ESAB Migmaster 250 Welding Packages Troubleshooting instruction

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INSTRUCTIONS for

MIGMASTER 250

WELDING PACKAGES

F-15-087-F

June, 1999

NOTE: This manual is also suitable for use with L-TEC Migmaster 250 package.

These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the principles of operation and safe practices for arc welding equipment, we urge you to read our booklet, "Precautions and Safe Practices for Arc Welding, Cutting and Gouging." Form 52-529. Do NOT permit untrained persons to install, operate, or maintain this equipment. Do NOT attempt to install or operate this equipment until you have read and fully understand these Instructions. If you do not fully understand these Instructions, contact your supplier for further information. Be sure to read the Safety Precautions Section before installing or operating this equipment.

Be sure this information reaches the operator. You can get extra copies through your supplier.

USER RESPONSIBILITY

This equipment will perform in conformity with the description thereof contained in this manual and accompanying labels and/or inserts when installed, operated, maintained and repaired in accordance with the instructions provided. This equipment must be checked periodically. Malfunctioning or poorly maintained equipment should not be used. Parts that are broken, missing, worn, distorted or contaminated should be replaced immediately. Should such repair or replacement become necessary, the manufacturer recommends that a telephone or written request for service advice be made to the Authorized Distributor from whom purchased.

This equipment or any of its parts should not be altered without the prior written approval of the manufacturer. The user of this equipment shall have the sole responsibility for any malfunction which results from improper use, faulty maintenance, damage, improper repair or alteration by anyone other than the manufacturer or a service facility designated by the manufacturer.

TABLE OF CONTENTS

SECTION NO. PAGE NO.

SECTION 1 - SAFETY PRECAUTIONS FOR WELDING

AND CUTTING ........................................................................................................... 3

SECTION II - INTRODUCTION .............................................................................................7

2.1 GENERAL ..................................................................................................................7

2.2 RECEIVING-HANDLING ............................................................................................7

2.3 DESCRIPTION, Available Packages/Contents ...........................................................7

2.4 OPTIONAL ACCESSORIES.......................................................................................8

2.5 SAFETY ................................................................................................................... 10

SECTION III - INSTALLATION ........................................................................................... 10

3.1 LOCATION ...............................................................................................................10

3.2 ELECTRICAL INPUT CONNECTIONS .................................................................... 10

3.3 SECONDARY OUTPUT CONNECTIONS................................................................ 13

3.4 TORCH CONNECTIONS ......................................................................................... 13

3.5 WIRE FEEDER MECHANISM.................................................................................. 13

3.6 CONNECTION OF THE SHIELD GAS ..................................................................... 14

3.7 WELDING CABLE CONNECTIONS......................................................................... 15

3.8 ASSEMBLE REAR WHEELS ................................................................................... 15

3.9 INSTALLING OPTIONAL SPOT/STITCH/ANTI-STICK MODULE ............................ 15

3.10 INSTALLING OPTIONAL DIGITAL METER .............................................................15

SECTION IV - OPERATION................................................................................................16

4.1 CONTROLS.............................................................................................................. 16

4.2 PROCESS SETUP ................................................................................................... 17

4.3 OPERATING PROCEDURES ..................................................................................20

SECTION V - SERVICE ...................................................................................................... 23

5.1 MAINTENANCE ....................................................................................................... 23

5.2 INSPECTION AND SERVICE .................................................................................. 23

5.3 TROUBLESHOOTING..............................................................................................24

SECTION VI - PARTS......................................................................................................... 27

6.1 SPARE PARTS ........................................................................................................27

6.2 REPLACEMENT PARTS.......................................................................................... 27

6.3 ORDERING ..............................................................................................................27

SAFETY PRECAUTIONS

WARNING: These Safety Precautions are for

your protection. They summarize precautionary information from the references listed in

Additional Safety Information section. Before performing any installation or operating procedures, be sure to read and follow the safety precautions listed below as well as all other manuals, material safety data sheets, labels, etc. Failure to observe Safety Precautions can result in injury or death.

PROTECT YOURSELF AND OTHERS -- Some welding, cutting, and gouging processes are noisy and require ear protection. The arc, like the sun, emits

ultraviolet (UV) and other radiation and can injure skin and eyes. Hot metal can cause burns. Training in the proper use of the processes and equipment is essential to prevent accidents. Therefore:

1. Always wear safety glasses with side shields in any work

area, even if welding helmets, face shields, and goggles are also required.

2. Use a face shield fitted with the correct filter and cover

plates to protect your eyes, face, neck, and ears from sparks and rays of the arc when operating or observing operations. Warn bystanders not to watch the arc and not to expose themselves to the rays of the electric-arc or hot metal.

3. Wear flameproof gauntlet type gloves, heavy long-sleeve

shirt, cuffless trousers, high-topped shoes, and a welding helmet or cap for hair protection, to protect against arc rays and hot sparks or hot metal. A flameproof apron may also be desirable as protection against radiated heat and sparks.

4. Hot sparks or metal can lodge in rolled up sleeves,

trouser cuffs, or pockets. Sleeves and collars should be kept buttoned, and open pockets eliminated from the front of clothing

5. Protect other personnel from arc rays and hot sparks

with a suitable non-flammable partition or curtains.

6. Use goggles over safety glasses when chipping slag or

grinding. Chipped slag may be hot and can fly far. Bystanders should also wear goggles over safety glasses.

FIRES AND EXPLOSIONS -- Heat from flames and arcs can start fires. Hot slag or sparks can also cause fires and explosions. Therefore:

1. Remove all combustible materials well away from the

work area or cover the materials with a protective nonflammable covering. Combustible materials include wood, cloth, sawdust, liquid and gas fuels, solvents, paints and coatings, paper, etc.

2. Hot sparks or hot metal can fall through cracks or

crevices in floors or wall openings and cause a hidden smoldering fire or fires on the floor below. Make certain that such openings are protected from hot sparks and metal.“

3. Do not weld, cut or perform other hot work until the

workpiece has been completely cleaned so that there are no substances on the workpiece which might produce flammable or toxic vapors. Do not do hot work on closed containers. They may explode.

4. Have fire extinguishing equipment handy for instant use,

such as a garden hose, water pail, sand bucket, or portable fire extinguisher. Be sure you are trained in its use.

5. Do not use equipment beyond its ratings. For example, overloaded welding cable can overheat and create a fire hazard.

6. After completing operations, inspect the work area to make certain there are no hot sparks or hot metal which could cause a later fire. Use fire watchers when necessary.

7. For additional information, refer to NFPA Standard 51B, "Fire Prevention in Use of Cutting and Welding Processes", available from the National Fire Protection Association, Batterymarch Park, Quincy, MA 02269.

ELECTRICAL SHOCK -- Contact with live electrical parts and ground can cause severe injury or death. DO NOT use AC welding current in damp areas, if movement is confined, or if there is danger of falling.

1. Be sure the power source frame (chassis) is connected to the ground system of the input power.

2. Connect the workpiece to a good electrical ground.

3. Connect the work cable to the workpiece. A poor or missing connection can expose you or others to a fatal shock.

4. Use well-maintained equipment. Replace worn or damaged cables.

5. Keep everything dry, including clothing, work area, cables, torch/electrode holder, and power source.

6. Make sure that all parts of your body are insulated from work and from ground.

7. Do not stand directly on metal or the earth while working in tight quarters or a damp area; stand on dry boards or an insulating platform and wear rubber-soled shoes.

8. Put on dry, hole-free gloves before turning on the power.

9. Turn off the power before removing your gloves.

10. Refer to ANSI/ASC Standard Z49.1 (listed on next page) for specific grounding recommendations. Do not mistake the work lead for a ground cable.

ELECTRIC AND MAGNETIC FIELDS — May be dangerous. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF). Welding and cutting current creates EMF around welding cables and welding machines. Therefore:

1. Welders having pacemakers should consult their physician before welding. EMF may interfere with some pacemakers.

2. Exposure to EMF may have other health effects which are unknown.

3. Welders should use the following procedures to minimize exposure to EMF: A. Route the electrode and work cables together. Secure

them with tape when possible. B. Never coil the torch or work cable around your body. C. Do not place your body between the torch and work

cables. Route cables on the same side of your body.

D. Connect the work cable to the workpiece as close as

possible to the area being welded. E. Keep welding power source and cables as far away

from your body as possible.

10/98

FUMES AND GASES -- Fumes and gases, can cause discomfort or harm, particularly in confined spaces. Do not breathe fumes and gases. Shielding gases can cause asphyxiation. Therefore:

1. Always provide adequate ventilation in the work area by natural or mechanical means. Do not weld, cut, or gouge on materials such as galvanized steel, stainless steel, copper, zinc, lead, beryllium, or cadmium unless positive mechanical ventilation is provided. Do not breathe fumes from these materials.

2. Do not operate near degreasing and spraying operations. The heat or arc rays can react with chlorinated hydrocarbon vapors to form phosgene, a highly toxic gas, and other irritant gases.

3. If you develop momentary eye, nose, or throat irritation while operating, this is an indication that ventilation is not adequate. Stop work and take necessary steps to improve ventilation in the work area. Do not continue to operate if physical discomfort persists.

4. Refer to ANSI/ASC Standard Z49.1 (see listing below) for specific ventilation recommendations.

5. WARNING: This product, when used for welding or

cutting, produces fumes or gases which contain chemicals known to the State of California to cause birth defects and, in some cases, cancer. (California Health &

Safety Code §25249.5 et seq.)

CYLINDER HANDLING -- Cylinders, if mishandled, can rupture and violently release gas. Sudden rupture of cylinder, valve, or relief device can injure or kill. Therefore:

1. Use the proper gas for the process and use the proper pressure reducing regulator designed to operate from the compressed gas cylinder. Do not use adaptors. Maintain hoses and fittings in good condition. Follow manufacturer's operating instructions for mounting regulator to a compressed gas cylinder.

2. Always secure cylinders in an upright position by chain or strap to suitable hand trucks, undercarriages, benches, walls, post, or racks. Never secure cylinders to work tables or fixtures where they may become part of an electrical circuit.

3. When not in use, keep cylinder valves closed. Have valve protection cap in place if regulator is not connected. Secure and move cylinders by using suitable hand trucks. Avoid rough handling of cylinders.

4. Locate cylinders away from heat, sparks, and flames. Never strike an arc on a cylinder.

5. For additional information, refer to CGA Standard P-1, "Precautions for Safe Handling of Compressed Gases in Cylinders", which is available from Compressed Gas Association, 1235 Jefferson Davis Highway, Arlington, VA 22202.

EQUIPMENT MAINTENANCE -- Faulty or improperly maintained equipment can cause injury or death. Therefore:

1. Always have qualified personnel perform the installation, troubleshooting, and maintenance work. Do not perform any electrical work unless you are qualified to perform such work.

2. Before performing any maintenance work inside a power source, disconnect the power source from the incoming electrical power.

3. Maintain cables, grounding wire, connections, power cord, and power supply in safe working order. Do not operate any equipment in faulty condition.

4. Do not abuse any equipment or accessories. Keep equipment away from heat sources such as furnaces, wet conditions such as water puddles, oil or grease, corrosive atmospheres and inclement weather.

5. Keep all safety devices and cabinet covers in position and in good repair.

6. Use equipment only for its intended purpose. Do not modify it in any manner.

ADDITIONAL SAFETY INFORMATION -- For more information on safe practices for electric arc welding and cutting equipment, ask your supplier for a copy of "Precautions and Safe Practices for Arc Welding, Cutting and Gouging", Form 52-529.

The following publications, which are available from the American Welding Society, 550 N.W. LeJuene Road, Miami, FL 33126, are recommended to you:

1. ANSI/ASC Z49.1 - "Safety in Welding and Cutting"

2. AWS C5.1 - "Recommended Practices for Plasma Arc Welding"

3. AWS C5.2 - "Recommended Practices for Plasma Arc Cutting"

4. AWS C5.3 - "Recommended Practices for Air Carbon Arc Gouging and Cutting"

5. AWS C5.5 - "Recommended Practices for Gas Tungsten Arc Welding“

6. AWS C5.6 - "Recommended Practices for Gas Metal Arc Welding"“

7. AWS SP - "Safe Practices" - Reprint, Welding Handbook.

8. ANSI/AWS F4.1, "Recommended Safe Practices for Welding and Cutting of Containers That Have Held Hazardous Substances."

