Tweco ARCMASTER 401S Operating Manual

ARCMASTER
401S

Operating
Manual

3163339

Art # A-12546_AB

Revision: AC Issue Date: November 11, 2014 Manual No.: 0-5345

Tweco.com

WE APPRECIATE YOUR BUSINESS!

Congratulations on receiving your new Tweco 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.

For more than 75 years Tweco has provided quality products you can trust, when your reputation is on
the line.

YOU ARE IN GOOD COMPANY!

Tweco 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 Tweco 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.Tweco.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 0-5345 for:
Tweco ArcMaster 401S Power Source Part Number W1009100

Published by:
Victor Technologies, Inc.
16052 Swingley Ridge Road,
Suite 300 St. Louis, MO 63017
USA

www.victortechnologies.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: April 25, 2014
Revision Date: November 11, 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 Principal Safety Standards .............................................................................. 1-6

1.03 Symbol Chart .................................................................................................. 1-7

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 ..................................................................................................... 2-2

2.05 User Responsibility ......................................................................................... 2-2

2.06 Transporting Methods ..................................................................................... 2-2

2.07 Packaged Items .............................................................................................. 2-2

2.08 Duty Cycle ....................................................................................................... 2-3

2.10 Specifications ................................................................................................. 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 Mains Supply Voltage Requirements .............................................................. 3-1

3.05 High Frequency Introduction .......................................................................... 3-3

3.06 High Frequency Interference ........................................................................... 3-4

3.07 Electromagnetic Compatibility ........................................................................ 3-4

3.08 ArcMaster 401S Power Source Controls, Indicators and Features .................. 3-6

3.09 Welding Parameters ...................................................................................... 3-10

3.10 Setup for TIG (GTAW) Welding ..................................................................... 3-12

3.11 Setup for STICK (SMAW) Welding .............................................................. 3-13

3.12 Special Function ........................................................................................... 3-15

3.13 Shielding Gas Flowmeter/ Regulator Operating Instructions ......................... 3-16

SECTION 4:

BASIC WELDING GUIDE ............................................................................ 4-1

4.01 Stick (SMAW) Basic Welding Technique ......................................................... 4-1

4.02 Stick (SMAW) Welding Troubleshooting ....................................................... 4-10

4.03 TIG (GTAW) Basic Welding Technique .......................................................... 4-12

4.04 TIG (GTAW) Welding Problems ..................................................................... 4-14

SECTION 5:

POWER SOURCE PROBLEMS AND ROUTINE SERVICE REQUIREMENTS .................... 5-1

5.01 Maintenance and Repair ................................................................................. 5-1

5.02 Power Source Status Messages ...................................................................... 5-2

5.03 Error Messages ............................................................................................... 5-2

5.04 Routine Inspection, Testing & Maintenance .................................................... 5-4

5.05 Cleaning the Welding Power Source ............................................................... 5-4

TABLE OF CONTENTS

SECTION 6:

KEY SPARE PARTS ................................................................................... 6-1

6.01 401S Power Source Spare Parts ..................................................................... 6-1

APPENDIX A: CIRCUIT DIAGRAM ........................................................................ A-1

TWECO - LIMITED WARRANTY TERMS ............................................iNSIDE REAR COVER

This Page Intentionally Blank

ARCMASTER 401S POWER SOURCE

!

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 European Standard EN60974-1 entitled: Safety in welding and allied processes
Part 2: Electrical. 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.

1.01 Arc Welding Hazards

5. Properly install and ground this equipment according
to its Owner’s Manual and national, state, and local
codes.

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 semi-automatic 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.

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.

Manual 0-5345 1-1 SAFETY INSTRUCTIONS AND WARNINGS

15. Keep all panels and covers securely in place.

ARCMASTER 401S POWER SOURCE

2. Wear approved safety glasses. Side shields
recommended.

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.

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.

AWS F2.2:2001 (R2010), Adapted with permission of the American Welding Society (AWS), Miami, Florida

Guide for Shade Numbers

Process

Shielded Metal Arc Welding
(SMAW)

Electrode Size in.

(mm)

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)

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,
flame-resistant material (wool and leather) and foot
protection.

5. Use approved ear plugs or ear muffs if noise level
is high.

6. Never wear contact lenses while welding.

Arc Current

(Amperes)

Less than 60

60-160
160-250
250-550

Minimum

Protective

Shade

7

8
10
11

Suggested*

Shade No.

(Comfort)

­10
12
14

Gas Metal Arc Welding (GMAW)
and Flux Cored Arc Welding
(FCAW)

Gas Tungsten arc Welding
(GTAW)

Air Carbon Arc Cutting (CAC-A)

Plasma Arc Welding (PAW)

Plasma Arc Cutting (PAC)

* 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.

