Art# A-12514
Firepower MST 140i
3-IN-1 Multi Process
Welding Systems
Operating
Manual
www.firepower.com
English
Canadien Français
Americas Español
Revision: AA Issue Date: March 12, 2014 Manual No.: 0-5338
WE APPRECIATE YOUR BUSINESS!
Congratulations on receiving your new Firepower product. We are proud to have you as our customer
and will strive to provide you with the best service and support in the industry. This product is backed
by our extensive warranty and world-wide service network.
We know you take pride in your work and we feel privileged to provide you with this high performance
product that will help you get the job done.
YOU ARE IN GOOD COMPANY!
Firepower is a Global Brand of Arc Welding Products for Victor Technologies Inc. We distinguish
ourselves from our competition through market-leading innovation and truly dependable products that
will stand the test of time.
We strive to enhance your productivity, efficiency and welding performance enabling you to excel in
your craft. We design products with the welder in mind delivering- advanced features, durability, ease
of use and ergonomic comfort.
Above all, we are committed to a safer working environment within the welding industry. Your
satisfaction with this product and its safe operation is our ultimate concern. Please take the time to
read the entire manual, especially the Safety Precautions.
If you have any questions or concerns regarding your new Firepower product, please contact our
friendly and knowledgeable Customer Service Team at:
1-800-462-2782 (USA) and 1-905-827-4515 (Canada),
or visit us on the web at www.Firepower.com
!
WARNINGS
Read and understand this entire Manual and your employer’s safety practices if applicable
before installing, operating, or servicing the equipment.
While the information contained in this Manual represents the Manufacturer’s best judgment,
the Manufacturer assumes no liability for its use.
Operating Manual Number 0-5338 for:
Firepower MST 140i Portable system Package Part Number: 1444-0870
Published by:
Victor Technologies, Inc.
16052 Swingley Ridge Road,
Suite 300 St. Louis, MO 63017
USA
www.firepower.com
Copyright © 2014 by
Victor Technologies, Inc.
® All rights reserved.
Reproduction of this work, in whole or in part, without written permission of the publisher
is prohibited.
The publisher does not assume and hereby disclaims any liability to any party for any loss
or damage caused by any error or omission in this Manual, whether such error results
from negligence, accident, or any other cause.
Publication Date: March 12, 2014
Record the following information for Warranty purposes:
Where Purchased: ____________________________________
Purchase Date: ____________________________________
Equipment Serial #: ____________________________________
TABLE OF CONTENTS
SECTION 1: SAFETY INSTRUCTIONS AND WARNINGS ............................................... 1-1
1.01 Arc Welding Hazards ....................................................................................... 1-1
1.02 General Safety Information for Victor CS Regulator .......................................... 1-5
1.03 Principal Safety Standards .............................................................................. 1-6
1.04 Symbol Chart .................................................................................................. 1-7
1.05 Precautions De Securite En Soudage A L’arc .................................................. 1-8
1.06 Dangers relatifs au soudage à l’arc ................................................................. 1-8
1.07 Informations Générales de Sécurité .............................................................. 1-12
1.08 Principales Normes De Securite ................................................................... 1-14
1.09 Graphique de Symbole .................................................................................. 1-15
1.10 Declaration Of Conformity ............................................................................ 1-16
SECTION 2: INTRODUCTION ............................................................................. 2-1
2.01 How to Use This Manual ................................................................................. 2-1
2.02 Equipment Identification ................................................................................. 2-1
2.03 Receipt of Equipment ...................................................................................... 2-1
2.04 Description ..................................................................................................... 2-1
2.05 Transportation Methods .................................................................................. 2-1
2.06 User Responsibility ......................................................................................... 2-1
2.07 Firepower MST 140i Portable System Package (Part No. 1444-0870) ............ 2-2
2.08 Duty Cycle ....................................................................................................... 2-2
2.09 Specifications ................................................................................................. 2-3
2.10 Options and Accessories ................................................................................ 2-4
SECTION 3: INSTALLATION, OPERATION AND SETUP ................................................ 3-1
3.01 Environment ................................................................................................... 3-1
3.02 Location .......................................................................................................... 3-1
3.03 Ventilation ....................................................................................................... 3-1
3.04 Electricity Supply Voltage .............................................................................. 3-1
3.05 Electromagnetic Compatibility ........................................................................ 3-3
3.06 Firepower Flowmeter/ Regulator ..................................................................... 3-4
3.07 Leak Testing the System ................................................................................. 3-6
3.08 When You Finish Using the Flowmeter/ Regulator ..........................................................3-6
3.09
Storage of the Flowmeter/ Regulator ..................................................................... 3-6
3.10 Power Source System Controls, Indicators and Features ............................... 3-7
3.11 Attaching the Firepower 140A MIG Gun ........................................................ 3-15
3.12 Inserting Wire into the Wire Feed Mechanism .............................................. 3-16
3.13 Installing 4" (100mm) Diameter Spool ......................................................... 3-17
3.14 Installing 8" (200mm) Diameter Spool .......................................................... 3-18
3.15 Feed Roller Pressure Adjustment .................................................................. 3-19
3.16 Changing the Feed Roll ................................................................................. 3-19
3.17 Wire Reel Brake ............................................................................................ 3-20
3.18 Flowmeter/ Regulator Operation ................................................................... 3-21
3.19 Setup for MIG (GMAW) Welding with Gas Shielded MIG Wire ..................... 3-21
3.20 Setup for MIG (FCAW) Welding with Flux Core (Gasless) Wire .................... 3-23
3.21 Setup for LIFT TIG (GTAW) Welding ............................................................. 3-24
3.22 Setup for STICK (SMAW) Welding .............................................................. 3-26
TABLE OF CONTENTS
SECTION 4: BASIC WELDING GUIDE .................................................................... 4-1
4.01 MIG (GMAW/FCAW) Basic Welding Technique ............................................... 4-1
4.02 MIG (GMAW/FCAW) Welding Troubleshooting ............................................... 4-6
4.03 Stick (SMAW) Basic Welding Technique ......................................................... 4-9
4.04 Effects of Stick Welding Various Materials .................................................... 4-10
4.05 Stick (SMAW) Welding Troubleshooting ....................................................... 4-17
4.06 TIG (GTAW) Basic Welding Technique .......................................................... 4-20
4.07 TIG (GTAW) Welding Problems ..................................................................... 4-22
SECTION 5: POWER SOURCE PROBLEMS AND ROUTINE SERVICE REQUIREMENTS ............ 5-1
5.01 Power Source Problems ................................................................................. 5-1
5.02 Routine Service............................................................................................... 5-3
5.03 Cleaning the Welding Power Source ............................................................... 5-4
5.04 Cleaning the Feed Rolls ................................................................................... 5-4
5.05 Volt-Ampere Curves ........................................................................................ 5-4
SECTION 6: KEY SPARE PARTS .......................................................................... 6-1
6.01 Firepower 140A MIG Gun Parts ...................................................................... 6-1
6.02 Power Source ................................................................................................. 6-2
6.03 Hardware List ................................................................................................. 6-4
APPENDIX ................................................................................................... A-1
APPENDIX: FIREPOWER MST 140I CIRCUIT DIAGRAM ............................................... A-2
FIREPOWER - LIMITED WARRANTY TERMS ......................................INSIDE REAR COVER
GLOBAL CUSTOMER SERVICE CONTACT INFORMATION ................................. REAR COVER
This Page Intentionally Blank
Firepower MST 140i
Manual 0-5338 1-1 SAFETY INSTRUCTIONS AND WARNINGS
1.01 Arc Welding Hazards
WARNING
ELECTRIC SHOCK can kill.
Touching live electrical parts can cause fatal
shocks or severe burns. The electrode and work
circuit is electrically live whenever the output is
on. The input power circuit and machine internal
circuits are also live when power is on. In semiautomatic or automatic wire welding, the wire,
wire reel, drive roll housing, and all metal parts
touching the welding wire are electrically live.
Incorrectly installed or improperly grounded
equipment is a hazard.
1. Do not touch live electrical parts.
2. Wear dry, hole-free insulating gloves and body protection.
3. Insulate yourself from work and ground using dry
insulating mats or covers.
4. Disconnect input power or stop engine before installing
or servicing this equipment. Lock input power disconnect
switch open, or remove line fuses so power cannot be
turned on accidentally.
5. Properly install and ground this equipment according to
its Owner’s Manual and national, state, and local codes.
6. Turn off all equipment when not in use. Disconnect power
to equipment if it will be left unattended or out of service.
7. Use fully insulated electrode holders. Never dip holder in
water to cool it or lay it down on the ground or the work
surface. Do not touch holders connected to two welding
machines at the same time or touch other people with the
holder or electrode.
8. Do not use worn, damaged, undersized, or poorly spliced
cables.
9. Do not wrap cables around your body.
10. Ground the workpiece to a good electrical (earth) ground.
11. Do not touch electrode while in contact with the work
(ground) circuit.
12. Use only well-maintained equipment. Repair or replace
damaged parts at once.
13. In confined spaces or damp locations, do not use a welder
with AC output unless it is equipped with a voltage reducer.
Use equipment with DC output.
14. Wear a safety harness to prevent falling if working above
floor level.
15. Keep all panels and covers securely in place.
WARNING
ARC RAYS can burn eyes and skin; NOISE can
damage hearing. Arc rays from the welding
process produce intense heat and strong
ultraviolet rays that can burn eyes and skin. Noise
from some processes can damage hearing.
SECTION 1: SAFETY INSTRUCTIONS AND WARNINGS
!
WARNING
PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN AWAY. PACEMAKER
WEARERS KEEP AWAY UNTIL CONSULTING YOUR DOCTOR. DO NOT LOSE THESE INSTRUCTIONS. READ OPERATING/
INSTRUCTION MANUAL BEFORE INSTALLING, OPERATING OR SERVICING THIS EQUIPMENT.
Welding products and welding processes can cause serious injury or death, or damage to other equipment or property, if the
operator does not strictly observe all safety rules and take precautionary actions.
Safe practices have developed from past experience in the use of welding and cutting. These practices must be learned through
study and training before using this equipment. Some of these practices apply to equipment connected to power lines; other
practices apply to engine driven equipment. Anyone not having extensive training in welding and cutting practices should
not attempt to weld.
Safe practices are outlined in the American National Standard Z49.1 entitled: SAFETY IN WELDING AND CUTTING. This
publication and other guides to what you should learn before operating this equipment are listed at the end of these safety
precautions. HAVE ALL INSTALLATION, OPERATION, MAINTENANCE, AND REPAIR WORK PERFORMED ONLY BY QUALIFIED
PEOPLE.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-2 Manual 0-5338
1. Wear a welding helmet fitted with a proper shade of filter
(see ANSI Z49.1 listed in Safety Standards) to protect
your face and eyes when welding or watching.
2. Wear approved safety glasses. Side shields recommended.
3. Use protective screens or barriers to protect others from
flash and glare; warn others not to watch the arc.
4. Wear protective clothing made from durable, flameresistant material (wool and leather) and foot protection.
5. Use approved ear plugs or ear muffs if noise level is high.
WARNING
FUMES AND GASES can be hazardous to your
health.
Welding produces fumes and gases. Breathing
these fumes and gases can be hazardous to your
health.
1. Keep your head out of the fumes. Do not breathe the
fumes.
2. If inside, ventilate the area and/or use exhaust at the arc
to remove welding fumes and gases.
3. If ventilation is poor, use an approved air-supplied
respirator.
4. Read the Material Safety Data Sheets (MSDSs) and the
manufacturer’s instruction for metals, consumables,
coatings, and cleaners.
5. Work in a confined space only if it is well ventilated, or
while wearing an air-supplied respirator. Shielding gases
used for welding can displace air causing injury or death.
Be sure the breathing air is safe.
6. Do not weld in locations near degreasing, cleaning, or
spraying operations. The heat and rays of the arc can react
with vapors to form highly toxic and irritating gases.
7. Do not weld on coated metals, such as galvanized, lead,
or cadmium plated steel, unless the coating is removed
AWS F2.2:2001 (R2010), Adapted with permission of the American Welding Society (AWS), Miami, Florida
Guide for Shade Numbers
Process
Electrode Size in.
(mm)
Arc Current
(Amperes)
Minimum
Protective
Shade
Suggested*
Shade No.
(Comfort)
Shielded Metal Arc Welding
(SMAW)
Less than 3/32 (2.4)
3/32-5/32 (2.4-4.0)
5/32-1/4 (4.0-6.4)
More than 1/4 (6.4)
Less than 60
60-160
160-250
250-550
7
8
10
11
10
12
14
Gas Metal Arc Welding (GMAW)
and Flux Cored Arc Welding
(FCAW)
Less than 60
60-160
160-250
250-550
7
10
10
10
11
12
14
Gas Tungsten arc Welding
(GTAW)
Less than 50
50-150
150-500
8
8
10
10
12
14
Air Carbon Arc Cutting (CAC-A)
(Light)
(Heavy)
Less than
500
500-1000
10
11
12
14
Plasma Arc Welding (PAW)
Less than 20
20-100
100-400
400-800
6
8
10
11
6 to 8
10
12
14
Plasma Arc Cutting (PAC)
Less than 20
20-40
40-60
60-80
80-300
300-400
400-800
4
5
6
8
8
9
10
4
5
6
8
9
12
14
* As a rule of thumb, start with a shade that is too dark to see the weld zone. Then go to a lighter
shade which gives sufficient view of the weld zone without going below the minimum. In oxyfuel gas
welding, cutting, or brazing where the torch and/or the flux produces a high yellow light, it is desirable
to use a filter lens that absorbs the yellow or sodium line of the visible light spectrum.
Firepower MST 140i
Manual 0-5338 1-3 SAFETY INSTRUCTIONS AND WARNINGS
from the weld area, the area is well ventilated, and if
necessary, while wearing an air-supplied respirator. The
coatings and any metals containing these elements can
give off toxic fumes if welded.
WARNING
WELDING can cause fire or explosion.
Sparks and spatter fly off from the welding arc.
The flying sparks and hot metal, weld spatter, hot
workpiece, and hot equipment can cause fires
and burns. Accidental contact of electrode or
welding wire to metal objects can cause sparks,
overheating, or fire.
1. Protect yourself and others from flying sparks and hot
metal.
2. Do not weld where flying sparks can strike flammable
material.
3. Remove all flammables within 35 ft (10.7 m) of the
welding arc. If this is not possible, tightly cover them
with approved covers.
4. Be alert that welding sparks and hot materials from
welding can easily go through small cracks and openings
to adjacent areas.
5. Watch for fire, and keep a fire extinguisher nearby.
6. Be aware that welding on a ceiling, floor, bulkhead, or
partition can cause fire on the hidden side.
7. Do not weld on closed containers such as tanks or drums.
8. Connect work cable to the work as close to the welding
area as practical to prevent welding current from traveling
long, possibly unknown paths and causing electric shock
and fire hazards.
9. Do not use welder to thaw frozen pipes.
10. Remove stick electrode from holder or cut off welding
wire at contact tip when not in use.
WARNING
FLYING SPARKS AND HOT METAL can cause
injury.
Chipping and grinding cause flying metal. As
welds cool, they can throw off slag.
1. Wear approved face shield or safety goggles. Side shields
recommended.
2. Wear proper body protection to protect skin.
WARNING
CYLINDERS can explode if damaged.
Shielding gas cylinders contain gas under high
pressure. If damaged, a cylinder can explode.
Since gas cylinders are normally part of the
welding process, be sure to treat them carefully.
1. Protect compressed gas cylinders from excessive heat,
mechanical shocks, and arcs.
2. Install and secure cylinders in an upright position by
chaining them to a stationary support or equipment
cylinder rack to prevent falling or tipping.
3. Keep cylinders away from any welding or other electrical
circuits.
4. Never allow a welding electrode to touch any cylinder.
5. Use only correct shielding gas cylinders, regulators,
hoses, and fittings designed for the specific application;
maintain them and associated parts in good condition.
6. Turn face away from valve outlet when opening cylinder
valve.
7. Keep protective cap in place over valve except when
cylinder is in use or connected for use.
8. Read and follow instructions on compressed gas
cylinders, associated equipment, and CGA publication
P-1 listed in Safety Standards.
!
WARNING
Engines can be dangerous.
WARNING
ENGINE EXHAUST GASES can kill.
Engines produce harmful exhaust gases.
1. Use equipment outside in open, well-ventilated areas.
2. If used in a closed area, vent engine exhaust outside and
away from any building air intakes.
WARNING
ENGINE FUEL can cause fire or explosion.
Engine fuel is highly flammable.
1. Stop engine before checking or adding fuel.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-4 Manual 0-5338
2. Do not add fuel while smoking or if unit is near any sparks
or open flames.
3. Allow engine to cool before fueling. If possible, check and
add fuel to cold engine before beginning job.
4. Do not overfill tank — allow room for fuel to expand.
5. Do not spill fuel. If fuel is spilled, clean up before starting
engine.
WARNING
MOVING PARTS can cause injury.
Moving parts, such as fans, rotors, and belts can cut fingers
and hands and catch loose clothing.
1. Keep all doors, panels, covers, and guards closed and
securely in place.
2. Stop engine before installing or connecting unit.
3. Have only qualified people remove guards or covers
for maintenance and troubleshooting as necessary.
4. To prevent accidental starting during servicing,
disconnect negative (-) battery cable from battery.
5. Keep hands, hair, loose clothing, and tools away from
moving parts.
6. Reinstall panels or guards and close doors when
servicing is finished and before starting engine.
WARNING
SPARKS can cause BATTERY GASES TO EXPLODE;
BATTERY ACID can burn eyes and skin.
Batteries contain acid and generate explosive gases.
1. Always wear a face shield when working on a battery.
2. Stop engine before disconnecting or connecting battery
cables.
3. Do not allow tools to cause sparks when working on a
battery.
4. Do not use welder to charge batteries or jump start
vehicles.
5. Observe correct polarity (+ and –) on batteries.
WARNING
STEAM AND PRESSURIZED HOT COOLANT can
burn face, eyes, and skin.
The coolant in the radiator can be very hot and
under pressure.
1. Do not remove radiator cap when engine is hot. Allow
engine to cool.
2. Wear gloves and put a rag over cap area when removing
cap.
3. Allow pressure to escape before completely removing
cap.
!
WARNING
WARNING: This product contains chemicals, including lead,
known to the State of California to cause birth defects and
other reproductive harm.
Wash hands after handling.
NOTE
Considerations About Welding And The Effects
of Low Frequency Electric and Magnetic Fields
The following is a quotation from the General Conclusions
Section of the U.S. Congress, Office of Technology Assessment, Biological Effects of Power Frequency Electric & Magnetic Fields - Background Paper, OTA-BP-E-63 (Washington,
DC: U.S. Government Printing Office, May 1989): “...there
is now a very large volume of scientific findings based on
experiments at the cellular level and from studies with animals
and people which clearly establish that low frequency magnetic fields interact with, and produce changes in, biological
systems. While most of this work is of very high quality, the
results are complex. Current scientific understanding does
not yet allow us to interpret the evidence in a single coherent
framework. Even more frustrating, it does not yet allow us to
draw definite conclusions about questions of possible risk or
to offer clear science-based advice on strategies to minimize
or avoid potential risks.”
To reduce magnetic fields in the workplace, use the following
procedures.
1. Keep cables close together by twisting or taping them.
2. Arrange cables to one side and away from the
operator.
3. Do not coil or drape cable around the body.
4. Keep welding Power Source and cables as far away
from body as practical.
Firepower MST 140i
Manual 0-5338 1-5 SAFETY INSTRUCTIONS AND WARNINGS
ABOUT PACEMAKERS:
The above procedures are among those also
normally recommended for pacemaker wearers.
Consult your doctor for complete information.
1.02 General Safety Information for Victor
CS Regulator
A Fire Prevention
Welding and cutting operations use fire or combustion
as a basic tool. The process is very useful when properly
controlled. However, it can be extremely destructive if not
performed cor rectly in the proper environment.
1. The work area must have a fireproof floor.
2. Work benches or tables used during welding or cutting operations must have fireproof tops.
3. Use heat resistant shields or other approved material to
protect nearby walls or unprotected flooring from sparks
and hot metal.
4. Keep an approved fire extinguisher of the proper
size and type in the work area. Inspect it regularly to
ensure that it is in proper working order. Know how
to use the fire extin guisher.
5. Move combustible materials away from the work site.
If you can not move them, protect them with fireproof
covers.
!
WARNING
NEVER perform welding, heating, or cutting operations on a container that has held toxic, combustible or flammable liq uids, or vapors. NEVER
perform welding, heating, or cutting operations in
an area containing combustible vapors, flam mable
liquids, or explosive dust.
B Housekeeping
!
WARNING
NEVER allow oxygen to contact grease, oil, or other
flam mable substances. Although oxygen by itself
will not burn, these substances become highly
explosive. They can ignite and burn violently in
the presence of oxygen.
Keep ALL apparatus clean and free of grease, oil and other
flammable substances.
C Ventilation
!
WARNING
Ade quately ventilate welding, heating, and cutting
work areas to prevent accumulation of explosive
or toxic concen trations of gases. Certain combinations of metals, coatings, and gases generate toxic
fumes. Use respiratory protection equipment in
these circumstances. When welding/brazing, read
and understand the Material Safety Data Sheet for
the welding/brazing alloy.
D Personal Protection
Gas flames produce infrared radiation which may have a
harm ful effect on the skin and especially on the eyes. Select
goggles or a mask with tempered lenses, shaded 4 or darker,
to protect your eyes from injury and provide good visibility
of the work.
Always wear protective gloves and flame-resistant clothing to
protect skin and clothing from sparks and slag. Keep collars,
sleeves, and pockets buttoned. DO NOT roll up sleeves or cuff
pants.
When working in a non-welding or cutting environment,
always wear suitable eye protection or face shield.
!
WARNING
Practice the following safety and operation precautions EVERY TIME you use pressure regulation
equipment. Deviation from the following safety
and operation instructions can result in fire, explosion, damage to equipment, or injury to the
operator.
E Compressed Gas Cylinders
The Department of Transportation (DOT) approves the design
and manufacture of cylinders that contain gases used for
welding or cutting operations.
