WIA TIGARC 140DC MC86-0 User manual

WELDING INDUSTRIES OF AUSTRALIA
A DIVISION OF WELDING INDUSTRIES LTD
ACN 004 547’ l l l
Head Office and International Sales
5 Allan Street, Melrose Park
South Australia, 5039
Telephone [phone] Facsimile [phone]
OWNERS MANUAL
TIGARC 140DC
MODEL
NO. MC86-0, REV. E
10195
QUALITY WELDING PRODUCTS, SYSTEMS AND SERVICE
4 5 ZL d

Page 2 TIGARC 140DC MANUAL
Theinformationcontained in thismanualissetouttoenableyou to properly
maintain your new equipment and ensure that you obtain maximum operating efficiency.
Please ensure that this information is kept in a safe place for ready reference when
required at any future time.
When requesting spare parts, please quote the serial number of the machine and if
possible, the partnumberof the itemrequired.
All relevantnumbersareshown in this
manual. Failure to supply this informationmayresult
in unnecessarydelays in supplying
the correct parts.
SAFETY
Before this equipmentisputintooperation,theSAFEPRACTICESsectionat the
back of the manual must be read completely. This will help to avoid possible injury due to
misuse or improper welding applications.
PLASTIC HANDLE
machine by hand only.
manner.
Please note that the handle fitted
to the TIGARC 140DC is intended for carrying the
DO NOT usethishandleforsuspendingormountingthemachine in anyother
CONTENTS
SECTION PAGE
1 ........................... Receiving ...................................................... .3
2,, ......................... Specifications.. .............................................. .4
3.. ......................... Connection To Mains .................................... .5
4.. ......................... Operation ...................................................... .5
5.. ......................... Maintenance .................................................. .8
6 ........................... Fault Finding ................................................. .8
7.. ......................... Service Information ........................................ 9
8... ........................ Parts Lists ..................................................... .IO
9.. ......................... Safe Practices. ............................................... 13
FIGURE PAGE
1 ........................... GTAW Welding .............................................. 5
2
........................... Connections For GTAW ................................. 6
3... ........................ Connections For MMAW .............................. ..7
4 ........................... MMAW Welding ............................................. 8
5 ........................... Circuit Diagram ............................................. .9
6 ........................... Power Source Assembly ............................... 11
6..
......................... GTAW Torch And Accessories ..................... .l2

I
i
TEGARC 140DC MANUAL Page 3
1. RECEIVING
Checktheequipment received against the shipping invoice to makesure the
shipment is complete andundamaged.
If anydamagehas occurred in transit,
please immediatelynotify your supplier.
I
The TIGARG 140DC carton contains:
W TIGARG140DC WeldingPowerSupply
D Sample pack of AUSTARC 12P and 13s electrodes
W (This)OwnersManual
The genuineWIA AA32 Acccessory Kit contains:
D Work leadwith spring ‘Work’clamp
W Electrode leadwith electrode holder
D Face shield
I
The genuineWIA AA47-0 AccessoryKit contains:
D 150 AmpGTAW torch
W Torch terminal adaptor
E Tungsten electrode, 2% thoriated
D Gas regulator and flowguage
W Gashoseassembly, 2 metre
o Heavy duty Worklead with spring ‘Work’ clamp.

Page 4 TIGARC 14cODC MANUAL
2. SPECIFICATIONS
INPUT VOLTAGE ........................................ 240 Volts AC 50 Hz
RATED INPUT CURRENT ........................... 12.5 Amps
MAXIMUM
SHORT CIRCUIT CURRENT ..... 34 Amps
MAXIMUM KVA REQUIREMENT
................ 8.2 kva
SUPPLY FLEXIBLE CABLE RATING ........... 15 Amps
APPROVALS NUMBER
............................... MC86/S221
OPEN CIRCUIT VOLTAGE
.......................... 44 Volts Max.
RATED OUTPUT CURRENT
GTAW
............................................... 105 A, 14 VDC, 25% Duty
52.5
A, 12 VDC, 100% Duty
MMAW
.............................................. IO0 A, 24 VDC, 25% Duty
50 A, 22 VDC, IOQ% Duty
WELDING CURRENT RANGE .....................
5 to 120 Amps
ELECTRODE RANGE
..................................
2.0 to3.2mm diameter
MASS ..........................................................
27 Kg
DIMENSIONS ..............................................
H 365mm(incl. handle),
W 240mm,
B 370mm
Duty Cycle is defined in Australian Standard AS1966.1 as the ratio of arcingtime to
5 minutes in any 5 minute period, expressed as a percentage.