MEANING OF SYMBOLS - As used throughout this manual: Means Attention! Be Alert! Your safety is involved.

Means immediate hazards which, if not avoided, will result in immediate, serious personal injury or loss of life.

Means potential hazards which could result in personal injury or loss of life.

Means hazards which could result in minor personal injury.

SP98-10

PRÉCAUTIONS DE SÉCURITÉ

AVERTISSEMENT: Ces règles de sécurité ont pour objet d’ assurer votre protection. Veillez à lire et à observer les précautions énoncées ci-dessous avant de monter l’ équipement ou de commercer à l’utiliser. Tout défaut d’observation de ces précautions risque d’entraîner des blessures graves ou mortelles.

1. PROTECTION INDIVIDUELLE-- Les brûlures de la peau et des yeux dues au rayonnement de l’arc électrique ou du métal incandescent, lors du soudage au plasma ou à l’électrode ou lors du gougeage à l’arc, peuvent s’avérer plus graves que celles résultant d’une exposition prolongée au soleil. Aussi convient-il d’observer les précautions suivantes:

a. Portez un écran facial adéquat muni des plaques

protectrices et des verres filtrants appropriés afin de vous protéger les yeux, le visage, le cou et les oreilles des étincelles et du rayonnement de l’arc électrique lorsque vous effectuez des soudures ou des coupes ou lorsque vous en observez l’exécution.

AVERTISSEZ les personnes se trouvant à proximité

de façon à ce qu’elles ne regardent pas l’arc et à ce qu’elles ne s’exposent pas à son rayonnement, ni à celui du métal incandescent.

b. Portez des gants ignifugés à crispins, une tunique

épaisse à manches longues, des pantalons sans rebord, des chaussures à embout d’acier et un casque de soudage ou une calotte de protection, afin d’éviter d’exposer la peau au rayonnement de l’arc électrique ou du métal incandescent. ll est également souhaitable d’utiliser un tablier ininflammable de façon à se protéger des étincelles et du rayonnement thermique.

c. Les étincelles ou les projections de métal incandes-

cent risquent de se loger dans des manches retroussées, des bords relevés de pantalons ou dans des poches. Aussi convient-il de garder boutonnés le col et les manches et de porter des vêtements sans poches à l’avant.

d. Protégez des étincelles et du rayonnement de l’arc

électrique les autres personnes travaillant à proximité à l’aide d’un écran ininflammable adéquat.

e. Ne jamais omettre de porter des lunettes de sécurité

lorsque vous vous trouvez dans un secteur où l’on effectue des opérations de soudage ou de coupage à l’arc. Utilisez des lunettes de sécurité à écrans ou verres latéraux pour piquer ou meûler le laitier. Les piquetures incandescentes de laitier peuvent être projetées à des distances considérables. Les personnes se trouvant à proximité doivent également porter des lunettes de protection.

f. Le gougeage à l’arc et le soudage à l’arc au plasma

produisent un niveau de bruit extrêmement élevé (de 100 à 114 dB) et exigent par conséquent l’emploi de dispositifs appropriés de protection auditive.

2. PRÉVENTION DES INCENDES-- Les projections de laitier incandescent ou d’étincelles peuvent provoquer de graves incendies au contact de matériaux combustibles solides, liquides ou gazeux. Aussi faut-il observer les précautions suivantes:

a. Éloigner suffisamment tous les matériaux combus-

tibles du secteur où l’on exécute des soudures ou des coupes à l’arc, à moins de les recouvrir complètement d’une bâche non-inflammable. Ce type de matériaux comprend notamment le bois, les vêtements, la sciure, l’essence, le kérosène, les peintures, les solvants, le gaz naturel, l’acétylène, le propane et autres substances combustibles semblables.

b. Les étincelles ou les projections de métal incandes-

cent peuvent tomber dans des fissures du plancher ou dans des ouvertures des murs et y déclencher une ignition lente cachée. Veiller à protéger ces ouvertures des étincelles et des projections de métal.

c. N’exécutez pas de soudures, de coupes, d’opérations

de gougeage ou autres travaux à chaud à la surface de barils, bidons, réservoirs ou autres contenants usagés, avant de les avoir nettoyés de toute trace de substance susceptible de produire des vapeurs inflammables ou toxiques.

d. En vue d’assurer la prévention des incendies, il

convient de disposer d’un matériel d’extinction prêt à servir immédiatement, tel qu’un tuyau d’arrosage, un seau à eau, un seau de sable ou un extincteur portatif.

e. Une fois le travail à l’arc terminé, inspectez le secteur

de façon à vous assurer qu’aucune étincelle ou projection de métal incandescent ne risque de provoquer ultérieurement un feu.

3. CHOC ÉLECTRIQUE-- Le gougeage à l’arc et à l’arc au plasma exige l’emploi de tensions à vide relativement importantes; or, celles-ci risquent de causer des dommages corporels graves et même mortels en cas d’utilisation inadéquate. La gravité du choc électrique reçu dépend du chemin suivi par le courant à travers le corps humain et de son intensité.

a. Ne laissez jamais de surfaces métalliques sous ten-

sion venir au contact direct de la peau ou de vêtements humides. Veillez à porter des gants bien secs.

b. Si vous devez effectuer un travail sur une surface

métallique ou dans un secteur humide, veillez à assurer votre isolation corporelle en portant des gants secs et des chaussures à semelles de caoutchouc et en vous tenant sur une planche ou une plate-forme sèche.

c. Mettez toujours à la terre le poste de soudage/coupage

en le reliant par un câble à une bonne prise de terre.

d. N’utilisez jamais de câbles usés ou endommagés. Ne

surchargez jamais le câble. Utilisez toujours un équipement correctement entretenu.

e. Mettez l’équipement hors tension lorsqu’il n’est pas en

service. une mise à la masse accidentelle peut en effet provoquer une surchauffe de l’équipement et un danger d’incendie. Ne pas enrouler ou passer le câble autour d’une partie quelconque du corps.

f. Vérifiez si le câble de masse est bien relié à la pièce en

un point aussi proche que possible de la zone de travail. Le branchement des câbles de masse à l’ossature du bâtiment ou en un point éloigné de la zone de travail augmente en effet le risque de passage d’un courant de sortie par des chaînes de

levage, des câbles de grue ou divers chemins électriques.

g. Empêchez l’apparition de toute humidité, notamment

sur vos vêtements, à la surface de l’emplacement de travail, des câbles, du porte-électrode et du poste de soudage/coupage. Réparez immédiatement toute fuite d’eau.

4. VENTILATION-- La respiration prolongée des fumées résultant des opérations de soudage/coupage, à l’intérieur, d’un local clos, peut provoquer des malaises et des dommages corporels. Aussi convient-il d’observer les précautions suivantes:

a. Assurez en permanence une aération adéquate de

l’emplacement de travail en maintenant une ventilation naturelle ou à l’aide de moyens mécaniques. N’effectuez jamais de travaux de soudage ou de coupage sur des matériaux de zinc, de plomb, de beryllium ou de cadmium en l’absence de moyens mécaniques de ventilation capables d’empêcher l’inhalation des fumées dégagées par ces matériaux.

b. N’effectuez jamais de travaux de soudage ou de

coupage à proximité de vapeurs d’hydrocarbure chloré résultant d’opérations voisines de dégraissage ou de pulvérisation. La chaleur dégagée ou le rayonnement de l’arc peut déclencher la formation de phosgène -- gaz particulièrement toxique -- et d’autres gaz irritants, à partir des vapeurs de solvant.

c. Une irritation momentanée des yeux, du nez ou de la

gorge constatée au cours de l’utilisation de l’équipement dénote un défaut de ventilation. Arrêtezvous de travailler afin de prendre les mesures nécessaires à l’amélioration de la ventilation. Ne poursuivez pas l’opération entreprise si le malaise persiste.

d. Certaines commandes comportent des canalisations

où circule de l’hydrogène. L’armoire de commande est munie d’un ventilateur destiné à empêcher la formation de poches d’hydrogène, lesquelles présentent un danger d’explosion; ce ventilateur ne fonctionne que si l’interrupteur correspondant du panneau avant se trouve placé en position ON (Marche). Veillez à manœuvrer cette commande en vérifiant si le couvercle est bien en place, de façon à assurer l’efficacité de la ventilation ainsi réalisée. Ne jamais débrancher le ventilateur.

e. Les fumées produites par l’opération de soudage ou

de coupage peuvent s’avérer toxiques. Aussi est-il nécessaire de disposer en permanence d’un dispositif adéquat de ventilation de type aspirant, afin d’éliminer du voisinage de l’opérateur tout dégagement de fumée visible.

f. Consultez les recommandations particulières en

matière de ventilation indiquées à l’alinéa 6 de la norme Z49.1 de l’AWS.

5. ENTRETIEN DE L’ÉQUIPEMENT-- Un équipement entretenu de façon défectueuse ou inadéquate risque non seulement de réaliser un travail de mauvaise

qualité mais, chose plus grave encore, d’entraîner des dommages corporels graves, voire mortels en déclenchant des incendies ou des chocs électriques. Observez par conséquent les précautions suivantes:

a. Efforcez-vous de toujours confier à un personnel qua-

lifié l’installation, le dépannage et l’entretien du poste de soudage et de coupage. N’effectuez aucune réparation électrique sur l’équipement à moins d’être qua-lifié à cet effet.

b. Ne procédez jamais à une tâche d’entretien

quelconque à l’intérieur du poste de soudage/ coupage, avant d’avoir débranché l’alimentation électrique.

c. Maintenez en bon état de fonctionnement les câbles,

le câble de masse, les branchements, le cordon d’alimentation et le poste de soudage/coupage. N’utilisez jamais le poste ou l’équipement s’il présente une défectuosité quelconque.

d. Prenez soin du poste de soudage et de coupage et

des équipements accessoires. Gardez-les à l’écart des sources de charleur, notamment des fours, de l’humidité, des flaques d’eau maintenez-les à l’abri des traces d’huile ou de graisse, des atmosphères corrosives et des intempéries.

e. Laissez en place tous les dispositifs de sécurité et tous

les panneaux de l’armoire de commande en veillant à les garder en bon état.

f. Utilisez le poste de soudage/coupage conformément à

son usage prévu et n’effectuez aucune modification.

6. INFORMATIONS COMPLÉMENTAIRES RELATIVES À LA SÉCURITÉ--

Pour obtenir des informations complémentaires sur les

règles de sécurité à observer pour le montage et l’utilisation d’équipements de soudage et de coupage électriques et sur les méthodes de travail recommandées, demandez un exemplaire du livret N° 52529 “Precautions and Safe Practices for Arc Welding, Cutting and Gouging” publié par ESAB. Nous conseillons également de consulter les publications sui-vantes, tenues à votre disposition par l’American Welding Society, 550 N.W. LeJuene Road, Miami, FL 32126:

a. “Safety in Welding and Cutting” AWS Z49.1 b. “Recommended Safe Practices for Gas-Shielded Arc

Welding “AWS A6. 1.

c. “Safe Practices for Welding and Cutting Containers

That Have Held Combustibles” AWS-A6.0.

d. “Recommended Safe Practices for Plasma Arc Cut-

ting” AWS-A6. 3.

e. “Recommended Safe Practices for Plasma Arc Weld-

ing” AWS-C5. 1.

f. “Recommended Safe Practices for Air Carbon Arc

Gouging and Cutting” AWS-C5. 3.

g. “Code For Safety in Welding and Cutting”

CSA-Standard W117. 2.

9/97

II. INTRODUCTION

2.1 GENERAL

This manual has been prepared especially for use in familiarizing personnel with the design, installation, operation, maintenance, and troubleshooting of this equipment. All information presented here in should be given careful consideration to assure optimum performance of this equipment.