1. Place the cylinder (Figure 1-1) where you will use it.
Keep the cylinder in a vertical position. Secure it to a cart,
wall, work bench, post, etc.
Art # A-12127
Figure 1-1: Gas Cylinders
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-6 Manual 0-5338
!
WARNING
Cylinders are highly pressurized. Handle with
care. Serious accidents can result from improper
handling or mis use of compressed gas cylinders
DO NOT drop the cylinder, knock it over, or expose
it to excessive heat, flames or sparks. DO NOT
strike it against other cylinders. Contact your
gas supplier or refer to CGA P-1 “Safe Handling
of Compressed Gases in Containers” publication.
NOTE
CGA P-1 publication is available by writing the
Compressed Gas Association, 4221 Walney Road,
5th Floor, Chantilly,VA 20151-2923
2. Place the valve protection cap on the cylinder whenever mov ing it, placing it in storage, or not using it.
Never drag or roll cylinders in any way. Use a suitable
hand truck to move cylin ders.
3. Store empty cylinders away from full cylinders. Mark
them “EMPTY” and close the cylinder valve.
4. NEVER use compressed gas cylinders without a
pressure reducing regulator attached to the cylinder
valve.
5. Inspect the cylinder valve for oil, grease, and damaged
parts.
!
WARNING
DO NOT use the cylinder if you find oil, grease or
damaged parts. Inform your gas supplier of this
condition immediately.
6. Momentarily open and close (called “cracking”) the
cylinder valve to dislodge any dust or dirt that may be
present in the valve.
CAUTION
Open the cylinder valve slightly. If you open the
valve too much, the cylinder could tip over. When
cracking the cylinder valve, DO NOT stand directly
in front of the cylinder valve. Always perform
cracking in a well ventilated area. If an acetylene
cylinder sprays a mist when cracked, let it stand
for 15 minutes. Then, try to crack the cylinder
valve again. If this problem persists, contact your
gas supplier.
1.03 Principal Safety Standards
Safety in Welding and Cutting, ANSI Standard Z49.1, from
American Welding Society, 550 N.W. LeJeune Rd., Miami,
FL 33126.
Safety and Health Standards, OSHA 29 CFR 1910, from
Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402.
Recommended Safe Practices for the Preparation for
Welding and Cutting of Containers That Have Held Hazardous
Substances, American Welding Society Standard AWS F4.1,
from American Welding Society, 550 N.W. LeJeune Rd.,
Miami, FL 33126.
National Electrical Code, NFPA Standard 70, from National
Fire Protection Association, Batterymarch Park, Quincy, MA
02269.
Safe Handling of Compressed Gases in Cylinders, CGA
Pamphlet P-1, from Compressed Gas Association, 1235
Jefferson Davis Highway, Suite 501, Arlington, VA 22202.
Code for Safety in Welding and Cutting, CSA Standard
W117.2, from Canadian Standards Association, Standards
Sales, 178 Rexdale Boulevard, Rexdale, Ontario, Canada
M9W 1R3.
Safe Practices for Occupation and Educational Eye and Face
Protection, ANSI Standard Z87.1, from American National
Standards Institute, 1430 Broadway, New York, NY 10018.
Cutting and Welding Processes, NFPA Standard 51B, from
National Fire Protection Association, Batterymarch Park,
Quincy, MA 02269.
Firepower MST 140i
Manual 0-5338 1-7 SAFETY INSTRUCTIONS AND WARNINGS
1.04 Symbol Chart
Note that only some of these symbols will appear on your model.
Gas Tungsten Arc
Welding (GTAW)
Air Carbon Arc
Cutting (CAC-A)
Constant Current
Constant Voltage
Or Constant Potential
High Temperature
Fault Indication
Arc Force
Touch Start (GTAW)
Variable Inductance
Voltage Input
Single Phase
Three Phase
Three Phase Static
Frequency ConverterTransformer-Rectifier
Dangerous Voltage
Off
On
Panel/Local
Shielded Metal
Arc Welding (SMAW)
Gas Metal Arc
Welding (GMAW)
Increase/Decrease
Circuit Breaker
AC Auxiliary Power
Remote
Duty Cycle
Percentage
Amperage
Voltage
Hertz (cycles/sec)
Frequency
Negative
Positive
Direct Current (DC)
Protective Earth
(Ground)
Line
Line Connection
Auxiliary Power
Receptacle RatingAuxiliary Power
Art # A-04130_AB
115V 15A
t
t1
t2
%
X
IPM
MPM
t
V
Fuse
Wire Feed Function
Wire Feed Towards
Workpiece With
Output Voltage Off.
Preflow Time
Postflow Time
Spot Time
Spot Weld Mode
Continuous Weld
Mode
Press to initiate wirefeed and
welding, release to stop.
Purging Of Gas
Inches Per Minute
Meters Per Minute
Welding Gun
Burnback Time
Press and hold for preflow, release
to start arc. Press to stop arc, and
hold for preflow.
4 Step Trigger
Operation
2 Step Trigger
Operation
S
See Note
See Note
S
Note: For environments with increased hazard of electrical shock, Power Supplier bearing the mark conform to EN50192
when used in conjunction with hand torches with exposed tips, if equipped with properly installed standoff guides.
Cannot be disposed with household garbage.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-8 Manual 0-5338
1.05 Precautions De Securite En Soudage A L’arc
!
MISE EN GARDE
LE SOUDAGE A L’ARC EST DANGEREUX
PROTEGEZ-VOUS, AINSI QUE LES AUTRES, CONTRE LES BLESSURES GRAVES POSSIBLES OU LA MORT. NE LAISSEZ PAS
LES ENFANTS S’APPROCHER, NI LES PORTEURS DE STIMULATEUR CARDIAQUE (A MOINS QU’ILS N’AIENT CONSULTE
UN MEDECIN). CONSERVEZ CES INSTRUCTIONS. LISEZ LE MANUEL D’OPERATION OU LES INSTRUCTIONS AVANT D’INSTALLER, UTILISER OU ENTRETENIR CET EQUIPEMENT.
Les produits et procédés de soudage peuvent sauser des blessures graves ou la mort, de même que des dommages au
reste du matériel et à la propriété, si l’utilisateur n’adhère pas strictement à toutes les règles de sécurité et ne prend pas les
précautions nécessaires.
En soudage et coupage, des pratiques sécuritaires se sont développées suite à l’expérience passée. Ces pratiques doivent être
apprises par étude ou entraînement avant d’utiliser l’equipement. Toute personne n’ayant pas suivi un entraînement intensif
en soudage et coupage ne devrait pas tenter de souder. Certaines pratiques concernent les équipements raccordés aux lignes
d’alimentation alors que d’autres s’adressent aux groupes électrogènes.
La norme Z49.1 de l’American National Standard, intitulée “SAFETY IN WELDING AND CUTTING” présente les pratiques
sécuritaires à suivre. Ce document ainsi que d’autres guides que vous devriez connaître avant d’utiliser cet équipement sont
présentés à la fin de ces instructions de sécurité.
SEULES DES PERSONNES QUALIFIEES DOIVENT FAIRE DES TRAVAUX D’INSTALLATION, DE REPARATION, D’ENTRETIEN
ET D’ESSAI.
1.06 Dangers relatifs au soudage à l’arc
AVERTISSEMENT
L’ELECTROCUTION PEUT ETRE MORTELLE.
Une décharge électrique peut tuer ou brûler gravement. L’électrode et le circuit de soudage sont
sous tension dès la mise en circuit. Le circuit d’alimentation et les circuits internes de l’équipement
sont aussi sous tension dès la mise en marche.
En soudage automatique ou semi-automatique
avec fil, ce dernier, le rouleau ou la bobine de fil,
le logement des galets d’entrainement et toutes
les pièces métalliques en contact avec le fil de
soudage sont sous tension. Un équipement inadéquatement installé ou inadéquatement mis à la
terre est dangereux.
1. Ne touchez pas à des pièces sous tension.
2. Portez des gants et des vêtements isolants, secs et non
troués.
3 Isolez-vous de la pièce à souder et de la mise à la terre
au moyen de tapis isolants ou autres.
4. Déconnectez la prise d’alimentation de l’équipement ou
arrêtez le moteur avant de l’installer ou d’en faire l’entretien. Bloquez le commutateur en circuit ouvert ou enlevez
les fusibles de l’alimentation afin d’éviter une mise en
marche accidentelle.
5. Veuillez à installer cet équipement et à le mettre à la terre
selon le manuel d’utilisation et les codes nationaux, provinciaux et locaux applicables.
6. Arrêtez tout équipement après usage. Coupez l’alimentation de l’équipement s’il est hors d’usage ou inutilisé.
7. N’utilisez que des porte-électrodes bien isolés. Ne jamais
plonger les porte-électrodes dans l’eau pour les refroidir.
Ne jamais les laisser traîner par terre ou sur les pièces à
souder. Ne touchez pas aux porte-électrodes raccordés
à deux sources de courant en même temps. Ne jamais
toucher quelqu’un d’autre avec l’électrode ou le porteélectrode.
8. N’utilisez pas de câbles électriques usés, endommagés,
mal épissés ou de section trop petite.
9. N’enroulez pas de câbles électriques autour de votre corps.
10. N’utilisez qu’une bonne prise de masse pour la mise à la
terre de la pièce à souder.
11. Ne touchez pas à l’électrode lorsqu’en contact avec le
circuit de soudage (terre).
12. N’utilisez que des équipements en bon état. Réparez ou
remplacez aussitôt les pièces endommagées.
13. Dans des espaces confinés ou mouillés, n’utilisez pas de
source de courant alternatif, à moins qu’il soit muni d’un
réducteur de tension. Utilisez plutôt une source de courant
continu.
14. Portez un harnais de sécurité si vous travaillez en hauteur.
15. Fermez solidement tous les panneaux et les capots.
Firepower MST 140i
Manual 0-5338 1-9 SAFETY INSTRUCTIONS AND WARNINGS
AVERTISSEMENT
LE RAYONNEMENT DE L’ARC PEUT BRÛLER LES
YEUX ET LA PEAU; LE BRUIT PEUT ENDOMMAGER L’OUIE.
L’arc de soudage produit une chaleur et des rayons
ultraviolets intenses, susceptibles de brûler les
yeux et la peau. Le bruit causé par certains procédés peut endommager l’ouïe.
1. Portez une casque de soudeur avec filtre oculaire de
nuance appropriée (consultez la norme ANSI Z49 indiquée ci-après) pour vous protéger le visage et les yeux
lorsque vous soudez ou que vous observez l’exécution
d’une soudure.
2. Portez des lunettes de sécurité approuvées. Des écrans
latéraux sont recommandés.
3. Entourez l’aire de soudage de rideaux ou de cloisons pour
protéger les autres des coups d’arc ou de l’éblouissement;
avertissez les observateurs de ne pas regarder l’arc.
4. Portez des vêtements en matériaux ignifuges et durables
(laine et cuir) et des chaussures de sécurité.
5. Portez un casque antibruit ou des bouchons d’oreille
approuvés lorsque le niveau de bruit est élevé.
AVERTISSEMENT
LES VAPEURS ET LES FUMEES SONT DANGEREUSES POUR LA SANTE.
Le soudage dégage des vapeurs et des fumées
dangereuses à respirer.
1. Eloignez la tête des fumées pour éviter de les respirer.
2. A l’intérieur, assurez-vous que l’aire de soudage est bien
ventilée ou que les fumées et les vapeurs sont aspirées
à l’arc.
AWS F2.2 : 2001 (R2010), Modifié avec l’accord de l’American Welding Society (AWS), Miami, Florida
Guide de teinte des lentilles
Procédé
Taille de l’électrode
enmm (po)
Courant
d’arc
(ampères)
Gamme
d’intensité
minimum
Numéro de teinte
recommandée*
(Confort)
Soudage à l’arc avec
électrode enrobée (procédé
SMAW)
Moins de 2,4 (3/32)
3/32-5/32 (2,4-4,0)
5/32-1/4 (4,0-6,4)
Plus de 1/4 (6,4)
Moins de 60
60-160
160-250
250-550
7
8
10
11
10
12
14
Soudage à l’arc sous gaz
avec fil plein (procédé
GMAW) et soudage avec fil
fourré (procédé FCAW)
Moins de 60
60-160
160-250
250-550
7
10
10
10
11
12
14
Soudage à l’électrode
réfractaire (procédé GTAW)
Moins de 50
50-150
150-500
8
8
10
10
12
14
Coupage à l’arc avec
électrode de carbone et jet
d’air (procédé AAC)
(Clair)
(Sombre)
Moins de
500 500-
1000
10
11
12
14
Soudage à l’arc au plasma
(procédé PAW)
Moins de 20
20-100
100-400
400-800
6
8
10
11
6 à 8
10
12
14
Coupage plasma (procédé
PAC)
Moins de 20
20-40
40-60
60-80
80-300
300-400
400-800
4
5
6
8
8
9
10
4
5
6
8
9
12
14
* En règle générale, commencer avec une teinte plus foncée pour voir la zone de soudage. Réduire ensuite
progressivement vers la teinte qui permet de voir la zone de soudage sans dépasser le minimum. Lors
dusoudage, du coupage ou du brasage au gaz oxygéné, la torche ou le fondant produit une puissante
lumière jaune; il est préférable d’utiliser un filtre qui absorbe cette lumière jaune ou le sodium du spectre
de la lumière visible.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-10 Manual 0-5338
7. Ne soudez pas un récipient fermé, tel un réservoir ou un
baril.
8. Connectez le câble de soudage le plus près possible de
la zone de soudage pour empêcher le courant de suivre
un long parcours inconnu, et prévenir ainsi les risques
d’électrocution et d’incendie.
9. Ne dégelez pas les tuyaux avec un source de courant.
10. Otez l’électrode du porte-électrode ou coupez le fil au
tube-contact lorsqu’inutilisé après le soudage.
11. Portez des vêtements protecteurs non huileux, tels des
gants en cuir, une chemise épaisse, un pantalon revers,
des bottines de sécurité et un casque.
AVERTISSEMENT
LES ETINCELLES ET LES PROJECTIONS BRULANTES PEUVENT CAUSER DES BLESSURES.
Le piquage et le meulage produisent des particules
métalliques volantes. En refroidissant, la soudure
peut projeter du éclats de laitier.
1. Portez un écran facial ou des lunettes protectrices
approuvées. Des écrans latéraux sont recommandés.
2. Portez des vêtements appropriés pour protéger la
peau.
AVERTISSEMENT
LES BOUTEILLES ENDOMMAGEES PEUVENT
EXPLOSER
Les bouteilles contiennent des gaz protecteurs
sous haute pression. Des bouteilles endommagées peuvent exploser. Comme les bouteilles
font normalement partie du procédé de soudage,
traitez-les avec soin.
1. Protégez les bouteilles de gaz comprimé contre les sources de chaleur intense, les chocs et les arcs de soudage.
2. Enchainez verticalement les bouteilles à un support ou
à un cadre fixe pour les empêcher de tomber ou d’être
renversées.
3. Eloignez les bouteilles de tout circuit électrique ou de tout
soudage.
4. Empêchez tout contact entre une bouteille et une électrode
de soudage.
5. N’utilisez que des bouteilles de gaz protecteur, des détendeurs, des boyauxs et des raccords conçus pour chaque
application spécifique; ces équipements et les pièces
connexes doivent être maintenus en bon état.
3. Si la ventilation est inadequate, portez un respirateur à
adduction d’air approuvé.
4. Lisez les fiches signalétiques et les consignes du fabricant
relatives aux métaux, aux produits consummables, aux
revêtements et aux produits nettoyants.
5. Ne travaillez dans un espace confiné que s’il est bien
ventilé; sinon, portez un respirateur à adduction d’air. Les
gaz protecteurs de soudage peuvent déplacer l’oxygène de
l’air et ainsi causer des malaises ou la mort. Assurez-vous
que l’air est propre à la respiration.
6. Ne soudez pas à proximité d’opérations de dégraissage,
de nettoyage ou de pulvérisation. La chaleur et les rayons
de l’arc peuvent réagir avec des vapeurs et former des gaz
hautement toxiques et irritants.
7. Ne soudez des tôles galvanisées ou plaquées au plomb ou
au cadmium que si les zones à souder ont été grattées à
fond, que si l’espace est bien ventilé; si nécessaire portez
un respirateur à adduction d’air. Car ces revêtements et
tout métal qui contient ces éléments peuvent dégager des
fumées toxiques au moment du soudage.
AVERTISSEMENT
LE SOUDAGE PEUT CAUSER UN INCENDIE OU
UNE EXPLOSION
L’arc produit des étincellies et des projections. Les
particules volantes, le métal chaud, les projections
de soudure et l’équipement surchauffé peuvent
causer un incendie et des brûlures. Le contact
accidentel de l’électrode ou du fil-électrode avec
un objet métallique peut provoquer des étincelles,
un échauffement ou un incendie.
1. Protégez-vous, ainsi que les autres, contre les étincelles
et du métal chaud.
2. Ne soudez pas dans un endroit où des particules volantes ou des projections peuvent atteindre des matériaux
inflammables.
3. Enlevez toutes matières inflammables dans un rayon de
10, 7 mètres autour de l’arc, ou couvrez-les soigneusement avec des bâches approuvées.
4. Méfiez-vous des projections brulantes de soudage susceptibles de pénétrer dans des aires adjacentes par de
petites ouvertures ou fissures.
5. Méfiez-vous des incendies et gardez un extincteur à portée
de la main.
6. N’oubliez pas qu’une soudure réalisée sur un plafond, un
plancher, une cloison ou une paroi peut enflammer l’autre
côté.
Firepower MST 140i
Manual 0-5338 1-11 SAFETY INSTRUCTIONS AND WARNINGS
6. Ne placez pas le visage face à l’ouverture du robinet de
la bouteille lors de son ouverture.
7. Laissez en place le chapeau de bouteille sauf si en utilisation ou lorsque raccordé pour utilisation.
8. Lisez et respectez les consignes relatives aux bouteilles
de gaz comprimé et aux équipements connexes, ainsi
que la publication P-1 de la CGA, identifiée dans la liste
de documents ci-dessous.
AVERTISSEMENT
LES MOTEURS PEUVENT ETRE DANGEREUX
LES GAZ D’ECHAPPEMENT DES MOTEURS PEU-
VENT ETRE MORTELS.
Les moteurs produisent des gaz d’échappement nocifs.
1. Utilisez l’équipement à l’extérieur dans des aires ouvertes
et bien ventilées.
2. Si vous utilisez ces équipements dans un endroit confiné,
les fumées d’échappement doivent être envoyées à l’extérieur, loin des prises d’air du bâtiment.
AVERTISSEMENT
LE CARBURANT PEUR CAUSER UN INCENDIE
OU UNE EXPLOSION.
Le carburant est hautement inflammable.
1. Arrêtez le moteur avant de vérifier le niveau e carburant
ou de faire le plein.
2. Ne faites pas le plein en fumant ou proche d’une source
d’étincelles ou d’une flamme nue.
3. Si c’est possible, laissez le moteur refroidir avant de faire
le plein de carburant ou d’en vérifier le niveau au début
du soudage.
4. Ne faites pas le plein de carburant à ras bord: prévoyez
de l’espace pour son expansion.
5. Faites attention de ne pas renverser de carburant. Nettoyez
tout carburant renversé avant de faire démarrer le moteur.
AVERTISSEMENT
DES PIECES EN MOUVEMENT PEUVENT CAUSER
DES BLESSURES.
Des pièces en mouvement, tels des ventilateurs,
des rotors et des courroies peuvent couper doigts
et mains, ou accrocher des vêtements amples.
1. Assurez-vous que les portes, les panneaux, les capots et
les protecteurs soient bien fermés.
2. Avant d’installer ou de connecter un système, arrêtez le
moteur.
3. Seules des personnes qualifiées doivent démonter des
protecteurs ou des capots pour faire l’entretien ou le
dépannage nécessaire.
4. Pour empêcher un démarrage accidentel pendant l’entretien, débranchez le câble d’accumulateur à la borne
négative.
5. N’approchez pas les mains ou les cheveux de pièces en
mouvement; elles peuvent aussi accrocher des vêtements
amples et des outils.
6. Réinstallez les capots ou les protecteurs et fermez les
portes après des travaux d’entretien et avant de faire
démarrer le moteur.
AVERTISSEMENT
DES ETINCELLES PEUVENT FAIRE EXPLOSER
UN ACCUMULATEUR; L’ELECTROLYTE D’UN
ACCUMU-LATEUR PEUT BRULER LA PEAU ET
LES YEUX.
Les accumulateurs contiennent de l’électrolyte
acide et dégagent des vapeurs explosives.
1. Portez toujours un écran facial en travaillant sur un accumu-lateur.
2. Arrêtez le moteur avant de connecter ou de déconnecter
des câbles d’accumulateur.
3. N’utilisez que des outils anti-étincelles pour travailler sur
un accumulateur.
4. N’utilisez pas une source de courant de soudage pour
charger un accumulateur ou survolter momentanément
un véhicule.
5. Utilisez la polarité correcte (+ et –) de l’accumulateur.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-12 Manual 0-5338
AVERTISSEMENT
LA VAPEUR ET LE LIQUIDE DE REFROIDISSEMENT BRULANT SOUS PRESSION PEUVENT
BRULER LA PEAU ET LES YEUX.
Le liquide de refroidissement d’un radiateur peut
être brûlant et sous pression.
1. N’ôtez pas le bouchon de radiateur tant que le moteur
n’est pas refroidi.
2. Mettez des gants et posez un torchon sur le bouchon pour
l’ôter.
3. Laissez la pression s’échapper avant d’ôter complètement
le bouchon.
!
AVERTISSEMENT
AVERTISSEMENT: Ce produitcontient des produits chimi-
ques, notamment du plomb, reconnu par l’Étatde la Californie
pour causerdes malformations congénitaleset d’autresdommages touchant le système reproductif.
Se laver les mains
après manipulation.
