WELDTECH WT140ARC User manual

OPERATING INSTRUCTIONS
WT140ARC
140A INVERTER ARC WELDER
www.weldtech.net.nz

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Congratulations on your new Weldtech product!
The Weldtech range from Euroquip uses latest technology design and engineering
to produce welding products that combine market leading value and features with
durability. Designed for discerning operators who seek professional results and
product quality without the price tag of a full professional setup. Design emphasis
is placed on simple, functional design and operation. Weldtech product is subject
to stringent quality control and designed and manufactured to NZ & Australian
standards.
Common use of Weldtech products include:
 • LightEngineering
 • Automotive
 • Home/hobbyEngineering
 • Farming
 • Maintenance&Repairs
Forindustrialweldingsolutions,checkouttheStratarangefromEuroquip:
www.strata.co.nz
Euroquip is a market leading provider of innovative power equipment solutions
to a wide range of industries across New Zealand and Australia. Key product
categories are; welding equipment, air compressors, power generators and
cleaning equipment.
Euroquip’s slogan is ‘empowering industries’, nd out more about the advantage
Euroquip brings at www.euroquip.co.nz.
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leading customer advantage focus. As part of this program, it is required for all
products to be registered with Euroquip to qualify for product support. Products
not registered with Euroquip are supported by a base 12 month warranty only.
Sparepartsandtechnicalsupportwillnotbeavailableforanunregisteredproduct
outside of this base warranty period. If a Euroquip dealer has not already registered
your product, please register it online at www.euroquip.co.nz. To request a physical
registration form, please contact Euroquip customer service on 0800 387 678.
We Appreciate Your Business!

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WT140ARC Welding Machine
www.weldtech.net.nz
Contents
Welcome to Euroquip..........................................2
KnowYourMachine..............................................5
QuickStartGuide....................................................6
Tips & Tricks.................................................................6
Accessories..................................................................6
Care&Maintenance..............................................6
MMA(Stick)BasicWeldingGuide..................7
Troubleshooting....................................................13
Knowledge&Resources....................................14
Safety.........................................................................14
Warranty....................................................................19

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Optional accessories to help you get the job done!
Cutting edge electronics help you weld like a pro
on home, workshop and on-site projects
Chipping Hammer
(#SPCH)
Welding Gloves
(#AWG02)
2 Sensor
Auto Helmet
(#DW2500)
Flip Front Helmet
(#AFF1000)
4 Sensor
Auto Helmet
with grind function
(#DW3000)
Welding Magnet
(#WMG05)
Powerful - 140A welding power up to 8mm steel thickness
Portable - Only 3.6kg super light weight and portable
Reliable - Cutting edge inverter technology ensures ultimate reliabilty
• Suitable for welding mild & high tensile steels
• Exceptionally smooth welding power
• Automatic ARC force and hot start for greater control and ease of use
• Electronically variable from 10 - 140A
• Extremely portable and convenient at only 3.6kg!
• High open circuit voltage
• Welds 1.6 - 3.2mm electrodes
• 60% Duty Cycle @100A
With 10A Plug - Ideal for home and workshop power supplies!
Dimensions: (L x W x H) 290 x 132 x 275mm
Weight: 3.6kg
Input Power: 230V, 10A
Max. Input Current: 21A
Generator Capacity: 5kVA
Output Power: 30 - 140A
Duty Cycle: 60% @ 100A
Electrode Size: 1.6 - 3.2mm
Output Socket: 16mm
WT140ARC
140A - INVERTER ARC WELDER