2.2 RECEIVING-HANDLING

Prior to installing this equipment, clean all packing material from around the unit and carefully inspect for any damage that may have occurred during shipment. Any claims for loss or damage that may have occurred in transit must be filed by the purchaser with the carrier. A copy of the bill of lading and freight bill will be furnished by the carrier on request if occasion to file claim arises.

When requesting information concerning this equipment, it is essential that Part, Serial and Model Numbers of the equipment be supplied.

2.3 DESCRIPTION

The Migmaster 250 is a portable Welding System designed for fine wire, (0.023, 0.030, 0.035 and 0.045 in.) welding using the short arc method, as well as for spray arc aluminum, short arc and spray arc stainless steel and spray arc cored wires. It incorporates a running gear with provisions for one gas cylinder, and a ST-23A spool-ongun control.

2.3.1 AVAILABLE PACKAGES AND CONTENTS

The following Migmaster 250 Packages are available with Argon Regulator:

MM-250 for 208/230-V.

Input w/12-ft. Pkg. ............................... P/N 604560

MM-250 for 208/230-V.

Input w/15-ft. Pkg. ............................... P/N 604561

MM-250 for 208/230/380/400/460/575-V.

Input w/12-ft. Pkg. ............................... P/N 604563

MM-250 for 208/230/380/400/460/575-V.

Input w/15-ft. Pkg. ............................... P/N 604570

The following Migmaster 250 packages are available with CO2 Regulator:

Depending on the primary input voltage of the MM-250, and the torch length, each package includes the following:

l One (1), Migmaster 250 Power Supply/Wire Feeder equipped with a dual-groove feed roll (for .035/.045 wire), a 6'-0" ft. primary input power cable and plug (plug is installed for 208/230-V. units only), a mating input power receptacle rated @ 50A./250-V. (packed loose for 208/ 230-V. input packages only), 10-ft. work cable w/clamp, a 6'-0" shielding gas supply hose w/fittings and running gear w/gas (cylinder) support, as follows:

-- Migmaster 250 for 208/230-Volt input ....P/N 32851

-- Migmaster 250 for 208/230/380/400/460/575-Volt

input.......................................................P/N 32852

l One (1), Migmaster 250 Kit as follows:

-- 12-ft. Pkg.

Includes: MT-200cc, ready-to-weld, 12-ft. lg. torch

for .035/.045 wire.......................................P/N 21116

R-33-FM-580 Regulator, (F-15-173) ...........P/N 21557

Mig Welding Process Handbook.............. P/N 791F18

10 # Sample Spool Wire .035 87 HP Wire

-- 15-ft. Pkg.

Includes same accessories as 12-ft. Kit except for torch, which is:

MT-200cc, 15-ft. lg. for .035/.045 wire, .......P/N 21117

CO2 Kits are the same as 12-ft. Pkg. except Regulator is R-33-FM-320. P/N 21558.

2.3.2 POWER SUPPLY

The power supply consists of a tapped single phase transformer, tap selection switches, secondary contactor, single phase full wave rectifier, stabilizing reactor, slope resistor, filtering capacitors and internal output connections for polarity reversal.

2.3.3 WIRE FEEDER

The wire feeder pushes 0.023, 0.030, 0.035 and 0.045 in. wire at speeds up to 650 IPM. Dynamic braking prevents excessive wire overrun. A double grooved drive roll (0.035 and 0.045 in. - supplied) provides a convenient means of changing the setup for either wire size.

MM-250 for 208/230-V

Input w/12-ft. Pkg. ................................P/N 35678

MM-250 for 208/230/380/400/460/575-V

Input w/12 ft. Pkg. ................................P/N 35763

The wire feeder is built into the power supply cabinet, and is housed in a compartment separated from the welding machine components. Machine ventilation is not drawn through this compartment, thus helping to keep the wire and feeding mechanism clean.

TABLE 1. SPECIFICATIONS

POWER SOURCE MIGMASTER 250

Rated Output 250 Amps @ 27 Volts d.c. Duty Cycle, 208/230V Unit 50% @ 60 Hz.; 40% @ 50 Hz. 208/230/380/400/460/575V Unit 35% for 208 through 400V; 50% for 460 & 575V Primary Input Single Phase 208/230; 208/230/380/400/460/575 Volts 50 60 Hz Primary Input Amperes 208-71, 230-62, 380-37,400-36, 460-31, 575-25 Output Current Range 30 to 280 Amps. Maximum Open Circuit Volts 55 v.d.c.

FEEDER

Feed Type Push Wire Sizes: Hard 0.023" (0.6mm) through 0.045" (1.2mm)

Cored 0.030" (0.8mm) through 1/16" (1.6mm) Soft 0.035" (0.9mm) and 3/64" (1.2mm)

Feed Rate 20-650 IPM

MT-200cc TORCH

Cooling Air Gooseneck Angle 45 degrees Rated 60% Duty Cycle (DCRP) Amps: 200 w/Argon Mixtures, 300 w/CO Conduit Length see section 2.3.1

PHYSICAL

Net Weight *210 lbs (95 Kg.) Height *32.25 inches (819 mm) Width *19.5 inches (495 mm) Depth *40.0 inches (1016 mm)

*Includes running gear & bottle tray.

2.3.4 MT-200cc WELDING TORCH (F-15-085),

The lightweight air cooled welding gun included in selected systems is supplied complete and ready to weld

0.035 in. steel wire. It is built with a one piece service conduit and includes a 45 degree gooseneck. Changing

2.3.6 RUNNING GEAR

The Migmaster 250 is equipped with a running gear w/ swiveled front wheels and a gas cylinder support. The rear wheels are packed loose for shipping, but are easily

installed, see Section 3.8. the contact tip to 0.045 in. allows the use of the larger wire.

2.3.5 CONTROLS

2.4 OPTIONAL ACCESSORIES

2.4.1 SPOT/STITCH/ANTI-STICK MODULE, P/N

32858.

The Migmaster 250 System can be used to weld hard and aluminum wire with an optional ST-23A spool-gun torch. An optional spot/stitch control allows a welder to spot or stitch weld within a range of 0.4 to 3.5 seconds. The builtin spool-on-gun adaptors and control, when used in conjunction with the optional ST-23A torch, permits aluminum wire welding with the machine.

This easy-to-install, plug-in module mounts in place of

the lower blank cover plate of the upper-right front panel

location in the 250 unit. It enables the operator to use the

250 for Spot or Stitch or Continuous welding operations.

It also includes an adjustable Anti-Stick feature that

allows you to select various wire burnback times to

prevent wire from sticking in the puddle after a weld. For

installation, see Section 3.9 and for operating instruc-

tions see Section 4.2.

If a Spotwelding operation is to be used, it is recommended that you also order a #12S Spotweld Nozzle,

P/N 999625.

2.4.2 DIGITAL VOLT/AMMETER MODULE, P/N 32857.

This easy-to-install, plug-in module mounts in place of the top blank cover plate of the upper-right front panel location in the 250 unit. This unique meter module alternately displays welding voltage and current (of the dial-set welding condition) every 4-seconds. Two L.E.D.’s labeled Amps and Volts provided below the meter windows, alternately illuminate to indicate which condition is being displayed. The voltage indication is displayed in 1/10-volt increments (e.g.: 20.5), while the current indication is usually displayed in three-whole digits (e.g.:

225). After the torch trigger is released, the meter will continue to flash for 20-seconds the last condition used during welding. At the end of this time, the meter will reset to zero. For installation see Section 3.10.

2.4.3 ST-23A SPOOL-ON-GUN TORCH, P/N 19164 (see F-14-353).

The Migmaster 250 unit is equipped with a built-in control for the ST-23A Spool-On-Gun welding torch. The ST23A is a high performance, 250 ampere continuous duty spool-on-gun torch designed for the mig welding process. It is completely portable (up to 30-ft.), air-cooled and hand operated, and weighs less than three (3) pounds. The gun is equipped with (30) foot lines. For installation and operation, see Section 4.2.2.

MT-250SG Spool-On-Gun ........................ P/N 36779

(Requires Adapter, P/N 36833) See F-15-380.

2.4.4 TORCH NOZZLES

A No. 8 Nozzle (1/2" I.D.), P/N 998893 for the MT-200CC Torch, is included in the Migmaster 250 package. This slip-on type nozzle incorporates a permanent insulator/ spatter shield. Other standard duty slip-on nozzles with insulator/spatter shield, are available seperatly:

No. 6 Nozzle, Tapered (3/8" I.D.)............ P/N 998895

No. 10 Nozzle (5/8" I.D.)......................... P/N 998894

No. 12S Spotweld Nozzle (3/4" I.D.)......... P/N 17316

The following heavy-duty slip-on nozzles with insulator/ spatter shield, are available seperatly:

No. 8 Nozzle (1/2" I.D.)........................... P/N 999471

No. 10 Nozzle (5/8" I.D.)......................... P/N 999472

No. 12 Nozzle (3/4" I.D.)......................... P/N 999473

No. 12 Spot Nozzle (3/4" I.D.) ................ P/N 999625

New Long Life MT Nozzles. These nozzles have a patented coating to reduce weld spatter and extend the life of the nozzle.

No. 6 XL Nozzle, (MT Std.).................P/N 998895XL

No. 8 XL Nozzle, (MT Std.).................P/N 998893XL

No. 10 XL Nozzle, (MT Std.)...............P/N 998894XL

No. 8 XL Nozzle, (MT HD)..................P/N 999471XL

No. 10 XL Nozzle, (MT HS) ................P/N 999472XL

2.4.5 TORCH/WIRE FEED ACCESSORIES -- See Tables 2.4.5.1 and 2.4.5.2.

2.4.6 SPOOL SPACER

For 8" dia. spools..................................... P/N 17511

For 10" dia. spools................................... P/N 34330

TABLE 2.4.5.1 Recommended MT-200cc Torch Accessories

Wire Contact Tips Liners Size & Type Short (S) Medium (M) Long (L) 10' 12' 15'

Hard Wires & Cored Wires

.023" (.6mm) - 20543 999742 999743* - .030" (.8mm) - 20544 996994 948850 17717 .035" (.9mm) - 996995 996996 2075237 17718 2075238 .040" (1.0mm) - 37287 37288 .045" (1.2mm) 999578u 37290u 996998u 2075237 17718 2075238 .052" (1.4mm) 948340u 2075349u - 2075239 17719 2075240 1/16" (1.6mm) 948341u 37289u - 2075239 17719 2075240

Soft Wires (aluminum)

.035" (.9mm) - 996995 996996 948862 - .040" (1.0mm) - 37287 37288 3/64" (1.2mm) 999578 996999 996998 948863 - -

(S) Short contact tips are recommended for proper wire stick out for flux cored wire welding. (M) Medium contact tips are recommended for proper wire stick out in spray transfer Mig

welding.

(L) Long contact tips are recommended for good visability and proper wire stick in dip transfer

Mig welding. * Requires support liner for .023" wire. Order P/N 999797. u New ID for improved arc performance on steel/flux cored wire.

Table2.4.5.2 Drive Roll & Guide Tube Selection

Wire Type / Lower Pressure Guide Diameter Drive Roll Roll Tube

Hard Wires (V groove)

.023 in. (0.6mm) 21155 23612397 21163

.030 in. (0.8mm) 21155 23612397 21164

.035 in. (0.9mm)* 21156 23612397 21165

.040 in. (1.0mm)* 21156 23612397 21165

.045 in. (1.2mm)* 21156 23612397 21165

Soft (aluminum) Wires (U groove)

.035 in. (0.9mm) 21158 23612397 21167** 3/64 in. (1.2mm) 21159 23612397 21168**

Cored Wires (Serrated V groove - lower)

.030 in. (0.8mm) 21160 23612369 21164 .035 in. (0.9mm) 21160 23612369 21165 .040 in. (1.0mm) 21161 23612369 21165 .045 in. (1.2mm) 21161 23612369 21165 .052 in. (1.4mm) 21161 23612369 21166 1/16 in. (1.6mm) 21161 23612369 21166

Cored Wires (Serrated V groove - upper and lower)†

.045 in. (1.2mm) 37319 37319 21165 .052 in. (1.4mm) 37319 37319 21166 1/16 in. (1.6mm) 37320 37320 21166

* Supplied with Migmaster 250. ** Requires Support Tube 21169. † Recommended for use with soft cored wires that are easy to

flatten.