REMARQUE
Facteurs relatifs au soudage et aux effets des
champs magnétiques et électriques de basse
fréquence
Voici une citation tirée du chapitre des conclusions générales
du document de base de l’Office of Technology Assessment
(bureau des évaluations technologiques) del’U.S. Congress,
« Biological Effects of Power Frequency Electric & Magnetic
Fields », OTA-BP-E-63 (Washington, DC : U.S. Government
Printing Office, mai 1989) : « ... il existe de nos jours, un
nombre très élevé de travaux scientifiques qui rapportent les
résultats d’expériences menées au niveau cellulaire et d’études
auprès d’homme et d’animaux qui établissent nettement le
rapport entre les champs magnétiques de basse fréquence
et les systèmes biologiques, soit par des interactions ou des
modifications. Quoique la plupart de ces travaux soient de
très bonne qualité, les résultats sont complexes. Àla lumière
des connaissances scientifiques actuelles, il nous est encore
impossible d’interpréter les évidences en un seul cadre de
référence cohérent. La situation est toutefois très contrariante.
En effet, il nous est aussi impossible de tirer des conclusions
définitives quant aux risques éventuels ou de proposer des
stratégies fondées sur des faits scientifiques visant à atténuer
ou éviter des risques potentiels ».
Pour atténuer les champs magnétiques sur les lieux detravail,
respectez les procédures qui suivent :
1. Maintenez les câbles l’un près de l’autre en les
entrelaçant ou les reliant ensemble au ruban.
2. Acheminez les câbles à un côté du soudeur, le plus
loin possible.
3. N’enroulez pas de câble autour du corps.
4. Maintenez le bloc d’alimentation du poste desoudage
et les câbles aussi loin que possible du corps.
STIMULATEURS CARDIAQUES :
Les procédures décrites ci-dessus sont
habituellement celles recommandées pour les
porteurs de stimulateurs cardiaques. Pour de plus
amples renseignements, consulter unmédecin.
1.07 Informations Générales de Sécurité
A Prévention D’incendie
Les opérations de soudage utilisent le feu ou la combustion
comme outil de base. Ce processus est très utile quand il est correctement contrôlé.
1. La zone doit comporter un sol ignifugé.
2. Les établis ou tables utilisés pendant les opérations
de soudage doivent avoir un revêtement ignifuge.
3. Utilisez des écrans résistants à la chaleur ou en matériau approuvé pour protéger les cloisons proches ou
le sol vul nérable des étincelles et du métal chaud.
4. Gardez un extincteur approuvé du bon type et de la bonne
taille dans la zone de travail. Inspectez-le régulièrement
pour vous assurer qu’il est en état de fonctionner. Apprenez à vous en servir.
5. Enlevez tous les matériaux combustibles de la zone de
travail. Si vous ne pouvez pas les enlever, protégez-les
avec une cou vre ignifuge.
!
AVERTISSEMENT
N’effectuez JAMAIS d’opérations de soudage sur
un récipient qui a contenu des liquides ou vapeurs
toxiques, combustibles ou inflammables. N’effectuez JAMAIS d’opérations de soudage dans une zone
contenant des vapeurs combustibles, des liquides
inflammables ou des poussières explosives.
Firepower MST 140i
Manual 0-5338 1-13 SAFETY INSTRUCTIONS AND WARNINGS
B Entretien des Locaux
!
AVERTISSEMENT
Ne laissez jamais l’oxygène en contact avec la
graisse, l’huile ou d’autres substances inflammables. Bien que l’oxygène elle même ne brûle pas,
ces substances peuvent devenir extrême ment
explosives. Elles peuvent prendre feu et brûler
violem ment en présence d’oxygène.
Gardez TOUS les appareils propres et exempts de graisse, huile
ou autres substances inflammables.
C Aération
!
AVERTISSEMENT
Ventilez les zones de soudage, chauffage et découpage de façon adéquate pour éviter l’accumulation
de gaz explosifs ou toxiques. Certaines combinaisons de métaux, revêtements et gaz génèrent
des fumées toxiques: Utilisez un équipement de
protection respiratoire dans ces circonstances.
Si vous soudez ou brasez, lisez et assimilez la
fiche technique de sécurité de matériau relative à
l’alliage de soudage/brasage.
D Protection Personnelle
Les flammes de gaz produisent une radiation infrarouge qui
peut avoir un effet néfaste sur la peau, et particulièrement
sur les yeux. Choisissez des lunettes ou un masque avec
des verres trempés assombris au niveau 4 ou plus sombre,
pour protéger vos yeux des dommages et garder une bonne
visibilité sur le travail.
Portez en permanence des gants de protection et des vêtements ignifuges pour la protection de la peau et des vêtements contre les étincelles et le laitier. Gardez col, manches
et poches boutonnés. Il ne faut pas remonter vos manches
ou les pantalons à revers.
Quand vous travaillez dans un environnement non dédié au
soudage ou découpage, portez toujours une protection des
yeux appropriées ou un masque facial.
!
AVERTISSEMENT
Mettez en pratique les procédures de sécurité et
de mode opératoire suivantes à chaque fois que
vous utilisez cet appareil de régulation de pression. Si vous déviez de ces procédures, cela peut
entraîner incendie, explosion, dégâts matériels et/
ou blessures corporelles pour l’opérateur.
E Bouteilles de Gaz Comprimé
Le Département des Transports américain (DOT) approuve la
conception et la fabrication des bouteilles qui contiennent les
gaz utilisés pour les opérations de soudage ou de découpage.
1. Placez la bouteille (Le schéma 1) là où elle sera utilisée.
Gardez-la en position verticale. Fixez-la sur un chariot une
cloison, un établi, etc.
Art # A-12127
Le schéma 1-1: Cylindres de gaz
!
AVERTISSEMENT
Les bouteilles sont sous haute pression. Manipulez-les
avec précautions. Des accidents sérieux peuvent résulter
d’une mauvaise manutention ou d’un mauvais emploi
des bouteilles de gaz comprimé. NE faites PAS tomber
la bouteille, ne la cognez pas, ne l’exposez pas à une
chaleur excessive, aux flammes ou étincelles. NE la
cognez PAS contre d’autres bouteilles. Contactez votre
fournisseur de gaz ou reportez vous à la publication CGA
P-1 “Manipulation sécurisée des gaz comprimés en
conteneur” pour plus d’informations sur l’utilisation et
la manutention des bouteilles.
AVIS
Ce document CGA p. t peut être obtenu en
écrivant à “Compressed Gas Association”,
4221 Walney Roed, 5th Floor. Chantilly, VA
20151.2923, USA.
2. Placez le bouchon de protection de vanne sur la
bouteille à chaque fois que vous la déplacez ou
ne l’utilisez pas. Ne faites jamais glisser ou rouler
d’aucune manière les bouteilles. Utilisez un diable
approprié pour les déplacer.
3. Entreposez les bouteilles vides à l’écart des bouteilles
pleines. Marquez-les “VIDE” et refermez leur vanne.
4. N’utilisez JAMAIS des bouteilles de gaz comprimé sans
un régulateur de pression en série sur la vanne de
bouteille.
5. Inspectez la vanne de bouteille pour y détecter de
l’huile ou de la graisse, ou dès pièces endommagées.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-14 Manual 0-5338
!
AVERTISSEMENT
N’UTILISEZ PAS la bouteille si vous trouvez de
l’huile, de la graisse ou des pièces endommagées.
Informez immédiate ment votre fournisseur de’
gaz de cet état.
6. Ouvrez et fermez momentanément la vanne de la
bouteille, délogeant ainsi d’éventu lIes poussières ou
saletés. qui pour raient être présentes dans la vanne.
Mise en Garde
Ouvrez la vanne de bouteille légèrement. Si vous
l’ouvrez trop en grand, la bouteille pourrait se renverser. Quand vous ouvrez/fermez rapidement la
vanne de bouteille, ne vous tenez pas directement
devant. Opérez toujours cette opération dans une
zone bien ventilée. Si une bouteille d’acétylène
crache un brouillard, laissez reposer pendant 15
minutes. Essayez de nouveau la vanne. Si le problème persiste, con tactez votre fournisseur de gaz.
1.08 Principales Normes De Securite
Safety in Welding and Cutting, norme ANSI Z49.1, American
Welding Society, 550 N.W. LeJeune Rd., Miami, FL 33128.
Safety and Health Standards, OSHA 29 CFR 1910, Superintendent of Documents, U.S. Government Printing Office,
Washington, D.C. 20402.
Recommended Safe Practices for the Preparation for Welding and Cutting of Containers That Have Held Hazardous
Substances, norme AWS F4.1, American Welding Society,
550 N.W. LeJeune Rd., Miami, FL 33128.
National Electrical Code, norme 70 NFPA, National Fire Protection Association, Batterymarch Park, Quincy, MA 02269.
Safe Handling of Compressed Gases in Cylinders, document
P-1, Compressed Gas Association, 1235 Jefferson Davis
Highway, Suite 501, Arlington, VA 22202.
Code for Safety in Welding and Cutting, norme CSA W117.2
Association canadienne de normalisation, Standards Sales,
276 Rexdale Boulevard, Rexdale, Ontario, Canada M9W 1R3.
Safe Practices for Occupation and Educational Eye and Face
Protection, norme ANSI Z87.1, American National Standards
Institute, 1430 Broadway, New York, NY 10018.
Cutting and Welding Processes, norme 51B NFPA, National
Fire Protection Association, Batterymarch Park, Quincy, MA
02269.
Firepower MST 140i
Manual 0-5338 1-15 SAFETY INSTRUCTIONS AND WARNINGS
1.09 Graphique de Symbole
Seulement certains de ces symboles apparaîtront sur votre modèle.
Soudage á L’arc Avec
Electrode Non Fusible
(GTAW)
Decoupe Arc Carbone
(CAC-A)
Courant Constant
Tension Constante
Ou Potentiel Constant
Haute Température
Force d'Arc
Amorçage de L’arc au
Contact (GTAW)
Inductance Variable
Tension
Mono Phasé
Trois Phasé
Tri-Phase Statique
Fréquence Convertisseur
Transformateur-Redresseur
Tension dangereuse
Hors Tension
SousTension
Panneau/Local
Soudage Arc Electrique
Avec Electrode Enrobé
(SMAW)
Soudage á L’arc Avec
Fil Electrodes Fusible
(GMAW)
Augmentez/Diminuer
Disjoncteur
Source AC Auxiliaire
Distant
Facteur de Marche
Pourcentage
Intensité de Courant
Tension
Hertz (cycles/sec)
Fréquence
Négatif
Positif
Courant Continue (DC)
Terre de Protection
Ligne
Connexion de la Ligne
Source Auxiliaire
Classement de PriseSource Auxiliaire
Art # A-07639_AB
115V 15A
t
t1
t2
%
X
IPM
MPM
t
Fusible
Déroulement du Fil
Alimentation du Fil Vers
la Pièce de Fabrication
Hors Tension
Durée de Pré-Dèbit
Durée de Post-Dèbit
Duréc du Pulse
Soudure Par Point
Appuyez pour dèruarer
l’alimentation du fils et la soudure,
le relâcher pour arrêter.
Purge Du Gaz
Mode Continu de
Soudure
Pouces Par Minute
Mètres Par Minute
Torch de
Soudage
Probléme de Terre
Maintenez appuyez pour pré-dèbit,
relailez pour initier l'arc. Appuyez
pour arrêter l'arc, et mainteuir pour
pré-dèbit.
Détente à 4-Temps
Détente à 2-Temps
V
S
S
Voir Note
Voir Note
Note: Pour les environnements avec des risques de choc électrique, le fournisseur d'énergie portant la marque conforme
à EN50192 lorsqu'utilisé en conjonction avec des lampes de poche avec des conseils exposés, si équipés avec des guide à
l'hauteur de buse correctement installé.
Ne pas déposer avec les déchets ménagers.
Firepower MST 140i
SAFETY INSTRUCTIONS AND WARNINGS 1-16 Manual 0-5338
1.10 Declaration Of Conformity
Manufacturer: Victor Technologies International, Inc.
Address: 16052 Swingley Ridge Road,
Suite 300
St. Louis, MO 63017
The equipment described in this manual has been designed to all applicable aspects and regulations of the ‘Low Voltage
Directive’ (2006/95 EC) and to the National legislation for the enforcement of this Directive.
Serial numbers are unique with each individual piece of equipment and details description, parts used to manufacture a unit
and date of manufacture.
National Standard and Technical Specifications
The product is designed and manufactured to a number of standards and technical requirements. Among them are:
• CSAE60974-1,UL60974-1andIEC60974-1applicabletoweldingequipmentandassociatedaccessories.
•
2002/95/EC RoHS directive
• Extensive product design verication is conducted at the manufacturing facility as part of the routine design and
manufacturing process. This is to ensure the product is safe, when used according to instructions in this manual and
related industry standards, and performs as specified. Rigorous testing is incorporated into the manufacturing process
to ensure the manufactured product meets or exceeds all design specifications.
Victor Technologies has been manufacturing products for more than 30 years, and will continue to achieve excellence in our
area of manufacture.
Manufacturers responsible representative:
Tom Wermert
Senior Brand Manager Firepower
Victor Technologies International, Inc
16052 Swingley Ridge Road
Chesterfield, MO 63017, USA
Firepower MST 140i
Manual 0-5338 2-1 INTRODUCTION
SECTION 2: INTRODUCTION
2.01 How to Use This Manual
This Manual usually applies to the part numbers listed on page
i. To ensure safe operation, read the entire manual, including
the chapter on safety instructions and warnings. Throughout
this manual, the word WARNING, CAUTION and NOTE may
appear. Pay particular attention to the information provided
under these headings. These special annotations are easily
recognized as follows:
!
WARNING
Gives information regarding possible personal
injury. Warnings will be enclosed in a box such
as this.
CAUTION
Refers to possible equipment damage. Cautions
will be shown in bold type.
NOTE
Offers helpful information concerning certain operating procedures. Notes will be shown in italics
You will also notice icons from the safety section appearing
throughout the manual. These are to advise you of specific
types of hazards or cautions related to the portion of information that follows. Some may have multiple hazards that apply
and would look something like this:
2.02 Equipment Identification
The Power Source's identification number (specification or
part number), model, and serial number usually appear on a
nameplate attached to the machine. Equipment which does
not have a nameplate attached to the machine is identified
only by the specification or part number printed on the shipping container. Record these numbers for future reference.
2.03 Receipt of Equipment
When you receive the equipment, check it against the invoice
to make sure it is complete and inspect the equipment for
possible damage due to shipping. If there is any damage,
notify the carrier immediately to file a claim. Furnish complete
information concerning damage claims or shipping errors
to the location in your area listed in the inside back cover of
this manual. Include all equipment identification numbers
as described above along with a full description of the parts
in error.
2.04 Description
The Firepower MST 140i is a self contained single phase multi
process welding system that is capable of performing MIG
(GMAW/FCAW), STICK (SMAW) and LIFT TIG (GTAW) welding processes. The Power Source System is equipped with
an integrated wire feed unit, digital voltage and amperage
meters, and a host of other features in order to fully satisfy the
broad operating needs of the modern welding professional.
The Power Source System is also fully compliant to Standard
CSA E60974-1-00 and UL 60974.1.
The Firepower MST 140i MIG provides excellent welding
performance across a broad range of applications when
used with the correct welding consumables and procedures.
The following instructions detail how to correctly and safely
set up the machine and give guidelines on gaining the best
efficiency and quality from the Power Source. Please read
these instructions thoroughly before using this equipment.
2.05 Transportation Methods
!
Disconnect input power conductors
from de-energized supply line before moving the welding
Power Source.
Lift Power Source with handle on top of case. Use handcart or
similar device of adequate capacity. If using a fork lift vehicle,
secure the Power Source on a proper skid before transporting.
2.06 User Responsibility
This equipment will perform as per the information contained
herein when installed, operated, maintained and repaired in
accordance with the instructions provided. This equipment
must be checked periodically. Defective equipment (including welding leads) should not be used. Parts that are broken,
missing, plainly worn, distorted or contaminated, should be
replaced immediately. Should such repairs or replacements
become necessary, it is recommended that such repairs be
carried out by appropriately qualified persons approved by
Firepower. Advice in this regard can be obtained by contacting
an Accredited Firepower Distributor.
This equipment or any of its parts should not be altered
from standard specification without prior written approval of
Firepower. The user of this equipment shall have the sole responsibility for any malfunction which results from improper
use or unauthorized modification from standard specification,
faulty maintenance, damage or improper repair by anyone
other than appropriately qualified persons approved by Firepower.
Firepower MST 140i
INTRODUCTION 2-2 Manual 0-5338
2.07 Firepower MST 140i Portable System Package (Part No. 1444-0870)
Art # A-12432
• Firepower MST 140i Power Source
• Firepower 140 Amp MIG Gun, 10ft (3.0m)
• Firepower Argon Regulator/Flowmeter & Hose
• Firepower Electrode Holder & Ground Clamp
• Drive Rolls & Contact Tips
• Shoulder Strap
• 20A to 15A Power Cord Adapter
• Operator Manual, Quick Start Guide, & CD
Comes Complete With
2.08 Duty Cycle
The rated duty cycle of a Welding Power Source, is a statement of the time it may be operated at its rated welding current
output without exceeding the temperature limits of the insulation of the component parts. To explain the 10 minute duty
cycle period the following example is used. Suppose a Welding Power Source System is designed to operate at a 20% duty
cycle, 100 amperes at 19 volts. This means that it has been designed and built to provide the rated amperage (100 A) for 2
minutes, i.e. arc welding time, out of every 10 minute period (20% of 10 minutes is 2 minutes). During the other 8 minutes
of the 10 minute period the Welding Power Source System must idle and be allowed to cool.
0
80
100
30
50
70
90
40
60
20
10
0102030405060708090100 110120 130140 150
Firepower MST 140i
Welding Current (amps)
Duty Cycle (percentage)
Safe
Operating
Region
STICK (SMAW)/ MIG (GMAW/ FCAW)
TIG (GTAW)
Art # A-12434
Figure 2-1: Firepower MST 140i Duty Cycle
Firepower MST 140i
Manual 0-5338 2-3 INTRODUCTION
2.09 Specifications
DESCRIPTION Firepower MST 140i MULTI PROCESS 3 IN 1 WELDER
Power Source System Part No. 1444-0870
Power Source System Dimensions H16.14” x W8.27” x D17.72” (410mm x 210mm x 450mm)
Power Source System Weight 32.2lb (14.6kg)
Cooling Fan Cooled
Welder Type Multi Process Welding System
Output Terminal Type DinseTM 25
Standards CSA E60974-1-00 / UL60974-1 / IEC 60974-1
Number of Phases Single Phase
Nominal Supply Voltage 115V AC
Supply Voltage Range 95-140V AC
Supply Frequency 50/60Hz
Welding Current Range (MIG Mode) 10- 90A
Welding Current Range (LIFT TIG Mode) 10- 140A
Welding Current Range (STICK Mode) 10- 90A
Wirefeed Speed Range 95-390 IPM
MIG Welding Voltage Range 10-19V DC
Nominal OCV 53V DC
Breaker Size 20A 30A
(Requires updated Power Cord and Plug)
Effective Input Current (I
1eff
)
MIG (GMAW/FCAW)
STICK (SMAW)
TIG (GTAW)
16.8A
16.8A
11.0A
16.1A*
11.8A*
14.3A*
Maximum Input Current (I
1max
)
MIG (GMAW/FCAW)
STICK (SMAW)
TIG (GTAW)
26.2A
28.4A
24.7A
41.5A*
30.5A*
37A*
Single Phase Generator Requirement 5 KW 6 KW*
MIG (GMAW/FCAW) Welding Output 90A@20%, 18.5V
60A@60%, 17.0V
45A@100%, 16.25V
140A@15%, 19V*
60A@60%, 17.6V*
45A@100%, 16.8V*
STICK (SMAW) Welding Output 80A@35%, 23.2V
60A@60%, 22.4V
45A@100%, 21.8V
90A@15%, 23.0V*
60A@60%, 22.8V*
45A@100%, 22.2V*
LIFT TIG (GTAW) Welding Output 100A@20%, 14.0V
60A@60%, 12.4V
45A@100%, 11.8V
140A@15%, 15.6V*
60A@60%, 12.8V*
45A@100%, 12.2V*
Protection Class IP23S
Table 2-1: Firepower MST 140i Specification
NOTE
* Indicates data tested by Victor Technologies International, Inc.
Firepower MST 140i
INTRODUCTION 2-4 Manual 0-5338
NOTE
The recommended time delay fuse or circuit breaker size is 20 amp. An individual branch circuit capable of carrying 20 amperes and protected by fuses or circuit breaker is recommended for this application. Fuse size is based
on not more than 200 percent of the rated input amperage of the welding Power Source System (Based on Article
630, National Electrical Code)
Firepower continuously strives to produce the best product possible and therefore reserves the right to change,
improve or revise the speci fications or design of this or any product without prior notice. Such updates or changes
do not entitle the buyer of equipment previously sold or shipped to the corresponding changes, updates, improvements or replacement of such items.
The values specified in the table above are optimal values, your values may differ. Individual equipment may differ
from the above specifications due to in part, but not exclusively, to any one or more of the following; variations or
changes in manufactured components, installation location and conditions and local power grid supply conditions.
The thermal protection switch is rated at 80°C.
2.10 Options and Accessories
DESCRIPTION PART NUMBER
TIG Torch, 17V, 12.5 ft, 25mm & Accessory Kit
1442-0020
Firepower MST 140i - 180i Carry Bag 1421-0099
Basic 4 Wheel Cart 1444-0900
Foot Control, 15 ft, 8 Pin (for remote amperage control when TIG welding) 1442-0025
Firepower Auto-Darkening Helmet Skull & Fire (USA Only) 1441-0086
Drive Roll .023" - .030" (0.6 - 0.8mm) V groove for solid wire 1444-0914
Drive Roll .045" (1.2mm) V knurled groove for flux cored wire 1444-0915
Firepower ground clamp with 16 mm2 lead and 25 mm2 Dinse, 6ft (1.8m) 1443-0491
Firepower electrode clamp with 16 mm2 lead and 25 mm2 Dinse, 9ft (2.7m) 1443-0490
Firepower GF250-50-580 Argon Flowgauge Regulator 0781-9832
Power Adapter, 115V, 20A- 15A 1444-0910
Table 2-2: Firepower MST 140i Options and Accessories List
Firepower MST 140i
Manual 0-5338 3-1 INSTALLATION, OPERATION AND SETUP
SECTION 3: INSTALLATION, OPERATION AND SETUP
3.01 Environment
This Power Source System is designed for use in environments
with increased hazard of electric shock.