TIGAR6 140DC MANUAL Page 5
3. CONNECTION PO ELECTRICAL MAINS POWER SUPPLY
The TIGARC 140DC is supplied with a 3 metre, 15 Amp Heavy Duty (30/0.25)
PVC mains power supply cable. This cable must only be connected to a correctly
installed
f5 Amp GPO (GeneralPurpose Outlet) . The plug and GPO are both
identified by a wide Earth pin, which is intended to prevent the
plug being inserted
into
a standard 10 Amp GPO . If it becomes necessaryto replacethe mains power
supply
cable, use only a cable with equivalentcurrent rating.
The recommended Supply
Fuse rating is 15 Amps.Due to peak current
requirements,the Electrical Mains supply to welding machines
is best protected by
a fuse.
A Circuit Breaker may trip frequently if used inthis application.
If it is necessaryto use an extension power supplycable, ensure that it is rated
for
a minimum of 15 Amps. Voltage drop over long lengths of cable will reduce the
maximumwelding current availablefrom the equipment.
4. OPERATION
The TIGARC: 140DC has outputs for two arc welding processes: Gas Tungsten
Arc Welding
(GTAW), and Manual MetalArc Welding (W.”).
GAS TUNGSTEN ARC WELDING
GTAW is a very clean welding method in which the welding arc is established
between a non-melting tungsten electrode and
the workpiece. The welding zone,
molten
weld metal and tungsten electrode are protected from Contamination by a
shield of inert
gas, usuallyArgon. The process can be used to fusion weld, ie. melt
the edges of the workpiece together without metalbeing added to the weld, or filler
metalmay
be fed intothe are by hand.
BUTT
JOINT
JOINT
OUTSIDE
JOINT
FtGURE 1. GAS TUNGSTEN ARC WELDING.

Page 6 PIGARC 140DC MANUAL
TheTIGARC 140DC is a Direct Current machine,and for GTAW the torch is
connected to the GTAW
(-) output terminal.Figure 2 illustrates the correct
connection of the welding torch and gas supply.
Tungsten electrodes for
DC GTAW should be 1 - 2% Thoriated. This type will
provide the best arc initiation, arc stability and tip shape retention characteristics.
Thoriated electrodes can be recognised by
a red coded end. The tungsten
electrode is ground to a point, with the grinding marks pointing towards the tip. Fqr
welding currents less than
20 amps, the included angle of the pojnt should be 30 ,
for currents greater than 20 amps, the recommended angle is 60 . When set in the
torch, the tungsten should protrude 12mmfrom the ceramic gas nozzle.
Before initial use of the welding torch, allow gas to purge the torch and hoses
for
5 minutes at approximately 10 litres/min. For welding purposes, the gas flow
rateshould
be set inthe range 2-5 litres/min.
To initiate the arc, the tungsten electrode should be touched preferably onto a
pieceofcopper adjacent to the workpiece, thenlifted in a smooth movement to
establish an arc length slightly larger than the diameter of the electrode. When the
arc
is stable, it can be transferred to the workpiece.
Useof a copper striking plate is recommended to avoid electrode
contamination. The electrode can also be contaminated by contact with the filler
rod.
A contaminatedelectrode producesan unstablearc.
GAS BOTTLE
FIGURE 2. CONNECTIONS FOR GTAW.

