WIA TIGARC 150DC User manual

WELDING INDUSTRIES OF AUSTRALIA
A DIVISION OF WELDING INDUSTRIES LTD
ACN 004 547 l1 1
Head Office and International Sales
5 Allan Street, Melrose Park
South Australia,
5039
Telephone [phone]Facsimile [phone]
OWNERS MANUAL
TIGARC 150DC
MODEL NO. MC86-2, REV. C
220V/240VVERSION
10195
QUALITY WELDING PRODUCTS, SYSTEMS AND SERVICE
dw

Page 2 TJGARC 150DC MANUAL
Theinformationcontained in thismanual is setouttoenableyoutoproperly
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,thepartnumberoftheitemrequired.Allrelevantnumbersareshown in this
manual.Failuretosupplythisinformationmayresult in unnecessarydelays in supplying
the correct parts.
SAFETY
Before this equipment is putintooperation,theSAFEPRACTICESsectionatthe
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 handlefitted 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 ...................................................... 10
9.. ......................... Safe Practices. .............................................. .l3
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 ............................... l1
6. .......................... GTAW Torch And Accessories ..................... .l2

TiGARC 150DC MANUAL Page 3
1 RECEIVING
Check the equipment received against the shipping invoice to makesure the
shipment is complete and undamaged.
If any damage has occurred in transit,
please immediately notify your supplier.
l The TIGARC 150DC carton contains:
TIGARC 150DC Weldin Power Supply
Sample pack of AUSTA W C 12P and 13s electrodes
8 (This)Owners Manuaf
The genuine WIA AA32 AcccessoryKit contains:
I Worklead with sprin ‘Work’ clamp
Electrode
lead with e 7 ectrode holder
Face shield
The genuineW1A
AA47-0 AccessoryKit contains:
D 150 Amp GTAW torch
Torch terminaladaptor
Tungstenelectrode, 2% thoriated
B Gas regulator and ffowguage
II Gas hose assembly, 2 metre
a Heavyduty Work lead with spring ‘Work’ clamp.

2. SPECfFlCATIONS
INPUT VOLTAGE ........................................
220/240 Volts AC 50/60 Hz
RATED iNPUT CURRENT ...........................
14 Amps@220V, 12.5 Amps@24BV
MAXIMUM SHORT CIRCUIT CURRENT ..... 38 Amps@220V. 34 Amps@240V
MAXIMUM KVA
REQUIREMENT ................
8.2 kva
SUPPLY FLEXIBLE CA5L.E RATJNG ...........
15 Amps
OPEN CIRCUIT VOLTAGE .......................... 44 Volts Max.
RATED OUTPUT CURRENT
GTAW
................................................ 05 A, l4 VDC, 25% Duty
52.5 A, 12 Vac, 180% Duty
MMAW..
............................................ 100 A, 24 VDC, 25% Duty
50 A, 22 VDC, 100% Duty
WELDING
CURRENT RANGE ..................... 5 to 120 Amps
ELECTRODE
RANGE ..................................
2.0 to 3.2mm diameter
MAS$
.......................................................... 27 Kg
DIMENSIONS ..............................................
H 365mm(inci. handle),
W 240mm, D 370mm
Duty Cycle is defined in Australian Standard AS1966.1 as the ratio of arcing time to
5 minutes in any 5 minute period, expressed as a percentage.

TIGARC 150DC MANUAL Page 5
3. CONNECTION TO ELECTRICAL MAINS POWER SUPPLY
The WELDARC140 can be set for a supply voltage of either 220 or 240 volts
AC.
To adjust the supply voltage tapping, remove the machine cover, and
terminate the white wire in the appropriately marked connection point. The
machine isfactory set for 240 volts.
TherecommendedSupplyFuse rating
is 15 Amps.Due to peak current
requirements,the mainssupply towelding machines
is best protected bya fuse. A
Circuit Breaker may trip frequently
if used inthis application.
Themachine is supplied with
a 3 metre, 15 AmpHeavy Duty (30/0.25) PVC
mainspowersupply cable. If it becomesnecessary to replace the mainspower
supply cable,useonly
a cablewith equivalentcurrent rating.
4. OPERATION
GAS TUNGSTEN ARC WELDING
GTAW is a very clean welding method inwhich the welding arc is established
between a non-meltingtungsten 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 oftheworkpiece together without metalbeingadded tothe weld, or filler
metalmay befed into
the arc by hand.
BUTT
JOINT
LAP
JOINT
30°
FILLET
JOINT
FIGURE 1. GAS TUNGSTEN ARC WELDtNG.