A. Examples of environments with increased hazard of
electric shock are:
1. In locations in which freedom of movement is
restricted, so that the operator is forced to perform
the work in a cramped (kneeling, sitting or lying)
position with physical contact with conductive parts.
2. In locations which are fully or partially limited by
conductive elements, and in which there is a high risk
of unavoidable or accidental contact by the operator.
3. In wet or damp hot locations where humidity or
perspiration considerable reduces the skin resistance
of the human body and the insulation properties of
accessories.
B. Environments with increased hazard of electric shock do
not include places where electrically conductive parts have
been insulated.
3.02 Location
Be sure to locate the welder according to the following
guidelines:
A. In areas, free from moisture and dust.
B. Ambient temperature between 32 to 104° F (0 to 40° C).
C. In areas, free from oil, steam and corrosive gases.
D. In areas, not subjected to abnormal vibration or shock.
E. In areas, not exposed to direct sunlight or rain.
F. Place at a distance of 12"(300mm) or more from walls or
similar that could restrict natural air flow for cooling.
G. The enclosure design of this Power Source System meets
the requirements of IP23S as outlined in EN 60529.
This provides adequate protection against solid objects
(greater than 1/2", 12mm), and direct protection from
vertical drops. Under no circumstances should the Power
Source System be operated or connected in a micro
environment that will exceed the stated conditions. For
further information please refer to EN 60529.
H. Precautions must be taken against the Power Source
System toppling over. The power source must be located
on a suitable horizontal surface in the upright position
when in use.
WARNING
This equipment should be electrically connected
by a qualified electrician.
3.03 Ventilation
!
WARNING
Since the inhalation of welding fumes can be
harmful, ensure that the welding area is effectively
ventilated.
3.04 Electricity Supply Voltage
The Electricity Supply voltage
should be within 95-140V AC.
Too low a voltage may cause poor
welding performance in STICK mode. Too high a supply
voltage will cause components to overheat and possibly fail.
The Welding Power Source System must be:
• Correctlyinstalled,ifnecessary,byaqualiedelectrician.
• Correctlyearthed(electrically)inaccordancewithlocal
regulations.
• Connectedtothecorrectsizepowerpointandfuseas
per the Specifications on page 2-4.
WARNING
The Firepower MST 140i must be electrically
connected by a qualified electrical trades-person.
Damage to the PCA (Power Control Assembly)
could occur if 140 VAC or higher is applied to the
Primary Power Cable.
WARNING
ELECTRIC SHOCK can kill; SIGNIFICANT DC
VOLTAGE is present after removal of input power.
DO NOT TOUCH live electrical parts.
SHUT DOWN welding Power Source, disconnect input power
employing lockout/tagging procedures. Lock-out/tagging
procedures consist of padlocking line disconnect switch in
open position, removing fuses from fuse box, or shutting off
and red-tagging circuit breaker or other disconnecting device.
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-2 Manual 0-5338
Electrical Input Requirements
Operate the welding Power Source System from a single-phase 50/60 Hz, AC power supply. The input voltage must match
one of the electrical input voltages shown on the input data label on the unit nameplate. Contact the local electric utility for
information about the type of electrical service available, how proper connections should be made, and inspection required.
The line disconnect switch provides a safe and convenient means to completely remove all electrical power from the welding
Power Source System whenever necessary to inspect or service the unit.
Do not connect an input (WHITE or BLACK) conductor to the ground terminal.
Do not connect the ground (GREEN) conductor to an input line terminal.
• Correctlyinstalled,ifnecessary,byaqualifiedelectrician.
• Correctlyearthed(electrically)inaccordancewithlocalregulations.
• Connectedtothecorrectsizepowerpoint,fuseandprimarysupplyleadbasedonTable3-1.
WARNING
An electric shock or fire hazard is probable if the following electrical service guide recommendations are not
followed. These recommendations are for a dedicated branch circuit sized for the rated output and duty cycle of
the welding Power Source.
50 / 60 Hz Single Phase Supply
Supply Voltage 115V AC
Input Current at Maximum Output 28.4 Amps
Maximum Recommended Fuse* or Circuit Breaker Rating
*Time Delay Fuse, UL class RK5. Refer to UL248
Maximum Recommended Fuse^ or Circuit Breaker Rating
^Normal Operating , UL class K5. Refer to UL248
30 Amps
30 Amps
Single Phase Generator Requirement 5 KW
Minimum Recommended Input Cable Size 12AWG
Maximum Recommended Input Cable Length 10ft (3m)
Minimum Recommended Grounding Cable Size 12AWG
Table 3-1: Electrical Service Guide
NOTE
Welding arc outs may be experienced if an extension cord is used when STICK welding when operating the Power
Source System on 95 VAC due to the lack of DC voltage at the STICK electrode.
Input Power
Each unit incorporates an INRUSH circuit. When the MAIN CIRCUIT SWITCH is turned on, the inrush circuit provides precharging for the input capacitors. A relay in the Power Control Assembly (PCA) will turn on after the input capacitors have
charged to operating voltage (after approximately 5 seconds)
NOTE
Damage to the PCA could occur if 140V AC or higher is applied to the Primary Power Cord.
Model
Primary Supply
Cord Size
(Factory Fitted)
Minimum Primary
Current Circuit Size
(Vin/Amps)
Current & Duty Cycle
MIG (GMAW/
FCAW)
STICK (SMAW)
LIFT TIG
(GTAW)
Firepower
MST 140i
12AWG (3.3mm2) 115V/20A 90A@20% 80A@35% 100A@20%
10AWG (5mm2) 115V/30A 140A@15% 90A@15% 140A@15%
Table 3-2: Primary Circuit Sizes to Achieve Maximum Current
Firepower MST 140i
Manual 0-5338 3-3 INSTALLATION, OPERATION AND SETUP
3.05 Electromagnetic Compatibility
WARNING
Extra precautions for Electromagnetic Compatibility
may be required when this Welding Power Source
System is used in a domestic situation.
A. Installation and Use - Users Responsibility
The user is responsible for installing and using the welding
equipment according to the manufacturer’s instructions.
If electromagnetic disturbances are detected then it shall
be the responsibility of the user of the welding equipment
to resolve the situation with the technical assistance of
the manufacturer. In some cases this remedial action
may be as simple as earthing the welding circuit, see
NOTE below. In other cases it could involve constructing
an electromagnetic screen enclosing the Welding Power
Source System and the work, complete with associated
input filters. In all cases, electromagnetic disturbances
shall be reduced to the point where they are no longer
troublesome.
NOTE
The welding circuit may or may not be earthed
for safety reasons. Changing the earthing
arrangements should only be authorized by a
person who is competent to assess whether the
changes will increase the risk of injury, e.g. by
allowing parallel welding current return paths
which may damage the earth circuits of other
equipment. Further guidance is given in EN 6097413 Arc Welding Equipment - Installation and use
(under preparation).
B. Assessment of Area
Before installing welding equipment, the user shall make
an assessment of potential electromagnetic problems in
the surrounding area. The following shall be taken into
account
1. Other supply cables, control cables, signaling and
telephone cables; above, below and adjacent to the
welding equipment.
2. Radio and television transmitters and receivers.
3. Computer and other control equipment.
4. Safety critical equipment, e.g. guarding of industrial
equipment.
5. The health of people around, e.g. the use of
pacemakers and hearing aids.
6. Equipment used for calibration and measurement.
7. The time of day that welding or other activities are to
be carried out.
8. The compatibility of other equipment in the
environment: the user shall ensure that other
equipment being used in the environment is
compatible: this may require additional protection
measures.
The size of the surrounding area to be considered will
depend on the structure of the building and other activities
that are taking place. The surrounding area may extend
beyond the boundaries of the premises.
C. Methods of Reducing Electromagnetic Emissions
1. Electricity Supply
Welding equipment should be connected to the
Electricity Supply according to the manufacturer’s
recommendations. If interference occurs, it may
be necessary to take additional precautions such
as filtering of the Electricity Supply. Consideration
should be given to shielding the supply cable of
permanently installed welding equipment in metallic
conduit or equivalent. Shielding should be electrically
continuous throughout it’s length. The shielding
should be connected to the Welding Power Source
System so that good electrical contact is maintained
between the conduit and the Welding Power Source
System enclosure.
2. Maintenance of Welding Equipment
The welding equipment should be routinely maintained
according to the manufacturer’s recommendations. All
access and service doors and covers should be closed
and properly fastened when the welding equipment
is in operation. The welding equipment should not
be modified in any way except for those changes
and adjustments covered in the manufacturer’s
instructions. In particular, the spark gaps of arc
striking and stabilizing devices should be adjusted
and maintained according to the manufacturer’s
recommendations.
3. Welding Cables
The welding cables should be kept as short as possible
and should be positioned close together, running at
or close to the floor level.
4. Equipotential Bonding
Bonding of all metallic components in the welding
installation and adjacent to it should be considered.
However. Metallic components bonded to the work
piece will increase the risk that the operator could
receive a shock by touching the metallic components
and the electrode at the same time. The operator
should be insulated from all such bonded metallic
components.
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-4 Manual 0-5338
5. Earthing of the Workpiece
Where the workpiece is not bonded to earth for
electrical safety, nor connected to earth because
of it’s size and position, e.g. ship’s hull or building
steelwork, a connection bonding the workpiece
to earth may reduce emissions in some, but not
all instances. Care should be taken to prevent the
earthing of the workpiece increasing the risk of injury
to users, or damage to other electrical equipment.
Where necessary, the connection of the workpiece
to earth should be made by direct connection to
the workpiece, but in some countries where direct
connection is not permitted, the bonding should be
achieved by suitable capacitance, selected according
to national regulations.
6. Screening and Shielding
Selective screening and shielding of other cables
and equipment in the surrounding area may alleviate
problems of interference. Screening the entire
welding installation may be considered for special
applications.
3.06 Firepower Flowmeter/ Regulator
Flowmeter/ Regulator (Figure 3-1) attached to the cylinder
valve reduces high cylinder pressures to suitable low working
pressures for welding, cutting, and other applications.
LOW PRESSURE
GAUGE (DELIVERY)
HIGH PRESSURE
GAUGE (SUPPLY)
INLET
CONNECTION
OUTLET
CONNECTION
PRESSURE
ADJUSTING
SCREW
A-12435
Figure 3-1: Firepower CS Flowmeter/ Regulator
!
WARNING
Use the flowmeter/ regulator for the gas and
pressure for which it is designed. NEVER alter a
flowmeter/ regulator for use with any other gas.
NOTE
Flowmeters/ Regulators supplied with 5/8" -18
standard inert gas connections. Flowmeters/
Regulators purchased with open 1/8”, 1/4”, 3/8”,
or 1/2” NPT ports must be assembled to their
intended system.
1. Note the maximum inlet pressure stamped on the
flowmeter/ regulator. DO NOT attach the flowmeter/
regulator to a system that has a higher pressure
than the maximum rated pressure stamped on the
flowmeter/ regulator.
2. The flowmeter/ regulator body will be stamped “IN”
or “HP” at the inlet port. Attach the inlet port to the
system supply pressure connection.
3. If gauges are to be attached to the flowmeter/
regulator and the flowmeter/ regulator is stamped
and listed by a third party (i.e. “UL” or “ETL”). The
following requirements must be met:
a) Inlet gauges over 1000 PSIG (6.87 mPa) shall
conform with the requirements of UL 404, “Indicating Pressure Gauges for Compressed Gas
Service.”
b) Low pressure gauges must be UL recognized for
the class of flowmeter/ regulator they are being
used on according to UL252A.
!
WARNING
DO NOT use a flowmeter/ regulator that delivers
pressure exceeding the pressure rating of the
downstream equipment unless pro visions are
made to prevent over-pressurization (i.e. system
relief valve). Make sure the pressure rating of the
down stream equipment is compatible with the
maximum delivery pressure of the flowmeter/
regulator.
4. Be sure that the flowmeter/ regulator has the correct
pressure rating and gas service for the cylinder used.
5. Carefully inspect the flowmeter/ regulator for
damaged threads, dirt, dust, grease, oil, or other
flammable substances. Remove dust and dirt with a
clean cloth. Be sure the inlet swivel filter is clean and
in place. Attach the flowmeter/ regulator (Figure 3-2)
to the cylinder valve. Tighten securely with a wrench.
Firepower MST 140i
Manual 0-5338 3-5 INSTALLATION, OPERATION AND SETUP
!
WARNING
DO NOT attach or use the flowmeter/ regulator if
oil, grease, flamma ble substances or damage is
present! Have a qualified repair technician clean
the flowmeter/ regulator or repair any damage.
Art # A-12436
Figure 3-2: Flowmeter/ Regulator to Cylinder
Valve
6. Before opening the cylinder valve, turn the flowmeter/
regulator adjusting screw counterclockwise until there
is no pressure on the adjusting spring and the screw
turns freely.
7. Relief Valve (where provided): The relief valve is
designed to protect the low pressure side of the
flowmeter/ regulator from high pres sures. Relief
valves are not intended to protect down stream
equipment from high pressures.
!
WARNING
DO NOT tamper with the relief valve or remove it
from the flowmeter/ regulator.
!
WARNING
Stand to the side of the cylinder opposite the
flowmeter/ regulator when opening the cylinder
valve. Keep the cylinder valve between you and
the flowmeter/ regulator. For your safety, NEVER
STAND IN FRONT OF OR BEHIND A FLOWMETER/
REGULATOR WHEN OPENING THE CYLINDER
VALVE!
8. Slowly and carefully open the cylinder valve (Figure
3-3) until the maximum pressure shows on the high
pressure gauge.
Art # A-09828
Figure 3-3: Open Cylinder Valve
9. On all cylinders, open the valve completely to seal the
valve packing. On gaugeless flowmeters/ regulators,
the indicator will register the cylinder contents open.
CAUTION
Keep the cylinder valve wrench, if one is required,
on the cylinder valve to turn off the cylinder
quickly, if necessary.
10. Attach the desired downstream equipment.
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-6 Manual 0-5338
3.07 Leak Testing the System
Leak test the system before putting into operation.
1. Be sure that there is a valve in the downstream
equipment to turn off the gas flow.
2. With the cylinder valve open, adjust the Flowmeter/
regulator to deliver the maximum required delivery
pressure.
3. Close the cylinder valve.
4. Turn the adjusting screw/knob counterclockwise one
turn.
a) If the high-pressure gauge reading drops, there
is a leak in the cylinder valve, inlet fitting, or highpressure gauge.
b) If the low-pressure gauge drops, there is a leak
in the down stream equipment, hose, hose fitting,
outlet fitting or low-pressure gauge. Check for
leaks using an approved leak detector solution.
c) If the high-pressure gauge drops and the low-
pressure gauge increases at the same time, there
is a leak in the flowmeter/ regulator seat.
d) If the flowmeter/ regulator requires service or
repair, take it to a qualified repair technician.
5. Once leak testing has been performed and there are
no leaks in the system, slowly open the cylinder valve
and proceed.
!
WARNING
If a leak has been detected anywhere in the
system, dis continue use and have the system
repaired. DO NOT use leaking equipment. Do
not attempt to repair a leaking system while the
system is under pressure.
3.08 When You Finish Using the Flowmeter/
Regulator
1. Close the cylinder valve.
2. Open the valve on the downstream equipment. This
drains all pressure from the system.
3. Close the valve on the downstream equipment.
4. Turn the adjusting screw counterclockwise to release
the ten sion on the adjusting spring.
5. Check the gauges after a few minutes for verification
that the cylinder valve is closed completely.
3.09
Storage of the Flowmeter/ Regulator
When the regulator is not in use and has been removed from
the cylinder, it should be stored in an area where it will be
pro tected from dust, oil, and grease. The inlet and outlet
should be capped to protect against internal contamination
and prevent insects from nesting.
Firepower MST 140i
Manual 0-5338 3-7 INSTALLATION, OPERATION AND SETUP
3.10 Power Source System Controls, Indicators and Features
See pages 3-8 through 3-14 for details.
MIG
STICK
4T
2T
POWER
SOFT
WIRESPEED
HARD
FAULT
DOWNSLOPE(S)
10 10
22
99
11
ARCFORCE(%)
INDUCTANCE
2
6
8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Art #
A-12437
MIG
LIFT TIG
STICK
4T
2T
WIRESPEED INDUCTANCE
- HARD
+
SOFT
DOWNSLOPE (S)
ARC FORCE (%)
A
V
10 10
22
44
77
99
11
33
66
88
2
4
6
8
Figure 3-4: Front Panel
Art #
A-10354
16
17
15
Figure 3-5: Rear Panel
18
19
Art #
A-12438
Figure 3-6: Wire Feed Compartment Control
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-8 Manual 0-5338
1. Power Indicator
The power indicator is illuminated when the Electricity Supply is applied to the Power Source
System and when the ON/OFF switch located on the rear panel is in the ON position.
POWER FAULT
1
Art #
A-12???
2. Digital Wirespeed/Amperage Meter (Left Digital Display)
This digital meter displays preview Wirespeed in MIG mode only then actual amperage (weld
current) once an arc has been established. It also displays preview amperage in both the
STICK and LIFT TIG modes only then actual amperage (weld current) once an arc has been
established.
At times of non-welding, the amperage meter will display a preview value in both STICK
and LIFT TIG modes. This value can be adjusted by varying the Wire speed / Amperage
potentiometer (Control No. 3). At times of non-welding, the amperage meter will preview a
wirefeed speed value (Inches Per Minute) in MIG mode only. This can be identified as preview
wirefeed speed by a decimal point at the lower right hand side of the display.
When welding, the amperage meter will display actual amperage (weld current) in all modes.
At the completion of welding, the amperage meter will hold the last recorded amperage value
for a period of approximately 10 seconds in all modes. The amperage meter will hold the
value until; (1) any of the front panel controls are adjusted in which case the Power Source
will revert to preview mode, (2) welding is recommenced, in which case actual welding
amperage will be displayed, or (3) a period of 10 seconds elapses following the completion
of welding in which case the Power Source will return to preview mode.
NOTE
The preview functionality provided on this power source is intended to act as a guide
only. Some differences may be observed between preview values and actual welding
values due to factors including the mode of welding, differences in consumables/gas
mixtures, individual welding techniques and the transfer mode of the welding arc (ie
dip versus spray transfer). Where exact settings are required (in the case of procedural
work), it is recommended that alternate measurement methods be utilized to ensure
output values are accurate.
POWER
2
A
V
44
7
33
6
3. Wirespeed/Amperage Control
In MIG mode, the Wirespeed/Amperage control knob adjusts the speed of the wire feed motor
(which in turn adjusts the output current by varying the amount of MIG wire delivered to
the welding arc). The optimum wire speed depends upon the material type and the welding
application. The setup chart on the inside of the wire feed compartment door provides a
brief summary of the required settings for a basic range of MIG (GMAW/FCAW) welding
applications.
In STICK and LIFT TIG modes, the Wirespeed/Amperage control knob adjusts the amount of
amperage (weld current) delivered to the welding arc by the Power Source. It directly adjusts
the Power Source System to deliver the desired level of weld current.
WIRESPEED
DOWNSLOPE(S
10
22
9
11
ARCFORCE(%
3
WIRESPEED
DOWNSLOPE
ARC FORCE (
%
A
V
10
22
44
7
9
11
33
6
8
4. MIG Gun
The MIG Gun adapter is euro connection for the Firepower MIG Gun. MIG Gun remote
control is routed through the euro adapter fitting. Connect the MIG Gun by pushing the MIG
Gun connector into the brass MIG Gun Adapter firmly and screw the locking screw in the
MIG Gun Adapter within the Wire Feed Compartment to secure the Firepower MIG Gun in
position. Failure to properly lock the Firepower MIG Gun into the MIG Gun Feedplate will
result in the MIG Gun being pushed out of the MIG Gun Feedplate by the MIG welding wire
or lack of shielding gas (porosity in the weld) at the weld zone.
4
Firepower MST 140i
Manual 0-5338 3-9 INSTALLATION, OPERATION AND SETUP
5. Positive Welding Output Terminal
The positive welding terminal is used to connect the welding output of the power source
to the appropriate welding accessory such as the MIG Gun (via the MIG Gun polarity lead),
electrode holder lead or work lead. Positive welding current flows from the power source via
25mm Dinse style connector. It is essential, however, that the Dinse adapter and male plug
are inserted and turned securely to achieve a sound electrical connection.
CAUTION
Loose welding terminal connections can cause overheating and result in the male
plug being fused in the Dinse connector.
5
6. MIG Gun Polarity Lead
The polarity lead is used to connect the MIG Gun to the appropriate positive or negative output
terminal (allowing polarity reversal for different welding applications). In general, the polarity
lead should be connected in to the positive welding terminal (+) when using steel, stainless
steel or aluminum electrode wire. When using flux cored (gasless) wire, the polarity lead is
generally connected to the negative welding terminal (-). If in doubt, consult the manufacturer
of the electrode wire for the correct polarity. It is essential, however, that the Dinse adapter
and male plug are inserted and turned securely to achieve a sound electrical connection.
CAUTION
Loose welding terminal connections can cause overheating and result in the male
plug being fused in the Dinse connector.
6
7. Negative Welding Output Terminal
The negative welding terminal is used to connect the welding output of the Power Source
System to the appropriate welding accessory such as the MIG Gun (via the MIG Gun polarity
lead), TIG Torch or work lead. Negative welding current flows to the Power Source System
via 25mm Dinse style connector. It is essential, however, that the Dinse adapter and male
plug are inserted and turned securely to achieve a sound electrical connection.
CAUTION
Loose welding terminal connections can cause overheating and result in the male
plug being fused in the Dinse connector.
7
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-10 Manual 0-5338
8. Remote Control
The 8 pin socket is used to connect the TIG Gun, remote control device to the welding
Power Source. To make connections, align keyway, insert plug, and rotate threaded collar
fully clockwise.