MANUAL METAL ARC WELDING.
MMAWis a welding process where an arc is struck between a flux-coated
consumable electrode and
the workpiece. The arc and the weld pool are both
shietded
by gases generatedfrom the coating of the electrode.The TIGARC 140DC
maybeused with 2,0mm,2.5mm, and 3.2mmdiameter welding electrodes. The
smallersizesareusedwhen welding at lower currents, such as sheet-metal
applications. tncreasing the electrode diameter permits higher welding currents to
be setected,
When using a DC (Direct Current) welding machine such as the TIGARC
140BC, it is important to select the electrode polarity in accordance with the
manufacturers’ recommendations for that electrode. Both methods
of connection
are shown inFigure
3 below.
W.I.A.manufacturesa wide range of mild steel and special purpose electrodes
which cater for home workshop, rural, and industrial requirements.Somepopular
AUSTARC electrodes are listed below. The correctly selected AUSTARC electrode
used in conjunctionwith the TIGARC
140D6 will provide a stable arc and high
quality weld deposit.
Austarc 12P, Classification
AS1553, E41 12.
A popular generalpurpose electrode used with ease in
all positions, vertical up or down. The smooth forceful
arcmakes it an ideal electrode for all general mild steel
applications. Preferredpolarity electrode positive.
Austarc 13S,Classification AS1553,
E41 13.
A smooth running electrode with a soft arc, particularly
suited to light sheetmetal and smooth mitre fillet welds.
Preferred polarity electrode positive.
Austarc 16TC, Classification
AS1553, €4816.
A low hydrogen electrode withgood arc stability and
out-of-positionwelding characteristics. This electrode
is
ideal for medium carbon steels,orsteels of unknown
analysis. Operateelectrode positive.
Unicord312, Classification AS2576, 1330-A3
A high tensile (770 MPa), high chromium nickel
electrode specially formulated for joining all alloy steels
and irons, and for tool
and die maintenance. Operate
electrode positive,

page 8 TIGARC 140DC MANUAL
To strike the arc, drag the end of the electrode along the workpiece as if
strikinga match. As the arc initiates,
lift the electrode slightly away, aiming to
establish an arc length of approximately 3mm.
As the electrode end is consumed,
feed the electrode into thearc in order to maintain a constant arc length. As a
generalrule, the arc should be held as short as possible while still giving stable
burn off and good weld appearance. An arc which is too long causes an unwieldy
flow
of metal with a rough weld apFearance and reduced penetration. An arc too
short leads to a narrow weld deposit and "stuttery" arc characteristic, and the
electrode is liable
to freeze onto the workpiece.
As the solidified weld deposit forms, move the end of the electrode slowly
along the weld path, aiming to maintaina
poot of moltenweld metal behind the arc.
Decreasing this rate
of travel will result in a wider weld deposit, and similarly
increasing
it will narrow the weld deposit. Always fit1 the crater which tends to form
at the endof a weld deposit, by pausing momentarily before withdrawing the
electrode to break the arc. Unfilled craters are a point of weakness, and can lead
toweld cracking.
onstantmolten pool widthmeans
ONSTANT beadwidth
StrikingthearcMaintainsteady
arc length 2
FIGURE 4. MANUAL METAL ARC WELDING.
5. MAINTENANCE
Care should be taken to prevent excessive build-up of dust and dirt within the
welding power source. It isrecommendedthat at regular intervals,according to the
prevailing conditions, the machine covers be removed and any accumulated dust
be removedby the use of dry, low pressurecompressedair, or avacuum cleaner.
6. FAULT FINDING, NOWELDING CURRENT
Check that Mains Supply is available at the TIGARC 140DC Power Source, i.e.
that the fan
is running. Check for continuity of the welding current circuit, i.e., work
lead,work clamp and electrode holder.
TheTIGARC
140DC welding power source incorporates an inbuilt protection
device which will trip if the unit is overloaded. In this event the machine will not
deliver welding current until the overload device hasbeenMANUALLYreset.The
overload device cannot be reset immediately after it has tripped. 8efore resetting,
establish and correct the causeof the overload condition. Thereset button is
located on the rear panel,just above the Supply Flexible Cableentry.
If equipment failure is suspected, forward the unit to yournearest WIASales
and ServiceBranch, or qualified serviceagent.

