL

WIRESIZE

SWITCH

WIRETYPE

SWITCH

VOLTAGESENSING

RECEPTACLE

REMOTECONTROL

RECEPTACLE

WIRE

RECEPTACLEFEEDER

REMOTE

PROTECTION

BOA

R

D

CURRENTTRANS

T3

MAIN TRANSFORMER

T2

115 VAC

115VAC

18VAC

24VAC

"A"LEAD

15VDC

THERMOSTAT

CURRENT FEEDBACK

42VAC

VOLTAGE FEEDBACK

10VAC AND 6VAC

DRIVE

SIGNAL

36VAC

GUN TRIGGER

LESS THAN 1VDC

PWM SIGNAL


GROUND GROUND

FET

FET

FET

FET

CAP

CAP

FIELD EFFECT TRANSISTOR (FET)OPERATIONAn FET is a type of transistor. FETs are semiconduc-tors 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 sourceand, therefore, no current flow. The drain terminal ofthe FET may be connected to a voltage supply; butsince there is no conduction, the circuit will not supplycurrent to downstream components connected to thesource. The circuit is turned off like a light switch in theOFF position.

Drawing B above shows the FET in an active mode.When the gate signal, a positive DC voltage relative tothe source, is applied to the gate terminal of the FET, itis capable of conducting current. A voltage supply con-nected to the drain terminal will allow the FET to con-duct and henceforth supply current to downstreamcomponents. Current will flow through the conductingFET to downstream components as long as the gatesignal is present. This is similar to turning on a lightswitch.

THEORY OF OPERATIONSE-8 E-8

INVERTEC STTRet

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SOURCE TERMINAL

GATE TERMINAL DRAIN

TERMINAL

DRAIN (N)

N CHANNELSUBSTRATE (P)

SOURCE (N)

(0 VOLTS)

GATE TERMINAL (+ 6 VOLTS)

DRAIN (N)

ELECTRONS

SOURCE (N)

B. ACTIVE

A. PASSIVE

FIGURE E-8 – FIELD EFFECT TRANSISTOR OPERATION

PULSE WIDTH MODULATIONThe term PULSE WIDTH MODULATION is used todescribe how much time is devoted to conduction inthe positive and negative portions of the cycle.Changing the pulse width is known as MODULATION.Pulse Width Modulation (PWM) is the varying of thepulse width over the allowed range of a cycle to affectthe output of the machine.

MINIMUM OUTPUT

By controlling the duration of the gate signal, the FETis turned on and off for different durations during acycle. The top drawing above shows the minimum out-put signal possible over a 50-microsecond time period.

The positive portion of the signal represents one FETgroup1 conducting for 1 microsecond. The negativeportion is the other FET group1. The dwell time (offtime) is 48 microseconds (both FET groups off). Sinceonly 2 microseconds of the 50-microsecond time peri-od is devoted to conducting, the output power is mini-mized.

MAXIMUM OUTPUT

By holding the gate signals on for 24 microsecondseach and allowing only 2 microseconds of dwell time(off time) during the 50-microsecond cycle, the outputis maximized. The darkened area under the top curvecan be compared to the area under the bottom curve.The more dark area under the curve, the more poweris present.


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MINIMUM OUTPUT

MAXIMUM OUTPUT

24

502

4850

secsec

secsec

sec

sec sec

24 sec

FIGURE E-9 – TYPICAL FET OUTPUTS

1 A FET group consists of the sets of FET modules grouped ontoone switch board.

PROTECTIVE CIRCUITSProtective circuits are designed into the Invertecmachine to sense trouble and shut down the machinebefore the trouble damages the internal machine com-ponents. Both overload and thermal protection circuitsare included.

OVERLOAD PROTECTION

The machine is electrically protected from producingabnormally high output currents due to short electrode“stick-out” or the nozzle shorting to the work. Shouldthe output current exceed 500 amps, an electronic pro-tection circuit will reduce the current to zero amps.Five seconds after the “short” is removed the InvertecSTT will produce normal output.

A protection circuit is included to monitor the voltageacross input filter capacitors. In the event that thecapacitor voltage is too high, the protection circuit willprevent output. The protection circuit may prevent out-put, if any of these circumstances occur:

1. Capacitor conditioning is required(Required if machine has been off for prolongedperiods of time.)

2. Line surges over 500 VAC

3. Internal Component damage

4. Improper connections

THERMAL PROTECTION

Thermostats protect the machine from excessive oper-ating temperatures. Excessive temperatures may becaused by a lack of cooling air or operating themachine beyond the duty cycle and output rating. Ifexcessive operating temperature should occur, thethermostat will prevent output voltage or current. Themeter will remain on during this time. (In addition, theyellow thermo LED will light.)

Thermostats are self-resetting once the machine coolssufficiently. If the thermostat shutdown was caused byexcessive output or duty cycle and the fan is operatingnormally, the Power Switch may be left on and thereset should occur within a 15-minute period. If the fanis not turning or the air intake louvers were obstructed,then the power must be switched off for 15 minutes inorder to reset. The fan problem or air obstruction mustalso be corrected.


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Section F-1 Section F-1

INVERTEC STT

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-13T1 Auxiliary Transformer Test........................................................................................F-13T4 Auxiliary Transformer Test........................................................................................F-18Input Rectifier Test.........................................................................................................F-24Capacitor Balance Test .................................................................................................F-27Switch Board Test..........................................................................................................F-30Snubber Resistors Test .................................................................................................F-34Power Board Test ..........................................................................................................F-37Protection Board Test ....................................................................................................F-41Trigger Circuit Test ........................................................................................................F-44

Replacement Procedures ....................................................................................................F-48Darlington Module Removal and Replacement.............................................................F-48Switch Board Replacement ...........................................................................................F-53Capacitor 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

TABLE OF CONTENTSTROUBLESHOOTING & REPAIR SECTION

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HOW TO USE TROUBLESHOOTING GUIDE

Service and repair should be performed by only Lincoln Electric Factory Trained Personnel.Unauthorized repairs performed on this equipment may result in danger to the technician and machineoperator and will invalidate your factory warranty. For your safety and to avoid Electrical Shock, pleaseobserve all safety notes and precautions detailed throughout this manual.

TROUBLESHOOTING & REPAIRF-2 F-2

INVERTEC STT

This Troubleshooting Guide is provided to helpyou locate and repair possible machine malfunc-tions. Simply follow the three-step procedure list-ed below.

Step 1. LOCATE PROBLEM (SYMPTOM). Lookunder the column labeled “PROBLEM (SYMP-TOMS). This column describes possible symp-toms that the machine may exhibit. Find the list-ing that best describes the symptom that themachine is exhibiting. Symptoms are groupedinto two main categories: Output Problems, andWelding Problems.

Step 2. PERFORM EXTERNAL TESTS. Thesecond column, labeled “POSSIBLE AREAS OFMISADJUSTMENT(S)”, lists the obvious externalpossibilities that may contribute to the machinesymptom. Perform these tests/checks in the orderlisted. In general, these tests can be conductedwithout removing the case wrap-around cover.

Step 3. PERFORM COMPONENT TESTS. Thelast column, labeled “Recommended Course ofAction” lists the most likely components that mayhave failed in your machine. It also specifies theappropriate test procedure to verify that the sub-ject component is either good or bad. If there area number of possible components, check thecomponents in the order listed to eliminate onepossibility at a time until you locate the cause ofyour problem.

All of the referenced test procedures referred to inthe Troubleshooting Guide are described in detailat the end of this chapter. Refer to theTroubleshooting and Repair Table of Contents tolocate each specific Test Procedure. All of thereferred to test points, components, terminalstrips, etc., can be found on the referenced elec-trical wiring diagrams and schematics. Refer tothe Electrical Diagrams Section Table ofContents to locate the appropriate diagram.

WARNING

If for any reason you do not understand the test procedures or are unable to perform the test/repairssafely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance beforeyou proceed. Call 216-383-2531 or 1-800-833-9353.

OSCILLOSCOPE WARNING

Do not use oscilloscopes and other test equipment which are powered by 115 VAC. This equipmentshould not be used with inverter-type machines, such as Invertec STT. There are high voltages pre-sent, 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 shockhazard as well as the possibility of damage to the equipment in question.

WARNING

CAUTION


Have an electrician install and servicethis equipment. Turn the machine OFFbefore working on equipment. Do nottouch electrically hot parts.

Sometimes machine failures appear to be due to PCboard failures. These problems can sometimes betraced to poor electrical connections. To avoid prob-lems when troubleshooting and replacing PC boards,please use the following procedure:

1. Determine to the best of your technical ability thatthe PC board is the most likely component causingthe failure symptom.

2. Check for loose connections at the PC board toassure that the PC board is properly connected.

3. If the problem persists, replace the suspect PCboard using standard practices to avoid static elec-trical damage and electrical shock. Read the warn-ing inside the static resistant bag and perform thefollowing procedures:

PC Board can be damaged bystatic electricity.

• Remove your body’s static chargebefore opening the static-shieldingbag. Wear an anti-static wriststrap. For safety, use a 1 Megohm resistive cord connected to agrounded part of the equipmentframe.

• If you don’t have a wrist strap,touch an unpainted, grounded,part of the equipment frame. Keeptouching the frame to prevent sta-tic build-up. Be sure not to touchany electrically live parts at thesame time.

• Tools which come in contact with the PC Board mustbe either conductive, anti-static or static-dissipative.

• Remove the PC Board from the static-shielding bagand place it directly into the equipment. Don’t set thePC Board on or near paper, plastic or cloth whichcould have a static charge. If the PC Board can’t beinstalled immediately, put it back in the static-shieldingbag.

• 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 ElectricCompany for credit, it must be in the static-shieldingbag. This will prevent further damage and allow prop-er failure analysis.

4. Test the machine to determine if the failure symp-tom has been corrected by the replacement PCboard.

NOTE: Allow the machine to heat up so that all electri-cal components can reach their operating tem-perature.

5. Remove the replacement PC board and substituteit with the original PC board to recreate the originalproblem.

a. If the original problem does not reappearby substituting the original board, then thePC board was not the problem. Continueto look for bad connections in the controlwiring harness, junction blocks, and termi-nal strips.

b. If the original problem is recreated by thesubstitution of the original board, then thePC board was the problem. Reinstall thereplacement PC board and test themachine.

6. Always indicate that this procedure was followedwhen warranty reports are to be submitted.

NOTE: Following this procedure and writing on thewarranty report, “INSTALLED ANDSWITCHED PC BOARDS TO VERIFY PROB-LEM,” will help avoid denial of legitimate PCboard warranty claims.


INVERTEC STTRet

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PC BOARD TROUBLESHOOTING PROCEDURES

WARNING

ATTENTIONStatic-SensitiveDevicesHandle only atStatic-SafeWorkstations

ReusableContainerDo Not Destroy

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INVERTEC STT

Observe Safety Guidelines TROUBLESHOOTING GUIDEdetailed in the beginning of this manual.

CAUTIONIf for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call216-383-2531 or 1-800-833-9353.

PROBLEMS(SYMPTOMS)

POSSIBLE AREAS OFMISADJUSTMENT(S)

RECOMMENDEDCOURSE OF ACTION

OUTPUT PROBLEMS

Major physical or electrical damageis evident.

1. Contact your local LincolnAuthorized Field ServiceFacility.

1. Contact the Lincoln ElectricService Department, 216-383-2531 or 1-800-833-9353 (WELD).

Machine has no open circuit volt-age. Wire feeds OK.

1. Check the control cablebetween the feeder and theSTT unit. Make sure the #2 and#4 leads are intact.

2. Put a jumper wire between Pins"C" and "D" on the 14 pinamphenol. If normal open cir-cuit voltage (85VDC) isrestored, the problem is in thefeeder control cable or the wirefeeder.

3. Make sure the reconnect switchS7 is in the correct position forthe three-phase input voltagebeing applied.

Do not switch reconnect switchwith input power applied tomachine.

1. Perform the T1 AuxiliaryTransformer Test.


3. Perform the Power Board Test.

4. Perform the Trigger CircuitTest.

5. Perform Capacitor BalanceTest.

6. Perform the Protection BoardTest.

7. Perform the Switch BoardTest.

8. Check for loose or broken con-nections on the heavy currentcarrying conductors (i.e., maintransformer, choke, outputdiodes, Darlington module andoutput terminals).

9. The control PC board may befaulty. Replace.

CAUTION

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INVERTEC STT

TROUBLESHOOTING GUIDE Observe Safety Guidelinesdetailed in the beginning of this manual.

CAUTIONIf for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.

PROBLEMS(SYMPTOMS)



OUTPUT PROBLEMSMachine has no welding output (noopen circuit voltage), and the wirefeeder does not feed wire when thegun trigger is pulled.

1. The 42VAC circuit breaker CB1may be tripped. Reset if neces-sary.

2. Check the 4 amp slow blow fuselocated on the reconnect panel.Replace if faulty.

3. Put a jumper between pins "A"and "C" on the 5 pin amphenollocated on the LN-742 wirefeeder. If wire feeds, check thegun trigger. Repair or replace ifnecessary.

4. Check for the presence of42VAC at pins "K" and "I" on the14 pin amphenol. If the 42VACis present and the feeder doesnot work, the problem is in thefeeder control cable or the wirefeeder.

1. If 42VAC is NOT present at pins"K" and "I" on the 14 pin amphe-nol, perform the T1 AuxiliaryTransformer Test.

2. Check leads #43 and #212C forloose or faulty connectionsbetween the T1 auxiliary trans-former and the remote protec-tion board. See the WiringDiagram. Also check the conti-nuity through the remote protec-tion board to the 14 pin amphe-nol. See the Remote ProtectionBoard Schematic.

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INVERTEC STT



PROBLEMS(SYMPTOMS)



OUTPUT PROBLEMS

Machine is dead - no output - nofan - no display.

1. The power switch must be in the"ON" position.

2. Check the input voltage. Makesure all three phases areapplied to the machine.

3. With input power removed,check that the input voltage set-up switch and jumper "A" (thereconnect auxiliary jumper) arein the proper position for theinput voltage being used.

4. With input power removed,check the continuity of the 4amp slow blow fuse located onthe reconnect panel.

1. The input power switch (S1)may be faulty. Check orreplace.


No output or reduced output thefirst time power is applied to themachine.

1. Check input voltages, fuses andinput voltage reconnect proce-dures. See the Installationsection.

2. If high input voltage (380VAC orhigher) is applied, the capaci-tors may need conditioning. Letthe "unloaded" machine idle for30 minutes.

1. Contact the Lincoln ElectricService Department. 1-216-383-2581 or 1-800-833-WELD(9353).

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INVERTEC STT



PROBLEMS(SYMPTOMS)



OUTPUT PROBLEMS

No output. Main fuses are open,indicating excessive current draw.

1. With the input power removed,inspect input leads for possibleshorts or grounds or miscon-nections.

2. Install new fuses and reapplypower. If fuses open again,contact your local LincolnAuthorized Field ServiceFacility.

1. Check the input power switch(S1) and the reconnect switchfor "shorted" or "grounded"wires or connections.

2. Perform the Input RectifierTest.

3. Perform the Switch BoardTest.

Machine loses output when guntrigger is pulled or arc is struck.Machine output returns after a fewseconds and trigger is pulled again.The thermal indicator light is lit.

1. The overcurrent sensor is acti-vated, indicating that too muchoutput current is being drawnfrom the machine. Reducewelding current demands orremove the "fault" in weldingcables.

2. Make sure that the gun tip is not"shorted" to the work surfaceand that the proper welding pro-cedures are being used.

1. The current sensor may befaulty.

2. The control PC board may befaulty.

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F-8 F-8

INVERTEC STT

TROUBLESHOOTING & REPAIR



PROBLEMS(SYMPTOMS)



OUTPUT PROBLEMS

Machine loses output while weld-ing. The thermal indicator light islit. Normal welding output returnsafter about 10 minutes.

1. Check to make sure the fan isrunning and operating correctly.

2. Welding application mayexceed recommended dutycycle.

3. Dirt and dust may have cloggedthe cooling channels. Blow outthe unit with clean, dry com-pressed air.

4. Air intake and exhaust louversmay be blocked due to inade-quate clearance around themachine.

1. The Darlington heat sink ther-mostat or fan thermostat maybe defective. Check or replace.

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INVERTEC STT



PROBLEMS(SYMPTOMS)



WELDING PROBLEMS

Porosity in the weld. 1. Make sure the gas type andflow rate is correct for the pro-cedure being used. Shield thework from excessive outside aircurrents.

2. Check the gun and nozzle forleaks or obstructions.

3. Make certain the machine andwire feed settings are correct forthe process.

1. Contact the Lincoln ElectricService Department. 1-216-383-2581 or 1-800-833-WELD(9353).

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INVERTEC STT



PROBLEMS(SYMPTOMS)



WELDING PROBLEMS

Weld bead appears "cold." 1. One or more of the machinesettings may be wrong. Checkthe Background, Peak Current,Tailout (STT II Only), and WireSpeed controls for proper set-tings. Adjust for optimum weld-ing performance.

2. Make sure the Wire Type andWire Size switches are in thecorrect position for the electrodewire being used.

1. Check for the correct open cir-cuit voltage (approximately85VDC). If the correct open cir-cuit voltage IS present, theBackground control (R12) or thePeak Current (R11) and associ-ated wiring may be faulty. Seethe Wiring Diagram. The controlPC board may be faulty. Alsocheck for loose or faulty con-nections on the heavy currentcarrying conductors (i.e., maintransformer, choke, outputdiodes, Darlington module andoutput terminals).

2. If the correct open circuit volt-age is NOT present, perform theSwitch Board Test.

3. The output diodes may befaulty. Check or replace if nec-essary.

4. The driver PC board and or con-trol PC board may be faulty.

5. The Darlington module may befaulty. Check or replace.

DEC 97

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INVERTEC STT



PROBLEMS(SYMPTOMS)



WELDING PROBLEMS

Molten weld puddle appears exces-sively "violent."

1. The Wire Type switch may be inthe wrong position for the elec-trode wire being used.

2. The Peak Current or Back-ground Setting may be too high.Adjust for optimum welding per-formance.

3. The Tailout may not be set cor-rectly for the process. (STT IIOnly)


2. The Darlington driver PC boardmay be faulty.


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INVERTEC STT



PROBLEMS(SYMPTOMS)



WELDING PROBLEMS

Excessive weld spatter. Arcsounds and looks like a standardMIG process.

