Thermal Arc 250S DC CC User manual

November 11, 2003 Manual No. 430429-506
INVERTER
ARC
WELDER
MODEL 250S DC CC
STICK
TIG - Lift Start
OPERATING MANUAL

3
CONTENTS
SYMBOL LEGEND ............................................................................................................................................................5
STATEMENT OF WARRANTY........................................................................................................................................6
1.0 GENERAL INFORMATION.........................................................................................................................................7
1.01 Notes, Cautions and Warnings ................................................................................................................................7
1.02 Important Safety Precautions....................................................................................................................................7
1.03 Publications .............................................................................................................................................................8
1.04 Note, Attention et Avertissement.............................................................................................................................9
1.05 Precautions De Securite Importantes.......................................................................................................................9
1.06 Documents De Reference......................................................................................................................................11
2.0 INTRODUCTION AND DESCRIPTION ...................................................................................................................13
2.01 Description .............................................................................................................................................................13
2.02 Functional Block Diagrams....................................................................................................................................14
2.03 Transporting Methods.............................................................................................................................................14
3.0 INSTALLATION RECOMMENDATIONS................................................................................................................15
3.01 Environment...........................................................................................................................................................15
3.02 Location..................................................................................................................................................................15
3.03 Electrical Input Connections...................................................................................................................................16
3.03.01 Electrical Input Requirements .......................................................................................................................16
3.03.02 Input Power ...................................................................................................................................................18
3.03.03 High Frequency Introduction.........................................................................................................................19
3.03.04 High Frequency Interference.........................................................................................................................19
3.04 Specifications .........................................................................................................................................................20
3.05 Duty Cycle..............................................................................................................................................................21
4.0 OPERATOR CONTROLS...........................................................................................................................................23
4.01 Pro-Lite 250S Controls...........................................................................................................................................23
4.02 Weld Parameter Description...................................................................................................................................25
4.03 Weld Parameters for Pro-Lite 250S........................................................................................................................26
4.04 Power Source Features ...........................................................................................................................................26
5.0 SET-UP FOR SMAW (STICK) AND GTAW (TIG) ..................................................................................................28
6.0 SEQUENCE OF OPERATION....................................................................................................................................29
6.01 Stick Welding.........................................................................................................................................................30
6.02 DC LIFT TIG Welding...........................................................................................................................................30
7.0 BASIC TIG WELDING GUIDE..................................................................................................................................31
7.01Electrode Polarity....................................................................................................................................................31
7.02 Tungsten Electrode Current Ranges.......................................................................................................................31
7.03 Tungsten Electrode Types ......................................................................................................................................31
7.04 Guide for Selecting Filler Wire Diameter...............................................................................................................32
7.05 Shielding Gas Selection..........................................................................................................................................32
7.06 TIG Welding Parameters for Low Carbon & Low Alloy Steel Pipe......................................................................32
7.07 Welding Parameters for Steel.................................................................................................................................33
8.0 BASIC ARC WELDING GUIDE................................................................................................................................34
8.01Electrode Polarity....................................................................................................................................................34
8.02 Effects of Stick Welding Various Materials...........................................................................................................34
9.0 BASIC TROUBLESHOOTING...................................................................................................................................37
9.01 TIG Welding Problems...........................................................................................................................................37
9.02 Stick Welding Problems.........................................................................................................................................39
9.03 Power Source Problems..........................................................................................................................................41
10.0 VOLTAGE REDUCTION DEVICE (VRD)..............................................................................................................42
10.01 VRD Specification................................................................................................................................................42
10.02 VRD Maintenance................................................................................................................................................42
11.0 POWER SOURCE ERROR CODES.........................................................................................................................43
12.0 PARTS LIST..............................................................................................................................................................46
APPENDIX A - INTERCONNECT DIAGRAM...............................................................................................................50
APPENDIX B - AUTOMATION ......................................................................................................................................52

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PAGE LEFT INTENTIONALLY BLANK

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SYMBOL LEGEND
Amperage STICK (Shielded Metal Arc
SMAW)
Voltage Pulse Current Function
Hertz (frequency) Spot Time (GTAW)
SEC Seconds Remote Control (Panel/Remote)
%Percent Remote Function
DC (Direct Current) Arc Control (SMAW)
AC (Alternating Current Gas Post-Flow
Standard Function Gas Pre-Flow
Slope Function VRD Voltage Reduction Device
Circuit
Slope W/Repeat Function Negative
Spot Function Positive
Impulse Starting (High
Frequency GTAW) Gas Input
Touch Start (Lift Start TIG
circuit GTAW) Gas Output