TIGARC 140DC MANUAL Page 9
7. SERVtCE INFORMATION.
The electrical components of the TIGARC 140DC are shown in the circuit
diagram below. The output
of the welding transformer is full-wave bridge rectified,
with the
GTAW output current smoothed by a DC inductance coil,
Primary voltage to the Welding Transformer is controlled
by means of a Triac
based phase shift circuit. Adjustment of the front panel potentiometer will vary the
open circuit output voltage
of the WeldingTransformer.
ACTWE
B"-----
NEUTRAL
AUXlLLlARY
TERMINAL
/ BLOCK
""""""""
"l
I RV1 I
CW RED
PRlMARY
OVERLOAD DEVICE
WELDING
MC84-0/3
TRANSFORMER TRANSFORMER
CP102-0/16
-VE
GTAW
AUXlLLlARY
RECTIFIER -VE
MMAW
CP38-31/5
+VE
WORK
CURRENT LIMITIN6 RESISTORS
MC82-15/10
FIGURE 5. TIGARC 140DC CIRCUIT DIAGRAM

page 10 TIGARC 140DC MANUAL
The TIGARC 140BC also includesan auxilliary transformer, rectifier, and
current limiting resistors.The current fromthese components maintainsthe GTAW
arc duringperiods when the triacisnotconducting. The printedcircuitboard
assembly provides the appropriate trigger
pulses to the Triac. As thiscircuit
incorporatesspecialized components,
it is not intendedto be repaired in the field,
Replacement assemblies obtained from
WIA are supplied complete with Priac and
Potentiometer.
Replacing the Triac requires removal
of the original partby first drilling out the
retainingpop-rivets. Clean
the mounting surface to removeswarf and any
remaining heat-sink compound. Alwaysapply clean heat-sink compound
tu the
new trimprior toassembly.
To correctly adjust the phase-shiftrange of a replacement circuit board:
I Rotate the Current Control potentiometer knobto the minimum current
I Disconnectthe red wire from the positiveterminal of the auxilliary rectifier
U Connect a DC Voltmeter to the welding output terminals "tve WORK" and
"-ve
MMAW".
I With theTIGARC energised, but not welding, adjust the potentiometer RV2
on the printed circuit boardto obtain 8 voltmeter reading of 12 volts.
Reconnect the redwire tothe positiveterminal of the auxilliaryrectifier.
position,(fully anti-clockwise).
(CP38-31/5).
8. PARTS LISTS
TIGARC 1408C POWER SOURCE
ITEM #.......PART# ...................... DESCRIPTION
1 .................. MC86-11 ................... PrintedCircuitAssembly
6P101-11 /8 ..............
Potentiometer
Includes
CPlOl-11/2 .............. Triac
2 .................. MC86-12 ...................
Transformer assembly
5..................SA140-0/1 ................
Handle
3 .................. MC86-l3 ...................
Base
4. ................. MC84-i 4 ................... Cover
6 .................. MC84-16 ...................
TerminalAssembly
7 .................. MC66-0/8 ................. Primary Flex and Plug
8 .................. CP27-U/15 ................
Fan and Motor
9..................CP101-0/19 ..............
Fan Finger Guard
10 ................. Wll-O/16 ..................
PotentiometerKnob
11 ................. MK6/4 ......................
Terminal Block
I2 ................. H390W ......................
Cup Terminal andWasher
13 ................. H285 .........................
EarthTab
15. ................ CP102-0/18 ............. .CircuitBoard Support
17 ................. WIP1199 ..................... tabel Set
18 ................. HF200-1/15 ..............
Foot
19 ................. MC84-0/3 .................
OverloadDevice
20 ................. MC84-0/2 .................
Cable Gland
21 ................. MC84-0/4 .................
Cable Gland Nut
22 ................. MC86-20 ...................
InductanceAssembly
23 ................. CP104-0/2 ................
RectifierAssembly
26 ................. MC82-15/10 ............. Resistor
includes
MCll-41/1 ............... Terminal Knob
24 ................ .W1 O2-0/16 .............. AuxilliaryTransformer
25 ................. CP38-31/5 ................
Diode Bridge