1. Check the Arc Sense leads forloose or faulty connections.

2. Make sure the Arc Sense"WORK" lead is as close aspossible to the welding arc.

3. Make sure the machine andwire feed settings are correct forthe process and wire beingused.


2. The Darlington driver PC boardmay be faulty.


Poor welding, weld settings drift, oroutput power is low.

1. Make sure the machine settingsare correct for the weldingprocess being used.

2. Check the welding cables forloose or faulty connections.

3. Make sure the reconnect switchS7 is in the correct position forthe three-phase input voltagebeing applied.

Do not switch reconnect switch withinput power applied to machine.

1. The current sensor may befaulty. Check associated leadsfor loose or faulty connections.


CAUTION

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INVERTEC STT

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 technicianor machine operator and will invalidate your factory warranty. For your safety and to avoidelectrical shock, please observe all safety notes and precautions detailed throughout thismanual.

If for any reason you do not understand the test procedures or are unable to perform thetest/repairs safely, contact the Lincoln Electric Service Department for electrical trou-bleshooting 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 diagrams5/16" Nut driver3/8" WrenchSlot head screw driver

Note: Component locations and disassembly procedures mayvary slightly on STT II models

DEC 97

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INVERTEC STT

T1 AUXILIARYTRANSFORMER

PLUGJ31

PLUGJ30

FIGURE F.1 – T1 AUXILIARY TRANSFORMER AND J30/J31 LOCATION

T1 AUXILIARY TRANSFORMER TEST (continued)

TEST PROCEDURE

1. Turn off Invertec STT and disconnect mainAC input power to the machine.

2. Using the 5/16" nut driver, remove the casewraparound cover.

3. Perform the Input Filter CapacitorDischarge Procedure. See theMaintenance section.


• Before continuing withthe test procedure, per-form the capacitor dis-charge procedure toavoid electric shock.

4. Locate the T1 auxiliary transformer and sec-ondary lead molex plugs (J30 and J31) onthe left side, just in front of the main trans-former assembly. Check for broken or loosewires. See Figure F.1.

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INVERTEC STT

5. Locate the primary lead molex plug (J21)just behind the reconnect panel assembly onthe right side of the machine. Check for bro-ken or loose wires. See Figure F.2.

6. Disconnect plugs J30 and J31 from thewiring harness.


• With input power ON,there are high voltagesinside the machine. Donot reach into themachine or touch anyinternal part.

7. Apply the correct input power to the machineand test for the correct secondary voltagesat plugs J30 and J31. (Make sure the recon-nect panel is configured properly for theinput voltage being applied.) See Table F.1.


RECONNECTPANEL

PLUG J21LOCATION BEHIND

RECONNECT PANEL

FIGURE F.2 – PRIMARY LEAD PLUG J21 LOCATION

WARNING

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INVERTEC STT

8. If the correct secondary voltages are present(according to Table F.1), the T1 transformeris functioning properly.

9. If the secondary voltages are missing orincorrect, the primary voltages must bechecked.

10. Remove input power to the STT machine.

11. Perform the Input Filter CapacitorDischarge Procedure.

12. Reconnect Plugs J30 & J31.



13. Gain access to the primary lead plug J21 byremoving the reconnect panel assemblyfrom the upper support panel using the 3/8"wrench and slot head screwdriver. This willallow the reconnect panel assembly to bemoved out of the way. Be careful NOT tostress the leads connected to the reconnectpanel. See Figure F.2.

14. Before applying input power make certainthe reconnect panel assembly is insulatedand supported for safe operation.


TABLE F.1 – T1 AUXILIARY TRANSFORMER VOLTAGES

TEST POINTS

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 6(LEADS H1 TO H5) (H6)

NORMAL VOLTAGE

115VAC

18VAC

24VAC

42VAC

200/208VAC

220/230VAC

380/415VAC

440/460VAC

WARNING

NOTE: If the main AC input supply voltage varies, the auxiliary transformer voltages will vary bythe same percentages.

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INVERTEC STT



15. Apply the correct input power and carefullytest for the correct primary voltages at plugJ21. See Table F.1.

16. If the correct AC input voltages are appliedto the primary windings and any or all of thesecondary voltages are missing or not cor-rect, the T1 auxiliary transformer may befaulty.

17. After all tests are complete, reconnect plugsJ30 and J31.

18. Install the case wraparound cover.


WARNING

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T4 AUXILIARY TRANSFORMER TEST

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

If for any reason you do not understand the test procedures or are unable to perform thetest/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshoot-ing 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.

MATERIALS NEEDED

Volt/Ohmmeter (Multimeter)Invertec STT Wiring DiagramsIsolated 115VAC supply5/16" Nut driver7/16" Wrench


INVERTEC STT

WARNING


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INVERTEC STT


FIGURE F.3 – OUTPUT CHOKE/DARLINGTON MODULE SPLICED CONNECTION

LOWERTRAYAREA

OUTPUT CHOKE/DARLINGTON MODULESPLICED CONNECTION

TEST PROCEDURE

1. Turn off the Invertec STT and disconnectmain AC input power to the machine.





4. Locate the lead connection splice from theoutput choke to the Darlington module.Remove the insulating sleeve. Cut anynecessary cable ties. Using the 7/16"wrench, disconnect the lead splice. Threadthe lower lead down into the lower trayassembly area. See Figure F.3.

WARNING

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INVERTEC STT


5. Disconnect the current sensing Plug J1 fromthe control PC board. Carefully remove PlugJ1 and associated leads from control boardcompartment. See Figure F.4.

FIGURE F.4 – PLUG J1 LOCATION

LOWERTRAYAREA


J1 CURRENTSENSING PLUG

6. Locate and disconnect plug J22 from thewiring harness. See Figure F.5.


PLUG J22

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INVERTEC STT


7. Carefully lift and tilt the Invertec STTmachine onto its right side. See Figure F.6.

8. Using the 7/16" wrench, remove the fivebolts holding the lower tray assembly to thecase bottom.

9. Carefully slide out and support the lower trayassembly for testing purposes.

10. Locate and remove plug J13 from theDarlington drive board. See Figure F.7.

FIGURE F.6 – STT ON ITS RIGHT SIDE

MOUNTINGBOLTS (5)


PLUG J13


DARLINGTONDRIVE BOARD


PLUG J13

DARLINGTONDRIVE BOARD

STT STT II

DEC 97

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INVERTEC STT


11. Locate and remove leads #32A, #32B and#33A, #33B from the T4 transformer tabs.See Figure F.8.



12. Carefully apply the 115VAC isolated supplyto the T4 transformer at the #32 and #33tabs.

FIGURE F.8 – T4 TRANSFORMER LEAD CONNECTIONS

LEADS32A, 32B, 33A, 33B


STT STT II


LEADS32A, 32B, 33A, 33B

WARNING

DEC 97

13. Check the secondary AC voltages accord-ing to Table F.2.

14. With the correct 115VAC applied to the pri-mary winding (#32 to #33), if any or all ofthe 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 thefollowing:

Leads #32A, #32B, #33A, #33B to theT4 transformer tabs

Plug J13 to the Darlington drive board

Plug J22 to the wiring harness

Reinstall lower tray assembly using7/16” wrench and 5 bolts

Plug J1 to the control PC board

Reconnect lead splice from the outputchoke to the Darlington module.Reposition insulating sleeve.



INVERTEC STTRet

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TABLE F.2 – T4 AUXILIARY TRANSFORMER VOLTAGES

TEST POINTS

PLUG J13 PINS 5 TO 6

PLUG J13 PINS 2 TO 3





NORMAL VOLTAGES

6VAC

10VAC

18VAC

18VAC

18VAC

18VAC


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OC INPUT RECTIFIER TEST



TEST DESCRIPTION

This test will help determine if the input rectifier and associated components are functioningproperly.

MATERIALS NEEDED

5/16" Nut driverAnalog Voltmeter/ohmmeter (Multimeter)Inverter STT Wiring Diagrams


INVERTEC STT

WARNING


DEC 97

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INVERTEC STT

INPUT RECTIFIER TEST (continued)

FIGURE F.9 - INPUT RECTIFIER LOCATION

INPUTRECTIFIERCA

9 12

B

TEST PROCEDURE



3. Perform the Input Filter CapacitorDischarge procedure. See theMaintenance section.



4. Locate the input rectifier. See Figure F.9.

5. Locate the leads needed to perform thetests. See Figure F.9.

6. Use an ANALOG ohmmeter to perform thetests shown in Table F.3.

WARNING

6. Replace the input rectifier when any of thetests are NOT OK.

NOTE: When installing a new input rectifier,torque the mounting nuts (in a cross-tighteningpattern) to 6 inch-pounds (.7 Nm). Torque ter-minals to 26 inch-pounds (3 Nm). PROCEEDTO STEP 7 TO CHECK RELATED COMPO-NENTS.

7. Inspect main power switch S1 and replaceif faulty. Go to step 8.

8. Test capacitors C1 and C2 and replace bothcapacitors if either is faulty.

NOTE: Faulty capacitors could be the reasonfor input rectifier failure.

Visually inspect the capacitors for leakage,damage, etc., and use appropriate test equip-ment to determine component integrity.

9. Perform the Switch Board Test.

10. After all tests are completed, install thecase wraparound cover.


INVERTEC STTRet

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OC INPUT RECTIFIER TEST (continued)

TABLE F.3 – INPUT RECTIFIER TEST

TEST POINTS

+PROBE -PROBE ACCEPTABLE METER READING

9 A Greater than 100K ohms9 B Greater than 100K ohms9 C Greater than 100K ohms

A 9 Less than 100 ohmsB 9 Less than 100 ohmsC 9 Less than 100 ohms

12 A Less than 100 ohms12 B Less than 100 ohms12 C Less than 100 ohms

A 12 Greater than 100K ohmsB 12 Greater than 100K ohmsC 12 Greater than 100K ohms

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OC CAPACITOR BALANCE TEST



TEST DESCRIPTION

This test will help determine if the capacitors, bleeder resistors and switch boards are func-tioning properly.

MATERIALS NEEDED

5/16" Nut driverAnalog Volt/ohmmeter (Multimeter)


INVERTEC STT

WARNING


DEC 97

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INVERTEC STT

CAPACITOR BALANCE TEST (continued)

FIGURE F.10 – SWITCH BOARD TEST POINTS

L8441 SWITCH

9 12

TEST PROCEDURE


2. Using the 5/16" nut driver, remove thecase wraparound cover.



3. Carefully apply the correct input power tothe machine.

NOTE: This test should only be conductedwhen the machine reconnect switch andjumper are set for high voltage (above380VAC) and the proper line voltage is applied.

4. Test for VDC across terminals #9 and #12 ofone switch board and repeat the test for theother switch board. See Table F.4 in thisprocedure for expected voltage readings.See Figure F.10.

A. If less than 25VDC difference is mea-sured between each switch board, thecapacitive balance is OK. This indi-cates that capacitors C1, C2, and resis-tors R1 and R9 are functioning proper-ly. Proceed to Step #5.

B. If more than 25VDC difference is mea-sured between each switch board, testeach of the following components:Capacitors C1, C2 and resistors R1and R9. See the Invertec STT WiringDiagram.

WARNING

5. Adjust the Peak and Background controls tothe minimum settings (controls on casefront).

6. Jumper together pins "C" and "D" on the 14pin amphenol. This will energize the outputterminals.

7. Test for VDC across terminals #9 and #12 ofone switch board and repeat the test for theother switch board. See Table F.4 in thisprocedure for expected voltage readings.See Figure F.10.

A. If less than 15VDC difference is mea-sured between each switch board, thetest is OK.

B. If more than 15VDC difference is mea-sured between each switch board, theswitch board(s) and or power PC boardmay be faulty. Perform the SwitchBoard Test. Perform the Power BoardTest.

8. After all tests are completed, remove thejumper between pins C and D on the 14-pinamphenol.



INVERTEC STTRet

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CAPACITOR BALANCE TEST (continued)

TABLE F.4 – EXPECTED VOLTAGE READINGS

If VAC Input is:

460 VAC440 VAC415 VAC380 VAC

VDC at terminals #9 (+) and #12 (-)should be approximately:

325VDC311VDC293VDC269VDC

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OC SWITCH BOARD TEST



TEST DESCRIPTION

The Switch Board Test determines if the switch boards are operating properly. This resistancetest is preferable to a voltage test with the machine energized because these boards can bedamaged 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


INVERTEC STT

WARNING


DEC 97

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INVERTEC STT

SWITCH BOARD TEST (continued)

FIGURE F.11 - SWITCH BOARD RESISTANCE TEST

TEST PROCEDURE

NOTE: There are two switch boards. One islocated on each side of the machine.

NOTE: The switch boards are designed toreceive gate (turn-on) signals from the driverboard (pulse transformer secondaries). Theinternal board circuitry processes the signals andoutputs them to the FETs. The switch board cir-cuitry contains snubber circuitry to protect theFETs. This protection is supplemented by off-board resistors. The switch board design accom-modates the connection point(s) for the capaci-tor(s), main transformer primary windings, inputrectifier, and reconnect switches.





• Before continuing with thetest procedure, performthe capacitor dischargeprocedure to avoid electricshock.

4. Disconnect all wiring harness leads(401/403, 1/8, 9, 12, 4/5, 402/404) from theswitch board.

5. Fold the leads up so they do not interfere withthe exposed terminals. See Figure F.11.

6. Using an analog ohmmeter, perform the resis-tance tests detailed in Table F.5 and shown inFigure F.11. If any test fails, replace bothswitch boards. See the Switch BoardRemoval and Replacement procedure.

7. If the switch boards appear to be burned oroverheated, or if the machine was supplied bya 380 VAC or higher voltage supply when thefailure occurred, replace the capacitors andthe switch boards.

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INVERTEC STT


Apply Positive Apply NegativeTest Probe to Test Probe toTerminal Terminal Test Result Conclusion Repair Action Next Procedure Notes

1/8 12 Greater than OK None Continue1K ohm

Less than Shorted Replace both Snubber Test100 ohms switch boards

12 1/8 Less than OK None Continue100 ohms

Greater than Open Replace both Snubber Test1K ohm switch boards

9 4/5 Greater than OK None Continue1K ohm


4/5 9 Less than OK None Continue100 ohms










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).

TABLE F.5 – SWITCH BOARD RESISTANCE TEST

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INVERTEC STT

Apply Positive Apply NegativeTest Probe to Test Probe toTerminal Terminal Test Result Conclusion Repair Action Next Procedure Notes










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).

TABLE F.5 – SWITCH BOARD RESISTANCE TEST (continued)

8. Reconnect all wiring harness leads (401/403,1/8, 9, 12, 4/5, 402/404) to the switch board.


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SNUBBER RESISTORS TEST



DESCRIPTION

This test will determine if the snubber resistors (R4, R5, R6, R7) are functioning properly.

MATERIALS NEEDED

Analog Volt/ohmmeter (Multimeter)STT Wiring Diagrams5/16” Nut driver


INVERTEC STT

WARNING


DEC 97


INVERTEC STTRet

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SNUBBER RESISTORS TEST (continued)

FIGURE F.12 - REMOVING LEADS

TEST PROCEDURE






4. Locate and gain access to the switch board.

5. Remove leads from terminals 401/403,402/404 on the switch board. See FigureF.12.

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INVERTEC STT

SNUBBER RESISTORS TEST (continued)

FIGURE F.13 - SWITCH BOARD TEST POINTS

6. Test for 25 ohms resistance from lead termi-nal 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, resistorR4 is faulty and must be replaced.

c. If 20 ohms or less is measured, resistorR4 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 theswitch board.


L8441 SWITCH

401/403 129 402/404

Check Test Result Conclusion Next Test Step Repair Action

Lead 401 to 25 ohms OK ContinueTerminal 12 >30 ohms R4 open Replace R4

<20 ohms R4 faulty


<20 ohms R5 faulty


<20 ohms R6 faulty


<20 ohms R7 faulty

> = GREATER THAN < = LESS THAN

TABLE F.6 – SNUBBER RESISTORS TEST

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OC POWER BOARD TEST



TEST DESCRIPTION

This test will help determine if the power PC board is receiving the correct AC voltages andalso if the correct DC voltages are being generated on the power PC board.

MATERIALS NEEDED

5/16" Nut driverVolt/ohmmeter (Multimeter)Wiring diagram


INVERTEC STT

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DEC 97

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INVERTEC STT

POWER BOARD TEST (continued)

FIGURE F.14 – REMOVING THE FRONT PANEL ASSEMBLY

POWERPC BOARD(Located on Back of Case Front)

QUICK CHECK PROCEDURE



3. Locate relays CR1 and CR2 just to the front ofthe fan motor.


• With input power ON,there are high voltagesinside the machine. Donot reach into the machineor touch any internal part.

4. Apply the correct input power and turn ON theInvertec STT machine.

5. After about a 5 second delay the relaysshould activate. This can be determined byan audible click which can be heard when therelays are activated. If the relays are beingactivated, the power PC board is most likely

OK. If the relays are NOT being activated, thepower PC board could be faulty. Continuewith the voltage tests.

VOLTAGE TEST PROCEDURE

1. Remove input power to the Invertec STT.

2. Perform the Input Filter Capacitor DischargeProcedure. See the Maintenance section.



3. Using the 5/16" nut driver, loosen the frontcontrol panel by removing the four sheetmetal screws from the top and bottom of thefront panel. Carefully move the front panelassembly to the right to gain access to thepower PC board. See Figure F.14.

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INVERTEC STT

POWER BOARD TEST (continued)

FIGURE F.15 – POWER PC BOARD TEST POINTS

POWER BOARD

J6J7 J14

L8033

501

504

302

275

211A 305

311313

309 310 301212A

4. Secure and insulate the front panel assemblyfor POWER ON testing.



5. Apply the correct input power and turn ON themachine.

6. Carefully test for 18VAC input from the T1Auxiliary Transformer between plug J7 pin 5(lead#501) and plug J7 pin 6 (lead #504) atthe power PC board. See Figure F. 15.

NOTE: If the 18VAC is NOT present, performthe T1 Auxiliary Transformer Test. Also checkassociated wiring. See the Wiring Diagram.