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STATEMENT OF WARRANTY
LIMITED WARRANTY: Thermal Arc®, Inc., A Thermadyne Company, hereafter, “Thermal Arc” warrants to customers of its
authorized distributors hereafter “Thermal; Arc” that its products will be free of defects in workmanship or material. Should any
failure to conform to this warranty appear within the time period applicable to the Thermal Arc products as stated below, Thermal Arc
shall, upon notification thereof and substantiation that the product has been stored, installed, operated, and maintained in accordance
with Thermal Arc’s specifications, instructions, recommendations and recognized standard industry practice, and not subject to
misuse, repair, neglect, alteration, or accident, correct such defects by suitable repair or replacement, at Thermal Arc’s sole option, of
any components or parts of the product determined by Thermal Arc to be defective.
THERMAL ARC MAKES NO OTHER WARRANTY, EXPRESS OR IMPLIED. THIS WARRANTY IS EXCLUSIVE AND IN LIEU
OF ALL OTHERS, INCLUDING, BUT NOT LIMITED TO ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
LIMITATION OF LIABILITY: Thermal Arc shall not under any circumstances be liable for special, indirect or consequential damages,
such as, but not limited to, lost profits and business interruption. The remedies of the Purchaser set forth herein are exclusive and the
liability of Thermal Arc with respect to any contract, or anything done in connection therewith such as the performance or breach
thereof, or from the manufacture, sale, delivery, resale, or use of any goods covered by or furnished by Thermal Arc whether arising
out of contract, negligence, strict tort, or under any warranty, or otherwise, shall not, except as expressly provided herein, exceed the
price of the goods upon which such liability is based. No employee, agent, or representative of Thermal Arc is authorized to change
this warranty in any way or grant any other warranty.
PURCHASER'S RIGHTS UNDER THIS WARRANTY ARE VOID IF REPLACEMENT PARTS OR ACCESSORIES ARE USED
WHICH IN THERMAL ARC’S SOLE JUDGEMENT MAY IMPAIR THE SAFETY OR PERFORMANCE OF ANY THERMAL ARC
PRODUCT.
PURCHASER'S RIGHTS UNDER THIS WARRANTY ARE VOID IF THE PRODUCT IS SOLD TO PURCHASER BY NON-
AUTHORIZED PERSONS.
The warranty is effective for the time stated below beginning on the date that the authorized distributor delivers the products to the
Purchaser. Notwithstanding the foregoing, in no event shall the warranty period extend more than the time stated plus one year from
the date Thermal Arc delivered the product to the authorized distributor.
POWER SUPPLIES POWER SUPPLIES & WIRE FEEDERS LABOR
MAIN POWER MAGNETICS (STATIC & ROTATING) 3 YEAR 3 YEAR
ORIGINAL MAIN POWER RECTIFIER 3 YEAR 3 YEAR
POWER SWITCHING SEMI-CONDUCTORS & CONTROL PC BOARD 3 YEAR 3 YEAR
ALL OTHER CIRCUITS AND COMPONENTS INCLUDING 1 YEAR 1 YEAR
BUT NOT LIMITED TO, CONTACTORS, RELAYS,
SOLENOIDS, PUMPS, SWITCHES, MOTORS
ENGINES: ENIGINES ARE NOT WARRANTED BY THERMAL ARC, ALTHOUGH MOST ARE WARRANTED BY THE ENGINE
MANUFACTURER, SEE THE ENGINE MANUFACTURES WARRANTY FOR DETAILS.
CONSOLES, CONTROL EQUIPMENT, HEAT 1 YEAR 1 YEAR
EXCHANGES, AND ACCESSORY EQUIPMENT
PLASMA TORCH AND LEADS, AND REMOTE CONTROLS 180 DAYS 180 DAYS
REPAIR/REPLACEMENT PARTS 90 DAYS 90 DAYS
Warranty repairs or replacement claims under this limited warranty must be submitted to Thermal Arc by an authorized Thermal Arc
repair facility within thirty (30) days of purchaser’s notice of any Warranty Claim. No transportation costs of any kind will be paid
under this warranty. Transportation charges to send products to an authorized warranty repair facility shall be the responsibility of the
Purchaser. All returned goods shall be at the Purchaser’s risk and expense. This warranty supersedes all previous Thermal Arc
warranties.
Thermal Arc® is a Registered Trademark of Thermadyne Industries Inc.
Effective April 1, 2002