TiGARC 140DC MANUAL Page 1 1
ITEM 25 FITTED
0 J
I
/
ITEMS 12&13
FITTED INSIDE
BACK COVER
FIGURE 6. PIGARC 140DC POWER SOURCE ASSEMBLY

page 12 TIGARC 140DC MANUAL
GTAW TORCH AND ACCESSORIES
ITEM #.............PART #.....................DESCRIPTION
1 ................. CK1512VR ................ GTAW Torch, Rigid
Includes
1.1 .............. 300 M .........................
Mediumbackcap
1.2 .............. 300HS .......................
Heatshield
1.3 .............. 3C332 ....................... Collet
1.4 .............. 3CB332 ..................... Collet body
1.5
.............. 387 ...........................
Alumina Nozzle
1.6 .............. IOOVK ....................... Gas Valve
2 ................. TUNGTH2.4 ..............
2.4mm diam. 2%Thoriated Tungsten
3
................. CK15P6A ..................
Torch TerminalAdaptor
4 ................. AA4 7-0/1 .................. Gas Hose Assembly
5 ................. HA101-185 ................
Gas Regulator and flowgauge
FIGURE 7. GTAW TORCH AND ACCESSORIES

PIGARC 140DC MANUAL Page l3
9. SAFE PRACTICES WHEN USING WELDING EQUJPMENT
Thesenotesare provided in the interestsof improving operatorsafety.Theyshouldbeconsidered
only as a basic guide
to Safe Working Habits. A full list of Standards pertaining to industry is available from
the Standards Association of Australia, also various StateElectricity Authorities, Departments of Labour and
Industry
or Mines Department and other Local Health or Safety Inspection Authorities may have additional
requirements. WTlA TechnicalNoteTN7-98also provides acomprehensiveguide
to safe practicesin
welding.
EYE PROTECTION
NEVER LOOK AT AN ARC WITHOUT PROTECTION. Wear a helmet with safety goggles or glasses
with side shields underneath, with appropriatefilter lenses protected by clearcover lens. This is a MUST for
welding, cutting, and chipping
to protect the eyes from radiant energy and flying metal. Replace the cover
lens when broken, pitted, or spattered.
Recommended shade filter lens.
Amps TIG MMAW MIG Pulsed MIG
0-100 ............. IO .................. 9 ................... 10 ................. 12-13
100-150 ......... 11 .................. IO ................. 10 .................
12-13
150-200 ......... 12 .................. 10-11 ............ 11-12 ............
12-13
200-300 ......... 13 .................. 11 ................. 12-13 ............
12-13
300400 ......... 14 .................. 12 ................. 13 ................. 14
400-500 ............................ ” 13 ................. 14 ................. 14
500 +
................................................... ” ” 14 ................. 14
BURN PROTECTION.
Theweldingarc is intenseandvisiblybright. Its radiation can damageeyes,penetratelightweight
clothing, reflect from light-coloured surfaces, and burn the skin and eyes. Burns resulting from gas-shielded
arcs resemble acute sunburn, but can be moresevere and painful.
Wear protective clothing
- leatherorheatresistant gloves, hat,andsafety-toeboots.Buttonshirt
collar and pocket flaps, and wearcufflesstrousers
to avoid entry of sparksand slag.
Avoid oily or greasy clothing.
A spark may ignite them. Hot metal such as electrode stubs and work
pieces shouldnever be handled without gloves.
Ear plugsshouldbewornwhenweldinginoverheadpositions or in aconfinedspace.Ahardhat
should be worn when others are working overhead.
Flammable hair preparations shoutd not be used by persons intending
to weld or cut.
TOXIC FUMES.
Adequate ventilation with air is essential. Severe discomfort, illness or death can result from fumes,
vapours, heat,or oxygen depletion that weldingor cutting may produce. NEVERventilate with oxygen.
Lead, cadmium, zinc, mercury, and beryllium bearing and similar materialswhen welded or cut may
produce harmful concentrationsof toxic fumes,Adequatelocalexhaust ventilation must be used,oreach
person inthe area aswell as the operator must wear an air-supplied respirator. For beryllium, both must be
used. Metals coatedwithorcontaining materials that emit fumes shouldnotbeheatedunlesscoatingis
removedfrom the work surface, the areaiswell ventilated, or the operator wears an air-supplied respirator.
Work in a confined space only while itis being ventilated and, if necessary,while wearing air-supplied
respirator.