Upper

2.5 SAFETY

Before the equipment is put into operation, the safety section at the front of this manual should be read completely. This will help avoid possible injury due to misuse or improper welding applications.

The symbol which precedes safety notes appearing throughout this manual means “Attention! Be Alert! Your safety is involved.” The definitions relating to the DANGER, WARNING and CAUTION safety notations are described at the end of the Safety Section in the front of this manual -- read them and their specific text references carefully.

III. INSTALLATION

3.1 LOCATION (Figure 3.1)

A proper installation site should be selected for the welding machine, if the unit is to provide dependable service and remain relatively maintenance free.

32 ¼" Overall

1/2"

40"

A proper installation site permits freedom of air movement into and out of the welding machine, and also least subjects the unit to dust, dirt, moisture, and corrosive vapors. A minimum of 18 inches (46 cm) unrestricted space must be maintained between the welding machine side and rear panels and the nearest obstruction.

The installation site should also permit easy removal of the welding machine outer enclosure for maintenance functions.

CAUTION: Do not place any filtering device over the

intake air passages of the welding machine as this would restrict the volume of intake air and thereby subject the welding machine internal components to an overheating condition and subsequent failure. Warranty is void if any type of filtering device is used.

If a forklift vehicle is used for lifting the unit, be sure that the lift forks are long enough to extend completely under the base.

Do not operate the machine without the running gear installed.

Figure 3.1 Dimensional Drawing

3.2 ELECTRICAL INPUT CONNECTIONS

It is recommended that a line disconnect switch be installed in the input circuit to the welding machine. This would provide a safe and convenient means to completely remove all electrical power from the welding machine whenever it is necessary to perform any internal function on the unit. (See Figure 3.2A.)

Before making electrical input connections to the welding machine, “Machinery Lockout Procedures” should be employed. If the connections are to be made from a line disconnect switch, the switch should be padlocked in the off position. If the connection is made from a fusebox, remove the fuses from the box and padlock the cover in the closed position. If locking facilities are not available, attach a red tag to the line disconnect switch (or fuse box) to warn others that the circuit is being worked on. If the plug-cap is used, (see 3.2B) remove plug from receptacle.

3.2.1 Input Electrical Requirements

TABLE 3.1 Input Conductor and Fuse Size

Models of this welding machine are designed to be operated from 208/230, or 208/230/380/400/460/575 volts single phase 50/60 Hz, depending on model. The primary input voltage requirements are shown on the welding machine nameplate.

3.2.2 Input Conductor Connections

The input power cord on 208/230 Volts primary input model is provided with an attachment plugcap. The plugcap will mate with a 250 Volts, 50 Ampere receptacle conforming to NEMA 6-50 R configuration.

The receptacle should be wired to a separately fused disconnect or circuit breaker of the size listed in Table

3.1. This disconnect or breaker can be wired to a single phase system or to two conductors of a three phase system. A third conductor for grounding should also be connected between the disconnect and the receptacle.

Figure 3.2A illustrates wiring to a single phase system and Figure 3.2B illustrates wiring to a three phase system.

The 208/230/380/400/460/575 primary input voltage unit is provided with a three conductor primary input cable without plugcap. The ground lead of this cable should be connected to a reliable ground and the two remaining wires should be connected to the separately fused lines of the disconnect or breaker as shown in Figures 3.2C and 3.2D.

All machines leave the factory with their primary electrical input requirements internally-connected for the highest voltage rating available in each model (e.g.: 230-volt for the 208/230-volt units; and 575-volt for the "multivoltage" units).

Recommended

Full Primary

Primary Load Input Ground

Input Line Fuse Conductor Conductor Volts Amperes Size Size Size

208 71 90 8 8 230 62 90 8 8 380 37 50 10 10 400 36 50 10 10 460 31 40 12 12 575 25 30 12 12

Only qualified personnel should make these changes. Make certain the primary power has been disconnected and all safety procedures have been followed before proceeding with these instructions.

Fig. 3.3A shows the 230v and 208v connections for the 208/230 dual voltage model. Change over is made by removing the right side panel below the wire feed compartment and switching the primary transformer tap at the top of the power switch with the unused alternate voltage tap located next to the main transformer (see Fig. 3.3B). Both voltage taps (the one currently connected to the switch and the unused alternate voltage) are marked with the input voltage requirement. All units are supplied from the factory connected for the highest voltage (230 vac). Before switching the voltage taps, verify the actual voltage requirement as well as the current voltage connection to be certain re-connection is necessary. If voltage tap re-connection is necessary, the following paragraphs cover the procedure to switch the voltage tap for either 208vac or 230vac input.

SINGLE-PHASE

GRD

Figure 3.2 A

208/230 MODEL ONLY (With Plug-Cap)

Fused

Line

Disconnect

Switch,

Circuit Breaker

Wall Receptacle

MIGMASTER

SYSTEM

CONNECTS HERE

THREE-PHASE

GRD

Figure 3.2 B

Figure 3.2 - Primary Connection

GRD

GREEN

208/230/380/400/460/575-V. MODELS

SINGLE-PHASE

CONDUCTOR

(GROUND)

THREE-PHASE

GRD

GREEN

Figure 3.2 DFigure 3.2 C

Figure 3.3A - Primary Reconnections at Switch

For 208/230 Volt Models

When changing the input voltage connections, the unused lead must be insulated and positioned to prevent contact with any other internal components of the machine or the machine side panel. The clearance between the unused lead and other components must be at least one inch (see Fig. 3.3B for illustration of the proper position). FAILURE TO INSULATE AND POSITION THIS LEAD PROPERLY WILL CAUSE A SERIOUS SHOCK HAZARD.

The terminal labeled GRD is connected to the welding machine chassis and is for ground purposes only. It must be connected to a good electrical ground. Do not connect a conductor from the terminal labeled GRD to any one of the L1, L2 terminals as this will result in an electrically hot welding machine chassis.

3.2.3 CONNECTING FOR 208 VAC INPUT

After the panel is removed, locate the 208 Vac lead (Fig.

3.3B) and cut the tie-wrap to remove the insulation sleeving (on early models this lead may have been wrapped with black electrical tape). Open the insulating cover around the power switch (Fig. 3.3C.) to expose the terminals and disconnect the 230 Vac lead from the top of the switch as shown in Fig. 3.3A. Insulate the 230 Vac lead that was removed from the power switch with sleeving or approved electrical tape and re-position to a safe area beside the transformer (see Fig. 3.3B), leaving a minimum of one inch clearance from other components and the side panel.

3.2.4 CONNECTING FOR 230 VAC INPUT

Fig. 3.3B - Position of Alternate Voltage Tap

After the panel is removed, locate the 230 Vac lead (Fig.

3.3B) and cut the tie-wrap to remove the insulation sleeving (on early models this lead may have been

Fig. 3.3C - Power Switch Connection

wrapped with black electrical tape). Open the insulating cover around the power switch (Fig. 3.3C.) to expose the terminals and disconnect the 208 Vac lead from the top of the switch as shown in Fig. 3.3A. Insulate the 208 Vac lead that was removed from the power switch with sleeving or approved electrical tape and re-position to a safe area beside the transformer (see Fig. 3.3B), leaving a minimum of one inch clearance from other components and the side panel.

Connect the proper voltage (208 Vac or 230 Vac) tap to the power switch and tighten securely. Check all other leads connected to the power switch for tightness and clearance from internal components before securing the insulating cover around the power switch. Replace the side panel.

3.2.5 Reconnecting from 575 VAC Input

Figure 3.3.1 shows you how to reconnect the "multivoltage" model from a 575-volt input to any of the remaining available voltage inputs 200 or 380 or 400 or 460-volts. These connections are made by unscrewing the right side panel below the wire feeding compartment, and locating the primary voltage changeover terminal board handing in the center of the lower compartment. This board contains copper links which must be reconnected to match the silk-screened voltage designations for the input you plan to use (it comes factory-connected for a 575-volt input), see Figure 3.3.1.

3.3 SECONDARY OUTPUT CONNECTIONS

The Migmaster 250 Welding System is completely selfcontained so that the front panel torch fittings (Euro-type MT and Spool gun) are internally connected to the welding polarity (D.C. Reverse or D.C. Straight) via the secondary output terminals located inside the wire feeding compartment (see Fig. 4.1). The machine comes set up for D.C.R.P. welding as described in Section 4.1.3.

3.4 TORCH CONNECTIONS

PRIMARY VOLTAGE CONNECTION CHART

VOLTAGE CONNECTION NO. OF STRIPS

1 - 2 1

208 6 - 7 1

7 - 8 FLEX 1 - 2 1

230 6 - 7 1

5 - 8 FLEX

380 3 - 7 2

4 - 8 FLEX

400 2 - 6 2

7 - 8 FLEX

460 2 - 6 2

4 - 8 FLEX

575 2 - 3 2

4 - 8 FLEX

The torch (MT-200cc), which is supplied as standard equipment with the Migmaster 250 System, is provided with a euro-type adapter which directly connects to the torch fitting mounted on the front panel. Line up matching holes, push on and tighten locking collar. As shipped from the factory, the euro or common connector type torches are set-up for D.C.R.P. welding polarity (see sections 3.3 or 4.1.3). To connect the spool-on-gun torch (ST-23A) see Section 4.2.2.

3.5 WIRE FEEDER MECHANISM

3.5.1 DRIVE ROLLS

The drive roll has two grooves: the small groove feeds

0.035 in. diameter wire, the large groove feeds 0.045 in. wire. The groove nearest the gear motor feeds the wire. If the required groove is not in that position:

A. Release the pressure drive roll lever and lift the

assembly upward.

B. Remove the two (2) screws holding the drive roll to

the gear.

C.Reverse the drive roll on the drive roll shaft.

Figure 3.3.1-Primary Reconnections at Voltage Changeover Terminal Board for 208/230/380/400/460/ 575Volt Models

D.Replace the screws and tighten. E. Secure the pressure drive roll assembly.

3.5.2 WELDING WIRE SPOOL

As with any work area, make sure safety glasses with side shields are worn when handling or changing wire or clipping wire off at the spool or at the end of the torch. Hold onto the wire coming off the spool with one hand before clipping. Serious eye injury can result due to the springiness of the wire which can quickly unravel, or a cut wire end which may shoot across the room.

Install a spool of welding wire on the hub as follows:

A. Unscrew spool nut from hub. B. Place wire spool on hub to rotate clockwise as wire

is unwound; hub pin must engage hole in spool.

C.Replace nut.

3.5.3 THREADING WELDING WIRE

A. Turn off power switch.

When the power switch is on, and gun trigger is depressed, the electrode wire becomes electrically hot, and the wire feed rolls are activated.

B. Release pressure drive roll assembly and lift up

ward. Check that proper wire diameter groove is in the inner position.

CAUTION: Before threading welding wire through cas-

ing, make sure chisel point and burrs have been removed from wire end to prevent wire from jamming in gun casing or liner.

3.5.4 BRAKE DRAG ADJUSTMENT

Brake disc friction should provide enough drag to keep the wire spool or core from spinning freely after wire feed stops. If adjustment is required, turn adjusting screw clockwise to increase drag, counterclockwise to decrease it. Drag should be just low enough to limit wire overrun.

3.6 CONNECTION OF SHIELDING GAS SUPPLY

The R-33-FM-580 Regulator-Flowmeter is designed for use with an argon or argon-mix cylinder of shielding gas. It is adjustable for delivering up to 50 cfh through the torch. To set up the system do the following:

Do Not adapt R-33-FM-580 for use with CO2. Relief device may rupture if CO2 is used with the R-33-FM-

580. For CO2 service, order R-33-FM-320, P/N 21558.

a. With the cylinder cap in place CAREFULLY slide

the cylinder of gas onto the Migmaster 250 cylinder rack.

b. Secure the cylinder to the unit, using the chain

provided. c. Unscrew the cylinder cap. d. Open the cylinder valve slightly, just for an instant,

to blow away any dirt or dust which may have ac-

cumulated in the cylinder valve outlet. Be sure to

keep your face away from the valve outlet

to protect your eyes.

e. Attach the regulator to the cylinder valve, tighten

the union nut securely with a 1-1/8in. open end or

an adjustable wrench.