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INVERTEC STT

POWER BOARD TEST (continued)FIGURE F.16 – SIMPLIFIED TRIGGER CIRCUIT

FROM PROTECTIONBOARD OVERVOLTAGE

PWM OUTPUTS

TO POWERBOARD

7J6

2J6

11J4

3J4

13J36

5J36

8J33

6J34

9J4

12J4

3J31 6J22 6J4

POWER BOARD CONTROL BOARD

REMOTE PROTECTION

BOARD

14 AMPHENOL

#301

#305

#503A

#224 #210

#212

#223

#212C

#413

#405

C

D


24VAC

PWM

5J4TOPOWERBOARD

2J31

3.5 ohms

3.5 ohms

STT II Only

#379

7. Carefully test for 15VDC output from thepower PC board at plug J6 pin1 (lead #275) (-) and plug J6 pin 6 (lead #302)(+). SeeFigure F.15.

NOTE: If the 18VAC is present but the 15VDC isNOT, the power PC board may be faulty.

8. Carefully test for 24VAC input from the T1Auxiliary 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 theT1 Auxiliary Transformer Test. Also check theassociated wiring. See the Wiring Diagram. Thecontrol PC board or thermostats may be faulty.See Figure F.16, the Simplified Trigger Circuitdiagram.

9. Carefully test for 24VDC at the power PCboard at plug J7 pin 2 (lead #309)(+) to plugJ6 pin1 (lead #275)(-). See Figure F.15.

NOTE: If the 24VAC is present but the 24VDC isNOT, the power PC board may be faulty.

10. Carefully test for approximately 24VDC atplug 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, performthe Protection Board Test.

NOTE: If approximately 1VDC IS present andthe 24VDC is NOT present at leads #309 to#310, the power PC board may be faulty.

11. After all tests are completed, install the frontpanel assembly.


DEC 97

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OC PROTECTION BOARD TEST



TEST DESCRIPTION

This test will help determine if the protection PC board is functioning properly.

MATERIALS NEEDED

5/16" Nut driverVolt/ohmmeter (Multimeter)Wiring Diagrams


INVERTEC STT

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DEC 97

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INVERTEC STT

PROTECTION BOARD TEST (continued)

FIGURE F.17 – PROTECTION PC BOARD TEST POINTS

PROTECTIONL7915-[ ]

313

311

J8 J15

315

317

314

316

TEST PROCEDURE 1. Turn off the Invertec STT and disconnect

main AC input power to the machine.





4. Locate the protection PC board just in frontof the input rectifier and relay mountings.



5. Apply the correct input power and turn themachine ON.

6. Test for approximately 1VDC from plug J8pin 1 (lead #311)(+) to plug J8 pin 3 (lead#313) (-). See Figure F.17.

A. If approximately 1VDC is present, theprotection PC board is functioning prop-erly.

B. If more than 5 VDC is measured, per-form the Capacitor Balance Test.

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INVERTEC STT

FIGURE F.18 - LEADS #309, #309A AT CR1, CR2 RELAYS

CR2 CR1

309A 309

PROTECTION BOARD TEST (continued)

7. If the Capacitor Balance Test is OK andmore than 5VDC is present at leads #311 to#313 (Step 6), the protection PC board maybe faulty.

NOTE: The above voltage checks pertain onlyto the over voltage signal from the protectionPC board to the power PC board. The capaci-tor precharge circuits are also incorporatedwithin the protection PC board. If the problemhas not been identified, carefully proceed withthe following steps.

8. Remove input power to the Invertec STTmachine.




10. Locate and remove leads #309 and #309Afrom CR1 and CR2 relays. See FigureF.18.



11. Apply correct input power and turn ON themachine.

12. Check for approximately 12VDC from plugJ15 pin 1 (lead #314)(+) to plug J15 pin 4(lead#315) (-). See Figure F.17.

13. Check for approximately 12VDC from plugJ15 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 12or 13 (approximately 1VDC), perform theCapacitor Balance Test.

15. If the Capacitor Balance Test is OK, theprotection PC board may be faulty.

16. Be certain to replace leads #309 and #309Aonto the CR1 and CR2 relays.

17. After all tests are completed, install thecase wraparound cover.

WARNING

WARNING

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TRIGGER CIRCUIT TEST



TEST DESCRIPTION

This test includes a few quick checks to troubleshoot the machine trigger circuit. TheSimplified Trigger Circuit Diagram will enable the technician to view the trigger circuit in anabbreviated, uncomplicated format.

MATERIALS NEEDED

5/16" Nut driverVolt/ohmmeter (Multimeter)Wiring Diagram and board Schematics


INVERTEC STT

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DEC 97

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INVERTEC STT

TRIGGER CIRCUIT TEST (continued)


PLUGJ31

TEST PROCEDURE

1. Turn off the Invertec STT and disconnect mainAC input power to the machine.


3. Perform the Input Filter CapacitorDischarge Procedure. See the Maintenancesection.



4. Locate plug J31 at the left side of themachine. See Figure F.19.

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INVERTEC STT

TRIGGER CIRCUIT TEST (continued)FIGURE F.20 – 14 PIN AMPHENOL AND PLUG J31 PIN ASSIGNMENTS

KB

I

HN

LC

DM

G

E

F

JA

5. Using the ohmmeter check for approximately3.5 ohms resistance from pin "D" of the 14 pinamphenol to plug J31 pin 2 (lead #212). SeeFigure F.20, and Figure F.22, SimplifiedTrigger Circuit Diagram.

FIGURE F.21 – CONTROL PC BOARD MOLEX PLUG

J4

223

210

G27

82-[

]S

TT

CO

NT

RO

L

J1J3J2J28J27J17J5

6. Using the ohmmeter, check for approximately3.5 ohms resistance from pin "C" of the 14 pinamphenol (see Figure F.20) to plug J4 pin 9

(lead#223) at the control PC board. SeeFigure F.21 and Figure F.22, SimplifiedTrigger Circuit Diagram.

PLUG J31212

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INVERTEC STT

TRIGGER CIRCUIT TEST (continued)FIGURE F.22 – SIMPLIFIED TRIGGER CIRCUIT DIAGRAM

FROM PROTECTIONBOARD OVERVOLTAGE

PWM OUTPUTS

TO POWERBOARD

7J6

2J6

11J4

3J4

13J36

5J36

8J33

6J34

9J4

12J4

3J31 6J22 6J4

POWER BOARD CONTROL BOARD

REMOTE PROTECTION

BOARD

14 AMPHENOL

#301

#305

#503A

#224 #210

#212

#223

#212C

#413

#405

C

D


24VAC

PWM

5J4TOPOWERBOARD

2J31

3.5 ohms

3.5 ohms

STT II Only

#379

7. Using the ohmmeter check for continuity (zeroohms) from plug J31 pin 3 (lead#503A) to plugJ4 pin 6 (lead#210). See Figure F.22,Simplified Trigger Circuit Diagram.

8. If any of the resistance checks are abnormal-ly high in steps 5, 6 or 7, check for broken orloose wires, connections or "open" ther-mostats. Also check the small inductors onthe Remote Protection Board. See FigureF.22, Simplified Trigger Circuit Diagram.


• With input power ON, thereare high voltages insidethe machine. Do not reachinto the machine or touchany internal part.

9. Apply the correct input power to the machineand turn ON.

10. Locate plug J6 on the power PC board. SeeFigure F. 15. in the Power Board Test.

11. Carefully check for approximately 1VDC fromplug J6 pin 2 (lead #305)(+) to plug J6 pin 7(lead #301) (-). If the approximately 1VDC ispresent the power PC board and protectionPC board are functioning properly for the trig-ger circuit to operate. If the correct DC volt-age is NOT present, perform the ProtectionBoard Test and the Power Board Test.

12. Test to make sure the T1 auxiliary transformeris 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 wiringmay be faulty. See Figure F.22, SimplifiedTrigger Circuit Diagram.

WARNING

DEC 97

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DARLINGTON MODULEREMOVAL AND REPLACEMENT



DESCRIPTION

The following procedure will aid the technician in the removal and replacement of theDarlington module located in the lower tray assembly.

MATERIALS NEEDED

5/16" Nut driverPhillips head screw driver7/16" wrenchNeedle nose pliers1/2" Wrench10mm Wrench3/16" Allen type wrenchDow Corning 340 Heat Sink Compound (Lincoln E1868).Silicone Rubber RTV Coating (Lincoln E2861 or Dow 3140)


INVERTEC STT

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DEC 97

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INVERTEC STT

DARLINGTON MODULE REMOVALAND REPLACEMENT (continued)

FIGURE F.23 – OUTPUT CHOKE LEAD DISCONNECTION

LOWERTRAYAREA


PROCEDURE






4. Locate the lead connection splice from theoutput choke to the Darlington module.Remove the insulating sleeve. Using the7/16" wrench disconnect the lead splice.Thread the lower lead down into the lower trayassembly area. See Figure F.23.

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INVERTEC STT


FIGURE F.24 – PLUG J1 DISCONNECTION

LOWERTRAYAREA



5. Disconnect the current sensing plug J1 fromthe control PC board. Carefully remove plug

J1 and associated leads from the control PCboard compartment. See Figure F.24.


PLUG J22


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INVERTEC STT


FIGURE F.26 – STT PLACED ON ITS RIGHT SIDE

MOUNTINGBOLTS (5)



9. Carefully slide out and support the lower trayassembly.

10. Using the needle nose pliers, remove thestrain relief holding the J22 lead harness tothe case bottom.

11. Using the 1/2" wrench, remove theDarlington cable from the negative outputterminal.

12. Carefully remove the lower tray assemblyclear from the machine.

13. Remove the rubber RTV coating from theDarlington module.

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INVERTEC STT


FIGURE F.27 – DARLINGTON MODULE CONNECTIONS

E

E

DARLINGTONMODULE

C

B

STT II STT

For steps 14-18, see Figure F.27.

14. Using the phillips head screw driver, removethe small leads from the small "E" and "B"terminals. Note lead placement for reassem-bly.

15. Using the 10mm wrench, remove the largelead and the #289 lead from the large "E" ter-minal. Note lead placement for reassembly.

16. Using the 10mm wrench, remove the largelead and the #287 lead from the large "C" ter-minal. Note lead placement for reassembly.

17. Using the 3/16" Allen type wrench, removethe four socket head cap screws that mountthe module to the heat sink.

18. Carefully remove the Darlington module.

19. Upon reassembly, use Dow Corning 340Heat Sink Compound (Lincoln E1868)between the module and the heat sink.

20. Mount the new module using the sockethead cap screws and torque to 26 inchpounds.

Note: The torque should be rechecked afterthree hours.

21. Using the 10mm wrench, assemble the large

lead and the smaller #289 lead to the large"E" terminal. Torque to 26 inch pounds.

22. Using the 10mm wrench, assemble the largelead 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 termi-nals and lead connections as was previouslyremoved.

25. Replace the lower tray assembly.

26. Connect plug J22 to the wiring harness andplug J1 to the control PC board.

27. Connect the lead splice between the outputchoke and the Darlington module.


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SWITCH BOARDREPLACEMENT



DESCRIPTION

This procedure will aid the technician in the removal and replacement of the switch boards.

MATERIALS NEEDED

5/16" Nut driver7/16" Wrench3/16" Allen type wrench3/16" Socket wrenchDow Corning 340 Heat Sink Compound (Lincoln E1868)ANALOG Ohmmeter


INVERTEC STT

WARNING


DEC 97

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INVERTEC STT

SWITCH BOARD REPLACEMENT (continued)

FIGURE F.28 – SWITCH BOARD REMOVAL

PROCEDURE

NOTE: If a test indicates that a switch board isdefective, both switch boards must be replaced atthe same time. In addition to replacing the switchboards, replace capacitors C1 and C2 if the fol-lowing conditions exist:

a. The machine was operating from 380 VACor higher when the failure occurred.

b. Burned areas are visible on the switchboards.





• Before continuing with thetest procedure, perform thecapacitor discharge proce-dure to avoid electricshock.

4. Carefully disconnect the leads at the top of theswitch board.

5. Using the 3/16" socket wrench, remove thefour cap screws from the switch board. SeeFigure F.28.

WARNING

SOCKETHEADSCREWS

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INVERTEC STT


6. Using the 7/16" wrench, remove the two hexhead capacitor screws located in the centerof the switch board. Hold the board firmly asyou remove the screws.

7. Carefully remove the switch board.

8. Clean the heat sink surfaces thoroughly toremove all the heat sink compound. (Duringmachine operation, this compound helpsconduct heat from the switch board to theheat sinks.

9. Apply a thin layer (.002") of Dow Corning340 Heat Sink Compound (Lincoln E1868) tothe mounting surfaces of the new switchboard and to the capacitor terminals. DONOT allow the compound to enter themounting screw holes. It can distort thetorque values.

10. Prepare to mount the new switch board onthe heat sink by first lining up the mountingholes. Then press the switch board intoplace.

11. Insert each of the four socket head screwsinto the mounting holes. Thread them fingertight. The threads are soft -- be careful no tocross-thread them.

12. Insert each of the two hex head screws intothe capacitor terminal holes. Thread themfinger tight. Be careful not to cross-thread thescrews.

13. Torque both sets of screws in 10 inch-poundincrements. Use a diagonal tighteningsequence. Torque the four socket headscrews to 44 inch-pounds (5 Nm). Torque thetwo hex head screws to 55 inch-pounds (6Nm).

Failure to connect the switch board leads correct-ly can result in damage to the Invertec STTmachine when power is applied.

14. Reconnect all the leads to the switch board.Be sure each lead is connected to the correctterminal.

15. Perform the Test after Repair of SwitchBoards and/or Capacitors.

NOTE: Always make sure that the switch boardsare changed in matched pairs. Never mix an oldstyle switch board (different part number) withnew style (new part number).

CAUTION

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INVERTEC STT


TEST AFTER REPAIR OF SWITCHBOARDS AND/OR CAPACITORS

The following test must be performed after theswitch boards and/or the capacitors have beenreplaced.

NOTE: Always make sure that switch boards arechanged in matched pairs. Never mix an old style(different part number) switch board with a newstyle (new part number).

TEST PROCEDURE

1. Turn main power OFF.

2. Perform Input Filter Capacitor DischargeProcedure. See the Maintenance section.



3. Connect a shorting conductor across termi-nals 14 and 53 of the protection PC board.See Figure F.29.

4. Set an ANALOG ohmmeter to X1000 rangeand place the probes on terminals 9 (+) and12 (–) of one switch board. The meter willshow the capacitors charging up and maytake a minute or so to stabilize. The finalmeter 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 CapacitorDischarge Procedure.

6. Remove the shorting conductor set up in step3.

7. Replace 20 amp fuses with 5-amp fuses inthe input supply fuse holders.

NOTE: These fuses should be installed to pro-tect against excessive current flow caused by ashort circuit during the procedure.

WARNING

FIGURE F.29 — SHORTING TERMINALS 14 AND 53 OF PROTECTION BOARD

L7915-[ ] PROTECTION

53 14

JUMPER TERMINALS

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INVERTEC STT



• With input power ON, thereare high voltages in themachine. Do not reachinto the machine or touchany internal part.

8. With the machine connected for 440/460 voltoperation and the proper input voltageapplied, turn on input power to the machine.

9. With the output free of a load, check open cir-cuit voltages of the output. Voltage should be85 VDC maximum.

10. Remove input power. Then remove the 5-amp fuses from the input supply fuse hold-ers.

11. Install 20-amp fuses and test under load.

NOTE: A resistive-type grid load bank is recom-mended.

14. Perform Retest After Repair.

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CAPACITOR REMOVAL ANDREPLACEMENT PROCEDURE



DESCRIPTION

This procedure will aid the technician in the removal and replacement of the input filter capac-itors C1 and C2.

MATERIALS NEEDED

5/16" Nut driverSlot head screw driver7/16" WrenchNeedle nose pliers1/2" Wrench


INVERTEC STT

WARNING


DEC 97

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INVERTEC STT

CAPACITOR REMOVAL AND REPLACEMENT PROCEDURE (continued)

FIGURE F.30 – OUTPUT CHOKE LEAD DISCONNECTION

LOWERTRAYAREA


PROCEDURE

1. Turn off Invertec STT and disconnect main ACinput power to the machine.




• Before continuing with thetest procedure, perform thecapacitor discharge proce-dure to avoid electricshock.

4. Locate the lead connection splice from theoutput choke to the Darlington module.Remove the insulating sleeve. Using the7/16" wrench disconnect the lead splice.Thread the lower lead down into the lower trayassembly area. See Figure F.30.

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INVERTEC STT



LOWERTRAYAREA



5. Disconnect the current sensing plug J1 fromthe control PC board. Carefully remove plugJ1 and associated leads from the control PCboard compartment.


PLUG J22


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INVERTEC STT


FIGURE F.33 – STT PLACED ON ITS RIGHT SIDE

MOUNTINGBOLTS (5)



9. Carefully slide out and support the lower trayassembly.

10. Using the needle nose pliers, remove thestrain relief holding the J22 lead harness tothe case bottom.

11. Using the 1/2" wrench, remove theDarlington cable from the negative outputterminal.

12. Carefully remove the lower tray assemblyclear from the machine and set aside.

13. Carefully disconnect the leads at the top ofthe switch board.

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INVERTEC STT

CAPACITOR REPLACEMENT

NOTE: Capacitors must always be replaced inmatched sets (C1 and C2 as a set)).

When replacing Capacitors, remove the entireFET heat sink assembly, including the capacitorsand switch board, as a unit.

Disassemble and reassemble only one unit at atime. Use the other unit as a model duringreassembly so that all parts are reinstalled prop-erly.

14. Remove the two 3/8” hex head nuts from thetop of the through-bolts. The hex nuts arelocated on top of the fan shroud. See FigureF.34.


FIGURE F.34 – REMOVING HEX HEAD NUTS OF THROUGH-BOLTS

HEX NUT

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INVERTEC STT

15. Place the machine on its side as shown inFigure F.35. Slide the plastic retaining insu-lators that go through the base of themachine to one side. Pull the through-boltsout of the machine, being careful to save allthe insulation and standoff material. Setaside for reassembly.

16. Remove the switch board and capacitorassembly from the machine.

FIGURE F.35 – REMOVING THROUGH-BOLTS


PLASTIC RETAININGINSULATORS

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INVERTEC STT

17. Remove the two 7/16” hex bolts that hold thecapacitor to the switch board. See FigureF.36.

18. Loosen the set screw of the capacitor clampring and remove the capacitor from the clampring. See Figure F.37.

FIGURE F.36 – REMOVING CAPACITOR NUTS


17. Remove the two 7/16” hex bolts that hold thecapacitor to the switch board. See FigureF.36.

18. Loosen the set screw of the capacitor clampring and remove the capacitor from the clampring. See Figure F.37.

FIGURE F.37 – LOOSENING THE CLAMP RING SET SCREW

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INVERTEC STT

19. Install the new capacitor and tighten the two7/16” hex bolts to a torque of 55 inch-pounds(6 Nm). Tighten these bolts in increments of10 inch-pounds, alternating between the twobolts. Capacitor installation is complete. SeeFigure F.38.