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WT140ARC Welding Machine
www.weldtech.net.nz
Know Your Machine
1. Overload indicator lamp*
2. Power indicator lamp
3. Current adjustment knob
4. Negative (-) welding power output
connection socket
5. Positive (+) welding power output
connection socket
1 2 3
4
5
* Overload indicator lamp -Lightswhendutycycle
is exceeded and thermal protection is activated.
When thermal protection is activated, welding out-
put will be disabled until machines cools suciently
and overload indicator lamp goes out. Also may
activate with inverter circuit failure issues.
6. 230V AC mains power input lead.
7. Mains power switch.
8. Cooling fan inlet.
67
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Quick Start Guide
Electrical Connection
TheWT140ARC is designed to operate on a stand-
ard 10A 230V AC power supply. If an extension cord
must be used, it should be no longer than 10m and
be a heavy duty version with a minimum cable core
of 2.0mm2. If an extension lead longer than 10m is
required, it is recommended to use a Euroquip indus-
trialduty15Aextensionlead,partnumber;#16895.
Operating Environment
Adequate ventilation is required to provide proper
coolingfortheWT140ARC.Ensurethatthemachine
is placed on a stable level surface where clean cool
aircaneasilyowthroughtheunit.TheWT140ARC
has electrical components and control circuit boards
which may be damaged by excessive dust and dirt,
so a clean operating environment is essential.
Basic Operation - ARC/ MMA
1.1 Connect the earth cable quick connector to the
negativeweldingpoweroutputsocket(4)Connect
the earth clamp to the work piece. Contact with
the work piece must be a rm contact, with clean
bare metal, with no corrosion, paint or scale at the
contact point.
1.2 Insert an electrode into the electrode holder and
connect the electrode holder and work lead to the
positiveweldingpoweroutputsocket(5).
NOTE: This polarity connection conguration is valid
for most GP (General Purpose) MMA electrodes. There
are variances to this. If in doubt, check the electrode
specications or consult the electrode manufacturer.
1.3 Connect the machine to suitable mains power
usingthemainsinputpowerlead(6).Switchthe
mainspowerswitch(7)to‘on’topowerupthe
machine.
1.4 Select the required output current using the
currentcontrolknob (3).Youarenowreadyto
weld!
Tips & Tricks
Duty Cycle Rating
Welding duty cycle is the percentage of actual weld-
ing time that can occur in a ten minute cycle. E.g.
15%at105amps-thismeanstheweldercanweldat
105ampsfor1.5minutesandthentheunitwillneed
toberestedfor8.5minutes.Alldutycycleratingsare
basedon an ambient air temperatureof 40°C with
50%humidity,whichistheinternationalstandardfor
such a rating.
In an environment with temperatures exceeding
40°C,thedutycyclewillbelessthanstated.Inam-
bienttemperaturelessthan40°C,dutycycleperfor-
mance will be higher.
Lift TIG Operation
The WT140ARC is not designed to be used for lift
TIGoperation,forliftTIG welding,theWT160MPor
WT200MPmodelsarerecommended.
Formoreusefultips&tricksonweldingorselecting
the right tool for the job, please visit www.euroquip.
co.nz
Accessories
Refer to page 3 for related accessories for this
machine.
Care &
Maintenance
Keep your Welding Machine in Top
Condition
TheWT140ARC does not require any special main-
tenance, however the user should take care of the
machine as follows:
• Regularlycleantheventilationslots.
• Keepthecasingclean.
• Checkallcablesbeforeuse.

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WT140ARC Welding Machine
www.weldtech.net.nz
• Checkelectrodeholders,worklead/clampsand
welding torches before use.
• Replacewornelectrodeholdersandearth
clamps, which do not provide a good
connection.
• Replacewornconsumablepartsinatimely 
manner.
• Useasoftclothorbrushtocleanelectrical 
components.
• Donotuseliquidcleaningproducts,wateror
especially solvents.
• Donotusecompressedairtocleanelectrical
components as this can force dirt and dust
further into components, causing electrical short
circuits.
• Checkfordamagedparts.Donotusethewelder
with damaged parts.
If damaged, before further use, the welder must be
carefully checked by a qualied person to determine
that it will operate properly. Check for breakage of
parts, mountings and other conditions that may
aect its operation.
Have your welder repaired by an expert. An
authorised service centre should properly repair a
damaged part.
This appliance is manufactured in accordance with
relevant safety standards. Only experts must carry
out repairing of electrical appliances, otherwise
considerabledangerfortheusermayresult.Useonly
genuine replacement parts. Do not use modied or
non-genuine parts.
Storing the Welder
When not in use the welder should be stored in the
dry and frost-free environment.
WARNING! Before performing cleaning/main-
tenance, replacing cables / connections , make
sure the welding machine is switched o and dis-
connected from the power supply.
MMA (Stick) Basic
Welding Guide
Size of Electrodes
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weld-
ingmachineswillonlyprovidecurrent(amperage)to
run smaller sized electrodes.
Forthinsections,itisnecessarytousesmallerelec-
trodes otherwise the arc may burn holes through the
job. A little practice will soon establish the most suit-
able 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 to the negative polarity
and is connected to the work piece. If in doubt con-
sult the electrode data sheet.
Eects of MMA(Stick) Welding
Various Materials
High Tensile and Alloy Steels
The two most prominent eects 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 underbead cracks in the weld
area may be reduced by using the correct electrodes,
preheating, using higher current settings, using larg-
er electrodes sizes, short runs for larger electrode de-
posits or tempering in a furnace.
Manganese Steels
The eect on manganese steel of slow cooling from
high temperatures causes embrittlement. For this
reason it is absolutely essential to keep manganese
steelcool during welding by quenching after each
weld or skip welding to distribute the heat.