Trigger Switch
Remote Wirespeed in MIG (GMAW/FCAW) mode
Remote Amps in LIFT TIG (GTAW) mode
Remote Volts in
MIG (GMAW/FCAW)
1
2
3
4
5
6
7
8
WV
3
4
5
6
7
8
1
2
Art # A-12440
Figure 3-7: Remote Control Socket
Socket Pin
Function
1 Not used
2
Trigger Switch Input
3
Trigger Switch Input
4
Not used
5
5k ohm (maximum) connection to 5k ohm remote control
potentiometer.
6
Zero ohm (minimum) connection to 5k ohm remote control
potentiometer.
7
Wiper arm connection to 5k ohm potentiometer for the remote control
of the Amperage (Weld Current) in LIFT TIG mode.
8
Wiper arm connection to 5k ohm remote control Volts MIG mode
potentiometer.
Table 3-3
Note that the Local/ Remote Switch (Control No. 18) located in the wirefeed compartment
should be set to Remote for remote amperage/voltage controls to operate.
8
Firepower MST 140i
Manual 0-5338 3-11 INSTALLATION, OPERATION AND SETUP
9. Multifunction Control - Voltage, Down Slope & Arc Force
The multifunction control knob is used to adjust Voltage (MIG Mode), Down slope (LIFT TIG
Mode) and Arc Force (STICK Mode) depending on the welding mode selected.
NOTE
The preview functionality provided on this power source is intended to act as a guide
only. Some differences may be observed between preview values and actual welding
values due to factors including the mode of welding, differences in consumables/gas
mixtures, individual welding techniques and the transfer mode of the welding arc (ie
dip versus spray transfer). Where exact settings are required (in the case of procedural
work), it is recommended that alternate measurement methods be utilized to ensure
output values are accurate.
When MIG Mode is Selected
In this mode the control knob is used to adjust the MIG welding voltage of the Power Source.
The welding voltage is increased by turning the knob clockwise or decreased by turning the
knob counterclockwise. The optimum voltage level required will depend on the type of welding
application. The setup chart on the inside of the wire feed compartment door provides a
brief summary of the required output settings for a basic range of MIG welding applications.
When STICK Mode is Selected
In this mode the multifunction control knob is used to adjust arc force. Arc force control
provides an adjustable amount of welding force (or “dig”) control. This feature can be
particularly beneficial in providing the operator the ability to compensate for variability in
joint fit-up in certain situations with particular electrodes. In general increasing the arc force
control toward ‘10’ (maximum arc force) allows greater penetration control to be achieved.
Arc force is increased by turning the control knob clockwise or decreased by turning the
knob counterclockwise.
When LIFT TIG Mode is Selected
In this mode the multifunction control knob is used to adjust down slope. Down slope allows
the user to select the ramp down time of the amperage at the completion of the weld. The
main function of down slope is to allow the welding current to be gradually reduced over a
pre-set time frame such that the welding pool is given time to cool sufficiently.
Note that when in 2T normal mode (Control No. 11), the Power Source System will enter down
slope mode as soon as the trigger switch is released (ie if the multifunction control knob is
set to 5, the Power Source will ramp down from the present welding current to zero over 5
seconds). If no down slope time is set then the welding output will cease immediately. If the
Power Source System is set to 4T latch mode, to enter down slope mode the trigger must
be held in for the selected time period (ie press and release trigger to commence welding,
then press and hold trigger again to enter down slope mode). Should the trigger be released
during the down slope phase (4T only), the output will cease immediately.
4T
2T
SOFT
HARD
DOWNSLOPE(S)
10 10
2
99
1
ARCFORCE(%)
INDUCTANCE
2
6
8
9
4T
2T
INDUCTANCE
- HARD
+
SOFT
DOWNSLOPE (S)
ARC FORCE (%)
V
10 10
2
4
77
99
1
3
66
88
2
4
6
8
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-12 Manual 0-5338
10. Arc Control (Inductance)
The arc control operates in MIG mode only and is used to adjust the intensity of the welding
arc. Lower arc control settings make the arc softer with less weld spatter. Higher arc control
settings give a stronger driving arc which can increase weld penetration. Soft means maximum
inductance while Hard means minimum inductance.
MIG
STICK
4T
2T
SOFT
HARD
2
6
8
10
11
12
MIG
LIFT TIG
STICK
4T
2T
- HARD
+
SOFT
2
4
6
8
11. Trigger Mode Control (MIG and LIFT TIG Mode only)
The trigger mode control is used to switch the functionality of the of the MIG or TIG Trigger
Switch between 2T (normal) and 4T (latch mode)
2T (Normal Mode)
In this mode, the MIG or TIG Trigger Switch must remain depressed for the welding output
to be active. Press and hold the MIG or TIG Trigger Switch to activate the Power Source
System (weld). Release the MIG or TIG Trigger Switch to cease welding.
4T (Latch Mode)
This mode of welding is mainly used for long welding runs to reduce operator fatigue. In this
mode the operator can press and release the MIG or TIG Trigger Switch and the output will
remain active. To deactivate the Power Source, the trigger switch must again be depressed
and released, thus eliminating the need for the operator to hold the MIG or TIG Trigger Switch
Note that when operating in LIFT TIG mode, the Power Source will remain activated until the
selected Downslope time has elapsed (refer Control No. 9).
12. Process Selection Control
The process selection control is used to select the desired welding mode. Three modes are
available, MIG, LIFT TIG and STICK modes. Refer to section 3.20 for MIG (GMAW/FCAW)
set up details, section 3.21 for LIFT TIG (GTAW) set-up details or section 3.22 for STICK
(SMAW) set-up details.
Note that when the Power Source is powered off the mode selection control will automatically
default to MIG mode. This is necessary so as to prevent inadvertent arcing should an electrode
holder be connected to the Power Source and mistakenly be in contact with the work piece
during power up.
Firepower MST 140i
Manual 0-5338 3-13 INSTALLATION, OPERATION AND SETUP
13. Digital Voltage Meter (Right Digital Display)
The digital voltage meter is used to display the both the preview voltage (MIG mode only)
and actual output voltage (all modes) of the Power Source.
At times of non-welding, the voltage meter will display a preview value in MIG mode. This
value can be adjusted by varying the multifunction control knob (Control No. 9). Note that
in STICK and LIFT TIG modes, the voltage meter will not preview welding voltage but will
display Open Circuit Voltage in STICK mode and 0V in LIFT TIG mode.
When welding, the voltage meter will display actual welding voltage in all modes.
At the completion of welding, the digital voltage meter will hold the last recorded voltage
value for a period of approximately 10 seconds in all modes. The voltage meter will hold the
value until; (1) any of the front panel controls are adjusted in which case the Power Source
will revert to preview mode, (2) welding is recommenced, in which case actual welding
amperage will be displayed, or (3) a period of 10 seconds elapses following the completion
of welding in which case the Power Source will return to preview mode.
NOTE
The preview functionality provided on this power source is intended to act as a guide
only. Some differences may be observed between preview values and actual welding
values due to factors including the mode of welding, differences in consumables/gas
mixtures, individual welding techniques and the transfer mode of the welding arc (ie
dip versus spray transfer). Where exact settings are required (in the case of procedural
work), it is recommended that alternate measurement methods be utilized to ensure
output values are accurate.
MIG
STICK
4T
2T
POWER FAULT
6
14
MIG
LIFT TIG
STICK
4T
2T
V
4
7
3
6
4
6
13
14. Fault Indicator
This welding Power Source is protected by a self resetting thermostat. The indicator will
illuminate if the duty cycle of the Power Source has been exceeded or if a fault is detected
in the Inverter. Should the Fault Indicator illuminate the output of the Power Source will be
disabled. Once the Power Source cools down this light will go OFF and the over temperature
condition will automatically reset. Note that the power switch should remain in the on position
such that the fan continues to operate thus allowing the Power Source to cool sufficiently. Do
not switch the Power Source off should a thermal overload condition be present. If the fault
condition does not extinguish, then the Power Supply will need to be taken to an authorized
repair center for analysis.
15. Gas Inlet (MIG mode only for MIG Gun)
The Gas Inlet connection is used to supply the appropriate MIG welding gas to the Power
Source. Refer to section 3.19 to 3.20 for MIG (FCAW/GMAW) set up details.
!
WARNING
Only Welding Shielding Gases specifically designed for arc welding applications
should be used.
16
15
(Back)
16. On / Off Switch
This switch is used to turn the Power Source on/off.
WARNING
When the front digital displays are lit, the machine is connected to the Mains supply
voltage and the internal electrical components are at Mains voltage potential.
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-14 Manual 0-5338
17. Intelligent Fan Control
When Power Supply is first turned on it will default in MIG Mode. The Fan will operate for
approximately 10 seconds, then shut down.
When triggered in MIG mode, fan will not turn on until Power Supply reaches temperatures
in which cooling is required. When in Lift TIG mode, as soon as output is enabled, the fan will
come on immediately and will not shut down until welding has ceased and Power Supply is at
proper operating temperature. When set to Stick mode, fan will turn on immediately and will
not turn off until welding has ceased and Power Supply is at proper operating temperature.
Note in STICK mode the fan operates continuously.
17
(Back)
18. Local / Remote Switch (located in wirefeed compartment)
The local/ remote switch is used only when a remote control device (such as a TIG Torch
with remote current control) is fitted to the Power Source via the remote control socket (8
Pin Remote Socket). When the local/remote switch is in the remote position, the Power
Source will detect a remote device and work accordingly. When in the local mode, the Power
Source will not detect the remote device and will operate from the Power Source controls
only. Note that the trigger will operate at all times on the remote control socket irrespective
of the position of the local remote switch (ie in both local and remote modes).
Should a remote device be connected and the local/ remote switch set to remote, the
maximum setting of the Power Source will be determined by the respective front panel control,
irrespective of the remote control device setting. As an example, if the output current on the
Power Source front panel is set to 50% and the remote control device is set to 100%, the
maximum achievable output from the Power Source will be 50%. Should 100% output be
required, the respective front panel control must be set to 100%, in which case the remote
device will then be able to control between 0-100% output.
18
19
(Inside side panel)
19. Burnback Control (located in wirefeed compartment)
The Burnback control is used to adjust the amount of MIG wire that protrudes from the MIG
Gun after the completion of MIG welding (commonly referred to as stick-out). To decrease
the Burnback time (or lengthen the amount of wire protruding from the MIG Gun at the
completing of welding), turn the Burnback control knob counterclockwise. To increase the
Burnback time (or shorten the amount of wire protruding from the MIG Gun at the completing
of welding), turn the Burnback Control knob clockwise.
Firepower MST 140i
Manual 0-5338 3-15 INSTALLATION, OPERATION AND SETUP
3.11 Attaching the Firepower 140A MIG Gun
Fit the MIG Gun to the Power Source by pushing the MIG Gun connector into the MIG Gun Adapter and tightening the Locking
Nut to secure the MIG Gun in the MIG Gun Adapter.
MIG Gun Connect
Tighten Locking Nut
Art #
A-12516
MIG Gun Adaptor
MIG Gun Connector
MIG Gun Locking Nut
Figure 3-8: Attaching MIG Gun
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-16 Manual 0-5338
3.12 Inserting Wire into the Wire Feed Mechanism
Release the tension from the Pressure Roller Arm by turning the adjustable Wire Drive Tension Screw in a counterclockwise.
Then to release the pressure roller arm push the tension screw toward the front of the machine which releases the pressure
roller arm. With the MIG welding wire feeding from the bottom of the spool (Figure 3-10) pass the electrode wire through
the inlet guide, between the rollers, through the outlet guide and into the MIG Gun. Re-secure the pressure roller arm and
wire drive tension screw and adjust the pressure accordingly (Figure 3-9). Remove the nozzle and contact tip from the MIG
Gun. With the MIG Gun lead reasonably straight, feed the wire through the MIG Gun by depressing the trigger switch. Fit the
appropriate contact tip.
WARNING
Before connecting the work clamp to the work piece, make sure you have ceased feeding wire so premature arcing
will not occur.
The electrode wire will be at welding voltage potential while it is being fed through the system.
Keep MIG Gun away from eyes and face.
Art #
A-10359_AB
Outlet Guide
Inlet Guide
Wire Drive Tension Screw
Pressure Roller Arm
Figure 3-9: Wire Drive Assembly Components
MIG Welding Wire
Art #
A-12442
Figure 3-10: MIG Welding Wire - Installation
Firepower MST 140i
Manual 0-5338 3-17 INSTALLATION, OPERATION AND SETUP
3.13 Installing 4" (100mm) Diameter Spool
As delivered from the factory, the Power Source is fitted with a Wire Spool Hub which accepts a 8" (200mm) diameter spools.
In order to fit a 4" (100mm) diameter spool assemble parts in the sequence shown below in Figure 3-11.
Adjustment of the nut with nylon insert will control the MIG Wire Spool Brake. Clockwise rotation of this nut with nylon insert
tightens the brake. The brake is correctly adjusted when the spool stops within 4" (100mm) to 8" (200mm) (measured at the
outer edge of the spool) after MIG Gun trigger is released. Wire should be slack without becoming dislodged from the spool.
CAUTION
Overtension of brake will cause rapid wear of mechanical WIREFEED parts, overheating of electrical components
and possibly an increased incidence of electrode wire Burnback into contact tip.
Art #
A-12443
Friction Washer
4”（100mm）
Diameter spool
Nut with
Nylon Insert
Spring
Plastic Spacer
Brass Flat
Washer
Flat Washer
Figure 3-11: 4" (100mm)Diameter Spool Installation
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-18 Manual 0-5338
3.14 Installing 8" (200mm) Diameter Spool
As delivered from the factory, the Power Source is set for a 8" (200mm) diameter spool.
In order to re-fit a 8" (200mm) spool assemble parts in the sequence shown below in Figure 3-12.
Adjustment of the nut with nylon insert will control the MIG Wire Spool Brake. Clockwise rotation of this nut with nylon insert
tightens the brake. The Brake is correctly adjusted when the spool stops within 3/8" (10mm) to 3/4" (20mm) (measured at the
outer edge of the spool) after MIG Gun trigger is released. Wire should be slack without becoming dislodged from the spool.
CAUTION
Overtension of brake will cause rapid wear of mechanical WIREFEED parts, overheating of electrical components
and possibly an increased incidence of electrode wire Burnback into contact tip.
Ensure that the alignment pin on the wire spool hub aligns with the hole allocated in 8" (200mm) diameter spool.
NOTE
This alignment pin can be removed by unscrewing in an counterclockwise direction and locating in the appropriate
position.
Art #
A-12444
Spring
Nut with
Nylon Insert
8” (200mm)
diameter spool
Spool Hub Nut
Alignment pin
Brass Flat
Washer
Wire Spool Hub
Friction
Washer
Plastic Spacer
Flat Washer
Alternate
Alignment Pin
Position
Figure 3-12: 8" (200mm) Diameter Spool Installation
Firepower MST 140i
Manual 0-5338 3-19 INSTALLATION, OPERATION AND SETUP
3.15 Feed Roller Pressure Adjustment
The pressure (top) roller applies pressure to the grooved feed roller via an adjustable pressure screw. These devices should
be adjusted to a minimum pressure that will provide satisfactory wire feed without slippage. If slipping occurs, and inspection
of the wire contact tip reveals no wear, distortion or burn back jam, the conduit liner should be checked for kinks and clogging
by metal flakes and debris. If it is not the cause of slipping, the feed roll pressure can be increased by rotating the pressure
screw clockwise.
WARNING
Before changing the feed roller ensure that the Electricity Supply to the Power Source is switched off.
CAUTION
The use of excessive pressure may cause rapid wear of the feed rollers, shafts and bearing.
3.16 Changing the Feed Roll
To change feed roll remove the feed roll retaining screw by turning in an counterclockwise direction. Once the feed roll is
removed then to replace feed roll simply reverse these directions.
A dual groove feed roller is supplied as standard. It can accommodate 023"(0.6mm) -.030" (0.8mm) diameter hard wires.
Select the roller required with the chosen wire size marking facing outward.
GROOVE “B”GROOVE “A”
GROOVE “A” SIZE
GROOVE “B” SIZE
A-09583
Figure 3-13: Dual Groove Feed Roller
Feed Roll
Retaining Screw
Feed Roll
Art #
A-12445
Figure 3-14: Changing the Feed Roll
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-20 Manual 0-5338
3.17 Wire Reel Brake
The wire reel hub incorporates a friction brake which is adjusted during manufacture for optimum breaking. If it is considered
necessary, adjustment can be made by turning the large nut inside the open end of the hub clockwise to tighten the brake.
Correct adjustment will result in the wire reel circumference continuing no further than 3/8" (10mm) - 3/4" (20mm) after
release of the trigger. The electrode wire should be slack without becoming dislodged from wire spool.
CAUTION
Overtension of brake will cause rapid wear of mechanical WIREFEED parts, overheating of electrical components
and possibly an increased incidence of electrode wire Burnback into contact tip.
Wire Reel Brake Adjustment Nut
Art #
A-12446
Figure 3-15: Wire Reel Brake
Firepower MST 140i
Manual 0-5338 3-21 INSTALLATION, OPERATION AND SETUP
3.18 Flowmeter/ Regulator Operation
With the flowmeter/ regulator connected to cylinder or pipeline, and the adjustment screw/knob fully disengaged, pressurize
as follows:
1. Stand to one side of flowmeter/ regulator and slowly open the cylinder valve. If opened quickly, a sudden pressure
surge may damage internal parts.
2. With valves on downstream equipment closed, adjust flowmeter/ regulator to approximate working pressure. It is
recommended that testing for leaks at the flowmeter/ regulator connection points be carried out using a suitable leak
detection solution or soapy water.
3. Purge air or other unwanted welding grade shielding gas from equipment connected to the flowmeter/ regulator by
individually opening then closing the equipment control valves. Complete purging may take up to ten seconds or more,
depending upon the length and size of the hose being purged.
Adjusting Flow Rate
With the flowmeter/ regulator ready for operation, adjust working flow rate as follows:
1. Adjust the gas flow rate. The recommended rate for MIG welding is 15-25 CFH. The recommended rate for LIFT TIG
welding is 10-25 CFH.
NOTE
It may be necessary to re-check the shielding gas flowmeter/ regulator flow rate following the first weld sequence
due to back pressure present within shielding gas hose assembly.
Shutdown
Close cylinder valve whenever the flowmeter/ regulator is not in use. To shut down for extended periods (more than 30 minutes).
1. Close cylinder or upstream valve tightly.
2. Open downstream equipment valves to drain the lines. Bleed gas into a well ventilated area and away from any ignition
source.
3. After gas is drained completely, disengage adjusting screw and close downstream equipment valves.
4. Before transporting cylinders that are not secured on a cart designed for such purposes, remove flowmeters/ regulators.
Put caps on all cylinders that do not have flowmeters/ regulators on them.
3.19 Setup for MIG (GMAW) Welding with Gas Shielded MIG Wire
A. Select MIG mode with the process selection control. (Refer to Section 3.10 for further information)
B. Connect the MIG Gun Polarity Lead to the positive welding terminal (+). If in doubt, consult the electrode wire manufacturer.
Welding current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is
inserted and turned securely to achieve a sound electrical connection.
C. Fit the MIG Gun to the Power Source. (Refer to Section 3.11 Attaching the Firepower 140A MIG Gun).
D. Connect the work lead to the negative welding terminal (-). If in doubt, consult the electrode wire manufacturer. Welding
current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is inserted
and turned securely to achieve a sound electrical connection.
E. Fit the flowmeter/ regulator to the shielding gas cylinder (Refer to Section 3.06) then connect the shielding gas hose from
the rear of the Power Source to the flowmeter/ regulator outlet.
F. Refer to the Weld Guide located on the inside of the wirefeed compartment door for further information.
G. Switch the LOCAL/REMOTE switch inside the wire feed compartment to LOCAL to use the Power Sources Wirespeed
and Voltage controls.
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-22 Manual 0-5338
!
WARNING
Before connecting the work clamp to the work piece, make sure you have ceased feeding wire so premature
arcing will not occur.
Secure the shielding gas cylinder in an upright position by chaining it to a suitable stationary support to prevent
falling or tipping.
CAUTION
Loose welding terminal connections can cause overheating and result in the male plug being fused in the terminal.
Art #
A-12520
Connect Shielding Gas
Hose to regulator
Primary Cord
Work Lead
Negative Welding
Terminal (-)
Positive Welding
Terminal (+)
MIG Gun
Polarity Lead
MIG Gun
Secure the gas cylinder
in an upright position
by chaining it to a
stationary support to
prevent falling or tipping.
Figure 3-16: Setup for MIG Welding with Gas Shielded MIG Wire
Firepower MST 140i
Manual 0-5338 3-23 INSTALLATION, OPERATION AND SETUP
3.20 Setup for MIG (FCAW) Welding with Flux Core (Gasless) Wire
A. Select MIG mode with the process selection control (refer to Section 3.10.12 for further information).
B. Connect the MIG Gun Polarity Lead to the negative welding terminal (-). If in doubt, consult the electrode wire manufacturer.
Welding current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is
inserted and turned securely to achieve a sound electrical connection.
C. Connect the work lead to the positive welding terminal (+). If in doubt, consult the electrode wire manufacturer. Welding
current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is inserted
and turned securely to achieve a sound electrical connection.
D. Refer to the Weld Guide located on the inside of the wirefeed compartment door for further information.
E. Switch the LOCAL/REMOTE switch inside the wire feed compartment to LOCAL to use the Power Sources Wirespeed
and Voltage controls.
WARNING
Before connecting the work clamp to the work piece, make sure you have ceased feeding wire so premature arcing
will not occur.
CAUTION
Loose welding terminal connections can cause overheating and result in the male plug being fused in the terminal.
Remove any packaging material prior to use. Do not block the air vents at the front or rear of the Welding Power
Source.
Art# A-12521
MIG Gun
Polarity Lead.
Negative Welding
Terminal (-)
Positive Welding
Terminal
(+)
MIG Gun
Work Lead
Figure 3-17: Setup for MIG (FCAW) Welding with Flux Cored (Gasless) Wire
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-24 Manual 0-5338
3.21 Setup for LIFT TIG (GTAW) Welding
A. Select LIFT TIG mode with the process selection control (refer to Section 3.10.12 for further information).
B. Using the supplied 50mm to 25mm DINSE adapter, connect the TIG torch to the negative welding terminal (-). Welding
current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is inserted
and turned securely to achieve a sound electrical connection.