Proper capacitor polarity must be noted whenattaching the capacitor to the switch boardassembly.

20. Install the switch board and capacitorassembly into the machine. Take specialcare that ALL insulators and sleevings are intheir proper positions. See Figure F.38.

21. Install the lower tray assembly and all previ-ously disconnected loads and plugs.

22. Perform the Test After Repair of SwitchBoards and/or Capacitors.

NOTE: Always make sure that the switch boardsare changed in matched pairs. Never mix an oldstyle switch board (different part number) withnew style (new part number).

INPUT FILTER CAPACITOR CONDITIONING

If the machine will not produce output whenturned on and the following two conditions exist:

The machine is connected to operate at aninput voltage of 380 VAC or higher and

Power has not been applied to the machine fora long period of time (many months). Then. . .

The Input Filter Capacitor Protection Circuit couldhave been activated and prevented output. Thismeans the Input Filter Capacitors must be condi-tioned.

The Input Filter Capacitor Protection Circuit mon-itors the voltage across input filter capacitors C1and C2. When it senses an overvoltage condi-tion, the protection circuit will prevent themachine from operating.

To condition the Input Filter Capacitors:


2. Remove any load and do not load machineuntil conditioning procedure is complete.

3. Turn main power ON.

4. Let the unloaded machine sit for 30 minutes.



NOTE: The machine should be ready to operate,and the protection circuit should have automati-cally reset once the capacitors have been condi-tioned and capacitor voltage has reached theacceptable operating level.

FIGURE F.38 – COMPLETE SWITCH BOARD ASSEMBLY READY FOR INSTALLATION


CAUTION

INSULATOR

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OUTPUT RECTIFIER REMOVAL AND REPLACEMENT



DESCRIPTION

This procedure will aid the technician in the removal and replacement of the output diode heatsink assembly.

MATERIALS NEEDED

5/16" Nut driver3/8" Nut driver7/16" WrenchSlot head screw driverDow Corning 340 Heat Sink Compound (Lincoln E1868)


INVERTEC STT

WARNING


DEC 97

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INVERTEC STT

OUTPUT RECTIFIER REMOVAL AND REPLACEMENT (continued)

FIGURE F.39 – CHOKE LEAD/HEAT SINK CONNECTION

CHOKE LEAD

HEAT SINK TAB

PROCEDURE






4. Using the slot head screw driver, loosen theinput cable strain relief.

5. Using the 5/16" nut driver, remove the fourscrews securing the case back to the inter-nal horizontal baffles.

6. Carefully pull the case back away from theoutput rectifier assembly.

NOTE: The case back will NOT detach fromthe case bottom.

7. Using the 7/16" wrench, remove the fourbolts and washers mounting the fan motorbracket to the top horizontal baffle.Carefully set the fan and motor assemblyaside. Note insulation placement forreassembly.

NOTE: The fan motor leads do NOT have tobe cut.

8. Using the 7/16" wrench, remove the chokelead from the heat sink tab. See Figure F.39.

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INVERTEC STT


FIGURE F.40 – MAIN TRANSFORMER DIODE CONNECTIONS

MAINTRANSFORMERSECONDARYLEADS

9. Remove the two sleevings from the diodeconnections at the main transformer. SeeFigure F.40.

10. Using the 7/16" wrench, remove the diodeleads from the main transformer sec-ondary leads. Note washer and leadplacement for reassembly.

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INVERTEC STT


FIGURE F.41 – SWITCH BOARD/CAPACITOR ASSEMBLY THROUGH-BOLTS

THROUGH-BOLTS

11. Using the 3/8" nut driver, remove the rearnuts and washers from the switchboard/capacitor assembly through-bolts.See Figure F.41.

12. Using the 3/8" nut driver, loosen the frontnuts from the switch board/capacitorassembly through-bolts.

13. Carefully lift the horizontal baffle awayfrom the upper tabs of the output rectifierheat sink assembly.

14. Slide the heat sink assembly to the right(facing the back of the machine) to disen-gage the bottom tabs from the lower hori-zontal baffle.

15. Carefully remove the output rectifier heatsink assembly and leads from the STTmachine.

16. Remove the nut that secures each diodethat is to be replaced.

NOTE: The output diodes must be replaced inmatched sets.

17. Before mounting the new diode sets, cleanand brighten the mounting surfaces ofboth the diode sets and the heat sink withfine steel wool.

18. Apply an even coating of DOW Corning340 Heat Sink Compound to the mountingsurfaces of the diodes that contact theheat sink. This compound layer should beless than .001 inch thick. DO NOT applythe compound to the diode studs ormounting nut threads.

19. Insert the diode sets into the mountinghole and tighten the diode mounting nutsto a torque of 25 inch-pounds (3 Nm).

20. Replace the rectifier heat sink assembly,leads and connections that were previous-ly removed. Install the fan and motorassembly (note insulation placement).Install the case back and the case wrap-around cover.

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INVERTEC STT

RETEST AFTER REPAIRRetest the INVERTEC STT:

• If it fails any test and the test requires removing or replacing any mechanical part that could affect the machine'selectrical 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 AMPS VOLTS

BACKGROUND 140 20

OPEN CIRCUIT VOLTAGE RANGE

73 TO 85 VDC

INPUT FILTER CAPACITOR CONDITIONING

If the machine will not produce output when turned onand the following two conditions exist:

The machine is connected to operate at an inputvoltage of 380 VAC or higher and

Power has not been applied to the machine for along period of time (many months). Then. . .

The Input Filter Capacitor Protection Circuit could havebeen activated and prevented output. This means theInput Filter Capacitors must be conditioned.

The Input Filter Capacitor Protection Circuit monitorsthe voltage across input filter capacitors C1 and C2.When it senses an overvoltage condition, the protec-tion circuit will prevent the machine from operating.

To condition the Input Filter Capacitors:


2. Remove any load and do not load machine untilconditioning procedure is complete.


4. Let the unloaded machine sit for 30 minutes.



NOTE: The machine should be ready to operate, andthe protection circuit should have automatically resetonce the capacitors have been conditioned and capac-itor voltage has reached the acceptable operatinglevel.

ENVIRONMENTAL PROTECTION

High voltage connections are covered with an RTVsealant to prevent malfunction in severe environments.Sealant must be applied to connections which havebeen opened or otherwise lost their protection. A non-corrosive, electronic grade sealant such as DowCorning 3140, 3145, or 738; Columbus Adhesives0172; or GE RTV-162 is recommended. Sealant mayalso be purchased from Lincoln Electric (order E2519Silicone Rubber RTV Coating). Apply sealant aftermachine is repaired and tested. All five terminals of theinput rectifier require this type of sealant.


INVERTEC STTRet

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ELECTRICAL DIAGRAMSG-1 G-1

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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

TABLE OF CONTENTSELECTRICAL DIAGRAMS SECTION

DEC 97

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to S

ectio

n T

OC

Ret

urn

to S

ectio

n T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

NOTES

INVERTEC STT

G-2ELECTRICAL DIAGRAMS

INVERTEC STT

Wiring Diagram

+

-

ELECTRICAL SYMBOLS PER E1537

H1

T1

FANMOTOR

GF

EJAIKCDML

BN

H

7576773132414224818221GNDSPARE

42VAC

T3 CURRENTTRANSFORMER

1

4

T2MAIN TRANSFORMER

R3

OFFON

H1 TP1

TP3TP2

I

I5

8

D1

D2

D3

CHOKE

L3

CONTROLBOARD

10K2W

R11

307308309310

302303

304

POWERBOARD

(VIEWED FROM COMPONENT SIDE OF BOARD)NOTES:

TRIGGER

INPUT PER

N.A.

POWERS1

1

2

3

1

78

J7

J6

CB1

504

43A

AUXILIARYTRANSFORMER

245613

N.E.

CW (MAX)

9

10

F

F S

S

S

TOPOUTSIDE

BOTTOMINSIDE

S

S

SF

F

TOP

TOPINSIDE

BOTTOMOUTSIDE

7

68

4

5

CONTROL

211A

212B150 5W

FANTHERMOSTAT

H2

H3

H4

F BOTTOM

F

212A

W

V

U

H1

2120V

24V

42V

18V1

4

2

3

.001/400

COLOR CODE:

R = RED

6H5

2

3

6

4

7

8

5

502

Y

301

D4

D5

D11

D10D9D8

D7

N.E.

210

6AMP

H2

H3

H4

A

9C

W

B

G

A

FOR THREE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.CONNECT BLACK, RED & WHITE LEADS TO SUPPLY CIRCUIT.

WRAP RED LEAD WITH TAPE TO PROVIDE 600V. INSULATION.

FOR THREE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.CONNECT TERMINALS U, V & W TO SUPPLY CIRCUIT.

CONNECT TERMINALS U & W TO SUPPLY CIRCUIT.

N.D. PLACE "A" LEAD ON APPROPRIATE CONNECTION FOR INPUT VOLTAGE.CONNECTION SHOWN IS FOR 440-460V OPERATION.

CONNECT BLACK & WHITE LEADS TO SUPPLY CIRCUIT.FOR SINGLE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.

FOR SINGLE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.

W = WHITE

B = BLACKG = GREEN

Y = YELLOW

H6

N.D.

R

H1

+ ARC

- ARC102W

C4

.001/400

9D

H1 H3

H3230V

415V

440-460V

200-208V

220-

380-

R2C3

102W

Y Y

3051234

J14311313

A

4 AMPSLOWBLOW

N.A.

N.B. SINCE COMPONENTS OR CIRCUITRY OF A PRINTED CIRCUIT BOARD MAY CHANGE WITHOUT AFFECTING

N.E. D1 THRU D5 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.

THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY NOT SHOW THE EXACTCOMPONENTS OR CIRCUITRY HAVING A COMMON CODE NUMBER.

D7 THRU D11 OUTPUT DIODES ARE A MATCHED SET.

CONNECTION SHOWN IS FOR 380-460V OPERATION.

12D

INPUTRECTIFIER D13

10K2W

CW (MAX)

CONTROL

BACKGROUNDMETER

METER

1

J2

11

8

10

4

9

3

2

7

13

126

14

5

BACKGROUND

BOARD

4

31

2

42

1

3

CURRENTSENSE

J1

J18DARLINGTON

MODULE

DARLINGTONBOARDDRIVE

J13

BE

1

23

6

4

5

J12

J5

J3

910

1

2

34

56

1. FOR MACHINES SUPPLIED WITH INPUT CABLE

2. FOR MACHINES NOT SUPPLIED WITH INPUT CABLE

1234

VOLTAGESENSECONNECTION

J19

1

18V

18V

AUXILIARYTRANSFORMER

115V

10V

18VR

W

R

B

B

U

U

E C

D7

U = BLUE

212A

212

501504

T4

275

351350

352353354355356357358

358

359

359

360

360

361

361

362

362

363

363

290

291

J21

2

9

3

4

12

13

N

O

12

43

67

5

8

109

R12

J18, J37 J6, J27, J33

J19

J15, J35

210A224

20/400C8

287

288A

288B

289A

289B

364365366

368369

372

376

CLEVELAND, OHIO U.S.A.

9-13-96

G2773

R

WIRING DIAGRAM - INVERTEC STT

NO

O = ORANGEN = BROWN

123456

123456

354355

356357

10K2W

CW (MAX)

CONTROLHOT START

R13

WIRE SIZE

WIREFEEDER

CB2

BOARD

+

12

C1

R4

R52525W

2525W

9 5

8

+

12

2525W

2525W

9

C2

R6

R74

1R1

750025W

9A

308307

402, 404

401, 403

4,5

1, 8

R

R W R W401, 403

1, 8

4, 5402, 404

SWITCH+

-

+

-

SWITCH

DRIVERBOARD

416 3

J10

2 5

BOARD

1

23

4

52

14

51

53

14

J8

PROTECTION52

2200 F450V

N.G.

N.F.

N.G.

2200 F450V

(LEFT)

BOARD(RIGHT)

12B

9B9B

R9

9A

5312A

H5

750025W

52

1

2

34

5

6

314315

317

J15

N.F.

12A

12B

51

41 32

J11

73

21

812

1314

J16

9D

3 6 4 1

J9

2 5

12B12D

501

115V

11

10371 371A374A374

J22

240

241

242243

244

245

246

O

O

18V

6V

N

N

240241242

3

4

5

6

1213

714

1

2

8

9

1011

303302304275

371A374A243244

J27

1112

J4

374

370371

367

J28

371374

1234

1516

364

365

366

(+)

(-)

367

368

369

367A

367A

WIRE TYPESTAINLESSMILD

JBCGADFHEI

TRIGGER

GND

.045.035

BG

PB

10K

10K

OPTIONALREMOTEINTERFACE

115VAC

3

2

5

4

1

U

W

R

R

Y

N

Y

2

1 32

33

32C

33C

32A32B

33A33B

7

8

1516

J22

2 300W289

288

2 300W

J33

223 7

J34

33C

1

2

3

4

5

643B

31A

J35

42

33D6AMP

J36

1234

J37

J30

J31

503A

R14

8

21

67

3

4

5

372

376374

370371

62371

8

54

109

61

584

32

J24 J23

J26 J25

353352

351350

123456

123456

42VAC

115VAC

J39

1

2

4

3

67

5

8

10

9

11

12

502

210

223

Y

305245

211A212C

Y

246

301

J17

503

503A

212C43A

212B32C

3

12

10912411

146

135

168

157

J38

503

REMOTEPROTECTION BOARD

S2

S3

(-)

(+)

THERMALOVERLOADINDICATOR

R13

J10, J13,J1, J8, J3, J9,

J5, J7, J34

J2, J36

J38 J39

PINOUT OF FRONT PANEL CONNECTORS (REAR VIEW)

P30 J30 P29, P31 J29. J31 P21 J21

P22 J22

INLINE CONNECTOR CAVITY NUMBERING SEQUENCE(VIEWED FROM WIRE SIDE OF CONNECTOR)

J23J24J25J26

P.C. BOARD CONNECTOR CAVITY NUMBERING SEQUENCE

METER PINOUT (VIEWED FROM BACK OF METER)

BWW

B

R

WB

BW

R

W

RB

B

PEAKCURRENT

PEAKCURRENT

B

WB

R

N.I. DENOTES A TWISTED WIRE PAIR OR GROUP.

N.J.

RW W

52

316

31131314

309

310CR1

9A

9A

9A

9A

53

9D

N.H.

9C

12C

9B

12A9B

12A

9B

S7RECONNECT

9D

12C12D

309A

310A

309310

CR2 309A

310A

12D

52

9B

12B51

12B

12B12B 12B

12B

14

6224

503A

224A

J22 THERMOSTAT

DARLINGTONHEATSINK

W

W

C

B

A

C

B

A

D

F

C

B

A

503B

J11, J12, J14

J4, J17 J16, J28

401402403

404

405

406

407

408

409410

411

412

413

414

415

416

C

B

A

C

B

A

LOAD

LINE

POWER LINEFILTER

ASSEMBLY

N.L.

N.K.

N.K. NOT PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.N.L. PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.

N.J. NOT PRESENT ON EUROPEAN VERSIONS.

TOROIDALCORE

N.L.

G-2R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

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.


INVERTEC STT

Control PC Board (G2782) Schematic 1 of 2

J2811

50V0.1C413

+15V_REM

50V0.1C411

+15V_REMREM

REM

3.92

K

R46

3

METER_2

METER_1

PB_SCALED

1.00

K

R43

6

3.92

K

R461

J2810

J286

J283

15.0K

R437

10.0K

R431

OCI4

Vcc

GND

HP2231

5

8

1.00

K

R43

2

0 .01

W4

FILE: G2781_1D1

+PWR

+VIN

-PWR

+VIN

+PWR

BA

CK

GR

OU

ND

MET

ER

-V IN

POWERTO

BOARD

4

2

3

J1

1 Input- CurrentFeedback

Vac InCOMMON CONNECTION

FRAME CONNECTION

LAST NO. USED

129, 211, 314, 475

165, 242, 345, 564

117, 211, 310, 424

VOLTAGE NET

1

9 16

8

to Control Panel

Analog Logic I/O

J2

to Control Panel

Analog Logic I/O1

6

3

4

J3

C-

D-

R-

SUPPLY

LABELS1/4W(UNLESS OTHERWISE SPECIFIED)

UNLESS OTHERWISE SPECIFIED)

200 SERIES- TRIGGER CIRCUIT100 SERIES- ARC SENSE CIRCUIT

REFERENCE DESIGNATOR SERIES DEFINITIONS

GENERAL INFORMATION

1A, 400VRESISTORS = Ohms (

MFDCAPACITORS =ELECTRICAL SYMBOLS PER E1537

DIODES =

( .022/50V

(SHEET 2)


(SHEET 2)

+15V

COMM

PHA OUTPUT

PHB OUTPUT

0.01 W

1

ON HOLES SIZES PER E-2056ON 2 PLACE DECIMALS IS + .O2

UNLESS OTHERWISE SPECIFIED TOLERANCE

3SEC

ARC_START

WITH PUBLISHED STANDARDS

ON 3 PLACE DECIMALS IS + .OO2ON ALL ANGLES IS + .5 OF A DEGREEMATERIAL TOLERANCE ("t") TO AGREE

J36

Ch'ge.Sht.No.

+5.1V

PLA

SM

A B

OO

ST

MET

ER

-PWR

-VIN

A

J2813

J285

3920V

C469

562

R47

9

Q62N4401

J274

J2812

33.2K

R485X18 3

2

1

J278

J289

J284

J282

J35

X22

3

5

4

RemoteControl106

51

J27

J28

14

1 7

8

Dar l ingtonDrive- Output

W4

STT CONTROL

Q10

POWER SUPPLY SOURCE POINT

SCHEMATIC (Sheet 1 of 2)

DZ20

EARTH GROUND CONNECTION

OCI7

SHT.NO. G

X36

SUP'S'D'G.04/12/94SCALE

DATE

NONECLEVELAND, OHIO U.S.A.

DR. MLD

300 SERIES- DIGITAL LOGIC CIRCUIT400 SERIES- ANALOG LOGIC CIRCUIT

THE LINCOLN ELECTRIC CO.