C.Feed the wire from the spool through the inlet

guide, across the drive roll groove and into gun outlet guide.

Make sure that the proper “outlet guide tube” is inserted into the front-panel gun fitting for the size and type of wire being used, see Table 2.4.5.2 for wire feed accessories (Section 2.4.5).

To insure proper wire feeding, it is important that the wire be kept clean and that the drive rolls be periodically cleaned of any chips or scale that might be carried into the gun liner and cause sticking.

D.Lower pressure roll assembly and secure. Check

that the gears mesh. Feed wire through to gun tip with gun trigger (power ON).

CYLINDER VALVE

Fig. 3.6 R-33-FM-580 Regulator (Illustrated)

CYLINDER PRESSURE GAUGE

OUTLET CONNECTION

f. Attach the gas hose from the rear of the Migmaster

250 to the regulator outlet connection (see Fig. 3.6).

g. Slowly open the cylinder valve a fraction of a turn.

When the regulator pressure gauge pointer stops moving, open the cylinder valve fully.

Never stand directly in front of or behind the regulator when opening the cylinder valve. Always stand to one side.

h. Using a leak test solution, such as P/N 998771 (8

oz. container) or soapy water, test for leakage about the cylinder valve stem, the regulator inlet connection, and the hose connections at the regulator and at the Migmaster 250 for leakage. Correct any leaks before starting work.

i. If work is to be stopped for a half-hour or more, or

the regulator is to be removed from the cylinder, shut down the regulator as follows:

a. Close the cylinder valve. b. Release gas from the regulator by closing the

torch trigger lever.

c. When pressure gauge drops to zero, the regu-

lator is de-pressurized and shutdown.

j. Each regulator is equipped with a porous metal

inlet filter, P/N 71Z33, pressed into the regulator inlet nipple. No. regulator should be connected to a cylinder or station valve unless it contains this filter. You can replace the filter if you have reason to do so. To remove a filter refer to the regulator instruction literature for details.

k. Regulators in need of repair should be returned to

your Welding Equipment distributor or to an authorized Remanufacturing Center.

Welding cables should be kept as short as possible and be of adequate current carrying capacity. Resistance of the welding cables and connections causes a voltage drop which is added to the voltage drop of the arc. Excessive cable resistance may result in a reduction of the maximum usable current output of the equipment.

The proper operation of this equipment is to a large extent dependent on the use of welding cables and connections which are in good condition and of adequate size.

3.8 ASSEMBLE REAR WHEELS

The unit's running board is factory assembled except for the rear wheels which are packed loose in the shipping carton. The rear gear consists of 2-wheels, 4-washers, 2-cotter pins, and an axle. To install the gear, do the following:

a. Insert the axle through the holes provided at the

rear of the gear.

b. Place a washer onto each end of the axle, then slip

on the wheels, then add another washer to the outside of each wheel, and secure the whole assembly by inserting a pin in each end of the axle.

c. Remove the existing shipping supports by un-

screwing from chassis.

3.9 INSTALLING OPTIONAL SPOT/STITCH/ANTISTICK MODULE

a. Remove lower blank-cover plate from upper-right

front panel of power supply -- save the four mounting screws.

If welding is performed in a confined area, shielding gas leaks could result in a buildup of shielding gas concentration, displacing oxygen, thereby endangering personnel enter the area.

3.7 WELDING CABLE CONNECTIONS

Connect the work clamp solidly to the workpiece or work table. Clamp onto a bare metal area.

A good electrical connection to the work is essential to proper welding operation and to prevent electric shock.

b. Locate the harness-connected 15-pin plastic plug,

P3, inside the mounting cavity. Note that this plug will have a jumper plug with jumper wires connected to it -- remove (and save) the jumper plug. (The jumper plug must be reinstalled if the module is ever removed.

c. Connect the 15-pin plug into the matching recep-

tacle on the rear of the optional control module. The plug will only fit one way.

d. Install the control module in place of the blank

panel removed in Step a., using the same four screws that you saved.

3.10 INSTALLING OPTIONAL DIGITAL METER

a. Remove the top blank-cover plate from the upper-

right front panel of the power supply -- save the four mounting screws.

b. Locate the harness-connected 10-pin plastic plug,

PL1, inside the mounting cavity. This plug does not have a jumper plug connected to it.

A. Gun trigger circuit 24 volts AC.

Wire feeder circuit 24 volts DC.

c. Connect the 10-pin plug into the matching recep-

tacle on the rear of the optional meter module.

d. Install the meter module in place of the blank-

panel removed in Step a., using the same four screws that you saved.

IV. OPERATION

4.1 CONTROLS (See Figure 4.1)

4.1.1 POWER SWITCH

A line toggle switch on the front panel energizes the primary of the main transformer. This switch also turns on the fan, which is connected across a portion of the primary winding.

Two transformer secondary windings also become energized:

B. Main welding secondary circuit. Depending upon

the tap switch position, various secondary voltages can be obtained. Then rectified, open circuit voltages can be selected between 18 and 56 volts DC when the secondary contactor is energized.

4.1.2 VOLTAGE CONTROL (Coarse Range Selector and Fine Adjustment Range Selector)

Voltage control is by means of two high current tap switches which connect the rectifier bridge to various secondary taps.

The COARSE VOLTAGE RANGE Selector is a threeposition switch, LOW/MED/HIGH, by which the operator selects the approximate range of voltage (or heat, that determines the arc length) to be applied to the weld. It is a coarse selection control and is used in conjunction with the Fine Voltage Adjustment selector following. It must not be switched under load.

4.1.2

4.1.5

2.4.2

4.2.3

4.2.2

4.1.1

4.1.3

Secondary Output Terminals for Welding Polarity Changeover, see 4.1.3.

Work Cable

10A. Fuse

4.1.6

Torch Cable

The FINE VOLTAGE ADJUSTMENT Selector is an eight-position switch by which the operator selects the exact amount of arc voltage (or heat) to be applied to the weld (within the coarse range selected above). This allows you to fine-tune the voltage required; the higher the number selected (1-8), the hotter the weld. The Fine Voltage Selector switch also has an "open" detent at the six o'clock position. Placing the switch in this position allows operation of the torch trigger to feed electrode wire without the wire being electircally "hot". This switch also, must not be switched under load.

4.1.5 WIRE FEED SPEED CONTROL

Wire feed speed is controlled by the wire speed potentiometer knob on the front panel. The solid state control allows for infinitely variable speeds up to 650 IPM.

This wire speed pot is used to set the speed at which the welding wire is fed out from the torch and hence the welding amperage. The panel-face numbers on the dial (0-10) are used for reference and do not directly indicate wire feed speed; the higher the number, the faster the speed.

CAUTION: These tap switches carry several hundred

amperes, and must not be switched under load, as this will cause the contacts of the switches to arc.

4.1.3 SECONDARY WELDING CONNECTIONS

The secondary contactor, with parallel poles, is used to make and break the circuit between the transformer secondary and the rectifier. This contactor is turned on and off when the torch trigger (in the 24 volt circuit) is operated.

The secondary output welding terminals, POS.(+) and NEG(-), are located in the right side wire feeding compartment and are used to set the welding polarity (D.C.R.P. or D.C.S.P.) in which the machine will operate (see Fig. 4.1). As shipped from the factory, the 250 is set up to operate in D.C.R.P. (TORCH fitting is connected to Positive, and WORK cable/clamp is connected to Negative output). To weld using D.C.S.P., simply mount the WORK cable to the Positive output and the TORCH fitting cable to the Negative output terminal.

4.1.4 CONTACTOR CONTROL

Refer to the schematic diagrams. Note that the coil of the 24 volt contactor is activated with the torch trigger and is energized when the trigger is pulled. The gas solenoid is in parallel with the contactor coil and is energized at the same time.

When the trigger switch is released, the contactor drops out and disconnects the load.

4.1.6 STD./SPOOL GUN SELECTOR

This two-position toggle switch is located inside the unit on the mid-wall of the wire feeding compartment and is labeled Standard and Spool Gun. It is used to select standard metal inert gas welding (MIG) with the MT200CC, or welding with the ST-23A (spool-on-gun) torch.

4.2 PROCESS SETUP

4.2.1 STANDARD MIG SEAM WELDING W/MT-200CC

Refer to Sections 4.3.1, 4.3.2, 4.3.3, 4.3.4, and Table

4.3.3.

4.2.2 ST-23A SPOOL-ON-GUN CONTROL CONNECTION/OPERATION

The Migmaster 250 is equipped with a built-in control for the Spool Gun which operates via the amphenol control receptacle and a screw adaptor that provides Gas and Power. The ST-23A Torch (see Section 2.4.3) has a amphenol-plug control cable connection, and a gas/ power cable, see Figure 4.2.2.

To operate the unit with the ST-23A Torch connected, do the following (refer to Fig. 4.2.2):

A. Place the STD./Spool Gun selector toggle switch

(4.1.6) in the 250 to its Spool Gun position.

B. Connect the ST-23A control cable amphenol to the

receptacle labeled CONTROL on the 250s front panel.

Because of the charged capacitor bank in the secondary circuit, the output voltage will take a few seconds before falling to zero volts.

The gas valve shuts off when the contactor opens.

C. Remove the threaded plastic plug from the Gas/

Power adaptor (on the 250's front panel) using a clockwise rotation. Connect the ST-23A gas/power cable to the panel adaptor using a counterclockwise rotation. As shipped from the factory, the 250's secondary output power terminals are set-up for D.C.R.P. welding polarity (see Section

4.1.3). IMPORTANT -- Always make sure that the plastic plug is screwed back into the adaptor when the ST-23A gas/power cable is disconnected, because hielding gas will escape from the adaptor unless the gas cylinder is shut-off.

MT-250SG

Figure 4.2.2 - Connecting Spool-On-Gun to Services

MT-250SG Requires Adapter 36833

D. Connect the 250s WORK cable to the workpiece.

E. Set Migmaster 250 voltage tap switches to

RANGE and FINE ADJUSTMENT VOLTAGE settings desir- ed.

F. Turn on the Migmaster 250s power switch and

begin seam mig welding.

If the optional Spot/Stitch/Anti-Stick control module is installed, the MT-250SG and the ST-23A gun may be operated using these optional features, see Section

4.2.3.

4.2.3 OPTIONAL SPOT/STITCH/ANTI-STICK CONTROL MODULE

This optional control module allows the operator to use the 250 for Spot or Stitch or Continuous welding operations. It also includes an adjustable Anti-Stick feature to select various burnback times to prevent wire from sticking in the puddle after a weld.

The module consists of three pots (one for Spot-Stitch Weld Time "ON", one for Stitch Weld Time "OFF", and one for Anti-Stick Time modes) and one three-position toggle switch to select the welding operation desired (Spot, Continuous or Stitch). For installation, see Section

3.9; for operation, see following:

4.2.3.1 ANTI-STICK WELDING OPERATION

Anti-Stick feature provides a time delay at the end of a weld from the time the torch trigger is released until the main contactor is deenergized. This delay allows the welding wire to burn back, away from the work, so it wont stick in the weld puddle.

This delay time, controlled by the anti-stick potentiometer, is variable from approximately 0.05 seconds to 0.5 seconds. The required delay time generally depends on the WIRE SPEED Adjustment setting on the front panel

- the higher the setting, the faster wire will feed into the

weld, and the more delay time will be required.

If, when using the Anti-Stick feature, the welding wire tends to stick in the puddle at the end of a weld, the AntiStick time should be increased; if, on the other hand, the wire burns back into the torch tip, the anti-stick time should be decreased. Setting the anti-stick time to Min effectively cancels the anti-stick feature.

This Anti-Stick feature is available for all three welding modes - Continuous, Spot, and Stitch.