C. Connect the work lead to the positive welding terminal (+). Welding current flows from the Power Source via Dinse
style terminals. It is essential, however, that the male plug is inserted and turned securely to achieve a sound electrical
connection.
D. Connect the TIG torch trigger switch via the 8 pin socket located on the front of the Power Source. The TIG torch will
require a trigger switch to weld in LIFT TIG Mode.
NOTE
A Firepower 17V TIG torch with an 8 pin plug must be used to turn the weld current on/off via the TIG torch trigger
switch to TIG weld OR a Firepower Foot Control with an 8 pin plug must be used to turn the weld current on/off
as well as providing remote control of the weld current. Please refer to "2.10 Options and Accessories".
E. Fit the flowmeter/ regulator to the shielding gas cylinder (refer to Section 3.06) then connect the shielding gas hose from
the TIG torch to the flowmeter/ regulator outlet. Note that the TIG torch shielding gas hose is connected directly to the
flowmeter/ regulator. The Power Source is not fitted with a shielding gas solenoid to control the gas flow in LIFT TIG mode
therefore the TIG torch will require a gas valve.
!
WARNING
Before connecting the work clamp to the work piece, make sure you have ceased feeding wire so premature arcing
will not occur.
Secure the shielding gas cylinder in an upright position by chaining it to a stationary support to prevent falling
or tipping.
CAUTION
Remove any packaging material prior to use. Do not block the air vents at the front or rear of the Welding Power
Source.
Loose welding terminal connections can cause overheating and result in the male plug being fused in the terminal.
F. Switch the LOCAL/REMOTE switch inside the wire feed compartment to LOCAL to use the Power Sources Amperage
control or REMOTE for remote amperage using a Foot Control.
Firepower MST 140i
Manual 0-5338 3-25 INSTALLATION, OPERATION AND SETUP
Art # A-12447
MIG Torch
polarity lead
not connected
Note: A Firepower 17V TIG torch with
an 8 pin plug must be used to turn the
weld current on/off via the TIG torch trigger
switch to TIG weld OR a Firepower Foot Control
with an 8 pin plug must be used to turn the
weld current on/off as well as providing
remote control of the weld current.
Connect to shielding gas
regulator/flow gauge.
Secure the gas cylinder
in an upright position by
chaining it to a stationary
support to prevent falling
or tipping.
Negative welding terminal (-)
50mm- 25mm Adaptor
Positive Welding
Terminal (+)
TIG Torch
Work Lead
(MIG Gun
not shown
for clarity)
Figure 3-18: Setup for TIG Welding
Firepower MST 140i
INSTALLATION, OPERATION AND SETUP 3-26 Manual 0-5338
3.22 Setup for STICK (SMAW) Welding
A. Connect the Electrode Holder lead to the positive welding terminal (+). If in doubt, consult the electrode manufacturer.
Welding current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is
inserted and turned securely to achieve a sound electrical connection.
B. Connect the work lead to the negative welding terminal (-). If in doubt, consult the electrode manufacturer. Welding
current flows from the Power Source via Dinse style connectors. It is essential, however, that the male plug is inserted
and turned securely to achieve a sound electrical connection.
WARNING
Before connecting the work clamp to the work and inserting the electrode in the electrode holder make sure the
Electricity Supply is switched off.
CAUTION
Remove any packaging material prior to use. Do not block the air vents at the front or rear of the Welding
Power Source.
C. Switch the LOCAL/REMOTE switch inside the wire feed compartment to LOCAL to use the Power Sources Amperage
control or REMOTE for remote amperage control using a Hand Pendant Control.
Art #
A-10365
Negative Welding
Terminal (-)
Positive Welding
Terminal (+
)
Work Lead
Electrode
Holder
MIG Gun
polarity lead
not connected.
(MIG Gun
not shown
for clarity)
Figure 3-19: Setup for Stick Welding(SMAW)
Firepower MST 140i
Manual 0-5338 4-1 BASIC WELDING GUIDE
SECTION 4: BASIC WELDING GUIDE
4.01 MIG (GMAW/FCAW) Basic Welding Technique
Two different welding processes are covered in this section (GMAW and FCAW), with the intention of providing the very basic
concepts in using the MIG mode of welding, where a welding MIG Gun is hand held, and the electrode (welding wire) is fed
into a weld puddle, and the arc is shielded by an inert welding grade shielding gas or inert welding grade shielding gas mixture.
GAS METAL ARC WELDING (GMAW): This process, also known as MIG welding, CO2 welding, Micro Wire Welding, short arc
welding, dip transfer welding, wire welding etc., is an electric arc welding process which fuses together the parts to be welded
by heating them with an arc between a solid continuous, consumable electrode and the work. Shielding is obtained from an
externally supplied welding grade shielding gas or welding grade shielding gas mixture. The process is normally applied semi
automatically; however the process may be operated automatically and can be machine operated. The process can be used
to weld thin and fairly thick steels, and some non-ferrous metals in all positions.
Art # A-8991_AB
Shielding Gas
Molten Weld Metal
Solidified
Weld Metal
Nozzle
Electrode
Arc
Base Metal
GMAW Process
Figure 4-1
FLUX CORED ARC WELDING (FCAW): This is an electric arc welding process which fuses together the parts to be welded
by heating them with an arc between a continuous flux filled electrode wire and the work. Shielding is obtained through
decomposition of the flux within the tubular wire. Additional shielding may or may not be obtained from an externally supplied
gas or gas mixture. The process is normally applied semi automatically; however the process may be applied automatically
or by machine. It is commonly used to weld large diameter electrodes in the flat and horizontal position and small electrode
diameters in all positions. The process is used to a lesser degree for welding stainless steel and for overlay work.
Art # A-08992_AB
Molten
Slag
Nozzle
(Optional)
FCAW Process
Flux Cored
Electrode
Arc
Shielding Gas
(Optional)
Slag
Molten Metal
Base Metal
Solidified
Weld Metal
Figure 4-2
Position of MIG Gun
The angle of MIG Gun to the weld has an effect on the width of the weld.
Push
Vertical
Drag/Pull
Art # A-07185_AB
Figure 4-3
Firepower MST 140i
BASIC WELDING GUIDE 4-2 Manual 0-5338
The welding Gun should be held at an angle to the weld joint. (see Secondary Adjustment Variables below)
Hold the MIG Gun so that the welding seam is viewed at all times. Always wear the welding helmet with proper filter lenses
and use the proper safety equipment.
CAUTION
Do not pull the welding MIG Gun back when the arc is established. This will create excessive wire extension (stickout) and make a very poor weld.
The electrode wire is not energized until the MIG Gun trigger switch is depressed. The wire may therefore be placed on the
seam or joint prior to lowering the helmet.
Butt & Horizontal Welds
Direction of
Travel
5° to 15°
Longitudinal
Angle
90°
Transverse
Angle
Art # A-08993
Figure 4-4
Horizontal Fillet Weld
Direction of
Travel
5° to 15°
Longitudinal Angle
30° to 60°
Transverse Angle
Art # A-08994
Figure 4-5
Vertical Fillet Welds
Art # A-08995
30° to 60°
Transverse
Angle
30° to 60°
Transverse
Angle
Direction of Travel
10°
Longitudinal Angle
10° to 20° Longitudinal
Angle
Figure 4-6
Art # A-08996
30° to 60°
Transverse Angle
Direction of Travel
5° to 15°
Longitudinal
Angle
Figure 4-7
Distance from the MIG Gun Nozzle to the Work Piece
The electrode wire stick-out from the MIG Gun nozzle should be between 3/8" (10mm) to 3/4" (20.0mm). This distance may
vary depending on the type of joint that is being welded.
Travel Speed
The speed at which the molten pool travels influences the width of the weld and penetration of the welding run.
MIG Welding Variables
Most of the welding done by all processes is on carbon steel. The items below describe the welding variables in short-arc
welding of 24 ga. (0.6mm) to ¼” (6.4mm) mild sheet or plate. The applied techniques and end results in the MIG process
are controlled by these variables.
Firepower MST 140i
Manual 0-5338 4-3 BASIC WELDING GUIDE
Preselected Variables
Preselected variables depend upon the type of material being welded, the thickness of the material, the welding position, the
deposition rate and the mechanical properties. These variables are:
• Type of electrode wire
• Size of electrode wire
• Type of gas (not applicable to self shielding wires FCAW)
• Gas flow rate (not applicable to self shielding wires FCAW)
Primary Adjustable Variables
These control the process after preselected variables have been found. They control the penetration, bead width, bead height,
arc stability, deposition rate and weld soundness. They are:
• Arc Voltage
• Welding current (wire feed speed)
• Travel speed
Secondary Adjustable Variables
These variables cause changes in primary adjustable variables which in turn cause the desired change in the bead formation.
They are:
1. Stick-out (distance between the end of the contact tube (tip) and the end of the electrode wire). Maintain at about
3/8" (10mm) stick-out
2. Wire Feed Speed. Increase in wire feed speed increases weld current, Decrease in wire feed speed decreases weld
current.
Art # A-08997_AD
Gas Nozzle
Electrode Wire
Average Arc Length
Electrode Stick-Out
Tip to
Work Distance
Actual Stick-out
Contact Tip (Tube)
Figure 4-8
3. Nozzle Angle. This refers to the position of the welding MIG Gun in relation to the joint. The transverse angle is usually
one half the included angle between plates forming the joint. The longitudinal angle is the angle between the centre
line of the welding MIG Gun and a line perpendicular to the axis of the weld. The longitudinal angle is generally called
the Nozzle Angle and can be either trailing (pulling) or leading (pushing). Whether the operator is left handed or right
handed has to be considered to realize the effects of each angle in relation to the direction of travel.
Transverse and Longitudinal
Nozzle Axes
Art # A-08998_AB
Longitudinal
Angle
Axis of Weld
Transverse
Angle
Figure 4-9
Firepower MST 140i
BASIC WELDING GUIDE 4-4 Manual 0-5338
Art # A-08999_AC
Nozzle Angle, Right Handed Operator
Direction of Gun Travel
Leading or “Pushing”
Angle
(Forward Pointing)
Trailing or “Pulling”
Angle
(Backward Pointing)
90°
Figure 4-10
Establishing the Arc and Making Weld Beads
Before attempting to weld on a finished piece of work, it is recommended that practice welds be made on a sample metal of
the same material as that of the finished piece.
The easiest welding procedure for the beginner to experiment with MIG welding is the flat position. The equipment is capable
of flat, vertical and overhead positions.
For practicing MIG welding, secure some pieces of 16 ga. (1.6mm) or 1/8" (3.2mm) mild steel plate 6” (150mm) x 6” (150mm).
Use 0.035” (0.9mm) gas shielded steel or gasless flux cored wire.
Setting of the Power Source
Power source and Wirefeeder setting requires some practice by the operator, as the welding plant has two control settings that
have to balance. These are the Wirespeed control (refer to section 3.10.3) and the welding Voltage Control (refer to section
3.10.9). The welding current is determined by the Wirespeed control, the current will increase with increased Wirespeed,
resulting in a shorter arc. Less wire speed will reduce the current and lengthen the arc. Increasing the welding voltage hardly
alters the current level, but lengthens the arc. By decreasing the voltage, a shorter arc is obtained with a little change in
current level.
When changing to a different electrode wire diameter, different control settings are required. A thinner electrode wire needs
more Wirespeed to achieve the same current level.
A satisfactory weld cannot be obtained if the Wirespeed and Voltage settings are not adjusted to suit the electrode wire
diameter and the dimensions of the work piece.
If the Wirespeed is too high for the welding voltage, “stubbing” will occur as the wire dips into the molten pool and does
not melt. Welding in these conditions normally produces a poor weld due to lack of fusion. If, however, the welding voltage
is too high, large drops will form on the end of the wire, causing spatter. The correct setting of voltage and Wirespeed can
be seen in the shape of the weld deposit and heard by a smooth regular arc sound. Refer to the Weld Guide located on the
inside of the wirefeed compartment door for setup information.
Electrode Wire Size Selection
The choice of Electrode wire size and shielding gas used depends on the following
• Thicknessofthemetaltobewelded
• Typeofjoint
• CapacityofthewirefeedunitandPowerSource
• Theamountofpenetrationrequired
• Thedepositionraterequired
• Thebeadproledesired
• Thepositionofwelding
• Costofthewire
Firepower MST 140i
Manual 0-5338 4-5 BASIC WELDING GUIDE
Firepower MIG, Lift TIG, Stick Wire Selection Chart
Art # A-12462
Table 4-1: MIG, Lift TIG, Stick Welding Set up Chart
Firepower MST 140i
BASIC WELDING GUIDE 4-6 Manual 0-5338
4.02 MIG (GMAW/FCAW) Welding Troubleshooting
Solving Problems Beyond the Welding Terminals
The general approach to fix Gas Metal Arc Welding (GMAW) problems is to start at the wire spool then work through to the
MIG Gun. There are two main areas where problems occur with MIG, Porosity and Inconsistent wire feed
Solving Problems Beyond the Welding Terminals - Porosity
When there is a gas problem the result is usually porosity within the weld metal. Porosity always stems from some contaminant
within the molten weld pool which is in the process of escaping during solidification of the molten metal. Contaminants range
from no gas around the welding arc to dirt on the work piece surface. Porosity can be reduced by checking the following points.
FAULT CAUSE
1 Limited or no shielding gas flows
out of the MIG Gun nozzle.
Check that the MIG Gun connection is fully engaged into the MIG
Gun Adapter. The o-rings in the MIG Gun connection must seal
the shielding gas within the MIG Gun Adapter so the shielding gas
flows into the MIG Gun and out thru the MIG Gun nozzle.
2 No shielding gas flow. Ensure that the shielding gas cylinder is not empty and the flow
meter is correctly adjusted to workshop welding: 15-25 CFH or
outdoors welding: 35-46 CFH.
3 Gas leaks. Check for gas leaks between the regulator/cylinder connection and
in the gas hose to the Power Source.
4 Welding in a windy environment. Shield the weld area from the wind or increase the gas flow.
5 Welding dirty, oily, painted,
oxidized or greasy plate.
Clean contaminates off the work piece.
6 Distance between the MIG Gun
nozzle and the work piece.
Keep the distance between the MIG Gun nozzle and the work piece
to a minimum. Refer to section 4.01
7 Maintain the MIG Gun in good
working order.
A Ensure that the gas holes are not blocked and gas is exiting out of
the MIG Gun nozzle.
B Do not restrict gas flow by allowing spatter to build up inside the
MIG Gun nozzle.
C Check that the MIG Gun O-rings are not damaged.
Table 4-2: Solving Problems beyond the Welding Terminals-Porosity
!
WARNING
Disengage the feed roll when testing for gas flow by ear.
Firepower MST 140i
Manual 0-5338 4-7 BASIC WELDING GUIDE
Solving Problems Beyond the Welding Terminals - Inconsistent Wire Feed
Wire feeding problems can be reduced by checking the following points.
FAULT CAUSE
1 Feed roller driven by motor in the
cabinet slipped
Wire spool brake is too tight or drive roll tension not
tight enough.
2 Wire spool unwinds and tangles Wire spool brake is too loose.
3 Wire slipping A Worn or incorrect feed roller size. Use a feed roller
matched to the size you are welding.
B Replace feed roller if worn.
4 Wire rubbed against the mis-aligned
guides and reduced wire feedability.
Mis-alignment of inlet/outlet guides
5 Liner blocked with debris A Increased amounts of debris are produced by the wire
passing through the feed roller when excessive pressure is applied to the pressure roller adjuster.
B Debris can also be produced by the wire passing
through an incorrect feed roller groove shape or size.
C Debris is fed into the conduit liner where it accumu-
lates thus reducing wire feedability.
6 Incorrect or worn contact tip A The contact tip transfers the weld current to the elec-
trode wire. If the hole in the contact tip is too large
then arcing may occur inside the contact tip resulting
in the wire jamming in the contact tip.
B When using soft wire such as aluminum it may be-
come jammed in the contact tip due to expansion of
the wire when heated. A MST contact tip designed for
soft wires should be used.
7 Poor work lead contact to work piece If the work lead has a poor electrical contact to the
work piece then the connection point will heat up and
result in a reduction of power at the arc.
8 Bent liner This will cause friction between the wire and the liner
thus reducing wire feedability
Table 4-3: Wire Feeding Problems
Firepower MST 140i
BASIC WELDING GUIDE 4-8 Manual 0-5338
Basic MIG Welding Troubleshooting
FAULT CAUSE REMEDY
1 Undercut A Welding arc voltage too high. A Decrease voltage or increase the wire feed
speed.
B Incorrect MIG Gun angle B Adjust angle.
C Excessive heat input C Increase the MIG Gun travel speed and/or
decrease welding current by decreasing the
voltage or decreasing the wire feed speed.
2 Lack of penetration A Welding current too low A Increase welding current by increasing wire
feed speed and increasing voltage.
B Joint preparation too narrow or
gap too tight
B Increase joint angle or gap.
C Shielding gas incorrect C Change to a gas which gives higher penetration.
3 Lack of fusion Welding current too low Increase welding current.
4 Excessive spatter A Voltage too high A Decrease voltage or increase the wirespeed
control.
B Voltage too low B Increase the voltage or decrease wirespeed.
5 Irregular weld shape A Incorrect voltage and travel
speed settings. Convex, voltage
too low. Concave, voltage too
high.
A Adjust voltage and travel speed by adjusting the
voltage control and the wirespeed control.
B Wire is wandering. B Check to see if it is near the end of the roll
of wire and replace when necessary. If the
problem continues, tighten the nozzle to see
if this corrects the problem. Then replace
contact tip.
C Incorrect shielding gas C Check shielding gas.
D Insufficient or excessive heat
input
D Adjust the wirespeed control or the voltage
control.
E Incorrect gun manipulation or
angle
E Manipulate the gun correctly or place it in
correct angle.
6 Weld cracking A Weld high carbon steel without
pre/post heat treatment
A Have sufficient pre/post heat treatment before
welding high carbon steel.
B Incompatible filler metal used
to the base metal
B Use correct filler metal.
C Weld beads too small C Decrease travel speed.
D Weld penetration narrow and
deep
D Reduce current and voltage and increase MIG
Gun travel speed or select a lower penetration
shielding gas.
E Excessive weld stresses E Increase weld metal strength or revise design
F Excessive voltage F Decrease voltage.
G Cooling rate too fast G Slow the cooling rate by preheating part to be
welded or cool slowly.
Firepower MST 140i
Manual 0-5338 4-9 BASIC WELDING GUIDE
FAULT CAUSE REMEDY
7 Cold weld puddle A Welding voltage too high A Decrease voltage or increase the wirespeed
control.
B Loose welding cable connec-
tion
B Check all welding cable connections.
C Low primary voltage C Contact supply authority.
D Fault in power source D Have an Accredited Firepower Service Provider
to test then replace the faulty component.
8 Arc does not have a
crisp sound that short
arc exhibits when the
wirefeed speed and
voltage are adjusted
correctly.
The MIG Gun has been connected to the wrong voltage
polarity on the front panel
Connect the MIG Gun to the positive (+)
welding terminal for solid wires and gas
shielded flux cored wires. Refer to the
electrode wire manufacturer for the correct
polarity.
9 Poor weld result from
setup chart parameters
A Incorrect welder setup, polar-
ity, shielding gas, wire type and
size
A Check to make sure that the welder is set up
correctly; also check polarity, shielding gas,
wire type and size.
B Contact tip has arc marks in the
bore causing excessive drag on
the wire
B Replace the contact tip with only a genuine
MST contact tip.
Table 4-4: MIG Welding Problems
4.03 Stick (SMAW) Basic Welding Technique
Size of Electrode
The electrode size is determined by the thickness of metals being joined and can also be governed by the type of welding
machine available. Small welding machines will only provide sufficient current (amperage) to run the smaller size electrodes.
For thin sections, it is necessary to use smaller electrodes otherwise the arc may burn holes through the job. A little practice
will soon establish the most suitable electrode for a given application.
Storage of Electrodes
Always store electrodes in a dry place and in their original containers.
Electrode Polarity
Electrodes are generally connected to the ELECTRODE HOLDER with the Electrode Holder connected positive polarity. The
WORK LEAD is connected negative polarity and is connected to the work piece. If in doubt consult the electrode data sheet
or your nearest Accredited Firepower Distributor.
Firepower MST 140i
BASIC WELDING GUIDE 4-10 Manual 0-5338
4.04 Effects of Stick Welding Various Materials
High Tensile and Alloy Steels
The two most prominent effects of welding these steels are the formation of a hardened zone in the weld area, and, if suitable
precautions are not taken, the occurrence in this zone of under-bead cracks. Hardened zone and under-bead cracks in the
weld area may be reduced by using the correct electrodes, preheating, using higher current settings, using larger electrodes
sizes, short runs for larger electrode deposits or tempering in a furnace.
Manganese Steels
The effect on manganese steel of slow cooling from high temperatures is to embrittle it. For this reason it is absolutely
essential to keep manganese steel cool during welding by quenching after each weld or skip welding to distribute the heat.
Cast Iron
Most types of cast iron, except white iron, are weldable. White iron, because of its extreme brittleness, generally cracks when
attempts are made to weld it. Trouble may also be experienced when welding white-heart
malleable, due to the porosity caused by gas held in this type of iron.
Copper and Alloys
The most important factor is the high rate of heat conductivity of copper, making pre-heating of heavy sections necessary to
give proper fusion of weld and base metal.
Types of Electrodes
Arc Welding electrodes are classified into a number of groups depending on their applications. There are a great number
of electrodes used for specialized industrial purposes which are not of particular interest for everyday general work. These
include some low hydrogen types for high tensile steel, cellulose types for welding large diameter pipes, etc The range of
electrodes dealt with in this publication will cover the vast majority of applications likely to be encountered; are all easy to use.
Arc Welding Practice
The techniques used for arc welding are almost identical regardless of what types of metals are being joined. Naturally enough,
different types of electrodes would be used for different metals as described in the preceding section.
Welding Position
The electrodes dealt with in this publication can be used in most positions, i.e. they are suitable for welding in flat, horizontal,
vertical and overhead positions. Numerous applications call for welds to be made in positions intermediate between these.