SUBJECT

CHK.

EQUIP.

(SHEET 1)

TYPE

(SHEET 1)

ANAND

B

HO

T S

TAR

T TI

ME

CW

10K

N.A. S INCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE

NUMBER.

WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY

NOTES :

NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE

PINCH SLOW RAMP

COMMAND SIGNAL

BALL

PINCH KNEE

KEEP_ALIVE LEVEL

PINCH FAST RAMP

BACKGND

P_BOOSTPINCH RAIL

RAMP

FUSE

KEEP_ALIVE LEVEL

TAILOUTBACKGND

OFF

J273

C453

100K

R496

X30

3

5

4

10.0K

R536100

R481

MILD

-> .045 DIA WIRE

< .035 DIA WIRE-

CURRENT FEEDBACK

1V/100A

WIRE TYPE SELECT

WIRE SIZE SELECT

SENSEBOARD

1014B

5V3V

BNAND

+15V POWER SUPPLY FORDIGITAL, TRIGGER & ANALOG SECTIONS

10K

CW

REM

OTE

PB

PO

T

STAINLESS

18 VAC

lm350

A1014

INTEGRATORCURRENT

CURRENT

COUNTERDUAL FFPWM

G

POWER PLANE

COUNTER

GROUND PLANE

33.2

K

R518

X351

2

3

1.035V

C423

X36 45

6

332K

R522

X357

6

5

68.1

K

R514

221K

R521

10.0K

R510

68.1K

R513

J271

200V.33

C46447.5K

R5191W10V

DZ9

J11

J12

1.035V

C412+ t56

R526

J31

J14

J13

10.0

R466+ t

.25

R4671 2

J34

X25

SG3846

12

13

1W10V

DZ20

1N914

D412

2.5V

LOC

AL

PB

PO

T

10K

CW

POWERPOTS

CONTROL10 VDC

REMOTE_POTS

+15V

+15V

C461

2.67K

R544

75.0

R504

100

R489

10.0

R50

0

100

R50

7

J272

J279

J2710

J33

X33

TL431 REF8

1

6

SS_WIRE

1.035V

C404

2.67K

R545

5.62

K

R47

2

1.30

K

R50

5

1 .035V

C402

2.67K

R406

1W12V

DZ11

1.0 35V

C446

1.035V

C460

1.00

M

R46

9

1 .0

35V

C400

C401

1.50

KR

503

D407

J215

100

R404

+15V

1W12VDZ10

1.30

K

R40

0

1.30

K

R401

J32

J216

J210

75.0

R40

2

1.30

K

R50

6

D400

C403

10.0

R501

1.00

MR

533

1W12V

DZ18

10.0K

R403

4.75

KR

502

2 .67K

R546

/PB_LOCAL

NAND

+15V

Q92N4401

/ARC

X14 11

12

13

X14 108

9 10K

R320

OCI1

HP2231

1

2

LT1014

X24

4

11

4066B

X30

14

7

LM2901

X23

3

12

50V0.1

C459

1N4936D303

50V0.1

C427

100V330pC306

+15V

/PINCH

/PWM_SYNC

/PWM_SYNC

NAND

14

7

/Q2

D1

VDDQ1

SET 2

CLOCK 2

/Q1 Q2

CLOCK 1

VSS

RESET 1

MC14013B

SET 1 D2

RESET 2

X19

11

10

13

8

12

2

1

6

4

9

5

3

50V0.1

C428

3.92K

R457

X17 45

6

X14 32

1

B

2.21

K

R317

100V

330p

C305

OCI3

HP2231

6

3.01

K

R45

6

3.01

K

R45

4

56.2

K

R321

4 .75K

R319

OCI3

HP2231

7

4.75K

R318

X16 45

6

+15V

ARC_START

/PWM_SYNC

START_RESET

NAND

D

PINCH SIGNALTO FE (SHEET 2)FOR ENERGYCONTROL OPTION

"DIGITAL LOGIC"

GROUND PLANE

C

A

BALL_OR_FUSE

NAND

OP AMP

B

A

NAND B

NAND

POWER PLANE

COMPARATORSWITCH

ENABLE (SHEET 2)ENERGY CONTROL OPTION

PINCH LATCH

P_BOOST ONLY AFTER

P_BOOST TIME (SHEET 2)ENERGY CONTROL OPTION

H = A>100V=ARC

KEEP IN P_BOOST

UNTIL ARC STARTS

CX16 10

8

9

150K

R422

SLOW RAMP

Q82N4401

2.67

KR

452

3 .32K

R426

13

12Vc

GND

SYNC

X25

V+ Vref

CLIM

OUTBCOMP

I-

I+

V-

OUTA

SHUT

CT

RT

Vin

SG38469

3

8

4

10

5

6

2

15

11

14

16

1

7

B

P_BOOST COMMAND

C473

L= .035H= .045

( SHEET 2 )

Verror

X22

8

6

9

10.0

K

R551

100

R405

1us MIN PULSEWIDTH

15.0K

R453

3us MAX DEADTIME

10KCW

R425

1N4936

D401

500

CW

R42

9

267K

R42

3

1 .00K

R427

47.5K

R419

100K

R424

100A/ms

A

RAMPPINCH

1014

X21

10

12

11

1.00K

R428

X24 1

2

3

100V47p

C410

475K

R421

47.5K

R420

100K

R416

X21

8

6

9

X31

10

12

11

100K

R55

2

X21

1

13

2

3920V

C465

15.0K

R410

B 1000A/ms

FAST RAMP

50V.018C418

10.0

KR

564

CURRENTERROR AMP

22.1

KR

555

GENERATOR

WAVEFORM

SAWTOOTH

1.820V

C419

D

Q42N4401

B

COMMAND

6.81K

R411

A

100V100pC472

Q102N4401

47.5K

R409

COMMAND

LOCAL_POTS

26.7

KR4

51

+15V

+5.1V

LOCAL +15V

NAND

MC14538BTIMERTIMER OP AMP

GROUND PLANE

ALM224

375us

+5 VOLT

POWERMETER

2.5V

BLM224

POWER PLANE

2.67K

R508

825

R48

6

10.0K

R527

X34 7

6

5

X26

TL431 REF8

1

6

1.035V

C448

1.00

MR5

11

D413

C314

X34 1

2

3

C463

10.0K

R528

1W12V

DZ19

825

R48

8

825

R48

2

825

R48

72.

21K

R47

3

2.43

K

R47

4

10.0

R484

10.0

R483

1.035V

C462

4093B

X11

7

14

50V0.1

C433

50V0.1

C432

50V0.1

C467

50V0.1

C466

LT1014

X35

4

11

4093B

X12

7

14

X9

16

8

MC14538B

X10

16

8

50V0.1

C445

LM224

X34

4

11

50V0.1

C443

50K CWR301

3.92

K

R30

0

4 .735V

C440

+15V

+15V

J2814

50V0.1

C439

50V0.1

C442

50V0.1

C456

50V0.1

C441

MC14040

X32

8

16

MC14040

X20

8

16

1N4007D307

1400V.0047C310 243

R337

100035VC311

C312

1N4007D308

J287

2.67K

R541

500

CWR33

9

2 .67K

R543

2.43

KR

338

2 .67K

R542

10020V

C313

MC14013B

X19

7

14

1N4007D306

1N4007D309

ADJ

IN OUTs18395-23

X8

D310

15.0

K

R33

5

15.0

R515

X23 1

6

7

100K

R45

0

OCI6

HP2231

1

2

X22

1

13

2

1N4936

D302

1N914

D424

X31

3

5

410.0K

R444

82.5

K

R56

0

X36 108

9

X36 1112

134.75K

R537

100

R525

D402100V

330pC471

D410

150K

R52

3

PRI_FB

PB_START

+15V

+15V

+15V

ARC

+15V

PINCH

CFB

+15V

PINCH PWM_EN

1014 B

BCNAND

1014

CO

MM

AN

D

ARC

& /

RAM

P C

TRL

A

PB_START SIGNALTO FE (SHEET 2)FOR ENERGYCONTROL OPTION

( SHEET 2 )

A

1014

OVERCURRENTTRIP TIMING

X30

1

13

2

LOCAL

56.2

K

R30

7

P BOOST

X21

3

5

4

X247

6

5

10K

.294V

C1014

PIN

CH

FAS

T R

AMP

ENAB

LE

2901C

PINCH LIMIT

500A MAX

PIN

CH

BRE

AKPO

INT

(PIN

CH K

NEE)

D

PINCH COMMAND

2901

B.PT

PIN

CH

CO

MM

AND

LM224C

B

LM224

"ANALOG LOGIC"

D

17.8

K

R40

8

X34 8

9

10

8.25K

R530

15.0K

R550

1.00K

R532

X2313

10

11

15.0K

R407

10K

R414

X2314

8

9

10KR412

50V

.0047C407

X248

9

10200

R413

/HOT_START

LOCAL_POTS

PB_SCALED

X34 14

13

12

2.21

KR4

17

2.21

KR4

18

1 .035V

C409

1W15VDZ12

100K

R471

47.5K

R415

OCI2

HP2231

7

4093B

X13

7

14

10.0K

R540RST

/Q

T2QA

B

T1

X9

1

3

4

2

6

5 7

4.75K

R302

GROUND PLANE

POWER PLANE

NANDNANDOP AMP

FROM FE (SHEET 2)ARC/SHORT DETECT

C300

AARC

+15V

/BALL

PINCH

METER_1

METER_2

+15V+15V

REMOTE

PWM_EN

RAMP

+5.1V

P BOOST

OUTA

+15V

OUTB

10.0K

R539

0.01

W2

10.0K

R529

1.00

MR

448

100K

R45

9

0.01

W3

OCI4

HP2231

7

OCI4

HP2231

6

OCI5

HP2231

4

3

100V330p

C470

10K C

W

R441

X29 8

9

10

50V.0047

C422

26.7

K

R53

8

50V.0047

C41456.2

K

R44

2

OCI5

HP2231

1

2

D419

100K

R44

6

X22

10

12

11

22.1

KR

499

475

R45

8

100

R44

0

50V820pC416

D418

D404

13.7

K

R44

7

4 .75KR468

C415

D417

6.81

K

R49

4

RST

/Q

T2QA

B

T1

X10

1

3

4

2

6

5 7

OCI4

HP2231

4

3

OCI4

HP2231

1

2

/ARC +15V

+15V

/RAMPRAMP

START_RESET

/AR

C O

R R

AMP

CTR

L

CLM224

RAMP INP BOOST

120us

B

A

B

A

A

+1.42V

D

CURRENT LEVEL"KEEP ALIVE"

SCALED_BGND

PWM OUTPUTTO FRONT END

( SHEET 2 )

CIRCUITISOLATED

A

B

(SHEET 2)

332

R430

15.0

KR

439

D405

B

DARLINGTON

/DON_MIN

150us MIN

ON TIME

COUNTER

NANDNAND

DON_MIN

/CO

UN

T

3.92

K

X15 32

1

X15 45

6

A

16

8

VDD

/C

Q7

Q12

MC14040

Q4

VSS

RQ3

Q11

Q8

Q10

Q9

Q6

Q2

Q5

Q1

X2013

12

14

11

10

9

15

7

6

5

4

3

1

2

X15

1112

13

X16 32

1

4.75K

R557

A

50V0.1

C307

RST

/Q

T2QA

B

T1

X10

15

13

12

14

10

11 9

1N4936D421

511

R32

6

B

1N4936

D30110.0K

R325

10.0

K

R331

1 .00K

R345

DISABLE OPTION TO START

NAND

H= OPTION ENABLEDL= NO OPTION

4.75K

R323

1N4936D422

4.75K

R322

1N4936

D420

15.0

K

R341

LM224

X29

4

11

A

BOOST TIME LIMIT

50V0.1

C458

1.3 msec PLASMA

NANDPWM_SYNC

D

OP AMP

/PB_OPTION

+15V

PINCH

PB_START

+15V +15V

C

ANAND

R32

9

10.0K

R324

1.035V

C309

50V0.1

C308

/HOT_START

ARC_START

+15V

H= OPTION PB TIMEL= LOCAL PB TIME

X31

1

13

2

3.92

K

R33

2

X15 10

8

9

OCI2

Vcc

GND

HP2231

5

8

50V0.1

C429

10K

R312

50V0.1

C425

4066B

X31

14

7

10K

R455

/RESET

CFB

RESET

+5.1V

OUTA OUTB

50V0.1

C426

X12 108

9

SWITCHSWITCH

X14

45

6

10KR316

39.2

K

R311

10.0K

R310

BAL

L_O

R_F

USE

PWM

2901B

1V=100A

DNAND

NAND

CNAND

3.1V

1014D

1V

RST

/Q

T2QA

B

T1

X9

15

13

12

14

10

11 9

24.3

KR

553

C47

4

100K

CW

R313

X3514

13

12

X17

108

9

15.0KR554

C304

4066B

X22

14

7

50V0.1

C457

CFB

/PINCH

+5.1V

+15V

+15V

33.2

K

R517

OVERCURRENT TRIP

33.2

K

R516

X35 8

9

10

+15V

+15V

FUSE

+15V

50V0.1

C438

DV/DT

NAND

FROM FE (SHEET 2)DV/DT LEVEL DETECT

4093B

X18

7

14

4093B

X14

7

14

D

4066B

X21

14

7

4093B

X36

7

14

X11 45

6

X1611

12

13

D305

OCI1

HP2231

4

3

50V0.1

C468

D300FUSE

+15V

PINCH

ARC

+15V +15V

NAND

FUSE GEN.

DV/DT

1ms

B

REPETITIOUSPINCH LIMITER

COUNTER

FORCES THIRD CONSECUTIVE

PINCH TO BREAK INTO ARC

DV/DT KILLER

/KIL

LER

NANDSWITCH

NAND NANDNANDNAND

BALL

A/KILLER

KILL_RC

CNAND

PINCH KILLER VarcADJUST FE (SHEET 2)

DNAND

D

/KIL

LER

NANDKILLER

KILL_START

B

750us

/KILLER

BALL_OR_FUSE

B

DNAND

3.92

KR

308

4 .75K

R340OCI2

HP2231

6

50V0.1

C434

50V0.1

C435

50V0.1

C436

50V0.1

C444

50V0.1

C437

4093B

X17

7

14

4093B

X16

7

14

4093B

X15

7

14

16

8

VDD

/C

Q7

Q12

MC14040

Q4

VSS

RQ3

Q11

Q8

Q10

Q9

Q6

Q2

Q5

Q1

X3213

12

14

11

10

9

15

7

6

5

4

3

1

2

X171112

13

C302

X1332

1

Q32N4401

X11 108

9

10.0K

R333

4.75KR305

100K

CW

R30

4

33.2

K

R30

9

X13 45

6

100V

330p

C303 10K

R314

Q72N4403

75.0

R512 X13 11

12

13

4.75K

R334

X11 1112

13

50V2700pC475

4.75K

R306

332KR562

10.0

K

R561

X12 45

6X12 11

12

13

5.62K

R303

100V100pC301

X36 32

1

D411

X12 3

2

1

10.0K

R509

10.0

K

R56

3

1N914D423

X11 32

1

X28 13

10

11

150K

R524 100KR559

12VdcCR1

C

/RESET

/ARC

PINCH

+15V

/BALL

/PINCH

ARC

/RESET+15V

+5.1V+15V

+15V

FUSESTART

FUSE_RESET

CNAND

B

ANAND

B

AMPS>100

A

NAND/ARC NAND

NANDA

BALL_DELAYED

OUTPUT DISABLEOVERCURRENT B

/BALL_DELAYED /(BALL & SHORT)

OVERCURRENT FAULT

( SHEET 2 )

TO TRIGGER CIRCUIT

ARC

B

RESETPULSENAND

/BALL_RC

CNAND

/KILLER

D2901 NAND

/ARCNAND

A

/RESET

ANAND

150us FUSE ENTRY

ARC KILLER PULSE

1N4936D416

X17 32

1

X13 108

9

ARC

/RAMP

+15V

CW

SHORT OR 500K POT

500KTAIL OUT

A

BACKGROUND COMMAND

DNAND

D

INCREASE TAILOUT

DURING HOT START

C

LOC

AL

BG

PO

T

10.0

R434

J211

J214

82.5KR443C406

J25

J27

267K

R490

10.0K

R435

D414X31

8

6

9

1.00M R44

9

10.0K

R445

50V0.1C450

50V2700pC417

D409

X24

14

13

12

D403

REMOTE_POTS

X29 7

6

5

/HOT_START+15V

+15V

HOT_START

REMOTE

+15V

ARC_START

1.035V

C447 D408 HOT_START

REMOTE

LOCAL

DURING HOT START

11% BACKGROUND INCREASE

LM224

Unused Devices

D

C

LM224

TIMINGHOT START

GENERATOR

D

REM

OTE

BG

PO

T

CW

CW

10K

LM224

B

J275

J23

100

R491

J277

2.67K

R547

2.67K

R549

10.0

R492

2.67K

R548

100

R493

J276

1.00

MR

534

2 .67K

R495

X29 1

2

3

20.0K

R498

150K

R497

1.00

M

R52

0

D415

1W12V

DZ16

X30

8

6

9

X30

10

12

11

C455

C454

100K

R48

0

+15V

1.00

MR

476

D406

1W12V

DZ1510.0K

R478

1W12V

DZ17

1.035V

C452

X2914

13

12

1.035V

C451

100

R47

7

10.0

K

R47

5

C449

C405

+15V

J21

4.75

K

R55

6

X232

4

5

10KCWR328

Q22N4401

100

R34

2

10.0

KR

330

511

R32

7

J281

D304

X18 1112

13

J288

2.21

KR

343

100

R470

J24

50V0.1

C424OCI3

Vcc

GND

HP2231

5

8

+15V

/PB_OPTION

/PB_LOCALP BOOST

SS_WIRE

+15V

ON

OPTO

H = STAINLESS

L = MILD

C

L=DISABLE LOCAL PB TIME

ISOLATOR

BOARD

DO

N_R

ESET

B

2901

H= OPTION PB TIME

1W15VDZ8

2.21

KR

344

TO FE (SHEET 2)FOR ENERGY CONTROLOPTION

WIRE TYPE POSITION

X18 108

9

+5.1V

L= O

PTIO

N P

B TI

ME

D

L=DISABLE OPTION PB TIME

B

DARL. DRIVE

OCI6

HP2231

4

3

100

R433

50V0.1

C430

X18 45

6

J26

J212

J28

J29

J213

J22

5-19-95

5-24-96E

2781-A

2781-A

G-3R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

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 providedfor 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

Control PC Board (G2782) Schematic 2 of 2

OCI2

HP2231

4

3

47.5K

R211 X28 2

4

5

J43

X281

6

7

1N4936

D2001.00K

R200

J48

26.7

R20

6

47.5

K

R231

10.0

R23

0

CNY17-3OCI7

42

1

6

5

1.30K

R220

+ t60V.13

R239

2.21K

R216

J42

1W43VDZ4

CR1

11

9

13

1.30K

R218

1.30K

R217

( SHEET 1 )

PWM ENABLE

OCI2

HP2231

1

2

TO DIGITAL LOGIC( SHEET 1 )

DV/DT LEVEL DETECT

( SHEET 1 )

( SHEET 1 )

PINCH KILLERVarc ADJUST

ARC/SHORT DETECTTO DIGITAL LOGIC

Y

CURRENTTRANS.