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1.0 GENERAL INFORMATION
1.01 Notes, Cautions and Warnings
Throughout this manual, notes, cautions, and
warnings are used to highlight important
information. These highlights are categorized as
follows:
NOTE
An operation, procedure, or
background information which
requires additional emphasis or is
helpful in efficient operation of the
system.
CAUTION
A procedure which, if not properly
followed, may cause damage to the
equipment.
WARNING
A procedure which, if not properly
followed, may cause injury to the
operator or others in the operating
area.
1.02 Important Safety Precautions
WARNING
OPERATION AND
MAINTENANCE OF ARC
WELDING EQUIPMENT CAN BE
DANGEROUS AND HAZARDOUS
TO YOUR HEALTH.
To prevent possible injury, read,
understand and follow all warnings,
safety precautions and instructions
before using the equipment. Call 1-
800-462-2782 or your local distributor
if you have any questions.
GASES AND FUMES
Gases and fumes produced during the Arc
welding/cutting process can be dangerous and
hazardous to your health.
• Keep all fumes and gases from the breathing
area. Keep your head out of the welding
fume plume.
• Use an air-supplied respirator if ventilation is
not adequate to remove all fumes and gases.
• The kinds of fumes and gases from the arc
welding/cutting depend on the kind of
metal being used, coatings on the metal, and
the different processes. You must be very
careful when cutting or welding any metals
which may contain one or more of the
following:
Antimony Chromium Mercury
Arsenic Cobalt Nickel
Barium Copper Selenium
Beryllium Lead Silver
Cadmium Manganese
Vanadium
• Always read the Material Safety Data Sheets
(MSDS) that should be supplied with the
material you are using. These MSDSs will
give you the information regarding the kind
and amount of fumes and gases that may be
dangerous to your health.
• For information on how to test for fumes and
gases in your workplace, refer to item 1 in
Subsection 1.03, Publications in this manual.
• Use special equipment, such as water or
down draft welding/cutting tables, to
capture fumes and gases.
• Do not use the welding torch in an area
where combustible or explosive gases or
materials are located.
• Phosgene, a toxic gas, is generated from the
vapors of chlorinated solvents and cleansers.
Remove all sources of these vapors.
ELECTRIC SHOCK
Electric Shock can injure or kill. The arc welding
process uses and produces high voltage electrical
energy. This electric energy can cause severe or
fatal shock to the operator or others in the
workplace.
• Never touch any parts that are electrically
“live” or “hot.”
• Wear dry gloves and clothing. Insulate
yourself from the work piece or other parts
of the welding circuit.
• Repair or replace all worn or damaged parts.
• Extra care must be taken when the workplace
is moist or damp.

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• Install and maintain equipment according to
NEC code, refer to item 4 in Subsection 1.03,
Publications.
• Disconnect power source before performing
any service or repairs.
• Read and follow all the instructions in the
Operating Manual.
FIRE AND EXPLOSION
Fire and explosion can be caused by hot slag,
sparks, or the arc weld.
• Be sure there is no combustible or flammable
material in the workplace. Any material that
cannot be removed must be protected.
• Ventilate all flammable or explosive vapors
from the workplace.
• Do not cut or weld on containers that may
have held combustibles.
• Provide a fire watch when working in an
area where fire hazards may exist.
• Hydrogen gas may be formed and trapped
under aluminum workpieces when they are
cut underwater or while using a water table.
DO NOT cut aluminum alloys underwater
or on a water table unless the hydrogen gas
can be eliminated or dissipated. Trapped
hydrogen gas that is ignited will cause an
explosion.
NOISE
Noise can cause permanent hearing loss. Arc
welding/cutting processes can cause noise levels
to exceed safe limits. You must protect your ears
from loud noise to prevent permanent loss of
hearing.
• To protect your hearing from loud noise,
wear protective ear plugs and/or ear muffs.
Protect others in the workplace.
• Noise levels should be measured to be sure
the decibels (sound) do not exceed safe
levels.
• For information on how to test for noise, see
item 1 in Subsection 1.03, Publications, in
this manual.
ARC WELDING RAYS
Arc Welding/Cutting Rays can injure your eyes
and burn your skin. The arc welding/cutting
process produces very bright ultra violet and infra
red light. These arc rays will damage your eyes
and burn your skin if you are not properly
protected.
• To protect your eyes, always wear a welding
helmet or shield. Also always wear safety
glasses with side shields, goggles or other
protective eye wear.
• Wear welding gloves and suitable clothing to
protect your skin from the arc rays and
sparks.
• Keep helmet and safety glasses in good
condition. Replace lenses when cracked,
chipped or dirty.
• Protect others in the work area from the arc
rays. Use protective booths, screens or
shields.
• Use the shade of lens as recommended in
Subsection 1.03, item 4.
1.03 Publications
Refer to the following standards or their latest
revisions for more information:
1. OSHA, SAFETY AND HEALTH STANDARDS,
29CFR 1910, obtainable from the
Superintendent of Documents, U.S.
Government Printing Office, Washington, D.C.
20402
2. ANSI Standard Z49.1, SAFETY IN WELDING
AND CUTTING, obtainable from the American
Welding Society, 550 N.W. LeJeune Rd, Miami,
FL 33126
3. NIOSH, SAFETY AND HEALTH IN ARC
WELDING AND GAS WELDING AND
CUTTING, obtainable from the Superintendent
of Documents, U.S. Government Printing
Office, Washington, D.C. 20402
4. ANSI Standard Z87.1, SAFE PRACTICES FOR
OCCUPATION AND EDUCATIONAL EYE
AND FACE PROTECTION, obtainable from
American National Standards Institute, 1430
Broadway, New York, NY 10018
5. ANSI Standard Z41.1, STANDARD FOR MEN’S
SAFETY-TOE FOOTWEAR, obtainable from
the American National Standards Institute,
1430 Broadway, New York, NY 10018