4.2.3.2 CONTINUOUS WELDING MODE OPERATION

A. Place the three-position toggle switch in Continu-

ous weld mode (center position) for mig seam welding.

B. Set the Anti-Stick Time as required (see 4.2.3.1).

C. Set the coarse and fine Voltage control

switches and wire speed pot to the desired settings and begin welding operation as described in Sections 4.3.2 and 4.3.3.

4.2.3.3 SPOT WELDING MODE OPERATION

A. Place the three-position toggle switch in Spot

position.

B. Replace the standard nozzle with the No. 12 Spot

weld Nozzle P/N 999625.

C. Trim the welding wire back so the end is slightly

inside the nozzle.

D. Set the coarse and fine voltage control switch-

es, wire speed, and the Spot-Stitch Weld Time see Table 4.3, for the thickness of the metal being welded and the diameter of the weld wire being used.

B. Be sure a standard nozzle (and not a spot weld

nozzle) is installed on the torch.

C. Set the length of time the arc will be ON for each

sequence by adjusting the Spot-Stitch Weld Time control on the power supplys front panel. This timer has an approximate range of from 0.4 seconds at the minimum setting to 3.5 seconds at the maximum setting. Set the length of time the arc will be OFF for each sequence by adjusting the Stitch Weld Time control on the front panel. This timer has an approximate range of from 0.4 seconds at the minimum setting to 3.5 seconds at the maximum setting.

D. Set the coarse and fine voltage control switches

and wire speed as specified in Table 4.3 under Continuous Weld Conditions for:

i. The type weld being made (see diagrams to the

left of each column of figures).

E. To spotweld:

i. Press the torch nozzle squarely on the top plate.

Apply enough pressure to hold the two pieces of metal firmly together, so there is no loose play between them.

Fig. 4.2.3 - Cross Section of Good Spotweld

ii. Pull the trigger, holding the gun motionless and

firmly. The electrode wire and shielding gas will be fed to the work, and the arc will be maintained for the length of time set in Step D. above.

iii. After the preset time has elapsed, the wire will

stop feeding, the arc will be broken, and the shielding gas will stop flowing.

A good spotweld will penetrate through both layers of metal, and will have a small nugget on the reverse side, (Fig. 4.2.3)

4.2.4 STITCH WELDING MODE OPERATION

A. Place the three-position toggle switch in Stitch

position. The stitch weld mode uses a series of pretimed arc-on/arc-off time sequences to allow cooler welding.

ii. The thickness of the metal being welded.

iii. The gap (if any) between the pieces being weld-

ed.

iv. The diameter of the welding wire being used.

E. When using the Stitch weld mode, before starting

the weld the welding wire should extend about 1/ 2-in. beyond the end of the nozzle. Adjust this length by either clipping off the end of the wire with insulated cutters or by using the torch switch.

Power supply contactor becomes energized the moment the torch trigger is depressed. Arcing can occur if the wire is brought to a ground. Keep the torch always from ground until welding is to begin.

F. During the welding, use the same welding techni-

ques as described in Section 4.3.3 and 4.3.4.

4.2.5 DUTY CYCLE (Figure 4.2.5)

The duty cycle of the equipment is the percentage of a 10 minute period which it can operate safely at a given output current. The Migmaster system is rated at 50% duty cycle. This means that the equipment can be safely operated at 250 amperes for five minutes out of every 10. This cycle can be repeated indefinitely (See Figure

4.2.5).

Fig. 4.2.5 Duty Cycle Curves

4.2.6 VOLT/AMPERE CURVES (Figure 4.2.6)

4.3 OPERATING PROCEDURES

4.3.1 OPERATING SAFETY PRECAUTIONS

Comply with all ventilation, fire and other safety requirements for arc welding as established in the SAFETY Section at the front of this manual.

Also remember the following:

A. Because of the radiant energy of the welding arc

and the possibility of drawing an arc before the helmet is lowered over the face, the operator should wear flash goggles with filter lenses under his helmet. The helmet filter plated should be shade number 11 (nonferrous) or 12 (ferrous). All those viewing the arc should use helmets with filter plates, as well as flash goggles. Nearby personnel should wear flash goggles.

The Volt/Ampere curves show the output Voltage available at any given output current for the various Voltage Selector positions in each range low, medium, and high.

The actual operating point of load Voltage and Current is determined by type of process, electrode, shield gas, wire feed speed, and operating technique.

B. The radiant energy of the arc can decompose

chlorinated solvent vapors, such as trichloroethylene and perchlorethylene, to form phosgene, even when these vapors are present in low concentrations. DO NOT weld where chlorinated solvents are present in atmospheres in or around the arc.

C. DO NOT touch the electrode, nozzle or metal parts

in contact with them when power in ON: all are electrically energized (HOT) and can cause a possibly fatal shock. DO NOT allow electrode to touch grounded metal: it will create an arc flash that can injure eyes. It may also start a fire or cause other damage.

D. When working in a confined space, be sure it is

safe to enter. The confined space should be tested for adequate oxygen (at least 19%) with an approved oxygen measuring instrument. The confined space should not contain toxic concentrations of fumes or gases. If this cannot be determined, the operator should wear an approved air supplied breathing apparatus.

Figure 4.2.6 VOLT/AMPERE CURVES

Avoid gas leaks in a confined space, as the leaked gas can dangerously reduce oxygen concentration in the breathing air.

DO NOT bring gas cylinders into confined spaces.

When leaving a confined space, shut OFF gas supply at the source to prevent gas from leaking into the space, if the switch is accidently kept depressed. Check the breathing atmosphere in the confined space to be sure it is safe to reenter.

E. Never operate the equipment at currents greater

than the rated ampere capacity; overheating will occur.

F. Never operate equipment in a damp or wet area

without suitable insulation for protection against shock. Keep hands, feet and clothing dry at all times.

G. Whenever the equipment is left unattended, turn

all control and power supply switches and gas supplies OFF and open the main line switch.

H. Wear dark substantial clothing to protect exposed

skin from arcburn, sparks and flying hot metal.

I. Turn off welding power before adjusting or replac-

ing electrodes.

Never operate the welding machine with any portion of the outer enclosure removed. In addition to a hazard, improper cooling may result in damage to the welding transformer and the welding machine components. Warranty is void if the machine is operated with any portion of the outer enclosure removed.

b. Attempting to weld over grease or oil can cause

weld defects.

c. Before welding on aluminum, be sure to clean

surface thoroughly using a stainless steel brush.

4.3.3 SET-UP PROCEDURE

A. Determine the material type, thickness and joint

configuration to be welded from Table 4.3 and use the recommendations to set the following:

a. Coarse Voltage Range, LOW/MED/HIGH.

b. Fine Arc Voltage Setting, 1 thru 8 (the higher the

number, the hotter the weld).

c. Wire Speed setting, 0 thru 10 (the higher the

number, the faster the speed).

B. Set the two-position switch in the wire feeder com-

partment to STANDARD for seam welding with the MT-200CC torch. (For ST-23A Spool-On-Gun welding, see Section 4.2.2).

C. If optional Spot/Stitch/Anti-Stick Control module is

installed, refer to Section 4.2.3 for operation, settings and welding condition table.

4.3.2 PRE-WELD REQUIREMENTS

Before welding commences, with all power OFF, check the following:

A. All safety requirements have been read and un-

der stood.

B. All hoses and cables are in good condition, safely

insulated and securely connected.

C.Turn on gas supply by slowly opening cylinder

valve to full ON.

D. Correct size wire accessories have been installed

on the wire feeder, drive gears are meshed, wire pressure set, and guide tube is installed for type and size wire you plan to use, refer to Tables

2.4.5, and 4.3..

E. Spool of correct size wire is locked in place, brake

tension is set, and wire is properly threaded through the inlet guide to the gun tip.

F. The wire feeding compartment cover is closed

and secure.

D. Make sure the MT-200CC torch fitting and the

Work cable are connected to the proper output terminals (inside unit) for the polarity desired.

Only qualified personnel should make these changes. Make certain the primary power has been disconnected and all safety procedures have been followed before proceeding with these instructions.

Normally, you will set-up for reverse polarity; this means the torch fitting is connected to the POS (+) output terminal and the Work cable to the NEG (-) output terminal.

For straight polarity, do just the opposite; torch fitting to NEG (-) output terminal and Work cable to POS (+) output terminal.

4.3.4 WELDING OPERATION

A. Turn Power switch (on unit) to ON position -- be

careful not to operate the torch switch.

G.Make sure that the metal to be welded is properly

prepared:

a. Remove loose surface rust, scale or paint with

wire brush or sander.

B. Before starting the weld, the welding wire should

extend about 1/2-inch beyond the end of the nozzle. Adjust this length by either clipping off the end of the wire with insulated cutters or by using the torch switch.

Power supply contactor becomes energized the moment the torch trigger is depressed. Arcing can occur if the wire is brought to a ground. Keep the torch away from ground until welding is to begin.

C. To start the weld, hold the torch so the welding wire is

approximately 1/4-in. from the work, then press the torch trigger.

D. The welding wire should be pointed into the joint at

angles of approximately 450 for fillet welds, and approxmately 900 for butt welds, (Fig 4.3.4.1).

up or down, it is very important to keep the arc on the leading edge of the puddle to ensure complete penetration.

G. Some welders who are accustomed to welding with

stick electrodes may tend to push the torch into the weld. This is neither necessary nor desirable, since the wire electrode is being mechanically fed into the weld.

Please note that the Wire Speed control can be adjusted for the gauge of metal to be welded. How-

ever, the Coarse Voltage Range and Fine Voltage setting must not be switched while welding.

E. The torch angle relative to the length of the weld should

be approximately 100 from the vertical (Fig. 4.3.4.2).

F. When welding in the vertical position, traveling either

TABLE 4.3, Continuous/Stitch Weld Conditions

H. To stop the weld, release the trigger and pull the torch

from the work. When leaving equipment unattended, always shut OFF and disconnect all input power and shut off shielding gas at source.

Fig. 4.3.4.1 - Angle of Welding Wire with Joint

MIG PROCESS SELECTION GUIDE

SETTING SHOWN AS:

Arc

Voltage

Voltage Range

Wire Feed

Speed

WIRE

DIAMETER

.023"

.030"

.035"

.045"

Settings were developed using 75% argon - 25% carbon dioxide shielding gas. For 100% carbon dioxide shielding gas, add 2 to the arc voltage setting shown above.

Settings were developed using 98% argon - 2% oxygen shielding gas.

TO SET MACHINE

Find the thickness of the base plate to be welded.

Find the diameter of the filler wire to be used. Find the suggested arc voltage, range and wire feed setting by following

3. the wire diameter row across (to the right) and the plate thicknesses column down. Set the arc voltage selector switch, voltage range switch and the wire

4. feed pot to the settings indicated.

CARBON STEEL BASE PLATE THICKNESS

24 GA. 20 GA. 18 GA. 16 GA. 3/32" 1/8" 3/16" 1/4" 3/32" 1/8" 3/16" 1/4"

LOW

1.2

SHORT CIRCUITING ARC SPRAY ARC

LOW

4.3

LOW

3.5

LOW

1.8

1.3

2.5

LOW

1.8

MED

6.5

LOW

4.5

LOW

3.8

LOW

MED

LOW

MED

5.5

MED

4.5

LOW

MED

2.8

MED

666.576.8

MED

5.5

MED

TABLE 4.3, Continuous /Stitch Weld Contitions

MED

HIGH

8.5

MED

HIGH

4.2

This equipment is provided with a thermostat (OL) in the transformer (T1) windings which will open and prevent the contactor (CON) from closing if the transformer windings are overheated. If the thermostat opens, allow the equipment to idle with fan running for approximately 15-min. before attempting to weld again.

V. SERVICE

5.1 MAINTENANCE

Be sure the branch circuit or main disconnect switch is off or electrical input circuit fuses are removed before attempting any inspection or work on the inside of the welding machine. Placing the power switch on the welding machine in the OFF position does not remove all power from inside of the equipment.

Inspection, troubleshooting and repair of this equipment may ordinarily be undertaken by a competent individual having at least general experience in the maintenance and repair of semi-conductor electronic equipment. Maintenance or repair should not be undertaken by anyone not having such qualifications.