Y

BOARD

OVERVOLTAGE

ON POWER

TRIGGEROPTOCOUPLER

FEEDBACK 125:1 RATIOPRIMARY CURRENT

CIRCUITTRIGGER

TSTAT

24 VAC

TSTATCHOKE

BOARD

OPTOCOUPLERSON PROTECTION

T1 AUX XFMR

OVERHEAT INDICATOR

150

FAN

R

5W

FAN

Y FROM SHEET 1OVERCURRENT FAULT

1N4936

D20522.1K

R210

C203

J46

J410

TO ANALOG LOGIC

TRIGGERINTERFACE

( SHEET 1 )

J411

1.30K

R219

J412

1.30K

R221

J45

1W43V

DZ5

1.30K

R224

1.30K

R223

4093B

X6

7

14

1N4007

D108

J58

C112

500

CWR158

X414

13

12

1N4007D109

J5

2735V

C119

243

R157

1.82K

R156100035VC111

J176

50V0.1C125

D107

SMP04

X3

Dgnd Vss

Vdd

8

16

13

50V0.1C121

2735V

C117

J1712

1400V.0047C113

J54

D114C120

OP470

X4

V+

V-

4

11

50V0.1C124

ADJ

IN OUT

s15128-15k1

X1

D112

OUTIN

GND

X2

s15128-12

D113

4735V

C115

C116

J1711

1400V.0047C114

1N4007D110

1N4007D111

J175

+12VFE

+12VFE

FE

+12VFE

FE

X6 45

650V0.1

C126

OCI6

HP2231

6

X48

9

10

+12VFE

-15VFE

COMPARATOR

FEFE

50V0.1

C128

50V0.1

C127

OCI6

Vcc

GND

HP2231

5

8

50V0.1

C122 OCI1

Vcc

GND

HP2231

5

8

50V0.1

C129

LM2901

X5

3

12

50V0.1

C123

C118

+12V OUT

XFMR

18 VAC

18 VAC

CT

36 VAC

COMMON OUT

-15V OUT

OP AMP7915

A

Energy Tr igger Circuit

I /O and VacOption

J5

1

85

4 Front EndVac and Varc 7

6

12

1

J4

7

6

12

1

J17

Control

ENERGYCONTROLOPTION

NEG FE POWER NET

DOP470

POWER SUPPLY FOR "FRONT END"

H = STAINLESS

L = MILD STEELB

UNUSED GATES

COP470

NANDC

POS FE POWER PLANE

OCI5

Vcc

GND

HP2231

5

8

J173

+12VFE

FE

ISOLATED CIRCUIT

LM350

NAND

POS FE POWER PLANE

FE GROUND PLANE

SENSE PANEL

ENERGY CONTROL

PHASE B

G

FRONT END

+ STUD

INPUT FROM

- STUD

VOLTAGE

H = START PLASMA BOOST TIMING

L = NOT PLASMA BOOSTOCI6

HP2231

7

OCI1

HP2231

7J171


ENERGY CONTROL OPTION


Ch'ge.Sht.No.

SCALE

DATE

NONE


Q10

OCI7

LABELSX36129, 211, 314, 475

D-

165, 242, 345, 564

LAST NO. USED

C-

R-

SUPPLY


COMMON CONNECTION

VOLTAGE NET

FRAME CONNECTION

NOTES :


N.A. S INCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE

NUMBER.

WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY

DZ20

117, 211, 310, 424

( SHEET 1 )

ENERGY CONTROL

PINCH SIGNAL FOR

OPTION ENABLE

ENERGY CONTROLOPTION P BOOSTTIME ( SHEET 1 )

-15VFE

FE

-15VFE

WIRE TYPE POSITION

CLEVELAND, OHIO U.S.A. SUBJECT

TYPE

G

STT CONTROL

NO.SHT.

04/04/94MLD CHK.DR. SUP'S'D'G.

200 SERIES- TRIGGER CIRCUIT (SHEET 2)

400 SERIES- ANALOG LOGIC CIRCUIT (SHEET 1)

ELECTRICAL SYMBOLS PER E1537UNLESS OTHERWISE SPECIFIED)

300 SERIES- DIGITAL LOGIC CIRCUIT (SHEET 1)

EQUIP.

DIODES =

+ t56

R238

CAPACITORS =

1A, 400V (UNLESS OTHERWISE SPECIFIED)

100 SERIES- ARC SENSE CIRCUIT (SHEET 2)

REFERENCE DESIGNATOR SERIES DEFINIT IONS

MATERIAL TOLERANCE ("t") TO AGREEON ALL ANGLES IS + .5 OF A DEGREE


ON 2 PLACE DECIMALS IS + .O2ON HOLES SIZES PER E-2056

ON 3 PLACE DECIMALS IS + .OO2

MFDRESISTORS = Ohms (

.022/50V1/4W

GENERAL INFORMATION

SCHEMATIC (Sheet 2 of 2)

(UNLESS OTHERWISE SPECIFIED)

W4

ENERGY CONTROL OPTION( SHEET 1 )

UNUSED

TO POWER ISOLATED CIRCUITBOARD

TRIGGER

C D

ON SHEET 1X28 "D" COMPARITOR

COMPARATOR

FILE: G2781_1D1

PB_START SIGNAL FOR

ENERGY CONTROL OPTION( SHEET 1 )

( SHEET 1 )

+15V

J44

J41

J49

LM2901

X28

3

12

J47

50V0.1C211

100V100p

C105

1N91

4D1

16X5 14

8

9

10K

R142

X3

SMP04

17

5

50V820pC110

825

R165

3 .92KR164

22.1

K

R132

X3

SMP04

1410

12

SMP_

STR

OB

E

13.7K

R122

+12VFE

+12VFE

FE

C

OLD DV/DTVarc SAMPLE

SHORT DETECTVarc SAMPLE

D

H=LOW DV/DTL=HIGH DV/DT

DV/DT 10XAMPLIFIER

ARCDETECTOR

A

2

2901A

ARC

ARC

_TRI

P

OP470B DV/DT

22901dv/dt

B

B

DV/DT SAMPLE PULSE

D2901

10K

R148

10K

R145

100K

R143

J174

68.1

KR1

27

1 .00M

R124

X52

4

5

X4 7

6

5

100K

R144

X5 13

10

11

8.25

K

R146

68.1

KR1

23

47.5

KR1

14

100V100pC103

51.1

K

R126

10K

R147

1N914D117

4.75K

R128

50V820pC109

X3

SMP04

159

11

1N914D102

4.75

K

R125

267K

R135

13.7K

R116

13.7K

R118

1N4007D100

26.7

K

R129

13.7K

R120

50V.0047

C104

20.0

K

R162

1W12V

DZ2

20.0

K

R108

DT

J178

X6 1112

13

1N4936D105

1N4936D106

J179

1.50K

R155

OCI5

HP2231

6

100V330pC106 X6 10

8

9

OCI3

HP2231

4

3

J177

OCI3

HP2231

1

2

681

R151

J172

1.50K

R161

332

R149

1 .50K

R160

X6 32

1

4.75

K

R136 1N914

D115

1.00K

R134 3.92KR163

47.5K

R133

3.92

K

R130

1 .50K

R154

OCI5

HP2231

7

3.92

K

R131

1N914D103

5KC

W

R150

1N914

D104

OCI1

HP2231

6

3.92

K

R152

Q12N4401

3.92KR153

X5 1

6

7

1W15V

DZ3

FE

FE

+12VFE

NEG_CLAMP

FE

FE

DT_

DEL

AYED

OU

T

B2901

A

C

DT_DELAYED D

DT_RC

OPTION ENABLE

PHASE A

OPTION P BOOSTTIME

ENERGY CONTROL DIODE ON = OPTION P_BOOST TIME

DIODE OFF = LOCAL P_BOOST TIMEOR NOT OPTIONP_BOOST TIME

B

AL = NOT PINCH

H = PINCH

ADIODE ON = OPTION ENABLED

DIODE OFF = OPTION DISABLED

1.89V NORMAL2.3V PINCH START

FOR INITIAL

ARC DETECTOR

PINCH PULSE

ADJUSTMENT

H=SHORTL=ARC

B

PWMFROM

FROMPWM

DT

DT

ATRUNCATES DT_DELAYED

B

13.7

K

R102

13.7

K

R100

2.67

K

R138

J1710

J53

J5+12VFE

+12VFE

FE

CONTROL OPTIONTO ENERGY

Varc FILTERED

ARC VOLT FILTER100V100p

C102

13.7

K

R106

13.7

K

R104

13.7

K

R107

13.7

K

R10513

.7K

R103

13.7

K

R101

B

8.95V

2901

CR 1( UNUSED

TO POWER BOARD

CONTACT )

L=PWM OFFH=PWM ON

100K

R23

5

C202

15.0

K

R212

100V330pC205

47.5

KR2

15 50V0.1C20410K

R214

D211

50V20C207

267

R229

1W3.3VDZ6

D210D209

10K

R24

0

D208D207

1.50K

R227

1.50K

R226

1.50K

R228

1.50K

R225

CR16

8

4

D206

1.30K

R222

ON=TRIGGER ONOFF=TRIGGER OFF

PWM_EN

PRI_FB

+15V

+15V

+15V+15V

3.6V

L=PWM ONH=PWM OFF

1.7V = 150A PRIMARY

C2901

2901A

( SHEET 1 )

10K

R213

10K

R23

7

X28 14

8

9

10.0

R20

3

10.0

R201

10.0

R20

2

10.0

R20

4

1N4936D202

1N4936D201

1.30

K

R24

2

10.0

R20

5

C201

26.7

R20

9

26.7

R207

267

R241

26.7

R208

+15V

1N4936D203

1N4936D204200V

.33

C200

100K

R23

2

10K

R23

6332K

R234

C206

10K

R23

3

AOP470

VARC_SCALED

13.7K

R115

50V0.1C10710K

CW

R140

BTURN10

.400V

243

R139

X3

SMP04

26

3

J51

1.820V

C108

10K

R137

8.25

K

R141

4 .75KR159

13.7K

R121

X41

2

3

47.5K

R110

4.75

K

R113

DV/DT VarcSAMPLE

DV/DT

DERI

VATI

VE_T

RIPA

Varc SAMPLENEW DV/DT

1V REF

1N914D101

J55

13.7K

R117

13.7K

R119

J56

FE

FE

NEG_CLAMP

FE

+12VFE

FE

+12VFE

+12VFE

FE

FE

+12VFE

+12VFE

+12VFE

FE

FE

3000V.0047

C100 47.5K

R112

1W12VDZ1

400V.001C101

4.75

K

R111

47.5K

R109

2781-BFV

2781-B

5-19-95

2

7

5-24-96E

G-4R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

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 notavailable 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 resultin danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the machine.

Ret

urn

to S

ectio

n T

OC

Ret

urn

to S

ectio

n T

OC

Ret

urn

to S

ectio

n T

OC

Ret

urn

to S

ectio

n T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

ITEM REQ'D PART NO IDENTIFICATIONIDENTIFICATIONPART NOREQ'DITEM

CAPACITORS = MFD/VOLTSRESISTORS = OHMS

J1 J4 J17 J5 J27 J28 J2 J3

D10

5 D

106

D200

D20

1 D

202

D20

3 D

204

D205

DZ1

DZ2

DZ3

DZ4

DZ5

DZ6

Q1

D10

1

D10

2

D103

D10

4

D107 D112

D113

D114

D20

6 D

207

D20

8

D209

D21

0

D211

D100

D108

D109

D110

D111

C113

C114 C100

R15

1

R12

3

R127

R14

1 R

146

R150

R111

R11

3

R12

8

R136

R159

R109

R110

R11

2

R11

4

R133

R211

R215

R231

R12

6

R23

4

R13

0

R13

1

R21

6

R210

R157

R22

9

R138

R14

9

R100 R101 R102 R103

R104 R105 R106 R107

R115

R116

R117

R118

R119

R120

R121

R122

R15

4 R

155

R16

0 R

161 R

225

R22

6

R22

7

R22

8

R212

R108 R162

R12

4

R21

7

R21

8

R21

9

R22

0

R22

1 R

222

R22

3 R

224

R13

7

R14

2

R14

5

R14

7

R148

R213

R214

R233

R237

R24

0

R14

3

R144 R232

R235

R134

R200

R201 R202 R203 R204 R205

R230

R20

6 R

207

R208 R209

C122

C12

3

C12

4

C125

C12

6

C12

7

C12

8

C204 C211

R23

8

R239

C106

C205

C107

C121

C11

2 C

116

C118

C120

C201

C202

C203

C206

C104

X6

X5

X28

X2

X1

R14

0

C102

C10

3

C105

C11

9

C20

0

C11

1

CR

1

OCI7

OC

I1

OC

I2

OC

I3

OC

I4

OC

I5

X3

C108

C20

7

C101

R43

3

C41

3

R47

0 C

411

C43

0

R463

R461

R46

7

R46

6

C42

3 D41

2

R51

9

R51

3

DZ2

0 D

Z9

C46

4

X35

R51

8

R52

1

R514

R52

2

R510

Q8

R525

R523

D410

R51

6 R

517

R52

4

R50

9 Q

7

D41

6 R

512

R51

5

R48

9

C446

R47

8 R

476

C447

D407

DZ15

C449

X29

D408 R475 R480

D406

R481

Q6

C469

R485

R47

7

R40

5

C409

DZ1

2

R50

7

R46

9

C404

DZ1

1

D40

9

C40

5

X31

X3

4

C466

C457

R403

R533

C402

DZ10

C403

C40

6

X22

R340

Q3

R33

3

X32

C42

9

R30

8 R

309

D305

X17

C444

C45

6

X12

X20

X15

X10

X13

X14

X9 X1

1

X18

X16

X19

X21

X23

X24

R30

1

R302

R313

R312 C304

C44

3

C435

R32

0

C306 R317

C433

C301 R303

R305

D30

0

R304

C30

2

C432

Q4

R322

C307

R323

R32

8

D301

C43

4

R314

C437

C445

C43

8

R33

2 R

329

R325

R32

7

D30

4

R32

6

R31

6 R

311

R310

R345

C309

DZ8

R34

2

Q9

R34

1

R31

9

R48

3 R

484

X26

R482

R486 R487

R488

R51

1

D413

C462

DZ19

C463 R527

R528

R52

6

C41

2

C31

0

D306

D307

D308

C312

R33

7 C31

4

X36

D411

R50

0

C460

DZ18

R50

1

C40

1

C40

0

X33

R50

5

R50

6 R

400

R40

1

R40

4

D400

R43

4

R49

1

X30

R

435

R44

3

R490 R

534

C452

D41

4

C45

4

R49

2

R49

3

R520

C451

DZ17

C455

D415

R496

C453

R440

C416

C450

R445

C417

R444

R448

R447

D404

R442

R499 C470

D418

D419

D417

R45

0

R52

9

R45

7

R458

R45

9

D40

5

C42

2

R455

R468 C414

R441

R449

D40

3

D402

R420

R419 R421

R422 R423

D401

C410

R532

R425

R427 R428

R426

R42

9

C42

4

C45

8

C42

8

C427

C426 C

425

C46

8

C436

C46

7

C44

2

C441

C43

9

C44

0

C459

C419

R45

4 R

456

D310

D309

DZ1

6

C465

C461

R30

0

C415

C407

R412

R41

3

R414

C44

8

R473

C308

R536

R479

STT

CO

NTR

OL

R158

R156

C11

7

R13

2 R

129

R15

3

R13

5

R12

5

C110

C11

5

C300

C31

3

X8

R33

8 R

339

R446

R47

1

R31

8 C

305

D30

3

R321

C41

8

R439

R453

R41

7 R

418

R472 R474 R432 R436 R437

R43

1

Q2

R343

X4

C10

9

R15

2

R50

4

R508

R40

7

R32

4

R494

R497 R498

R50

2

R503

R40

6

R411

R410 R409

R451

R452

R424

R49

5

R344

R416

R415

D302

R306

R307

C303

C31

1 R334

R33

5

R408

R430

R242 R241

R236

R54

3

R54

2

R541

R561

R56

2 R

563

D42

3

R560 D424

C475

R55

9

Q10

R55

0

R54

9

R548 R547

R54

6

R545 R544

R551

C472

R552

R55

5

C473

R564

R554

R55

3 C

474

R539

C471

R53

7

R538

D420

R557

R33

0

D421

D422

R331

R16

4

D11

7 D

116

R16

5 D

115

R163

OC

I6

R139

R40

2

R54

0

R556

C12

9

R53

0

X25

W1

W2

W3

W4

G27

82-[

]

2782-1

5-19-95

7-28-95C

5-24-96E

STT INVERTER WELDER CONTROL P.C. BOARD ASSEMBLY

F.V.

FULL

2782-1 FV 6-8-94 L8441-3 t

UNLESS OTHERWISE SPECIFIED TOLERANCEON HOLE SIZES PER E2056ON 2 PLACE DECIMALS IS .02

WITH PUBLISHED STANDARDS.

ON 3 PLACE DECIMALS IS .002ON ALL ANGLES IS .5 OF A DEGREEMATERIAL TOLERANCE (" ") TO AGREE

THE LINCOLN ELECTRIC CO.CLEVELAND, OHIO U.S.A.

EQUIP.

TYPE

SCALE

DR DATE CHK REF.

SUBJECT

SUP'S'D'G

SHT.

NO.