(Light)

(Heavy)

Less than 60

60-160
160-250
250-550

Less than 50

50-150
150-500

Less than

500

500-1000

Less than 20

20-100
100-400
400-800

Less than 20

20-40
40-60
60-80

80-300
300-400
400-800

7
10
10
10

8

8
10

10
11

6

8
10
11

4

5

6

8

8

9
10

­11
12
14

10
12
14

12
14

6 to 8

10
12
14

4
5
6
8

9
12
14

SAFETY INSTRUCTIONS AND WARNINGS 1-2 Manual 0-5345

ARCMASTER 401S POWER SOURCE

3. Remove all flammables within 35 ft (10.7 m) of the
welding arc. If this is not possible, tightly cover them

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 vapours 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 from the weld area, the area is well
ventilated, and if necessary, while wearing an air­supplied respirator. The coatings and any metals
containing these elements can give off toxic fumes
if welded.

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 travelling 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

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.

Manual 0-5345 1-3 SAFETY INSTRUCTIONS AND WARNINGS

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.

ARCMASTER 401S POWER SOURCE

!

4. Never allow a welding electrode to touch any
cylinder.

5. Use only correct shielding gas cylinders, flowmeters/
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

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.

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.

2. Do not add fuel while smoking or if unit is near any
sparks or open flames.

3. Allow engine to cool before fuelling. If possible,
check and add fuel to cold engine before beginning
job.

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

4. Do not overfill tank — allow room for fuel to expand.

5. Do not spill fuel. If fuelling is spilled, clean up before
starting engine.

SAFETY INSTRUCTIONS AND WARNINGS 1-4 Manual 0-5345

STEAM AND PRESSURIZED HOT COOLANT
can burn face, eyes, and skin.

The coolant in the radiator can be very hot
and under pressure.

ARCMASTER 401S POWER SOURCE

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.

ABOUT PACEMAKERS:

3. Allow pressure to escape before completely
removing cap.

!

WARNING: This product contains chemicals, including
lead, known to the State of California to cause birth
defects and other reproductive harm.

after handling.

WARNING

Wash hands

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, OTA­BP-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.”

The above procedures are among those
also normally recommended for pacemaker
wearers. Consult your doctor for complete
information.

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.

Manual 0-5345 1-5 SAFETY INSTRUCTIONS AND WARNINGS

ARCMASTER 401S POWER SOURCE

1.02 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.

SAFETY INSTRUCTIONS AND WARNINGS 1-6 Manual 0-5345

ARCMASTER 401S POWER SOURCE

1.03 Symbol Chart

Note that only some of these symbols will appear on your model.

On

Off

Dangerous Voltage

Increase/Decrease

Circuit Breaker

AC Auxiliary Power

Fuse

Amperage

Voltage

Hertz (cycles/sec)

Frequency

X

%

Single Phase

Three Phase

Three Phase Static
Frequency Converter­Transformer-Rectifier

Remote

Duty Cycle

Percentage

Panel/Local

Shielded Metal
Arc Welding (SMAW)

Gas Metal Arc
Welding (GMAW)

Gas Tungsten Arc
Welding (GTAW)

Air Carbon Arc
Cutting (CAC-A)

Wire Feed Function

Wire Feed Towards
Workpiece With
Output Voltage Off.

Welding Gun

Purging Of Gas

Continuous Weld
Mode

Spot Weld Mode

Spot Time

t

t2

Preflow Time

Postflow Time

2 Step Trigger
Operation

t1

Press to initiate wirefeed and
welding, release to stop.

Negative

Positive

Direct Current (DC)

Protective Earth
(Ground)

Line

Line Connection

Auxiliary Power

115V 15A

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.

Receptacle Rating­Auxiliary Power

Constant Current

Constant Voltage
Or Constant Potential

High Temperature

Fault Indication

Arc Force

Touch Start (GTAW)

Variable Inductance

Voltage Input

V

Press and hold for preflow, release
to start arc. Press to stop arc, and
hold for preflow.

t

IPM

MPM

S

S

4 Step Trigger
Operation

Burnback Time

Inches Per Minute

Meters Per Minute

See Note

See Note

Art # A-04130_AB

Manual 0-5345 1-7 SAFETY INSTRUCTIONS AND WARNINGS

ARCMASTER 401S POWER SOURCE

This Page Intentionally Blank

SAFETY INSTRUCTIONS AND WARNINGS 1-8 Manual 0-5345

ARCMASTER 401S POWER SOURCE

!

SECTION 2:

INTRODUCTION

2.01 How To Use This Manual

To ensure safe operation, read the entire manual, includ­ing the chapter on safety instructions and warnings.

Throughout this manual, the words 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

A WARNING gives information regarding
possible personal injury.

CAUTION

A CAUTION refers to possible equipment
damage.

NOTE

A NOTE offers helpful information concern­ing certain operating procedures.

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 unit’s identification number (specification or part
number), model, and serial number usually appear on
a nameplate attached to the control panel. In some
cases, the nameplate may be attached to the rear panel.
Equipment which does not have a control panel such
as gun and cable assemblies is identified only by the
specification or part number printed on the shipping
container. Record these numbers on the bottom of page
ii 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.

Move the equipment to the installation site before
un-crating the unit. Use care to avoid damaging the
equipment when using bars, hammers, etc., to un-crate
the unit.