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Cast Iron
Mosttypesofcastiron,exceptwhiteiron,areweld-
able. 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 classied into a number
of groups depending on their applications. There are
a great number of electrodes used for specialised in-
dustrial 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 encoun-
tered; are all easy to use.
MILD STEEL :
E6011 - This electrode is used for all-position welding or
for welding on rusty, dirty, less-than- new metal. It has
a deep, penetrating arc and is often the rst choice for
repair or maintenance work.
E6013 - This all-position electrode is used for welding
clean, new sheet metal. Its soft arc has minimal spatter,
moderate penetration and an easy-to-clean slag.
E7014 - All positional, ease to use electrode for use on
thicker steel than E6013. Especially suitable for sheet metal
lap joints, llet welds and general purpose plate welding.
E7018 - A low-hydrogen, all-position electrode used when
quality is an issue or for hard-to-weld metals. It has the ca-
pability of producing more uniform weld metal, which has
better impact properties at low temperatures.
CAST IRON:
ENI-CL -Suitableforjoiningallcastironsexceptwhite
cast iron.
STAINLESS STEEL:
E318L-16 -Highcorrosionresistances.Idealfordairy
work etc.
Electrodes for joining dierent metals:
Flat Position,
Down Hand Butt Weld
(Fig 1-11)
Flat Position,
Gravity Fillet Weld
(Fig 1-12)
Horizontal Position,
Butt Weld
(Fig 1-13)
Horizontal-Vertical
(HV) Position
(Fig 1-14)
Vertical Position,
Butt Weld
(Fig 1-15)
Vertical Position,
Fillet Weld
(Fig 1-16)
Overhead Position,
Butt Weld
(Fig 1-17)
Overhead Position,
Fillet Weld
(Fig 1-18)

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WT140ARC Welding Machine
www.weldtech.net.nz
Joint Preparations
In many cases, it will be possible to weld steel sec-
tions 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1-19.
Open Square Butt Joint
(Fig 1-19a)
Gapvariesfrom1.6mm(1/16”)
to4.8mm(3/16”)dependingonplatethickness
Single Vee Butt Joint
(Fig 1-19b) Notlessthan45°
Single Vee Butt Joint
(Fig 1-19c) Notlessthan70°
1.6mm(1/16”)max.
1.6mm(1/16”)
Double Vee Butt Joint
(Fig 1-19d) Notlessthan70°
1.6mm(1/16”)max.
1.6mm(1/16”)
Lap Joint (Fig 1-19e)
Fillet Joint (Fig 1-19f)
Corner Weld
(Fig 1-19g)
Tee Joints
(Fig 1-19h)
Edge Joint
(Fig 1-19i)
Plug Welds
(Fig 1-19j)

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Arc Welding Techniques
- A Word for 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6.0mmthick
and a 3.2mm electrode.
Clean any paint, loose scale or grease o the plate and
set it rmly on the work bench so that welding can
becarriedoutinthedownhandposition.Makesure
thattheWorkLead/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.
The Welder
Place yourself in a comfortable position before be-
ginning to weld. Get a seat of suitable height and
do as much work as possible sitting down. Don’t
hold your body tense. A taut attitude of mind and
a tensed body will soon make you feel tired. Relax
and you will nd that the job becomes much easier.
You can add much to your peace of mind by wearing
a leather apron and gauntlets. You won’t be worry-
ing then about being burnt or sparks setting alight
to your clothes.
Place the work so that the direction of welding is
across, rather than to or from, your body. The elec-
trode holder lead should be clear of any obstruction
so that you can move your arm freely along as the
electrode burns down. If the lead is slung over your
shoulder, it allows greater freedom of movement
andtakesalotofweightoyourhand.Besurethe
insulation on your cable and electrode holder is not
faulty; otherwise you are risking an electric shock.
Striking the Arc
Practice this on a piece of scrap plate before going
on to more exacting work. You may at rst experi-
ence diculty due to the tip of the electrode “stick-
ing”totheworkpiece.Thisiscausedbymakingtoo
heavy a contact with the work and failing to with-
draw the electrode quickly enough. A low amper-
age 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 1.6mm to
3.2mm gap between the burning electrode end and
the parent metal. Draw the electrode slowly along
as it melts down.
Another diculty you may meet is the tendency, af-
ter 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.
20o
1.6mm(1/16”)
Striking an Arc
(Fig 1-20)
Arc Length
The securing of an arc length necessary to produce a
neat weld soon becomes almost automatic. You will
nd 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, ir-
regular blobs. The weld bead is attened 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 elec-
trode tip being solidied 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 main-
tain 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 ad-
justed 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 individ-
ual globules. If the travel is too slow, the weld metal
piles up and the bead will be too large.