THE LINCOLN ELECTRIC CO.OWNED BY AND IS

NOT TO BE REPRODUCED, DISCLOSED OR USED

THE LINCOLN ELECTRIC CO. GG

WITHOUT THE EXPRESS PERMISSION OF

THIS SHEET CONTAINS PROPRIETARY INFORMATION


INVERTEC STT

Control PC Board (G2782) Layout

G-5



INVERTEC STT

Power Board (L8033) Schematic

X414

13

12

P6 J64

267

R24

4.75

K

R23

P6 J65

D12

5.11

K

R25

D10D8

C11

P6 J610

LM350

ADJ

OUTIN X5

33.2K

R13J14

4

D11

50050V

C10

15.0K

R14

P6 J69

15J50VTP2

D9

C7

X41

2

3

Ch'ge.Sht.No.

COM

+24V

COMCOM

C

24Vac

A

ON 3 PLACE DECIMALS IS + .OO2ON 2 PLACE DECIMALS IS + .O2

ON HOLES SIZES PER E-2056

ON ALL ANGLES IS + .5 OF A DEGREEMATERIAL TOLERANCE ("t") TO AGREE


85

41J7

1

3

J142

4

J65

6

1

10

LM224

X4

4

11

33.2

KR1

6

1N4936D14

1W15VDZ1 S

G

D Q5

P7J74

X47

6

5

2.21K

R21

UNLESS OTHERWISE SPECIFIED) LABELS

SUP'S'D'G.

TYPE

VOLTAGE NET

DZ- 6D-

SUPPLY

C-R-


SUBJECT

EQUIP.

161/4W.022/50V

FRAME CONNECTION

11/10/92SHT.

INVERTEC

MM

(

P7J72

P6J62

NO.

10K

R19

LAST NO. USED

33.2K

R17

14

COMMON CONNECTION

CHK.


NONE

69

475K

R12

COM

COM

B

IRF513

D13

X48

9

10

100K

R22

CNY17-3

OCI1

2

1

6

5

4

1.820V

C6

267K

R20

26.7K R18

C14

3920V

C540V600mAQ40

1W6.2VDZ6

10K

R11

100K

R10

100

R43

10K

R41

100

R42

150K

R9

33.2K

R15

16018

F

E

P6

J6

8

1.0A30V

D161.0A30V

D15

P7J77

CONTROLTRIGGER

TO PULSE

TOPILOTLIGHT

(-)

TOCONTROLBOARD(COM)

DIAGRAM MAY NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS

WITH PUBLISHED STANDARDSDATE

TRANSFORMER

16018MJHDR.

HAVING A COMMON CODE NUMBER.


GENERAL INFORMATION


WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS

RESISTORS = Ohms (CAPACITORS = MFD

NOTES :

1A, 400VDIODES =

POWER BD SCHEMATIC


UNUSED

SCALECLEVELAND, OHIO U.S.A.


FILENAME: M16018_6JA

M

TOCONTROL

BOARD(+15V)

PWMSIGNAL

TRANSFORMERFROM AUXILIARY

18Vac

LM350

PWMSIGNAL

TOPILOTLIGHT

(+)

N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE

RELAY COILS

FROM PROTECTION BD.

P6J67

+15V

J142

267

R7

P7J78

+ t.24

R69

Vin + Vc

OUT

GND

N.I. IN

INV IN

X67

267

R8

P7

J7

1

1W12V

DZ5

P6

J6

1

100K

R6

15J50VTP1

D1 D3

ADJ

OUTINX1

5W1.0

R1

330050V

C1

243

R3

+ t

.25R44

D4

P7

J7

3

P6

J6

6

P7 J76

2.67

KR

2

P6

J6

3

1.0A30V

D71W12VDZ4

15050V

C3

D2

100K

R5

P7 J75

C2

D5

1.50

K R4

50V0.1C9

J143

J141

50V0.1C8

1.0A30V

D6

Vin + Vc

OUT

GND

N.I. IN

INV IN

X68

COM

+24V

COM

+24V

+24V

COM

D

+24V

3-22-919-11-92B6-25-93A9-24-93D

4-13-95C3-29-96L9-27-96F

10-25-96

G-6R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Power Board (L8033) Layout

CAPACITORS = MFD/VOLTS

ITEM REQ'D PART NO. IDENTIFICATION

INDUCTANCE = HENRYS

DC

B

F

E

PO

WER

BO

AR

D

X1

X5

C1

C3

C10

X4

TP2

TP1

J6 J14 J7

OC

I1

Q5

Q40

R44 R1

L803

3-[ ]

X67 X68

R69

R2

R3

R

4

D5

R21

R22

R16

R17

R18

R19

C5

C7

R

9

R10

R

42

R14

R

13

R12

R11

R20

D13

R15

D10

D8

DZ1

D11

D9

C11

C

14

DZ6

R43

R41

R24 R23

R25

D12

D14

C6

D1

D3 D

2

D4

C2

C9

D15

D16

R6

DZ5

R7

R5

DZ4

R8

D7

D6

C8

G-7R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Darlington Drive Board (G2778) Schematic

ON 2 PLACE DECIMALS IS + .O2



SUPPLY

POWER

Ch'ge.Sht.No.


1A, 400VDIODES =

BASEDRIVE

2 AMP

Sym

met

ric G

ate

Driv

e La

yout

UNLESS OTHERWISE SPECIFIED)UNLESS OTHERWISE SPECIFIED)


ELECTRICAL SYMBOLS PER E1537(

GENERAL INFORMATION

.022/50V1/4W

NEGATIVE BIAS

HOLD - OFF

forDARLINGTON

NUMBER.

DZ-17

COMMON CONNECTION

R-

SUPPLY

LAST NO. USED

CHK.

VOLTAGE NET

LABELSC-

D-



MLD NO.SHT.

318

03/23/94

FRAME CONNECTION

DR. DATE

13

SUP'S'D'G.

SCALE NONE

EQUIP.TYPE

SUBJECTCLEVELAND, OHIO U.S.A.


BLACK

PAIR

BLUE

MODULE

TWISTED

B

C

E

DARLINGTON

FILE: M17581_1AB

3.92

K

R4

+V

1.50K

R3

D5

J134

J131

OCI1

HP2201

7

3

2

OCI1

Vcc

GND

HP2201

5

8

GND

50V0.1C14

330050V

C15

8A400V

D1

8A400V

D2

.5 5W

R1

8A400V

D3

8A400V

D4

J136

330050V

C12J13

2

J135

C16J13

3

GND

+V





WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAYN.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE

10VAC

R

6VAC

R

6

1 3

4

J13

NOTES :

+15V

1

3

J12

4

2

WINDINGTRANSFORMER

AUXILLARY

OFF = Dar l ington OFF

M 17581

STT CONTROL BOARD

1K

ON = Dar l ington ON

1.50K

R2

+V

50V0.1C6

10W

2.7

R10

10.0R6

D131N5402

S

G

D

100V

Q2

330050V

C9

1W18V

DZ3

D71N5402

10.0R7

D111N5402

10W

2.7

R9

D101N5402 1.

00K

R15D12

1N5402

10W2.7

R13

D91N5402

10W2.7

R14

J124

1000V500pC17

1.00

KR1

7

1.00

KR1

8

J121

1W18VDZ1

1000V500pC8

200V.33C10

6A100V

Q113

2

D81N5402 J12

2

10W

2.7

R11

D61N5402

1W12VDZ2

10W

2.7

R12

1.00

KR1

6

5W20

R8

267

R5

50V0.1C5 NC

GND

S V

OUT

IN OUT

GND

V S

X23

4

7

5

1

6

8

2

4429GND

+V

GND

J123

M17581

INVERTER WELDERSSCHEMATIC, DARLINGTON DRIVE

BS

4A

5-19-953-29-96L

G-8R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Darlington Drive Board (G2778) Layout

J12 J13

R15 R18 R17 R16

R14

R13

R10

R12

R9

R11

DZ1

C17

Q

1

R6

D4

D1

D3

D2

R1

C12 C15

C16

OCI1

D5

R3

R

2

D10

D11

D12

D13

R8

D6 D7 D8

D9

C10

C9

Q2

C8

DZ3

R7

C14

X2

C5

DZ2

R5

R4

C6

STT DARLINGTON DRIVE



XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XXX

XX XX

XX

XXX

X

XXXX X X

XX

X

XXXX

X XX

X

X

XXX

XXX

RESISTORS = OHMS

G2778-[ ]

G-9R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Switch Board (L8441) Schematic

W

W

R

600mA40V

Q7

1W3.3VDZ5

1.00K

R12

1/2W1

R15

100V1A

Q2

600mA40V

Q6

15.0K

R10

50V2700pC2

47.5

R35

1N4936D9

600mA40V

Q5

1W10VDZ1

1N4936D3

1W6.2V

DZ6

100V1A

Q3

1W10VDZ3

1/2W1

R11

1 .50KR7

1N4936D5

22.1K

R16

1N4936D2

40V600mAQ4

221

R4

100

R5

1.00K

R14

C1

20

R13

100R3

2N4401

2N4403

IRFD110

IRFD110

2N4403

2N4403

475

R42

RESISTORSNUBBER

1

---401

8

403

-

WIT

H P

UB

LISH

ED S

TAN

DAR

DS

8440

TRANSFORMER

LU

NLE

SS O

THER

WIS

E SP

ECIF

IED

TO

LER

ANC

E

NO

TES

:

NU

MBE

R.

ON

HO

LES

SIZE

S PE

R E

-205

6O

N 2

PLA

CE

DEC

IMAL

S IS

+ .O

2

R

Ch'g

e.Sht

.No.

CAPACITOR

ON

ALL

AN

GLE

S IS

+ .5

OF

A D

EGR

EEM

ATER

IAL

TOLE

RAN

CE

("t")

TO A

GRE

E

ON

3 P

LAC

E D

ECIM

ALS

IS +

.OO

2

FRANCE CANADA AUSTRALIA

INPUT12 NEGATIVE

PRIMARY

39.2K

R38

1N4936D10

600mA40V

Q8

100

R24

40V600mAQ12

22.1K

R23

475

R291N4936

D8

C5

39.2K

R41

1200V.047C4

39.2K

R40

BYT30P600

A2

C2A1

2N4401

2N4403

IRFD110

IRFD110

2N4403

2N4403

A

1/2W1

R28

475R

37

C6

10.0

R27

10.0

R34

10.0

R26

10.0

R25

G1

IRFP460

D2

S4

D1 D3

G2

D4

S2 S5

D5

G3

S1G5

G4

S3

A110.0

R19

1W15VDZ7

100V1A

Q1

1/2W1

R22

1W10VDZ12

50V2700pC8

100V1A

Q10

15.0K

R32

1W10VDZ2 600mA

40V

Q9

1N4936D7

1W6.2V

DZ9

47.5

R36

BYT12P600C1

A1

A1

39.2K

R39

221

R2

1.00K

R21

20

R31

1 .50KR30

100R1

1N4936D6

600mA40V

Q11

1W3.3VDZ8

1N4936D1

1.00K

R20

CAP

ACIT

OR

S =

B

NO.

GEN

ERAL

INFO

RM

ATIO

N

(1/

4W.0

22/5

0VLA

BEL

S(U

NLE

SS O

THER

WIS

E SP

ECIF

IED

)

UN

LESS

OTH

ERW

ISE

SPEC

IFIE

D)

RESI

STO

RS =

Ohm

s (

1A, 4

00V

8440

NO

NE

M. A

. P.

THE

LIN

CO

LN E

LEC

TRIC

CO

.

CHK.

C-

D-

8

SC

ALE

DA

TE

SUPP

LYVO

LTAG

E N

ET

FRAM

E C

ON

NEC

TIO

N

CO

MM

ON

CO

NN

ECTI

ON

INVE

RTE

C V

300

EQUI

P.

LSH

T.

42 10

SUP'

S'D'

G.

CLEV

ELAN

D, O

HIO

U.S

.A.

TYP

E

SU

BJE

CT

MFD

---

4

402404

POSITIVE

1N4936D4

1W15VDZ4

475

R18

10.0

R9

10.0

R8

10.0

R17

10.0

R33

C7

10.0

R6

RESISTORSNUBBER

POW

ER S

UPP

LY S

OU

RC

E PO

INT

EAR

TH G

RO

UN

D C

ON

NEC

TIO

N

DR.

DIO

DES

=

LAST

NO

. USE

D

R-

SW

ITC

H B

OA

RD

SC

HEM

ATI

C

NO

T SH

OW

TH

E EX

ACT

CO

MPO

NEN

TS O

R C

IRC

UIT

RY

OF

CO

NTR

OLS

HAV

ING

A C

OM

MO

N C

OD

EW

ITH

OU

T AF

FEC

TIN

G T

HE

INTE

RC

HAN

GEA

BIL

ITY

OF

A C

OM

PLET

E B

OAR

D, T

HIS

DIA

GR

AM M

AYN

.A.

SIN

CE

CO

MPO

NEN

TS O

R C

IRC

UIT

RY O

N A

PRI

NTE

D C

IRC

UIT

BO

ARD

MAY

CH

ANG

E

UN

LESS

OTH

ERW

ISE

SPEC

IFIE

D)

ELEC

TRIC

AL S

YMB

OLS

PER

E15

37

PRIMARY5-

FILTERINPUT

TRANSFORMER

9 INPUT

1200V.047C3

BYT30P600

A2

C2

A2

G1

IRFP460

D2

S4

D1 D3

G2

D4

S2 S5

D5

G3

S1G5

G4

S3

A2BYT12P600

C1

A1

A2

FILE

NO

. L84

40-1

AA

11-2

5-91

BS

9-11

-92

10-8

-93A

G-10R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Switch Board (L8441) Layout


2

2

S16668-5 .022/50C1, C5, C6, C7

C3, C4C2, C8

4

2 S13490-112 .047/12002 S16668-4 2700pF/50

D1, D2, D3, D4, D5, D6,D7, D8, D9, D10 10 T12705-34 1N4936

2DZ1, DZ2, DZ3, DZ12DZ4, DZ7

T12702-27 1N47404T12702-29 1N4744AT12702-40 1N4735

Q4, Q12 2 T12704-686 T12704-69 2N4403

2N4401Q1, Q2, Q3, Q10 4 T12704-73 IC PKG MOSFET

R1, R3, R5, R24 4 S19400-1000 100 1/4WR2, R4 2 S19400-2210 221 1/4W

10 S19400-10R0 10 1/4W

R7, R30 2 S19400-1501 1.5K 1/4WR10, R32 S19400-1502 15K 1/4WR11, R15, R22, R28 4 T14231-20 1 1/2W

4R12, R14, R20, R21 S19400-1001 1K 1/4W

22

2

R13, R31R16, R23

R38, R39, R40, R41

R18, R29, R37, R42R35, R36

4

4

R6, R8, R9, R17, R19, R25R26, R27, R33, R34

S19400-20R0 20 1/4WS19400-2212 22.1K 1/4WS19400-4750 475 1/4WS19400-47R5 47.5 1/4WS19400-3922 39.2K 1/4W

Q5, Q6, Q7, Q8, Q9, Q11

DZ6, DZ9DZ5, DZ8 2 T12702-53 3.3V 1W

C3 C4

SWITCHR

19

R26

R

25

R27

R34

R33

R9

R

6

R8

R

17

R29

R1

R3

R18

R21

R23

R

20

R30

R31

R24

R

2

R32

R4

R

5

R7

R10

R

12

R13

R14

R16

R41

R40

R39

R38

R42

R37

R

36

R35

C

2

C8

C7

C1

C6

C5

C3 C4

DZ2

DZ1

D

9

D10

D5

D

4

D3

D

2

DZ6

D

Z4

DZ3

D8

DZ7

D

Z12

D7

D

Z9

D1

D6

Q10 Q1 Q3 Q2

B10 B3 B12 B1 B5 B9 B6 B7 B2 B11

R15

R11

R28

R22

B4 B8

Q

7

Q

6

Q

5

Q

4

Q

9

Q

8

Q12

Q

11

L8441-[ ]

DZ5

DZ8

G-11R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Driver Board (L9134) Schematic

Capacitor Pre-charging Circuits

J16

7

J113

J16

8

100

R12

DRIVE

GATE

GATE

GATE

GATE

T1

6

3

7

104

9

8

5

1

12

J91

J94

J93

J111

J104

150K

R6

100

R74A900V

Q1

20W

250

R1

1W12V

DZ1

150K

R3

150K

R4

20W250R2

150K

R5

J96

J106

J16

3

J101

J103

20W250R14

J16

1

1W12V

DZ2

150K

R10

150K

R11

4A900V

Q2

150K

R9

20W250

R13

150K

R8

J16

2

J16

13

J16

12

20799

Power Switch Drive Transformer

11-4-92LC

Ch'ge.Sht.No.

J11

S4 PROTECTION

N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGEWITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY

DATE

SUBJECT

EQUIP.TYPE

S2

NOTES :

NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODENUMBER.

G1

FROM

SUP'S'D'G.


S3




TO POWER

BOARD

TO


SWITCH

64

1 3

J16

MATERIAL TOLERANCE ("t") TO AGREES

G2

DR.

SCALE


G4

BOARD

S1

G3

NONE

CHK.

PROTECTION

SHT.NO. S

J9,J10

4

1 2

3

ON ALL ANGLES IS + .5 OF A DEGREE


BD.

20799

FROM

BD.

J16

14

7

14

1

8

FILE: S20799-1AA

INVERTER WELDERS

SCHEMATIC, DRIVER BOARD

BS

6-25-93C

G-12R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Driver Board (L9134) Layout



INDUCTANCE = HENRYS

T1

J9 J10

J11

J16

R7

DZ1

Q1

R1 R2

R3

R4

R5

R6

Q2

R13 R14

DZ2 R12

R11

R

10

R9

R

8

L9134-[ ]DRIVER

XXXXXXX

XXXXXXX

XXXX

XXXX

XXXXX

XXXXXXXXXXXXX

XXXX XXXXXXXXXXXX

XXXX XXXXRESISTORS = OHMS/WATTS

G-13R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Protection Board (L7915) Schematic

2735V

C2

1.82K

R3

J15

6

J15

3

332

R35

267K

R36

50V.022C4

1W10VDZ1

CNY17-3VOCI4

42

1

6

5

10K

R26

332K

R22

X11

2

3

D6

56.2K

R9

1.82K

R16

1 .82K

R13

150K

R11

10K

R28

D4 15.0K

R33

CW

5KR7

150K

R12

267K

R34

CW

5KR20

332

R37

J15

1

50V.022C3

GND

IN OUTX2

J15

4

CNY17-3VOCI3

42

1

6

5

+5V

+5V

TO CONTROL BD.