5.2 INSPECTION AND SERVICE

Keep Equipment in clean and safe operating condition free of oil, grease, and (in electrical parts) liquid and metallic particles which can cause short-circuits.

Regularly check cylinder valves, regulators, hoses, and gas connections for leaks with soap solution.

Check for and tighten loose hardware including electrical connection. Loose power connections overheat during welding.

Immediately replace all worn or damaged power cables and connectors. Check for frayed and cracked insulation, particularly in areas where conductors enter Equipment.

The electrode wire and all metal parts in contact with it are electrically energized while welding. Inspect these parts periodically for defective insulation and other electrical hazards.

If uninsulated cable and parts are not replaced, an arc caused by a bared cable or part touching a grounded surface may damage unprotected eyes or start a fire. Body contact with a bared cable, connector, or uncovered conductor can shock, possible fatally.

Shut OFF shielding gas supply at source.

To aid in checking and servicing, use Schematic, Figure

5.1.

Keep power cables dry, free of oil and grease, and protected at all times from damage by hot metal and sparks.

Clean dirt and metal particles from drive roll groove weekly; replace roll if badly worn.

5.2.1 POWER SOURCE

feeder compartment. Failure of this fuse will shut off the contactor, shielding gas and wire feeder.

5.2.1.1 RECTIFIER

It is recommended that the rectifier be cleaned occasionally by blowing it out with compressed air. This cleaning operation is necessary so that maximum cooling will be accomplished by the air stream. This should be done periodically, depending upon the location of the unit and the amount of dust and dirt in the atmosphere.

The hermetically sealed silicon diode rectifiers are specially designed for welding machine use and will not age or deteriorate in use. The four diodes are mounted on heat sinks. A periodic cleaning of dust and dirt from these is necessary to insure cooling of the rectifiers. Access is by removal of top cover and side panels. Should any diode accidentally be damaged and need replacement, it can be quickly removed from the heat sink. The replacement diode should be of the same type as the one removed, and should be locked securely to the sink, preferably with a torque wrench set for maximum of 25 ft. lbs. and a minimum of 20 ft. lbs. Excessive torque will distort the mechanical structure and may break the hermetic seal, whereas too little torque will result in improper electrical connections.

NOTE: Thermal conductive compound (Wakefield En-

gineering #120 Thermal Compound or equivalent) must be reapplied to heat sink-diode mating surface whenever a diode is replaced.

5.2.1.2 FAN MOTOR

If it should become necessary to replace this or any other fuse in the welding machine, ensure that the proper size fuse is used as a replacement.

5.2.1.5 OVER-TEMPERATURE PROTECTION

The machine is equipment with a thermostat. On continued high current application, if the thermostat reaches an abnormally high temperature, it will deenergize the contactor. This thermostat will reset itself automatically after the transformer windings have cooled to a safe level. While deenergized, neither the contactor, shielding gas nor wire feeder can be operated.

5.2.2 WIRE FEEDER

When soft wire is fed, the drive rolls may pick up metal from the wire surface. Accumulation on the rolls may score the wire with resulting unwanted friction and improper feeding.

Inspect the rolls regularly and clean them with a fine-wire power brush. Avoid roughening, or removing the hardness of groove surfaces in grooved rolls. Any roughening may score the wire, just as the accumulation being removed may do.

5.3 TROUBLESHOOTING

If welding equipment doesnt work right despite compliance with checklist inspect as follows:

All models are equipped with an exhaust fan and rely on forced draft for adequate cooling for high duty cycles and overloads. Lubricate the fan motor with a few drops of SAE-20 non-detergent oil every three months.

5.2.1.3 TRANSFORMER

Occasional blowing out of the dust and dirt from around the transformer is recommended. This should be done periodically depending upon the location of the unit and the amount of dust and dirt in the atmosphere. The welding machine case cover should be removed and a clean, dry air stream should be used for this cleaning operation.

5.2.1.4 24 VOLTS WIRE FEEDER AND CONTROL CIRCUITS

The 24-volts circuit is protected by a 10 amp fuse in a panel mounted fuseholder, accessible from the wire

A. With all power controls ON and other operating

controls at required settings, visually check all power cables and connections for evidence of overheating or sparking.

To avoid shock, do NOT touch electrode wire or parts in contact with it, or uninsulated cable or

connections.

B. Check all gas (and water) hoses and connections,

flowmeters, and regulators for possible sources of leakage, breakdown or intermittent failure.

C. Isolate trouble to one part of the welding installa-

tion: primary power supply, power source, Feeder or wire guide train (casing, drive rolls, liners and contact tip). If this inspection indicates trouble in the Feeder, use Troubleshooting Guide, Table II and schematic diagram (Figure 5.1).

5.3.1 IF MOTOR DOES NOT RUN:

General Replacement

A. Check for blown fuse. If blown, check that motor is

not binding before replacing fuse.

B. Check for continuity across speed potentiometer

(POT) and wiper contact. Voltage from center tap to MIN end should vary from 0 to 5.4 VDC as potentiometer is rotated clockwise.

C. Check wiring for continuity. Then turn power ON

and check for 30 volts d.c. across input terminals 8 and 9 on the feeder printed circuit board connector (PL1).

D. Press torch trigger, and check for voltage across

motor (Pins 4 to 7) of speed control board; should vary from 1 to 24 VDC as speed control potentiometer is rotated clockwise.

5.3.2 DRIVE ROLL PRESSURE ADJUSTMENT

Adjust the drive roll pressure knob until no wire slippage occurs. DO NOT OVERTIGHTEN - EXCESSIVE PRESSURE CAN CAUSE WIRE FEEDING PROBLEMS.

The exploded views in the Parts Section indicate generally, in numbered parts sequence, the disassembly of the wire drive and feeder parts.

Reassemble in reverse order.

5.3.3 SOLENOID VALVE REPLACEMENT

When replacing the gas solenoid valve, the inlet (with the word IN) must face the rear of the Unit.

Many troubleshooting situations require that the power remain On and that power terminals in the equipment carry voltage. Exercise extreme caution when working on LIVE equipment. Avoid contact with electrical components, except when testing with an appropriate instrument.

Do not make any repairs to equipment unless you are fully qualified, as described in the maintenance section.

TABLE II. TROUBLESHOOTING GUIDE

WELD CONDITION POSSIBLE CAUSE REMEDY

1. No weld or control power. a. Primary input power not available. a. Check for Voltage at primary input. b. Faulty connection, primary input b. Repair or replace cable or switch

cable, or power switch (S3) (TGS1) as necessary.

c. Blown line fuse. c. Replace fuse. If it blows again,

contact ESAB representative.

2. No welding power. a. Thermostat has opened. a. Wait 15 minutes with fan running. If

still no power, contact ESAB repre-

sentative. b. Shorted diode in main rectifier. b. Check diodes and replace if reqd. c. Open in wiring c. Check all wiring.

3. Fan does not run. a. See Weld Condition 1. a. Repair or replace cable or switch as necessary.

b. Malfunctioning fan motor (M1) b. Replace fan motor (M1).

4. Erratic welding current. a. Poor workpiece connection. a. Check workpiece grounding connection.

b. Loose welding connections. b. Check all connections. c. Wrong polarity. c. Check for correct polarity.

5. Welding output Voltage a. Low line Voltage. a. Use correct Voltage.

and/or current too low. b. Welding cables too long or too b. Use correct cable size.

small.

WELD CONDITION POSSIBLE CAUSE REMEDY

c. Loose connection. c. Check all welding cable

connections.

d. Malfunctioning capacitor bank. d. Check capacitors for low

leakage resistance.

6. Stringy irregular bead, a. Torch moved too fast. a. Move Torch slower along seams. poor penetration. b. Controls are not set properly for b. Reset control properly.

metal gauge thickness.

c. Wrong polarity. c. Check for correct polarity.

7. Bead not centered. a. Nozzle not aligned. a. Move Torch nozzle parallel to

and centered over seam.

8. Bead too large. a. Torch moved too slowly. a. Move Torch faster along seam.

9. Unstable arc, excess a. Incorrectly set controls. a. Reset controls. spatter, weld porous.

b. Shield gas flow is too low or b. See Condition 10.

stopped.

c. Torch nozzle is too far from work. c. Maintain 1/4" (.6 mm) wire

protrusion; hold closer to work.

d. Faulty regulator or adapter. d. Check flow at outlet;

replace faulty item. e. Faulty gas solenoid valve (SOL). e. Replace solenoid valve. f. Wrong polarity. f. Check polarity.

10.Shield gas flow low or a. Cylinder valve closed. a. Turn off regulator, slowly open stopped valve, until regulator reaches

35 c.f.h. pressure. b. Cylinder empty. b. Replace if gauge so indicates. c. Faulty regulator or adaptor. c. Check flow at outlet; replace

faulty item. d. Faulty gas solenoid valve. d. Replace solenoid valve.

11.Wire stubs on work a. Controls not set properly for a. Reset controls properly. while welding. metal gauge, thickness.

12.Wire burns back into a. Contact tip loose. a. Firmly tighten with pliers. contact tip. b. Tip too close to work. b. Maintain 1/4" (.6 mm) wire

protrusion; hold Torch further from work.

c. Wire feed slipping. c. Increase pressure on pressure

roll by adjusting pressure knob.

d. Contact tip damaged. d. Trim back tip 1/16" (1.6 mm) max.

Replace if still faulty. e. Voltage setting too high. e. Adjust setting. f. Drive or pressure roll dirty or worn. f. Clean rolls or replace.

13.Wire does not feed; motor a. Kink, etc. in wire, or wire bound a. Straighten; or feed wire until running (drive roll turns). on reel. clear and cut off.

b. Wire freezing to contact tip b. Free freeze, or remove contact

(burnback). tip feed wire until clear cut end free,

and replace tip.

c. Clogged liner. c. Replace liner.

WELD CONDITION POSSIBLE CAUSE REMEDY

14.Wire does not feed; a. Motor a. With wire speed dial on 10, motor NOT running press trigger. If voltage (drive roll does not turn). appears across motor leads

but motor does not run, check motor gears and commutator areas.

b.Power switch S3 and fuses. b. With S3 ON, if voltage

across terminal 1 and 3 is 24 VAC, switch and fuses are good.

c. Speed Potentiometer (POT). c. Check for 1K ohms across

POT outside terminals.

d. Malfunctioning speed control board. d. Check board voltages

(Para 5.3.1 b. and c.)

15.Wire feed does not stop. a. Torch trigger switch. a. Check continuity of Torch trigger

circuit; check to see if trigger lever is stuck in ON position.

b. Malfunctioning relay (K3). b. Check for proper action.

16.Gas continues to flow a. Gas solenoid valve stuck open. a. Tap solenoid or click on and off after trigger release. to clear valve.

VI. PARTS

6.1 SPARE PARTS

To assure minimum downtime, it is recommended that the spare parts noted by the symbol (*) in the Stock No. column of the parts list be kept on hand.

6.2 REPLACEMENT PARTS

The following illustrations of the equipment identify each replacement part by item number as tabulated in the related parts lists. The list identifies each part by part, number, description, and quantity used (in parentheses, if more than 1). Some assemblies can be ordered as complete units or broken down as individual parts. These parts are listed - indented one space - below the assembly. When any of the parts can be broken down as a subassembly, its individual parts as listed below it - indented two spaces.

Attaching hardware items are listed, deeply indented, below the part they attach. They may not be shown. Order them separately.

6.3 ORDERING

To assure proper operation, it is recommended that only genuine ESAB parts and products be used with this equipment. To order replacement parts:

a. Give the part number, description and quantity of

each part required.

b. Give part number and description of equipment on

which the parts are to be used.

c. Indicate any special shipping instructions.

D-32860-D

*NOTE: Switch position mumbers refer to numbers on back of switch

NOTE: Recent modifications to the power source may not be reflected in this schematic. For up-to-date information on your model, refer to the schematic on the inside cover

of the power source or contact the factory.