Some of the common types of welds are shown in Figures 4-11 through 4-18.
Art # A-07687
Figure 4-11: Flat Position, Down Hand Butt Weld
Art # A-07688
Figure 4-12: Flat Position, Gravity Fillet Weld
Art # A-07689
Figure 4-13: Horizontal Position, Butt Weld
Art # A-07690
Figure 4-14: Horizontal-Vertical (HV) Position
Firepower MST 140i
Manual 0-5338 4-11 BASIC WELDING GUIDE
Art A-07691
Figure 4-15: Vertical Position, Butt Weld
Art # A-07692
Figure 4-16: Vertical Position, Fillet Weld
Joint Preparations
In many cases, it will be possible to weld steel sections without any special preparation. For heavier sections and for repair
work on castings, etc., it will be necessary to cut or grind an angle between the pieces being joined to ensure proper penetration
of the weld metal and to produce sound joints.
In general, surfaces being welded should be clean and free of rust, scale, dirt, grease, etc. Slag should be removed from
oxy-cut surfaces. Typical joint designs are shown in Figure 4-19.
Gap varies from
1/16" (1.6mm) to 3/16" (4.8mm)
depending on plate thickness
Joint
Open Square Butt
1/16" (1.6mm) max
1.6mm (1/16”)
Single Vee Butt Joint
Not less than
70°
Double Vee Butt Joint
1/16" (1.6mm)
Lap Joint
Tee Joints
(Fillet both sides of the
joint)
Edge Joint
Fillet Joint
Corner Weld
Plug Weld Plug Weld
Not less than
70°
Single Vee Butt Joint
Not less than
45°
1/16" (1.6mm) max
Art # A-10367
Figure 4-19: Typical Joint Designs for Arc Welding
Art# A-07693
Figure 4-17: Overhead Position, Butt Weld
Art # A-07694
Figure 4-18: Overhead Position, Fillet Weld
Firepower MST 140i
BASIC WELDING GUIDE 4-12 Manual 0-5338
Arc Welding Technique - A Word to Beginners
For those who have not yet done any welding, the simplest way to commence is to run beads on a piece of scrap plate. Use
mild steel plate about 1/4" (6.4mm) thick and a 1/8"(3.2mm) electrode. Clean any paint, loose scale or grease off the plate and
set it firmly on the work bench so that welding can be carried out in the downhand position. Make sure that the work clamp
is making good electrical contact with the work, either directly or through the work table. For light gauge material, always
clamp the work lead directly to the job, otherwise a poor circuit will probably result.
Striking the Arc
Practice this on a piece of scrap plate before going on to more exacting work. You may at first experience difficulty due to
the tip of the electrode "sticking" to the work piece. This is caused by making too heavy a contact with the work and failing
to withdraw the electrode quickly enough. A low amperage will accentuate it. This freezing-on of the tip may be overcome
by scratching the electrode along the plate surface in the same way as a match is struck. As soon as the arc is established,
maintain a 1/16"(1.6mm) to 1/8"(3.2mm) gap between the burning electrode end and the parent metal. Draw the electrode
slowly along as it melts down.
Another difficulty you may meet is the tendency, after the arc is struck, to withdraw the electrode so far that the arc is broken
again. A little practice will soon remedy both of these faults.
Art # A-10368
1/16" (1.6mm)
Figure 4-20: Striking an Arc
Arc Length
The securing of an arc length necessary to produce a neat weld soon becomes almost automatic. You will find that a long
arc produces more heat. A very long arc produces a crackling or spluttering noise and the weld metal comes across in large,
irregular blobs. The weld bead is flattened and spatter increases. A short arc is essential if a high quality weld is to be obtained
although if it is too short there is the danger of it being blanketed by slag and the electrode tip being solidified in. If this should
happen, give the electrode a quick twist back over the weld to detach it. Contact or "touch-weld" electrodes such as E7014
Stick electrodes do not stick in this way, and make welding much easier.
Rate of Travel
After the arc is struck, your next concern is to maintain it, and this requires moving the electrode tip towards the molten
pool at the same rate as it is melting away. At the same time, the electrode has to move along the plate to form a bead. The
electrode is directed at the weld pool at about 20º from the vertical. The rate of travel has to be adjusted so that a well-formed
bead is produced.
If the travel is too fast, the bead will be narrow and strung out and may even be broken up into individual globules. If the travel
is too slow, the weld metal piles up and the bead will be too large.
Making Welded Joints
Having attained some skill in the handling of an electrode, you will be ready to go on to make up welded joints.
A. Butt Welds
Set up two plates with their edges parallel, as shown in Figure 4-21, allowing 1/16"(1.6mm) to 3/32"(2.4mm) gap between
them and tack weld at both ends. This is to prevent contraction stresses from the cooling weld metal pulling the plates
out of alignment. Plates thicker than 1/4" (6.4mm) should have their mating edges beveled to form a 70º to 90º included
angle. This allows full penetration of the weld metal to the root. Using a 1/8"(3.2mm) E7014 Stick electrode at 100 amps,
deposit a run of weld metal on the bottom of the joint.
Do not weave the electrode, but maintain a steady rate of travel along the joint sufficient to produce a well-formed bead.
At first you may notice a tendency for undercut to form, but keeping the arc length short, the angle of the electrode at
about 20º from vertical, and the rate of travel not too fast, will help eliminate this. The electrode needs to be moved along
fast enough to prevent the slag pool from getting ahead of the arc. To complete the joint in thin plate, turn the job over,
clean the slag out of the back and deposit a similar weld.
Firepower MST 140i
Manual 0-5338 4-13 BASIC WELDING GUIDE
Art # A-07699_AB
45° from
vertical
60° - 70° from line
of weld
Figure 4-23: Electrode Position for HV Fillet Weld
Art # A-07700_AB
1
2
3
4
5
6
Figure 4-24: Multi-runs in HV Fillet Weld
Art # A-07697_AB
Tack Weld
20°-30°
Electrode
Tack Weld
Figure 4-21: Butt Weld
Art # A-07698
Figure 4-22: Weld Build up Sequence
Heavy plate will require several runs to complete the joint. After completing the first run, chip the slag out and clean the
weld with a wire brush. It is important to do this to prevent slag being trapped by the second run. Subsequent runs are
then deposited using either a weave technique or single beads laid down in the sequence shown in Figure 4-22. The width
of weave should not be more than three times the core wire diameter of the electrode. When the joint is completely filled,
the back is either machined, ground or gouged out to remove slag which may be trapped in the root, and to prepare a
suitable joint for depositing the backing run. If a backing bar is used, it is not usually necessary to remove this, since it
serves a similar purpose to the backing run in securing proper fusion at the root of the weld.
B. Fillet Welds
These are welds of approximately triangular cross-section made by depositing metal in the corner of two faces meeting
at right angles. Refer to Figure 4-14.
A piece of angle iron is a suitable specimen with which to begin, or two lengths of strip steel may be tacked together at
right angles. Using a 1/8"(3.2mm) E7014 Stick electrode at 100 amps, position angle iron with one leg horizontal and the
other vertical. This is known as a horizontal-vertical (HV) fillet. Strike the arc and immediately bring the electrode to a
position perpendicular to the line of the fillet and about 45º from the vertical. Some electrodes require to be sloped about
20º away from the perpendicular position to prevent slag from running ahead of the weld. Refer to Figure 4-23. Do not
attempt to build up much larger than 1/4"(6.4mm)width with a 1/8"(3.2mm) electrode, otherwise the weld metal tends to
sag towards the base, and undercut forms on the vertical leg. Multi-runs can be made as shown in Figure 4-24. Weaving
in HV fillet welds is undesirable.
Firepower MST 140i
BASIC WELDING GUIDE 4-14 Manual 0-5338
Art # A-07701
Figure 4-25: Single Run Vertical Fillet Weld
C. Vertical Welds
1. Vertical Up
Tack weld a three feet length of angle iron to your work bench in an upright position. Use a 1/8"(3.2mm) E7014 Stick
electrode and set the current at 100 amps. Make yourself comfortable on a seat in front of the job and strike the
arc in the corner of the fillet. The electrode needs to be about 10º from the horizontal to enable a good bead to be
deposited. Refer Figure 4-25. Use a short arc, and do not attempt to weave on the first run. When the first run has
been completed de-slag the weld deposit and begin the second run at the bottom. This time a slight weaving motion
is necessary to cover the first run and obtain good fusion at the edges. At the completion of each side motion, pause
for a moment to allow weld metal to build up at the edges, otherwise undercut will form and too much metal will
accumulate in the centre of the weld. Figure 4-26 illustrates multi-run technique and Figure 4-27 shows the effects
of pausing at the edge of weave and of weaving too rapidly.
Art # A-07702
Figure 4-26: Multi Run Vertical Fillet Weld
Art # A-07703
Figure 4-27: Examples of Vertical Fillet Welds
2. Vertical Down
The E7014 Stick electrode makes welding in this position particularly easy. Use a 1/8"(3.2mm) electrode at 100 amps.
The tip of the electrode is held in light contact with the work and the speed of downward travel is regulated so that the
tip of the electrode just keeps ahead of the slag. The electrode should point upwards at an angle of about 45º.
3. Overhead Welds
Apart from the rather awkward position necessary, overhead welding is not much more difficult that downhand welding.
Set up a specimen for overhead welding by first tacking a length of angle iron at right angles to another piece of angle
iron or a length of waste pipe. Then tack this to the work bench or hold in a vice so that the specimen is positioned
in the overhead position as shown in the sketch. The electrode is held at 45º to the horizontal and tilted 10º in the line
of travel (Figure 4-28). The tip of the electrode may be touched lightly on the metal, which helps to give a steady run.
A weave technique is not advisable for overhead fillet welds. Use a 1/8"(3.2mm) E6013 Stick electrode at 100 amps,
and deposit the first run by simply drawing the electrode along at a steady rate. You will notice that the weld deposit
is rather convex, due to the effect of gravity before the metal freezes.
Firepower MST 140i
Manual 0-5338 4-15 BASIC WELDING GUIDE
Art # A-07704
Figure 4-28: Overhead Fillet Weld
Distortion
Distortion in some degree is present in all forms of welding. In many cases it is so small that it is barely perceptible, but
in other cases allowance has to be made before welding commences for the distortion that will subsequently occur. The
study of distortion is so complex that only a brief outline can be attempted hear.
The Cause of Distortion
Distortion is caused by:
A. Contraction of Weld Metal:
Molten steel shrinks approximately 11 per cent in volume on cooling to room temperature. This means that a cube of
molten metal would contract approximately 2.2 per cent in each of its three dimensions. In a welded joint, the metal
becomes attached to the side of the joint and cannot contract freely. Therefore, cooling causes the weld metal to flow
plastically, that is, the weld itself has to stretch if it is to overcome the effect of shrinking volume and still be attached
to the edge of the joint. If the restraint is very great, as, for example, in a heavy section of plate, the weld metal may
crack. Even in cases where the weld metal does not crack, there will still remain stresses "Locked-up" in the structure.
If the joint material is relatively weak, for example, a butt joint in 5/64" (2.0mm) sheet, the contracting weld metal may
cause the sheet to become distorted.
B. Expansion and Contraction of Parent Metal in the Fusion Zone:
While welding is proceeding, a relatively small volume of the adjacent plate material is heated to a very high temperature
and attempts to expand in all directions. It is able to do this freely at right angles to the surface of the plate (i.e., "through
the weld", but when it attempts to expand "across the weld" or "along the weld", it meets considerable resistance, and
to fulfill the desire for continued expansion, it has to deform plastically, that is, the metal adjacent to the weld is at a
high temperature and hence rather soft, and, by expanding, pushes against the cooler, harder metal further away, and
tends to bulge (or is "upset". When the weld area begins to cool, the "upset" metal attempts to contract as much as it
expanded, but, because it has been "upset" it does not resume its former shape, and the contraction of the new shape
exerts a strong pull on adjacent metal. Several things can then happen.
The metal in the weld area is stretched (plastic deformation), the job may be pulled out of shape by the powerful
contraction stresses (distortion), or the weld may crack, in any case, there will remain "locked-up" stresses in the job.
Figures 4-29 and 4- 30 illustrate how distortion is created.
Art # A-07705_AB
Hot
Hot
Weld
Upsetting
Expansion with
compression
Cool
Figure 4-29: Parent Metal Expansion
Art # A-07706_AC
Weld
Permanent Upset
Contraction
with tension
Figure 4-30: Parent Metal Contraction
Firepower MST 140i
BASIC WELDING GUIDE 4-16 Manual 0-5338
Overcoming Distortion Effects
There are several methods of minimizing distortion effects.
A. Peening
This is done by hammering the weld while it is still hot. The weld metal is flattened slightly and because of this the tensile
stresses are reduced a little. The effect of peening is relatively shallow, and is not advisable on the last layer.
B. Distribution of Stresses
Distortion may be reduced by selecting a welding sequence which will distribute the stresses suitably so that they tend
to cancel each other out. See Figures 4-31 through 4-33 for various weld sequences. Choice of a suitable weld sequence
is probably the most effective method of overcoming distortion, although an unsuitable sequence may exaggerate it.
Simultaneous welding of both sides of a joint by two welders is often successful in eliminating distortion.
C. Restraint of Parts
Forcible restraint of the components being welded is often used to prevent distortion. Jigs, positions, and tack welds are
methods employed with this in view.
D. Presetting
It is possible in some cases to tell from past experience or to find by trial and error (or less frequently, to calculate)
how much distortion will take place in a given welded structure. By correct pre-setting of the components to be welded,
constructional stresses can be made to pull the parts into correct alignment. A simple example is shown in Figure 4-31.
E. Preheating
Suitable preheating of parts of the structure other than the area to be welded can be sometimes used to reduce distortion.
Figure 4-32 shows a simple application. By removing the heating source from b and c as soon as welding is completed,
the sections b and c will contract at a similar rate, thus reducing distortion.
Art # A-07707
Figure 4-31: Principle of Presetting
Art # A-07708
B
PreheatPreheat
Dotted lines show effect if no preheat is used
Weld
C
Figure 4-32: Reduction of Distortion by Preheating
Art # A-07709
Figure 4-33: Examples of Distortion
Art # A-07710_AB
1
Block Sequence.
The spaces between the welds are
filled in when the welds are cool.
2
3
Figure 4-34: Welding Sequence
Firepower MST 140i
Manual 0-5338 4-17 BASIC WELDING GUIDE
4.05 Stick (SMAW) Welding Troubleshooting
FAULT CAUSE REMEDY
1 Welding current
varying
ARC FORCE control knob is
set at a value that causes the
welding current to vary excessively with the arc length.
Reduce the ARC FORCE control knob until welding
current is reasonably constant while prohibiting the
electrode from sticking to the work piece when you
“dig” the electrode into the workpiece.
2 A gap is left by
failure of the weld
metal to fill the
root of the weld.
A Welding current too low A Increase welding current.
B Electrode too large for joint. B Use smaller diameter electrode.
C Insufficient gap. C Allow wider gap.
3 Non-metallic par-
ticles are trapped
in the weld metal.
A Non-metallic particles may
be trapped in undercut from
previous run.
A If a bad undercut is present clean slag bout and
cover with a run from a smaller gauge electrode.
B Joint preparation too re-
stricted.
B Allow for adequate penetration and room for clean-
ing out the slag.
C Irregular deposits allow slag
to be trapped.
C If very bad, chip or grind out irregularities.
D Lack of penetration with slag
trapped beneath weld bead.
D Use smaller electrode with sufficient current to give
adequate penetration. Use suitable tools to remove
all slag from comers.
E Rust or mill scale is prevent-
ing full fusion.
E Clean joint before welding.
F Wrong electrode for position
in which welding is done.
F Use electrodes designed for position in which
welding is done, otherwise proper control of slag is
difficult.
Art # A-07711_AB
4
3
2
1
Figure 4-35: Step back Sequence
Art # A-07428_AB
Figure 4-36: Chain Intermittent Welding
Art # A-07713_AB
Figure 4-37: Staggered Intermittent Welding
Firepower MST 140i
BASIC WELDING GUIDE 4-18 Manual 0-5338
FAULT CAUSE REMEDY
Insufficient Gap
Incorrect Sequence
Art # A-05866_AC
Figure 1- Example of insufficient gap or incorrect sequence
4 A groove has been
formed in the base
metal adjacent to
the toe of a weld
and has not been
filled by the weld
metal (undercut).
A Welding current is too high. A Reduce welding current.
B Welding arc is too long. B Reduce the length of the welding arc.
C Angle of the electrode is
incorrect.
C Electrode should not be inclined less than 45° to
the vertical face.
D Joint preparation does not
allow correct electrode angle.
D Allow more room in joint for manipulation of the
electrode.
E Electrode too large for joint. E Use smaller gauge electrode.
F Insufficient deposit time at
edge of weave.
F Pause for a moment at edge of weave to allow weld
metal buildup.
G Power Source is set for MIG
(GMAW) welding.
G Set Power Source to STICK (SMAW) mode.
5 Portions of the
weld run do not
fuse to the surface
of the metal or
edge of the joint.
A Small electrodes used on
heavy cold plate.
A Use larger electrodes and preheat the plate.
B Welding current is too low. B Increase welding current.
C Wrong electrode angle. C Adjust angle so the welding arc is directed more
into the base metal.
D Travel speed of electrode is
too high.
D Reduce travel speed of electrode.
E Scale or dirt on joint surface. E Clean surface before welding.
Art # A-05867_AC
Lack of
inter-run fusion
Lack of side fusion,
scale dirt, small electrode,
amperage too low
Lack of root fusion
Lack of fusion caused by dirt,
electrode angle incorrect,
rate of travel too high
Figure 2: Example of Lack of Fusion
Firepower MST 140i
Manual 0-5338 4-19 BASIC WELDING GUIDE
FAULT CAUSE REMEDY
6 Gas pockets or
voids in weld
metal (porosity)
A High levels of sulfur in steel. A Use an electrode that is designed for high sulfur
steels.
B Electrodes are damp. B Dry electrodes before use.
C Welding current is too high. C Reduce welding current.
D Surface impurities such as
oil, grease, paint, etc.
D Clean joint before welding.
E Welding in a windy environ-
ment.
E Shield the weld area from the wind.
F Electrode damaged ie flux
coating incomplete.
F Discard damaged electrodes and only use elec-
trodes with a complete flux coating.
7 Crack occurring in
weld metal soon
after solidification
commences
A Rigidity of joint. A Redesign to relieve weld joint of severe stresses or
use crack resistance electrodes.
B Insufficient throat thickness. B Travel slightly slower to allow greater build up in
throat.
C Weld current is too high. C Decrease welding current.
Not cleaned,
or incorrect
electrode
Slag
trapped in
undercut
Slag trapped in root
Art # A-05868_AC
Figure 3: Example of Slag Inclusion
8 The Stick elec-
trode is difficult to
run with multiple
arc-outs when
welding
The Stick electrode being
used is not suitable for use
with this machine.
Use E6013 or E7018 Stick electrodes for steel or
300 series stainless steel Stick electrodes for 300
series stainless steel.
Table 4-5: Welding Problems - Stick (SMAW)
Firepower MST 140i
BASIC WELDING GUIDE 4-20 Manual 0-5338
4.06 TIG (GTAW) Basic Welding Technique
Gas Tungsten Arc Welding (GTAW) or TIG (Tungsten Inert Gas) as it is commonly referred to, is a welding process in which
fusion is produced by an electric arc that is established between a single tungsten (non-consumable) electrode and the work
piece. Shielding is obtained from a welding grade shielding gas or welding grade shielding gas mixture which is generally
Argon based. A filler metal may also be added manually in some circumstances depending on the welding application.
Welds Made With or Without
Addition of Filler Metal
Work Piece
Can Be Any Commercial
Metal
Gas Cup
Either Ceramic,
High Impact or
Water Cooled
Metal
Inert Gas
Shields Electrode
and Weld Puddle
Tungsten Electrode
Non-Consumable
Art # A-10369_AB
Figure 4-38: TIG Welding Application Shot
Tungsten Electrode Current Ranges
Electrode Diameter DC Current (Amps)
0.040” (1.0mm) 30-60
1/16” (1.6mm) 60-115
3/32” (2.4mm) 100-165
1/8” (3.2mm) 135-200
5/32” (4.0mm) 190-280
3/16” (4.8mm) 250-340
Table 4-6: Current Ranges for Various Tungsten Electrode Sizes
Guide for Selecting Filler Wire Diameter
Filler Wire Diameter DC Current Range (Amps)
1/16” (1.6mm) 20-90
3/32” (2.4mm) 65-115
1/8” (3.2mm) 100-165
3/16” (4.8mm) 200-350
Table 4-7: Filler Wire Selection Guide
Firepower MST 140i
Manual 0-5338 4-21 BASIC WELDING GUIDE
Tungsten Electrode Types
Electrode Type
(Ground Finish)
Welding Application Features Color Code
Thoriated 2%
DC welding of mild
steel, stainless steel
and copper
Excellent arc starting,
Long life, High current
carrying capacity
Red
Zirconated 1%
High quality AC welding of aluminum,
magnesium and their
alloys.
Self cleaning, Long
life, Maintains balled
end, High current carrying capacity.
Brown
Ceriated 2%
AC & DC welding of
mild steel, stainless
steel, copper, aluminum, magnesium and
their alloys
Longer life, More
stable arc, Easier
starting, Wider current
range, Narrower more
concentrated arc.
Grey
Table 4-8
NOTE
The Firepower MST 140i is not suited for AC TIG welding.