page 14 TIGARC140DC MANUAL
Work in a confined space only whileit is being ventilatedand, if necessary, while wearing air-
supplied respirator.
Vapours from chlorinatedsolvents can bedecomposed by the heat of thearc (orflame) toform
PHOSGENE, ahighlytoxic gas,and lung and eye irritatingproducts. The ultra-violet(radiant)
energy ofthe arc can alsodecomposetrichlorethylene and perchlorethylene vapors to form
phosgene.
Do notweld or cut where solvent vapors can be drawn intothewelding orcutting
atmosphere or where theradiant energy canpenetrate to atmospheres containing even minute
amounts of trichlorethylene or percholorethylene.
FIREAND EXPLOSION PREVENTION.
Be aware thatflying sparks or fallingslag can pass throughcracks,alongpipes,through
windows or doors, and through wall or flooropenings, out of sight ofthe operator. Sparks and slag
cantravel upto
10 metresfrom the arc.
Keep equipmentcleanandoperable,freeofoil, grease, and(inelectricalparts) af metallic
particles thatcan causeshort circuits.
If combustibles are present in the work area, do
NOT weld or cut. Movethe work if practicable,
toan areafree of combustibles. Avoid paintspray rooms,dip tanks,storage areas,ventilators. If the
work can notbe moved,movecombustibles atleast
10 metresawayoutof reach of sparksand heat;
or protect against ignition with suitableand snug-fitting fire-resistant covers or shields.
Wallstouching combustibles on oppositesides should not be welded onor cut. Walls, ceilings,
andfloor nearwork shouldbe protectedbyheat-resistantcoversor shields.
A person actingas FireWatcher must be standingbywith suitable fire extinguishingequipment
duringandfor some time after welding orcutting if;
D Combustibles(includingbuildingconstruction) arewithin 10 metres.
m Combustibles are furtherthan 10 metresbut can be ignited by sparks.
D Openings (concealedorvisible) infloorsorwallswithin 10 metres may expose
D Combustiblesadjacent to walls,ceilings,roofs, or metalpartitions can be ignited by
After work is done, check that area is free of sparks, glowing embers, andflames.
An tank or drumwhich has containedcombustibles can produceflammable vapors when
heated. Such acontainer must never be wetdedon or cut, unless
it has first been cleaned as
described in
AS. 1674-1 974, the S.A.A.Cutting and WeldingSafety Code. This includes a thorough
steamor caustic cleaning (or a solventor water washing, depending onthe combustible’s solubility),
followed by purgingand inerting with nitrogen
or carbon dioxide,and using protective equipmentas
recommended in
AS.1674-1974. Water-filling just below workinglevelmay substitute for inerting.
combustiblestosparks.
radiant or conducted heat.
Hollowcastingsorcontainersmustbe vented beforeweldingorcutting. They canexplode.
Neverweld or cut wherethe airmay contain flammable dust,gas, or liquidvapours.
SHOCK PREVENTION.
Exposed conductors or otherbare metal inthe welding circuit, or ungrounded electrically alive
equipment can fatallyshock a personwhose body becomesa conductor. Ensurethat themachineis
correctlyconnected and earthed. If unsure have machine installedbyaqualifiedelectrician. On
mobile or portable equipment, regularly inspect condition of trailing power leads and connecting
plugs. Repair or replacedamaged leads.
Fully insulated electrode holders should be used.
Bo not use holders with protruding screws.
Fully insulated lock-type connectors shouldbe usedto joinwelding cable lengths.
Terminals and otherexposedpartsofelectricalunitsshould have insulatedknobsor covers
secured before operation.