9
6. ANSI Standard Z49.2, FIRE PREVENTION IN
THE USE OF CUTTING AND WELDING
PROCESSES, obtainable from American
National Standards Institute, 1430 Broadway,
New York, NY 10018
7. AWS Standard A6.0, WELDING AND
CUTTING CONTAINERS WHICH HAVE
HELD COMBUSTIBLES, obtainable from
American Welding Society, 550 N.W. LeJeune
Rd, Miami, FL 33126
8. NFPA Standard 51, OXYGEN-FUEL GAS
SYSTEMS FOR WELDING, CUTTING AND
ALLIED PROCESSES, obtainable from the
National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269
9. NFPA Standard 70, NATIONAL ELECTRICAL
CODE, obtainable from the National Fire
Protection Association, Batterymarch Park,
Quincy, MA 02269
10. NFPA Standard 51B, CUTTING AND
WELDING PROCESSES, obtainable from the
National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269
11.CGA Pamphlet P-1, SAFE HANDLING OF
COMPRESSED GASES IN CYLINDERS,
obtainable from the Compressed Gas
Association, 1235 Jefferson Davis Highway,
Suite 501, Arlington, VA 22202
12. CSA Standard W117.2, CODE FOR SAFETY IN
WELDING AND CUTTING, obtainable from
the Canadian Standards Association, Standards
Sales, 178 Rexdale Boulevard, Rexdale, Ontario,
Canada M9W 1R3
13. NWSA booklet, WELDING SAFETY
BIBLIOGRAPHY obtainable from the National
Welding Supply Association, 1900 Arch Street,
Philadelphia, PA 19103
14. American Welding Society Standard AWSF4.1,
RECOMMENDED SAFE PRACTICES FOR
THE PREPARATION FOR WELDING AND
CUTTING OF CONTAINERS AND PIPING
THAT HAVE HELD HAZARDOUS
SUBSTANCES, obtainable from the American
Welding Society, 550 N.W. LeJeune Rd, Miami,
FL 33126
15. ANSI Standard Z88.2, PRACTICE FOR
RESPIRATORY PROTECTION, obtainable
from American National Standards Institute,
1430 Broadway, New York, NY 10018
1.04 Note, Attention et Avertissement
Dans ce manuel, les mots “note,” “attention,” et
“avertissement” sont utilisés pour mettre en relief
des informations à caractère important. Ces mises
en relief sont classifiées comme suit :
NOTE
Toute opération, procédure ou
renseignement général sur lequel il
importe d’insister davantage ou qui
contribue à l’efficacité de
fonctionnement du système.
ATTENTION
Toute procédure pouvant résulter
l’endommagement du matériel en cas
de non-respect de la procédure en
question.
AVERTISSEMENT
Toute procédure pouvant provoquer
des blessures de l’opérateur ou des
autres personnes se trouvant dans la
zone de travail en cas de non-respect
de la procédure en question.
1.05 Precautions De Securite
Importantes
AVERTISSEMENT
L’OPÉRATION ET LA
MAINTENANCE DU MATÉRIEL
DE SOUDAGE À L’ARC AU JET
DE PLASMA PEUVENT
PRÉSENTER DES RISQUES ET
DES DANGERS DE SANTÉ.
Il faut communiquer aux opérateurs et
au personnel TOUS les dangers
possibles. Afin d’éviter les blessures
possibles, lisez, comprenez et suivez
tous les avertissements, toutes les
précautions de sécurité et toutes les
consignes avant d’utiliser le matériel.
Composez le + 1-800-462-2782 ou
votre distributeur local si vous avez
des questions.