Base Metal
Thickness
DC Current
for Mild
Steel
DC Current
for Stainless
Steel
Tungsten
Electrode
Diameter
Filler Rod
Diameter (if
required)
Argon Gas
Flow Rate
CFH
Joint Type
0.040”
1.0mm
35-45
40-50
20-30
25-35
0.040”
1.0mm
1/16”
1.6mm
10-15 Butt/Corner
Lap/Fillet
0.045”
1.2mm
45-55
50-60
30-45
35-50
0.040”
1.0mm
1/16”
1.6mm
10-15 Butt/Corner
Lap/Fillet
1/16”
1.6mm
60-70
70-90
40-60
50-70
1/16”
1.6mm
1/16”
1.6mm
15 Butt/Corner
Lap/Fillet
1/8”
3.2mm
80-100
90-115
65-85
90-110
1/16”
1.6mm
3/32”
2.4mm
15 Butt/Corner
Lap/Fillet
3/16”
4.8mm
115-135
140-165
100-125
125-150
3/32”
2.4mm
1/8”
3.2mm
20 Butt/Corner
Lap/Fillet
1/4”
6.4mm
160-175
170-200
135-160
160-180
1/8”
3.2mm
5/32”
4.0mm
20 Butt/Corner
Lap/Fillet
Table 4-9
TIG Welding is generally regarded as a specialized process that requires operator competency. While many of the principles
outlined in the previous Arc Welding section are applicable a comprehensive outline of the TIG Welding process is outside
the scope of this Operating Manual. For further information please refer to www.firepower.com or contact Firepower.
Firepower MST 140i
BASIC WELDING GUIDE 4-22 Manual 0-5338
4.07 TIG (GTAW) Welding Problems
FAULT CAUSE REMEDY
1 Excessive bead build up or
poor penetration or poor
fusion at edges of weld.
Welding current is too
low
Increase weld current and/or faulty joint
preparation.
2 Weld bead too wide and
flat or undercut at edges
of weld or excessive burn
through.
Welding current is too
high
Decrease weld current.
3 Weld bead too small or
insufficient penetration or
ripples in bead are widely
spaced apart.
Travel speed too fast Reduce travel speed.
4 Weld bead too wide or
excessive bead build up or
excessive penetration in
butt joint.
Travel speed too slow Increase travel speed.
5 Uneven leg length in fillet
joint
Wrong placement of
filler rod
Re-position filler rod.
6 Electrode melts or oxidizes
when an arc is struck.
A TIG Torch lead
connected to positive
welding terminal.
A Connect TIG Torch lead to negative welding
terminal.
B No gas flowing to weld-
ing region.
B Turn TIG Torch gas valve ON. Check the gas
lines for kinks or breaks and gas cylinder
contents.
C TIG Torch is clogged
with dust or dirt.
C Clean TIG Torch.
D Gas hose is cut. D Replace gas hose.
E Gas passage contains
impurities.
E Disconnect gas hose from the rear of Power
Source then raise gas pressure and blow out
impurities.
F Gas regulator turned off
or cylinder shut off.
F Turn on.
G TIG Torch valve is
turned off.
G Turn on.
H The electrode is too
small for the welding
current.
H Increase electrode diameter or reduce the
welding current.
I Power Source is set for
MIG welding.
I Set Power Source to LIFT TIG mode.
Firepower MST 140i
Manual 0-5338 4-23 BASIC WELDING GUIDE
FAULT CAUSE REMEDY
7 Dirty weld pool A Electrode contaminated
by contact with work
piece or filler rod material.
A Clean the electrode by grinding off the con-
taminates.
B Work piece surface has
foreign material on it.
B Clean surface.
C Gas contaminated with
air.
C Check gas lines for cuts and loose fitting or
change gas cylinder.
8 Poor weld finish Inadequate shielding
gas.
Increase gas flow or check gas line for gas
flow problems.
9 Arc start is not smooth. A Tungsten electrode is
too large for the welding current.
A Select the right size electrode. Refer to Table
4-7 Current Ranges for Various Tungsten
Electrode Size.
B The wrong electrode
is being used for the
welding job.
B Select the right electrode type. Refer to Table
4-9 Tungsten Electrode Types.
C Gas flow rate is too
high.
C Select the right rate for the welding job. Refer
to Table 4-10.
D Incorrect shielding gas
is being used.
D Select the right shielding gas.
E Poor work clamp con-
nection to work piece.
E Improve connection to work piece.
F Tungsten not properly
sharpened.
F Grind tungsten to proper shape.
10 Arc flutters during TIG
welding.
Tungsten electrode is
too large for the welding current.
Select the right size electrode. Refer to Table
4-7 Current Ranges for Various Electrode
Size.
11 Tungsten blackens due to
lack of shielding gas or
wrong shield gas.
A Gas valve on the TIG
Torch has not be turned
on.
A Turn on TIG Torch gas valve before you
commence welding.
B Gas cylinder valve off
or TIG Torch hose not
connected to regulator
B Turn on gas cylinder valve or connect TIG
Torch hose to regulator.
C Incorrect shielding gas
is being used.
C Select the right shielding gas.
Table 4-10: TIG (GTAW) Welding Problems
Firepower MST 140i
BASIC WELDING GUIDE 4-24 Manual 0-5338
This Page Intentionally Blank
Firepower MST 140i
Manual 0-5338 5-1 TROUBLE SHOOTING AND SERVICE
SECTION 5:
POWER SOURCE PROBLEMS AND ROUTINE SERVICE REQUIREMENTS
5.01 Power Source Problems
FAULT CAUSE REMEDY
1 Primary Power Supply is
ON, power indicator is illuminated however the Power
Source will not commence
welding when the torch trigger switch is depressed.
A Power Source is not in the correct
mode of operation.
A Set the Power Source to the cor-
rect mode of operation with the
process selection switch.
B Welding leads, or polarity cable
not connected.
B Connect welding leads or polar-
ity cable.
C Faulty torch trigger. C Repair or replace torch trigger
switch/lead.
2 Fault Indicator is illuminat-
ed and the Power Source
will not commence welding when the torch trigger
switch is depressed.
Duty cycle of Power Source has
been exceeded.
Leave the Power Source
switched ON and allow it to cool.
Note that fault indicator must
be extinguished prior to commencement of welding.
3 The Power Source will not
feed wire in MIG mode.
A Electrode wire stuck in conduit
liner or contact tip (burn-back
jam).
A Check for clogged / kinked MIG
Gun conduit liner, loose nozzle
or worn contact tip. Replace
faulty components.
B 8 pin gun connector not con-
nected.
B Connect 8 pin gun connector.
C Faulty torch trigger. C Repair or replace torch trigger.
D Wire tension too loose. D Tighten wire tension.
E Brake tension too tight. E Loosen brake tension.
4 Welding wire continues to
feed when torch trigger is
released.
A Trigger mode selection switch is in
4T latch mode.
A Change the trigger mode selec-
tion switch from 4T latch mode
to 2T normal mode.
B Torch trigger leads shorted. B Repair or replace torch trigger
switch/lead.
5 Welding arc cannot be
established in MIG mode.
A MIG Gun polarity lead is not
connected into a welding output
terminal.
A Connect the MIG Gun polar-
ity lead to either the positive
welding output terminal or the
negative welding output terminal
as required.
B Poor or no work lead contact. B Clean work clamp area and en-
sure good electrical contact.
6 Inconsistent wire feed. A Fouled contact tip. A Replace contact tip if necessary.
B Drive roll tension not tight enough. B Tighten drive roll tension.
C Worn feed roll. C Replace.
D Excessive brake tension on wire
reel hub.
D Reduce brake tension on spool
hub
E Worn, kinked or dirty conduit liner. E Clean or replace conduit liner
Firepower MST 140i
TROUBLE SHOOTING AND SERVICE
5-2 Manual 0-5338
FAULT CAUSE REMEDY
7 No gas flow in MIG mode. A Gas hose is damaged. A Replace or repair.
B Gas passage contains debris. B Disconnect gas hose from the
rear of Power Source and blow
out debris.
C Shielding gas cylinder valve shut
off.
C Turn on the cylinder.
D Flowmeter/ Regulator turned off. D Turn on flowmeter/ regulator.
E Empty gas cylinder. E Replace gas cylinder.
8 Gas flow continues after
the torch trigger switch has
been released (MIG mode).
Gas valve has jammed open due to
debris in the gas or the gas line.
Have an accredited Firepower
service provider repair or replace gas valve.
9 Power indicator will not
illuminate and welding arc
cannot be established.
The Electricity supply is inadequate.
Ensure that the Electricity Supply
voltage is within 95-140 VAC.
10 TIG electrode melts when
arc is struck.
TIG Torch is connected to the (+)
polarity terminal.
Connect the TIG Torch to the (-)
polarity terminal.
11 Arc flutters during TIG
welding.
Tungsten electrode is too large for
the welding current.
Select the correct size of tungsten electrode. Refer to Table
4-7.
Table 5-1
Firepower MST 140i
Manual 0-5338 5-3 TROUBLE SHOOTING AND SERVICE
5.02 Routine Service
WARNING
There are extremely dangerous voltage and power levels present inside this Power Source. Do not attempt to
open or repair unless you are an accredited Firepower Service Provider. Disconnect the Welding Power Source
from the Electricity Supply Voltage before disassembling.
Routine Inspection, Testing & Maintenance
The inspection and testing of the Power Source and associated accessories shall be carried out in accordance with Section
5 of EN 60974-1: Safety in Welding and Allied Processes-Part 2 Electrical. This includes an insulation resistance test and an
earthing test to ensure the integrity of the Power Source is compliant with Firepower's original specifications.
If equipment is to be used in a hazardous location or environments with a high risk of electrocution as outlined in EN 609741, then the above tests should be carried out prior to entering this location.
A. Testing Schedule
1. For transportable equipment, at least once every 3 months; and
2. For fixed equipment, at least once every 12 months.
The owners of the equipment shall keep a suitable record of the periodic tests and a system of tagging, including the
date of the most recent inspection.
A transportable Power Source is deemed to be any equipment that is not permanently connected and fixed in the position in which it is operated.
NOTE
Please refer to local guidelines for further information.
B. General Maintenance Checks
Welding equipment should be regularly checked by an accredited Firepower Service Provider to ensure that:
1. Flexible cord is of the multi-core tough rubber or plastic sheathed type of adequate rating, correctly connected
and in good condition.
2. Welding terminals are in suitable condition and are shrouded to prevent inadvertent contact or short circuit.
3. The Welding System is clean internally, especially from metal filing, slag, and loose material.
C. Accessories
Accessory equipment, including output leads, electrode holders, torches, wire feeders and the like shall be inspected
at least monthly by a competent person to ensure that the equipment is in a safe and serviceable condition. All unsafe
accessories shall not be used.
D. Repairs
If any parts are damaged for any reason, it is recommended that replacement be performed by an accredited Firepower
Service Provider.
Firepower MST 140i
TROUBLE SHOOTING AND SERVICE
5-4 Manual 0-5338
5.03 Cleaning the Welding Power Source
WARNING
There are dangerous voltage and power levels present inside this product. Do not attempt to open or repair unless you are a qualified electrical tradesperson. Disconnect the Welding Power Source from the Electricity Supply
Voltage before disassembling.
5.04 Cleaning the Feed Rolls
Clean the grooves in the drive rolls frequently. This can be done by using a small wire brush. Also wipe off, or clean the
grooves on the upper feed roll. After cleaning, tighten the feed roll retaining knobs.
CAUTION
Do not use compressed air to clean the Welding Power Source. Compressed air can force metal particles to lodge
between live electrical parts and earthed metal parts within the Welding Power Source. This may result in arcing
between this parts and their eventual failure.
5.05 Volt-Ampere Curves
Voltage-Amperage Curves shows maximum voltage and amperage output capabilities of welding power source. Curves of
other settings fall between curves shown.
Welding Current (Amps)
0102030405060708090 100 110 120 130 140 150
Output Voltage (Volts)
0
30
50
40
60
20
10
MIG (GMAW/ FCAW)
STICK (SMAW)
TIG (GTAW)
Fabricator 141i
Art # A-11807
Figure 5-1: Firepower MST 140i Volt-Ampere Curves
Firepower MST 140i
Manual 0-5338 6-1 KEY SPARE PARTS
SECTION 6: KEY SPARE PARTS
6.01 Firepower 140A MIG Gun Parts
Item
No.
Description Part No.
1 MST Nozzle**
MST Nozzle 3/8" Bore,
Flush
1444-0885
MST Nozzle 1/2" Bore,
Flush
1444-0886
MST Nozzle 5/8" Bore,
Flush
1444-0887
MST Nozzle Flux Cored 1444-0888
MST Spot Nozzle, 3/4" 1444-0889
2
MST Contact
Tip**
MST Contact Tip, .023" 1444-0890
MST Contact Tip, .030" 1444-0891
MST Contact Tip, .035" 1444-0892
MST Contact Tip, .045" 1444-0893
3
Handle /
Trigger Repair
Kit
4 Universal Conduit Liner* 1444-0883
5
Conductor Tube, Firepower Fusion
140A/180A/220A MIG Gun, 60 Deg
16201108
Table 6-1: Firepower 140A MIG Gun Parts
** Patent Pending
* Refer to Firepower Catalog No. ???? for additional options.
Torch Part No: 1444-0880
Art# A-12519
Figure 6-1
Firepower MST 140i
KEY SPARE PARTS 6-2 Manual 0-5338
6.02 Power Source
Art #
A-12518
31
Firepower MST 140i
Manual 0-5338 6-3 KEY SPARE PARTS
Figure 6-2
Firepower MST 140i POWER SOURCE SPARE PARTS
ITEM PART NUMBER DESCRIPTION
1 W7006216 PCB, Power, MST 140i
2 W7006227 PCB, Control, MST 140i
3 W7003033 Solenoid, Valve, 24VDC
4 W7006226 PCB, Remote Interface Integrated with Display, MST 140i
5 W7006209 Wiredrive Assy, w/ Motor, MST 140i
6 W7004906 Feedroll retaining thumb screw
7 7977036 Feed Roll .024(0.6mm)-.030"(0.8mm) V groove Installed
8 W7004947 Fan, 24VDC, 4.75"x4.75"x1", MST 140i
9 W7003010 Rectifier Bridge, 1000V, 50A
10 W7003215 Connector, Gas Inlet, 5/8"-18UNF
11 W7006210 Dinse, Socket, MST 140i
12 W7004983 Shoulder strap, MST 140i (not shown)
13 W7006224 Input Power Cable (not shown)
14 W7004942 Socket, 8 Pin, w/ Harness
15 W7003053 Switch, On/Off, 250V
16 W7004911 CT Sensor, Output, MST 140i
17 W7004912 Wire Hub Assy, MST 140i
18 1444-0933 Panel, Front FP MST 140i
19 1444-0935 Panel, Rear FP MST 140i
20 W7004922 Handle, MST 140i
21 1444-0936 Side and Top Panels (not shown)
22 EURO Adapter
23 W7004925 Guide, Inlet, .023-.045, MST 140i
24 W7004967 Guide, Outlet, .023-.045, MST 140i
25 1444-0937 Panel, Door, FP MST 140i (not shown)
26 1444-0934 Panel, Base, FP MST 140i
27 870734 Knob, 1/4" IDx.72" ODx.9" H
28 W7004972 Knob, 1/4" IDx1" ODx0.9" H
29 1444-0938 Panel, Front Control, FP MST 140i
30 W7004953 Push Button Actuator
31 OTWAK/1S Screw, Locking, MIG Gun
32 W7004961 Thermistor, NTC, K45 47K, MST 140i
33 W7004940 PCB Burnback Potentiometer
34
35
36
37 1444-0939 Label, Setup Chart - English Version, FP MST 140i, (not shown)
38 Label, Setup Chart, FP MST 140i, French (not shown)
39 W7006212 Inductor, MST 140i (not shown)
40 W7004951 Spool Hub, MST 140i
41 W7004943 Remote/Local Switch
42 W4017500 Dinse Adapter, 50mm- 25mm (not shown)
Firepower MST 140i
KEY SPARE PARTS 6-4 Manual 0-5338
Table 6-2
6.03 Hardware List
ITEM DESCRIPTION WHERE USED Qty
1 Nut Lock, M20 25mm Dinse 2
2 Screw Hexagon, M10 × 1.5-20 ST ZP 25mm Dinse 2
3 Washer, M4, ET Lock Handle 2
Side Panel 3
4 SC PHCR M4 × 0.7-10 ST ZP Handle 2
Rear Panel 2
Front Panel 3
Side Panel 3
Door Assy 2
5 SC PHCR M4 × 0.7-16 ST BK Front Panel 2
Rear Moulding 2
6 SC PHCR ST 6G × 3/8 STBK 8 Pin Remote Socket 2
Front PCB 4
7 Nut Hexagon M4 × 0.7 ST ZP Fan 4
8 SC PHSL M4 × 0.7-30 ST ZP Fan 4
9 Nut Hexagon M12 × 1.75 ST ZP Gas Adaptor Inlet 1
10 Washer Flat, 7.91 D (M8) Wirefeeder Plate 2
11 Washer Spring, 7.91 D Wirefeeder Plate 2
12 Screw Hexagon M8 × 1.25-30 ST ZP Wirefeeder Plate 2
13 Nut Hexagon M8 × 1.25 ST ZP Wirefeeder Plate 2
14 Screw Hexagon HD 9/32 × 16 ×19 Wirefeeder Plate 2
15 Screw Skt Set M4 × 0.7 Firepower No. 4 Torch Adaptor 1
16 Screw Hexagon M6 × 1.0-10 ST ZP Firepower No. 4 Torch Adaptor 1
17 Nut Hexagon M10 × 1. 5 ST ZP Firepower No. 4 Torch Adaptor 1
Table 6-3
Firepower MST 140i
Manual 0-5338 6-5 KEY SPARE PARTS
NOTE
All the hardware can be purchased from local store.
SCREW ITEM 4, OFF
USED TO SECURE
MOULDING TO INTERNAL
PANEL
SCREW ITEM 5, OFF USED
TO SECURE MOULDING TO
BASE PANEL
5
2
1
2
2
2
4
1
4
1
4
1
8
4
7
4
4
1
3
1
4
1
3
1
4
1
4
1
3
1
4
1
3
1
4
1
3
1
4
1
6
4
6
2
9
1
SCREW ITEM 5, 2 OFF USED
TO SECURE REAR MOULDING
TO BASE PANEL
SCREW ITEM 4, 2 OFF USED
TO SECURE DOOR ASSY TO
BASE PANEL
17
1
12
1111101
13
2
14
2
16
1
15
1
4
1
4
1
5
2
Art # A-12464
Figure 6-3
Firepower MST 140i
KEY SPARE PARTS 6-6 Manual 0-5338
This Page Intentionally Blank.
Firepower MST 140i
Manual 0-5338 1
APPENDIX
APPENDIX
This Page Intentionally Blank.
Firepower MST 140i
APPENDIX
2 Manual 0-5338
8
I
Art # A-12517
APPENDIX: Firepower MST 140i CIRCUIT DIAGRAM
Firepower MST 140i
Manual 0-5338 3
APPENDIX
Art # A-12517
FIREPOWER - LIMITED WARRANTY TERMS
LIMITED WARRANTY: Firepower®, Inc, A Victor Technologies Company, warrants to customers of its authorized
distributors hereafter “Purchaser” 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 Firepower products as stated
below, Firepower shall, upon notification thereof and substantiation that the product has been stored, installed,
operated, and maintained in accordance with Firepower’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 Firepower’s sole option, of any components or parts of the product
determined by Firepower to be defective.
Firepower 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: Firepower 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 Firepower 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 Firepower 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 Firepower 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 Firepower’S SOLE JUDGMENT MAY IMPAIR THE SAFETY OR PERFORMANCE OF ANY Firepower
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 Firepower delivered the product to the authorized distributor.
WARRANTY SCHEDULE
2 Years Parts* and Labor
* 2 years on the Original Main Power Transformer and Inductors not mounted on PC Boards.
* 2 years on Power Supply Components
2 Years Parts / No Labor
Auto-Darkening Welding Helmet (electronic Lens), ** 1 Month Harness Assy
Firepower Regulator for Firepower MST 220i (No labor)
90 days parts / No Labor
Remote Controls
MIG and TIG Torches (Supplied with power sources)
Replacement repair parts
Victor Technologies limited warranty shall not apply to:
Consumable Parts for MIG, TIG, Plasma welding, Plasma cutting and Oxy fuel torches, O-rings, fuses, filters or other
parts that fail due normal wear.
* Warranty repairs or replacement claims under this limited warranty must be submitted by an authorized Victor
Technologies repair facility within thirty (30) days of the repair.
* No employee, agent, or representative of Victor Technologies is authorized to change this warranty in any way or grant
any other warranty, and Victor Technologies shall not be bound by any such attempt. Correction of non-conformities,
in the manner and time provided herein, constitutes fulfillment of Victor Technologies’s obligations to purchaser with
respect to the product.
* This warranty is void, and seller bears no liability hereunder, if purchaser used replacement parts or accessories
which, in Victor Technologies's sole judgment, impaired the safety or performance of any Victor Technologies product.
Purchaser’s rights under this warranty are void if the product is sold to purchaser by unauthorized persons.
© 2012 Victor Technologies International, Inc. www.firepower.com Printed in China
THE AMERICAS
Denton, TX USA
U.S. Customer Care
Ph 1-800-426-1888 (tollfree)
Fax: 1-800-535-0557 (tollfree)
International Customer Care
Ph 1-940-381-1212
Fax: 1-940-483-8178
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Sales Office, Latin America
Ph 1-954-727-8371
Fax: 1-954-727-8376
Oakville, Ontario, Canada
Canada Customer Care
Ph 1-905-827-4515
Fax: 1-800-588-1714 (tollfree)
EUROPE
Chorley, United Kingdom
Customer Care
Ph +44 1257-261755
Fax: +44 1257-224800
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Customer Care
Ph +39 0236546801
Fax: +39 0236546840
ASIA/PACIFIC
Cikarang, Indonesia
Customer Care
Ph 6221-8990-6095
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Customer Care
Ph +603 6092-2988
Fax: +603 6092-1085
Melbourne, Australia
Australia Customer Care
Ph 1300-654-674 (tollfree)
Ph 61-3-9474-7400
Fax: 61-3-9474-7391
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Ph 61-3-9474-7508
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Sales Office
Ph +86 21-64072626
Fax: +86 21-64483032
Singapore
Sales Office
Ph +65 6832-8066
Fax: +65 6763-5812
U.S. Customer Care: 800-426-1888 / FAX 800-535-0557
Canada Customer Care: 905-827-4515 / FAX 800-588-1714
International Customer Care: 940-381-1212 / FAX 940-483-8178
INNOVATION TO SHAPE THE WORLD™
T ECHNOLOGIES
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