(Single Phase)C5

CNY17-3VOCI1

42

1

6

5

J84

CHK.

15.0K

R25

SUBJECT

15.0K

R24

NO.DATEDR.

CLEVELAND, OHIO U.S.A.SHT.


MMSUP'S'D'G.

NONE

TYPE

_

R-

LAST NO. USED

INVERTEC V300

PROTECTIONSCALE


_

_

(Over Voltage)

C-

TO DRIVER BD.

D-

VOLTAGE NET

COMMON CONNECTION

FRAME CONNECTION


1/4W(

UNLESS OTHERWISE SPECIFIED).022/50V

EQUIP.

(UNLESS OTHERWISE SPECIFIED)1A, 400V


SUPPLY

WITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAYNOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE

LABELS


N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGE


DIODES =

GENERAL INFORMATION



(Over Voltage)

UNLESS OTHERWISE SPECIFIED TOLERANCE Ch'ge.Sht.No.ON HOLES SIZES PER E-2056


TO DRIVER BD.

M

FROM (-) LOWER CAPACITOR

FROM (+) UPPER CAPACITOR

FROM BLEEDER RESISTOR

16097

15.0KR30

X114

13

12

FROM (-) UPPER CAPACITOR


J82

15.0K

R31

15.0K

R23

1N4007D8

LM224

X1

4

11

15.0K

R29

C1

D3

+5V

H5

NUMBER.

NOTES :

FROM CENTER LEG OF INPUT

B51

B14

B53

D7

681K

R1

+5V

56.2K

R10

+5V

150K

R5

C6

X17

6

5

D5

10K

R32

CNY17-3VOCI2

42

1

6

5

(Over Voltage)TO POWER BD.D1

X18

9

10

56.2K

R6

B52J8

1

100K

R14

3.32K

R19

475

R15

56.2K

R27

10K

R18

J83

56.2K

R8

150K

R4

15.0K

R21

681K

R2

FILE: M

16097BS/DB 9-7-89 TJP

1-25-919-11-92B

16097-2F1

12-10-93A

G-14R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Protection Board (L7915) Layout

PR

OTEC

TION

52

5314

H5

51

L7915-[ ]

R37

R34 R36

R35

R12

R14

R13

R23

R24

R25

R29

R31

R30

R16

R33

R19 R28

R21

R22

R15

R1 R2

R3

R4

R9

R10

R8

R27

R6

R5

R11

R32

R26

R18

C1

C3 C4

C2

DZ1

D8

D7

D1

D5

D4

D6

D3

X1

J8

J15

OCI1 OCI2

OCI4 OCI3

B5

B53

B52

B51

B14

R20

R7

X2

C5 C6

G-15R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Current Sense Board (M17591) Schematic

C1

20K

CW

R6

2KCW

R2

6.81KR7

1.50

KR1

1.00K

R4

50V150pC2

X1 1

2

31.

00K

R3

100

R5

681K

R11

10.0

K

R16

13.7K

R9

681KR8

J181

X17

6

5

13.7K

R10

X1 8

9

10

+VH

-VH

-IC

+IC

X2 1

4

2

3

1.50KR14

X3

TL431 REF8

1

6

100

R12

50V0.1C4

LT1014

X1

4

11

50V50C3

J182

C5X1 14

13

12

2.94K

R13

10.0

R15

J183

+15V

+15V

100V3AQ1

J184

CURRENT CAL

FILE: S21410_1BA

SENSOR

3.8V = 38 mA

EXCITATION CURRENT MIN OFF SETADJUSTMENT

HALL EFFECT

100A/V CURRENT OUT

1014

S

1014

1.6V = 16 mA

VREF

SOURCE

21410

1014


NOTES :

UNLESS OTHERWISE SPECIFIED)BOARD.

1J18

2

43


THE LINCOLN ELECTRIC CO.AND IS NOT TO BE REPRODUCED, DISCLOSED OR USED WITHOUT THE EXPRESS PERMISSION OF

VOLTAGE NET


LABELS

FRAME CONNECTIONSUPPLY

1014


21410


RESISTORS = Ohms (

SINCE COMPONENTS OR CIRCUITRY ON

CODE NUMBER.


THE INTERCHANGEABILITY

Ch'ge.Sht.No.

SHOW THE EXACT COMPONENTS

OR CIRCUITRY OF

THIS SHEET CONTAINS PROPRIETARY INFORMATION OWNED BY

( UNLESS OTHERWISE SPECIFIED)

N.A.

OF A COMPLETE

A PRINTED

THIS DIAGRAM MAY NOT

CIRCUIT BOARD

1A, 400VDIODES =


MAY CHANGE

1/4W

GENERAL INFORMATION

CAPACITORS = .022/50VWITHOUT AFFECTING

MFD

EQUIP.

NONEON 2 PLACE DECIMALS IS + .O2

CONTROLS HAVING A COMMON

ON ALL ANGLES IS + .5 OF A DEGREE


MATERIAL TOLERANCE ("t") TO AGREE

COMMON CONNECTION

SCHEMATIC

DR. SUP'S'D'G.DATE SCHK.SHT.NO.MLD


SCALE03/21/94

STT-CURRENT SENSE

SUBJECTCLEVELAND, OHIO U.S.A.TYPETHE LINCOLN ELECTRIC CO.

FV

5-19-95

9-27-96F

11-15-96E

G-16R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Current Sense Board (M17591) Layout

C1

C2 C5

J18

R1 R2

R3

R4

R5

R6 R7

R8 R9

R10 R11

R12

X1

STT CURRENT SENSE

R13

R14 R15

R16

X3 C4

C3

M17

591-

[ ]

X2

ITEM REQ'D PART NO. DESCRIPTION


XXXX

XXXX

XX

XXXXXX XXX

XXXXXXXXXX

XX XXX XXX

XXXX

X

XXXX

X X X

X X

Q1

G-17R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

Remote Protection Board Schematic

J361

600V.05C15

3000V.0047C7

.39mH

L6.39mH

L5

.39mH

L3

3KV.0047C63KV

.0047C1

3KV.0047C43KV

.0047C3

3KV.0047C2 3KV

.0047C5

J3616

J365

.39mH

L2

J333

J356

J3612

J3614

J3613

J368

J332

J3610

J3611

J336

J345

J346

3000V.0047C8

J362

J337

3000V.0047C9

160J320V

TP1

B25W1200

R1

J364

J353

J354

J367

80J150VTP3

J351

3000V.0047C11

3000V.0047C10

J355

J352

J344

J348

J335

B1

160J320V

TP2

J3615

3000V.0047C12

600V.05C16

J334

J366

.39mH

L4

.39mH

L7

J338

J369

J341

(+) STUD

(-) STUD5W1200

R2

TYPE

SUBJECTNONE

CHASSISCHASSIS CHASSIS

04/20/94

3000V.0047C14 J37

3

332

R4J37

1

3000V.0047

C13

J3310

332

R8

332

R3

332

R5

332

R6J33

9

DATE


NOTES :

NUMBER.NOT SHOW THE EXACT COMPONENTS OR CIRCUITRY OF CONTROLS HAVING A COMMON CODE

N.A. SINCE COMPONENTS OR CIRCUITRY ON A PRINTED CIRCUIT BOARD MAY CHANGEWITHOUT AFFECTING THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY

GENERAL INFORMATION

ON ALL ANGLES IS + .5 OF A DEGREEON 3 PLACE DECIMALS IS + .OO2



MATERIAL TOLERANCE ("t") TO AGREE

UNLESS OTHERWISE SPECIFIED TOLERANCE Ch'ge.Sht.No.

(UNLESS OTHERWISE SPECIFIED)RESISTORS = Ohms (

(

DIODES =

CAPACITORS = MFD

1A, 400V

VOLTAGE

1

SENSE

THE LINCOLN ELECTRIC CO.EQUIP.


332

R7

10 PIN REMOTE

OPTIONAL

J

A

10K

POT

GND

C

D

FILE: M17609_1BA

UNLESS OTHERWISE SPECIFIED) LABELS.022/50V

1/4W

STT REMOTE PROTECTION BOARD

3


DR.WITH PUBLISHED STANDARDS

FEEDER AMPHENOL

N

42 VAC

MSHT.NO. M

SCHEMATIC


17609MLD CHK.

SCALE

POT

INTERFACE

10K

REMOTE

PB

COMMON CONNECTION

VOLTAGE NET

FRAME CONNECTION


J343

J331

17609

I

E

J347

J363

J374

J372

J342

M

AMPHENOL

.39mH

L1

7

2

I

K

8

C- 16

TRIGGER

BG

GND

SUP'S'D'G.

C

0

115 VAC

SUPPLY

LAST NO. USED

D-

R-

42

H

F

TRIGGER

41

B

31

A

J

L-

TP- 3

32

21

B

G

D

14 PIN WIRE

G

F

E

M

H

L

4

F.V.

5-19-95

G-18R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC



INVERTEC STT

G-19R

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

CR

etur

n to

Sec

tion

TO

C

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC

Ret

urn

to M

aste

r T

OC Wiring Diagram

R

32A32B

1516

J22

R

B18V

32C

43A

R

U3

18V

501

B

504

W45 5

2751863

311 10J6

1

212A97

212

352

212B503A

Y301305245223

81131

3 50324V

351

244

CASE

CASEBACK

PLATFORM

4 AMP

S

BOTTOM

S

OUTSIDEIY Y

4,5

12D

NO

O12

H3H1

FAN

SLOW

12B

RIGHT

MOTOR

BLOW

H1

1

J11

6 5

379

2

J9

CR2

H3

3 4

2W10K

CW (MAX)

353

362

363

CONTROLBACKGROUND

2

12674

10

3

ASSEMBLY

INPUT

LINE

POWERLINE

LOAD

N.L.

DC

B

A

F

S1POWER

OFFW

ON

U

A

INPUT PER

R

N.A.V

B

BW

C

G

C

B

C

A

B

FILTER

A

52

TRIGGER

CORE

31756824

8

714

12C12D

- ARC

+ ARC

CURRENTMETER

VAC

12D

A

37811

363

J4

CW (MAX)

1 12 23 34 4565

359

358

2W10K R11

3

5

377

56

6TRANSFORMER D1

O

374N

I

OT3 CURRENT

N2

5N.E.

4371 1

3

43

10

J5R

210

211A

502

246

212C

J36

B

Y

9

364365366

25

1 367

369368

WB

2

4

129

1

5

789

13

10

1

J281011

89

7

5

8

10

53

14

2

46

6

J332

3723724371

5

J1

67

J27

2376

R

1

1

4

370 370

376374

371B

3

8

12

115V

37410

1

322

33B8

7 33A

J26

B

3

E

R

BW

4

290A

110

367A

369

.045

502 (-)

INDICATOR

J25

115

223

357356

5

3556

354

6

21

CB2

J37

403

504

TRANSFORMER AUXILIARYT1

AUXILIARY

T4N.D.

TRANSFORMER

131 501

220-

212A

150 5W

4

0V

H3

H2

H1H1

9A

9A

9D

9A

PROTECTION

13

9C

RW

S7RECONNECT

1

12B

12B

212C

287

43A

R18V

413

359

714

2

356

358

355354

357

352

1610

351

360

15

353

361

21

362

244303303

242

302

371A

302

374A

304304275

305

243

2301

4

240241

DARLINGTON

12

522

12D

24

W

1

D3

4

SF

5

D4

1BOARD3

J16

TOPD5

57 DRIVER

F

12B

MOTOR FANLEFT

H1

MOTOR

TOP

H3

FAN

H1 H3

H1

D13RECTIFIER

TP2

TP1

-TP3

9D

J16, J28

J34

A

N.K.413416

405

408

406

VAC

1

VAC

73

4321

F8

52

314315

J13

ELECTRODE SENSE LEAD

360

367

S2

VAC

368

367A

STAINLESS

R12

42

S3

.035

INTERFACE

503

TRIGGER

MILD

378

PEAK

377

PEAK

METERBACKGROUND

CONTROLHOT START

CW

WIRE TYPE

2W500K

TAILOUTCONTROL

R14

N.J.

REMOTE

15

407

2

6

63

115

350

J35

9

1211

6J17

J23J24

METER PINOUT (VIEWED FROM BACK OF METER)


W

18V

N

J2

2

J23

Y

380-

4

415V

H3

1

H2H3

230V

200-208V

N.M.

BACK

FOR SINGLE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.

6V

10V

J24

18V

THERMOSTAT

COLOR CODE:

U

FAN

U

Y

WRAP RED LEAD WITH TAPE TO PROVIDE 600V. INSULATION.

J26

CONNECT BLACK & WHITE LEADS TO SUPPLY CIRCUIT.

B = BLACK CASE TRAYG = GREENN = BROWN

FRONT

NOTES:

O = ORANGER = REDW = WHITE

N.A.

J25

Y = YELLOWU = BLUE

1. FOR MACHINES SUPPLIED WITH INPUT CABLE

N.M. PRESENT ON EUROPEAN VERSIONS, CODE 10383 AND HIGHER.

FOR SINGLE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.

CONNECT TERMINALS U, V & W TO SUPPLY CIRCUIT.

CONNECT TERMINALS U & W TO SUPPLY CIRCUIT.FOR THREE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.

N.B. SINCE COMPONENTS OR CIRCUITRY OF A PRINTED CIRCUIT BOARD MAY CHANGE WITHOUT AFFECTING

COMPONENTS OR CIRCUITRY HAVING A COMMON CODE NUMBER.THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY NOT SHOW THE EXACT

CONNECTION SHOWN IS FOR 440-460V OPERATION.N.D. PLACE "A" LEAD ON APPROPRIATE CONNECTION FOR INPUT VOLTAGE.

N.E. D1 THRU D5 OUTPUT DIODES ARE A MATCHED SET.D7 THRU D11 OUTPUT DIODES ARE A MATCHED SET.

9

N.F. R1, R9 BLEEDER RESISTORS ARE A MATCHED SET.

J21

1 N.G. C1, C2 CAPACITORS ARE A MATCHED SET.

P21

2

PINOUT OF FRONT PANEL CONNECTORS (REAR VIEW)

34

35

J29. J31

2

CONNECTION SHOWN IS FOR 380-460V OPERATION.6 N.H. PLACE SWITCH IN APPROPRIATE POSITION FOR INPUT VOLTAGE.

16

N.I. DENOTES A TWISTED WIRE PAIR OR GROUP.

15

P29, P31

24

3

J30

43

52

61

P30

6

1

15

J22

9

FOR THREE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.

2

24

3

2

N.K. NOT PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.4

1

105

3

11

4

612

N.L. PRESENT ON EUROPEAN VERSIONS, CODE 10309 AND HIGHER.

4

138

3

14

P22

158

16765

164

153

142

131

1211107

J38

J19

N.J. NOT PRESENT ON EUROPEAN VERSION.

2. FOR MACHINES NOT SUPPLIED WITH INPUT CABLECONNECT BLACK, RED & WHITE LEADS TO SUPPLY CIRCUIT.

J39

1 2 3 4

310309

310A310

309A

309A

310A

2

6

J7224A

102W

309

INSIDE

12B

25W

+2200 F

C1

-

BOARD25

450VR4

(RIGHT)

3415

307

236

308

J1089D

4

5252

2B

2

9

J34

J36

C42W R310 .001/400

N.E.

5W

12C 12A

S

F

OUTSIDETOP

CHOKE

BOARD

3

12A

J12J8

14

N.H.

BOARD

224

R

310

J15

316

9B9B

12B401, 403

1, 8 8

371J22

5112B

12B

TOP

12B

.001/400

CR1

25 2200 F450V

9A

25W -

+

53

9A

+

N.G.9

R612A

R7

12A 12R W R W

401, 403

402, 404

(LEFT)BOARDSWITCH

1, 8

25W25

4, 5

I

21

WIRE

8182

GND

424241

FEEDER

3231

J39

NBHLM

42

414

B

H1

+C

432

JA

812

TRANSFORMER

C8

288

4

2 300W289 R16

288A

SENSE

C2

L34

MAIN

13

289A

20/400

D11

T2

2J18 4

F S

4

313

3

32 J14

210A

210

THERMOSTATCHOKE

FANCASEBOTTOM

1

1

S

INSIDE

FBOTTOM

D9

BOTTOMD10

1

14

311

53

3

4

33C

N

J30

33

1

2 6

6

224

H6

H4

A

440-460VA

5

9

J3142V

H5

H4

115V

J21

R15

CE

2 300W

G

J38

409 A412 D404

CURRENT

F411

291

H GND

B

MODULEBR

DRIVE BOARD

14317

99B9B

402, 404+

N.G.N.F.R52525W25W

7500

R9

9B SWITCH

G3136

INLINE CONNECTOR CAVITY NUMBERING SEQUENCE(VIEWED FROM WIRE SIDE OF CONNECTOR)

DARLINGTON

EB

B402

W

401W

C

J

410 10K

PB10K

OPTIONAL

D

CB1

C

7675

6AMP

FG

43B42

9A

9D9C

345

BOARDPOWER

8309

7308307

W

14THERMOSTATW

HEATSINKJ22

503A

DARLINGTON

503B

242243

241

240

374A371A

11

211A

9

350

5

R125W7500

N.F.

D7

D8

R2

12

W

D2

C3

35314

J10, J13,J15, J35

J3, J9,

J2, J36J4, J17

(VIEWED FROM COMPONENT SIDE OF BOARD)

J5, J7,

E

1

I

34

77

K

Y

R13

(+)

10K

2

2W

CW (MAX)

3

361

CONTROL

366

503A

WIRE SIZE

THERMALOVERLOAD

364

365

7

6

8

5

1613

15

14

412

11

CONTROL

CURRENT

BOARD

415

31A33D

6AMP

46

246

245

2122

SHROUD

212B32C33C

D12

313

WIRING DIAGRAM - INVERTEC STT II

J6, J27, J33J18, J37J11, J12, J14

P.C. BOARD CONNECTOR CAVITY NUMBERING SEQUENCE

J1, J8,

BG

SENSE

(-)

VOLTAGE

CONNECTION(+)

21

J19

290

PROTECTION BOARDREMOTE

288B

TOROIDAL

289B

374

351H56

51

9B

N.L.

D-RW

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

january 1998 invertec & stt ii

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