Figure 5.1 - Schematic Migmaster 250 for 208/230 V. Model

D-33310-C

PRIMARY VOLTAGE

CONNECTION CHART

VOLTAGE CONNECTION STRIPS

1 - 2 1

208 6 - 7 1

7 - 8 FLEX 1 - 2 1

230 6 - 7 1

5 - 8 FLEX

380 3 - 7 2

4 - 8 FLEX

400 2 - 6 2

7 - 8 FLEX

460 2 - 6 2

4 - 8 FLEX

575 2 - 3 2

4 - 8 FLEX

NO. OF

*NOTE: Switch position numbers refer to numbers on back of switch

NOTE: Recent modifications to the power source may not be reflected in this schematic. For up-to-date information on your model, refer to the schematic on the inside cover of the power source or contact

the factory.

Figure 5.2 - Schematic Migmaster 250 for 208/230/380/400/460/575 V. Model

D-32861-E

Figure 5.3 - Wiring Migmaster 250 for 208/230 V. Model

D-33311-C

Figure 5.4 - Wiring Migmaster 250 for 208/230/380/400/460/575 V. Model

FAN/CAPACITOR BANK ASSEMBLY See Figure 6.4

}

20, 19

15, 16

5, 25

6,722,

FIGURE 6.1 MIGMASTER 250 MAIN ASSEMBLY (Left Side)

ITEM QTY. PART CKT.

NO. REQ. NO. DESCRIPTION (Figure 6.1) DESIG.

1 1 33184GY BASE 4 1 672225 INSULATOR STANDOFF 5 1 1373 6750 TRANSFORMER, MAIN - for 208/230 v. model T1

1 33176 TRANSFORMER, MAIN - for 208-575 v. model T1

6 1 951634 VALVE, SOLENOID, 24 V(from 1/1/94) SOL1

1373 0628 VALVE, SOLENOID (before 1/94)

7 1 951633 CONNECTOR, "Y" from 1/1/94)

2360 6726 HOSE CONNECTION (before 1/94)

8 7 1373 2230 CAPACITOR 10,000 MT, 50V C 1-7 10 2 950396 CASTER, SWIVEL 5" 11 2 1373 0912 WHEEL 12 3 1373 0222 BUSHING 13 1 951672 HANDLE (from 1/1/94)

950695 HANDLE (from 1/94) 14 1 31484 P.C. BOARD, SPEED CONTROL PCB1 15 1 2360 8111 TERMINAL BLOCK, 8 PT TB1 16 1 1373 5940 MARKER, TERMINAL 17 2 950760 RELAY (from 1/1/94) K2, K3

2361 0322 RELAY, 4 PDT, 24 VAC, 10A

18 1 1373 0469 BRIDGE, RECTIFIER BR1



19 1 1373 4781 CONTACTOR (see Note below) K1 20 2 1373 0665 BUSBAR E STAMPING 21 1 9951 2178 RESISTOR, 50 OHM, 50W R3 22 1 2360 9967 TERMINAL, 3 POS TB3 23 3 674216 CAPICATOR .02uf 1KV C9-11 24 1 1371 5289 RESISTOR 1 OHM 25W R5 25 1 1373 1989 THERMOSTAT 145° TS1

Capacitor C9-11 and R5 resistor were added 4/93 (starting with Serial No. B93H36548) to provide greater relay protection.



NOTE: If contactor, 13734781, life is short due to high current, repetitive welding, replace with 60 amp contactor, 952173.

11, 12

8 13, 14

18, 19

16, 17

21, 22, 23

FIGURE 6.2 MIGMASTER 250 SYSTEMS

ITEM QTY PART CKT.

NO. REQ. NO. DESCRIPTION (Figure 6.2) DESIG.

2 1 33188YL PANEL, SIDE, RIGHT 3 1 950769 STRAIN, RELIEF 5 2 1373 0623 LATCH, DOOR 6 1 33192GY PLATE, BLANK COVER* 7 1 33291YL COVER, HINGED

8 1 33189GY PANEL, CONTROL, SILKSCREENED 10 1 33187YL PANEL, SIDE, LEFT 11 1 2360 3918 POTENTIOMETER, 1K, WIRE SPEED CTRL. R1 12 1 950584 KNOB 13 1 32818 SWITCH, FINE VOLTS ADJ., 8 POS. S1 14 2 2062171 KNOB 15 1 647233 RECEPTACLE, 8 PIN J3 16 2 2062171 KNOB w/ SET SCREW 17 1 32902 SWITCH, COARSE VOLTS ADJ., 3 POS. S2 18 1 951069 PLUG, PLASTIC "C" SIZE 19 1 680552 ADAPTOR, POWER & GAS (SPOOL GUN) 20 1 950721 SWITCH, TOGGLE, (ON/OFF) S3 21 1 21165 GUIDE TUBE 22 1 952924 TORCH ADAPTOR ASSY. includes:

1 2361 2350 POWER LUG 1 2361 0696 ADAPTOR BLOCK ASS'Y. 1 2361 0528 HOUSING, GUN ADAPTOR (STRAIGHT) 1 952929 CONNECTION TUBE, 4" LG BRASS

23 1 33190 BUSBAR, COPPER

* Photo shows optional Digital Volt/Ammeter Module, P/N 32857, and Spot/Stitch/Anti-Stick Control Module, P/N 32858.

• Was 97W63, changed to 950769, 6/95.

9, 10

FIGURE 6.3 MIGMASTER 250 MAIN ASSEMBLY (Right Side)

ITEM QTY PART CKT.

NO. REQ. NO. DESCRIPTION (Figure 6.3) DESIG.

1 1 33186GY REAR, PANEL 2 1 2360 5057GY SUPPORT, REEL 3 1 2360 6237 HUB, REEL (See Figure 6.5) 5 1 634519 SWITCH, TOGGLE, 4 PDT S4 6 1 1373 5464 FUSE, 10A F1 7 1 634709 HOLDER, FUSE

9 1 2361 2348 GEAR MOTOR, 50-675 IPM 10 1 2361 2479 KEY, MOTOR SHAFT 11 1 33199GY COVER P.C. BOARD 14 1 952939 DRIVE STAND ASSEM. (See Fig. 6.6) 15 1 82F31 WORK CLAMP 16 1 1373 2232 FILTER, CHOKE L1 17 1 951649 POWERCORD 18 1 1373 0583 BUSHING, TERMINAL TP 19 2 676701 TERMINAL ASS'Y., OUTPUT

+ -

1 97W63 STRAIN RELIEF

+ - DENOTES RECOMMENDED ON HAND SPARE PART

- Added "D" Edition, 3/96

10, 9

4, 3

FIGURE 6.4 MIGMASTER 250 FAN & CAPACITOR BANK

ITEM QTY. PART CKT.

NO. REQ. NO. DESCRIPTION (Detail "B" FAN) DESIG.

2 2 99511916 DIODE, SILICON, STRAIGHT POLARITY D1, D2 3 4 1373 0680 INSULATOR, COLLAR 4 4 1373 0681 INSULATOR, SHOULDER 5 2 1373 1597 WELDMENT, RESISTOR 6 2 9511915 DIODE, SILICON, REVERSE POLARITY D3, D4 9 1 951939 BLADE, FAN

10 1 1373 2226 MOTOR, FAN M1

REF.

FIGURE 6.5 MIGMASTER 250 LEXAN HUB KIT

ITEM QTY. PART CKT.

NO. REQ. NO. DESCRIPTION (HUB KIT) DESIG.

2360 5780 REEL HUB KIT (INCLUDES 1-8) 1 1 2360 0255 BRAKE, DISC 2 1 2360 6237 HUB, REEL 3 1 2360 0982 SPRING 4 1 2360 0010 NUT, PLASTIC 5 1 9204 0101 SCREW, R.H.M., 3/8-16 x .75 6 1 9205 6007 WASHER, PLAIN 7 1 2360 0952 WASHER, "D" 8 1 2360 5057GY SUPPORT, REEL 9 1 SHELF (REF.)

10,6

2,4

7,8

1,3

12,13

Figure 6-6. 2-Roll Drive Stand

ITEM QTY. PART

NO. REQ. NO. DESCRIPTION

952939 2 ROLL WIRE DRIVE SYSTEM, CONSISTS OF: 1 1 952704 PRESSURE ARM ASSY., (incls. 2, 3, 4, 7, 8) 2 1 23612477 AXLE, PRESSURE 3 1 23612475 PRESSURE ARM 4 1 23612474 AXLE NUT 5 1 23612625 PIVOT PIN 6 1 23612472 CIRCLIP 7 1 23612368 PRESSURE ROLL, SMOOTH (see Table 2.1) 8 2 23612476 SPACER 9 1 23612460 PRESSURE DEVICE ASSY.

10 1 23612473 LOCATING PIN 11 1 23612461 INLET GUIDE 12 1 21156 DRIVE ROLL, (see Table 2.1) 13 1 952944 ADAPTOR DRIVE ROLL 14 1 952925 FEED ROLL THUMB SCREW 15 1 23612478 FEED PLATE 16 1 34608 WASHER RETAINING SCREW 17 1 952945 FEED ROLL SPACER 18 2 952926 THUMB SCREW M6X16 19 3 23612462 SCREW, MOTOR MOUNTING 20 1 23612662 SPACER TUBE (Pressure Arm) 21 1 23612663 SPRING PRESSURE ARM

INSTRUCTION MANUAL CHANGES

The "F" edition (6/99) of this manual covers the following:

1. Added contact tips modified for improved arc performance on steel and cored wires in Table 2.4.5.1.

2. Added end drive roll/pressure roll combinations for use with soft cored wires in Table

2.4.5.2.

3. Added optional spool spacers for 8" and 10" dia. spools

4. Added the torch adaptor assy and copper busbar (33190) in the torch connection circuit to the replacement parts list of Figure 6.2.

5. Changed the drive stand from 23612627 to 952939.

ESAB Welding & Cutting Products, Florence, SC Welding Equipment

COMMUNICATION GUIDE - CUSTOMER SERVICES

A. CUSTOMER SERVICE QUESTIONS:

Order Entry Product Availability Pricing Delivery Order Changes Saleable Goods Returns Shipping Information

Telephone: (800)362-7080 / Fax: (800) 634-7548

Telephone: (800)783-5360 / Fax: (800) 783-5362

Telephone: (800) 235-4012/ Fax: (888) 586-4670

B. ENGINEERING SERVICE: Telephone: (843) 664-4416 / Fax : (800) 446-5693

Welding Equipment Troubleshooting Hours: 7:30 AM to 5:00 PM EST Warranty Returns Authorized Repair Stations

C. TECHNICAL SERVICE: Telephone: (800) ESAB-123/ Fax: (843) 664-4452

Part Numbers Technical Applications Hours: 8:00 AM to 5:00 PM EST Performance Features Technical Specifications Equipment Recommendations

D. LITERATURE REQUESTS: Telephone: (843) 664-5562 / Fax: (843) 664-5548

E. WELDING EQUIPMENT REPAIRS: Telephone: (843) 664-4487 / Fax: (843) 664-5557

Repair Estimates Repair Status Hours: 7:30 AM to 3:30 PM EST

F. WELDING EQUIPMENT TRAINING:

Telephone: (843)664-4428 / Fax: (843) 679-5864 Training School Information and Registrations Hours: 7:30 AM to 4:00 PM EST

G. WELDING PROCESS ASSISTANCE:

Telephone: (800) ESAB-123 / Fax: (843) 664-4454 Hours: 7:30 AM to 4:00 PM EST

H. TECHNICAL ASST. CONSUMABLES:

Telephone : (800) 933-7070 Hours: 7:30 AM to 5:00 PM EST

Eastern Distribution Center

Central Distribution Center

Western Distribution Center

Hours: 7:30 AM to 4:00 PM EST

F-15-087-F 6/99

IF YOU DO NOT KNOW WHOM TO CALL

Telephone: (800) ESAB-123/ Fax: (843) 664-4452/ Web:http://www.esab.com

Hours: 7:30 AM to 5:00 PM EST

ESAB Migmaster 250 Welding Packages Troubleshooting instruction

Specifications and Main Features

Frequently Asked Questions

User Manual