Manual 0-5345 2-1 INTRODUCTION

ARCMASTER 401S POWER SOURCE

2.04 Description

The Tweco ArcMaster 401S is a welding power source
incorporating to provide TIG, Stick and Gouging weld­ing process.

The units are also fully compliant to CSA E 60974-1
and UL 60974-1.

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
the unit.

2.05 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 Tweco.
Advice in this regard can be obtained by contacting an
Accredited Tweco Distributor.

2.06 Transporting 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.

2.07 Packaged Items

ArcMaster 401S Inverter Power Source (Part
No. W1009100)

• ArcMaster 401SInverterPower Sourcew/10ft

input power cable

• 50mm male Dinse connector × 2

• OperatingManual,English

• CD-OperatingManual(Eng/Fr/Sp)

This equipment or any of its parts should not be altered
from standard specification without prior written ap­proval of Tweco. 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 Tweco.

INTRODUCTION 2-2 Manual 0-5345

ARCMASTER 401S POWER SOURCE

100

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 is designed to
operate at a 40% duty cycle, 170 amperes at 26.8 volts. This means that it has been designed and built to provide
the rated amperage (170A) for 4 minutes, i.e. arc welding time, out of every 10 minute period (40% of 10 minutes
is 4 minutes). During the other 6 minutes of the 10 minute period the Welding Power Source must idle and be
allowed to cool. The thermal cut out will operate if the duty cycle is exceeded.

90

80

70

60

50

40

30

SAFE OPERATING REGION

20

Duty Cycle (PERCENTAGE)

10

3 phase

1 phase

0

0255075 100 125150 175 200 225 250 275 300 325350 375400 425 450 475 500

Art # A-12450

Welding Current (AMPS)

Figure 2-1: Duty Cycle

Manual 0-5345 2-3 INTRODUCTION

ARCMASTER 401S POWER SOURCE

2.10 Specifications

Description ArcMaster 401S

Power Source Part Number W1009100
Power Source Mass 51lb (23kg)
Power Source Dimensions 16.5"(H) x 8.3"(W) x 17.7(D)

H420mm x W210mm x D450mm
Cooling Fan Cooled
Welder Type Inverter Power Source
Output Terminal Type DinseTM 50
Standards CSA E 60974-1

UL 60974-1
Number of Phases 1/3 phase
Nominal Supply Voltage 208-230/460VAC (1 phase)

+/-15%
Nominal Supply Frequency 50/60Hz
Welding Current Range 10 - 300A (1 phase) 10 - 400A, (3 phase)
Effective Input Current (I1eff) (note2) 40A (208V, 1 phase)

38.1A (230V, 1 phase)
20A (460V, 1 phase)

Maximum Input Current (I1max) 84.7A (208V, 1 phase)

76.2A (230V, 1 phase)

40.1A (460V, 1 phase)

Generator Requirement (note4) 14.4kW
STICK (SMAW)
Welding Output, 40ºC, 10 min.

TIG (GTAW)
Welding Output, 40ºC, 10 min.

Open Circuit Voltage 80V DC
Protection Class IP23S

300A @ 22%, 32V (1 phase)

230A @ 60%, 29.2V (1 phase)

180A @ 100%, 27.2V (1 phase)

300A @ 25%, 22V (1 phase)

230A @ 60%, 19.2V (1 phase)

180A @ 100%, 17.2V (1 phase)

208-230/460VAC (3 phase)

+/-15%

26.6A (208V, 3 phase)

24.6A (230V, 3 phase)

14.3A (460V, 3 phase)

53.2A (208V, 3 phase)

49.1A (230V, 3 phase)

28.6A (460V, 3 phase)

400A @ 25%, 36V (3 phase)
300A @ 60%, 32V (3 phase)

220A @ 100%, 28.8V (3 phase)

400A @ 25%, 26V (3 phase)
300A @ 60%, 22V (3 phase)

220A @ 100%, 18.8V (3 phase)

INTRODUCTION 2-4 Manual 0-5345

Table 2-2: Specification

ARCMASTER 401S POWER SOURCE

NOTE

Note 1: Due to variations that can occur in manufactured products, claimed performance, voltages,
ratings, all capacities, measurements, dimensions and weights quoted are approximate only. Achiev­able capacities and ratings in use and operation will depend upon correct installation, use, applications,
maintenance and service.

Note 2: The Effective Input Current should be used for the determination of cable size & supply require­ments.

Note 3: Motor start fuses or thermal circuit breakers are recommended for this application. Check local
requirements for your situation in this regard.

Note 4: Generator Requirements at the Maximum Output Duty Cycle.

Due to large variations in performance and specifications of different brands and types of generators,
Tweco cannot guarantee full welding output power or duty cycle on every brand or type of generator.

Tweco recommends that when selecting a generator, that the particular power source / generator com­bination be adequately tested to ensure the combination performs to the users expectations.

Note 5: Tweco reserves the right to change product performance and specifications without notice.

Manual 0-5345 2-5 INTRODUCTION

ARCMASTER 401S POWER SOURCE

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INTRODUCTION 2-6 Manual 0-5345