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FUMÉE et GAZ
La fumée et les gaz produits par le procédé de jet
de plasma peuvent présenter des risques et des
dangers de santé.
• Eloignez toute fumée et gaz de votre zone de
respiration. Gardez votre tête hors de la
plume de fumée provenant du chalumeau.
• Utilisez un appareil respiratoire à
alimentation en air si l’aération fournie ne
permet pas d’éliminer la fumée et les gaz.
• Les sortes de gaz et de fumée provenant de
l’arc de plasma dépendent du genre de métal
utilisé, des revêtements se trouvant sur le
métal et des différents procédés. Vous devez
prendre soin lorsque vous coupez ou soudez
tout métal pouvant contenir un ou plusieurs
des éléments suivants:
antimoine cadmium mercure
argent chrome nickel
arsenic cobalt plomb
baryum cuivre sélénium
béryllium manganèse
vanadium
• Lisez toujours les fiches de données sur la
sécurité des matières (sigle américain
“MSDS”); celles-ci devraient être fournies
avec le matériel que vous utilisez. Les MSDS
contiennent des renseignements quant à la
quantité et la nature de la fumée et des gaz
pouvant poser des dangers de santé.
• Pour des informations sur la manière de
tester la fumée et les gaz de votre lieu de
travail, consultez l’article 1 et les documents
cités à la page 5.
• Utilisez un équipement spécial tel que des
tables de coupe à débit d’eau ou à courant
descendant pour capter la fumée et les gaz.
• N’utilisez pas le chalumeau au jet de plasma
dans une zone où se trouvent des matières
ou des gaz combustibles ou explosifs.
• Le phosgène, un gaz toxique, est généré par la
fumée provenant des solvants et des
produits de nettoyage chlorés. Eliminez
toute source de telle fumée.
CHOC ELECTRIQUE
Les chocs électriques peuvent blesser ou même
tuer. Le procédé au jet de plasma requiert et
produit de l’énergie électrique haute tension. Cette
énergie électrique peut produire des chocs graves,
voire mortels, pour l’opérateur et les autres
personnes sur le lieu de travail.
• Ne touchez jamais une pièce “sous tension”
ou “vive”; portez des gants et des vêtements
secs. Isolez-vous de la pièce de travail ou des
autres parties du circuit de soudage.
• Réparez ou remplacez toute pièce usée ou
endommagée.
• Prenez des soins particuliers lorsque la zone
de travail est humide ou moite.
• Montez et maintenez le matériel
conformément au Code électrique national
des Etats-Unis. (Voir la page 5, article 9.)
• Débranchez l’alimentation électrique avant
tout travail d’entretien ou de réparation.
• Lisez et respectez toutes les consignes du
Manuel de consignes.
INCENDIE ET EXPLOSION
Les incendies et les explosions peuvent résulter
des scories chaudes, des étincelles ou de l’arc de
plasma. Le procédé à l’arc de plasma produit du
métal, des étincelles, des scories chaudes pouvant
mettre le feu aux matières combustibles ou
provoquer l’explosion de fumées inflammables.
• Soyez certain qu’aucune matière combustible
ou inflammable ne se trouve sur le lieu de
travail. Protégez toute telle matière qu’il est
impossible de retirer de la zone de travail.
• Procurez une bonne aération de toutes les
fumées inflammables ou explosives.
• Ne coupez pas et ne soudez pas les
conteneurs ayant pu renfermer des matières
combustibles.
• Prévoyez une veille d’incendie lors de tout
travail dans une zone présentant des dangers
d’incendie.
• Le gas hydrogène peut se former ou
s’accumuler sous les pièces de travail en
aluminium lorsqu’elles sont coupées sous
l’eau ou sur une table d’eau. NE PAS couper
les alliages en aluminium sous l’eau ou sur
une table d’eau à moins que le gas