The TIGARC 150DC is a DirectCurrentmachine, and for GTAW the torchis
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, withthe 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 recommendedangle is 60 . When set inthe
torch, the tungsten shouldprotrude
12mm from the ceramic gasnozzle.
Before initial use
of the welding torch, allow gas to purge the torch and hoses
for 5 minutesatapproximately 70 litres/min. Forweldingpurposes,thegasflow
rateshould
be set inthe range 2-5 litres/min.
To initiatethe arc, the tungsten electrode should be touched preferably onto a
piece of copperadjacent to theworkpiece, then lifted in a smoothmovement to
establish an arc length slightly larger than the diameter of the electrode. When the
arc isstable, it can be transferred to the workpiece.
Use of 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 unstable arc.
n
GAS 0OTTLE
& RESULATOR
GTAW ( - 1
CONNECTION
WORK ( $- )
CONNECTION
I l1
FIGURE 2. CONNECTIONS FOR GTAW.

TlGARC 150DC MANUAL Page 7’
MMAW is a welding processwhere an areisstruck between B flux-coated
consumable electrode
and the workpiece.The arc and the weld pool are both
shielded
by ases generated from the coating of the electrode. The TIGARC 150DC
may be use 8 with 2.0mm,2.5mm, and 3.2mm diameterweldingelectrodes.The
smallersizesareusedwhen welding atlowercurrents, such
as sheet-metal
applications. tncreasing the electrode drameter permits higher welding currents to
be selected.
When
using a DC (DirectCurrent) welding machinesuch as the TIGARC
150DC, it is important to selectthe electrode polarity in accordance with the
rnanufaeturers’ recommendationsfor that electrode. Both methods of connection
are shown inFigure
3 below.
Austarc 12P, Classification AS1553, E41 i2.
A populargeneralpurposeelectrodeused with ease in
all positions, vertical up or down. The smooth forceful
arc makes
it an ideal electrode for all general mild steel
applications. Preferredpolarityelectrode positive.
Austarc
13S, ClassificationAS1553, E41 13.
A smooth running electrode with a soft arc, particularly
suited to light sheetmetal
and smooth mitre fillet welds,
Preferred polarityelectrode positive.
Austarc
16K, Classification AS1553, E4816.
A IOW hydrogen electrode with good arc stability and
out-of-positionwelding characteristics.
This electrode is
ideal for medium carbon steels,orsteels of unknown
analysis. Operateelectrodepositive.
Unicord
312, Classification AS2576, 1330-A3
A high tensile (770 MPa), high chromium nickel
alectrade specially formulated for joining
all alloy steels
and irons, and fortoot and die maintenance.Operate
electrode positive.
R ELECTROUENEGATIVE ELECTRODE
POSITIVE
FIGURE 3.CONNECTIONS FOR MMAW.

Page 8 TIGARC f50DC MANUAL
To strike thearc,dragthe end of the electrode along theworkpiece as if
striking a match. As thearcinitiates, lift the electrode slightly away, aiming to
establish an arc length of approximately
3mm. As the electrode end is consumed,
feedtheelectrode into
the arc in arder to maintain a constant arclength. As a
generalrule,the arc shouldbe held as short as possiblewhile still giving stable
burn off and
good weld a pearance. An arc which is too long causes an.unwieldly
flow of metal with a roug R weld appearance and reduced penetration. An arc too
short leads to
a narrow weld deposit and"stuttery" arccharacteristic,andthe
electrode
is liableto freeze onto the workpiece.
As the solidified welddeposit forms, move the end of the electrodeslowly
along the weld path, aimingto maintaina
pool of moltenwetd metal behind the arc,
Decreasing this rate
of travel willresult in a wider weld deposit,andsimilarly
increasing
it will narrow the weld deposit. Always fill the crater which tendsto form
at the end of a welddeposit, by pausing momentarily before withdrawing the
electrode to break the arc. Unfilled craters are a point of weakness, and can lead
to weld cracking.
Striking the arc Maintainsteadyarc kngth d
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 is recommendedthat at regular intervals,according to the
prevailing conditions, the machine covers be removed and any accumulated dust
be removed by the use of dry, low pressure compressedair, or a vacuum cleaner.
6. FAULT FINDING, NO WELDING CURRENT
Check that Mains Supply is available at the T1GARC 150DC Power Source, i.e.
that the fan isrunning. Check forcontinuity of the welding current circuit,
i.e., work
lead, work
clamp andelectrode holder.
The
TIGARC 15ODC welding powersource incorporates an inbuilt protection
device which will
trip if the unit is overloaded. In this event themachine will not
deliver Welding current until the overload device has been MANUMY reset. The
overload device cannot be reset immediately after it has tripped. Before resetting,
establish and correct
the cause of the overload condition. Thereset buttonis
located on
the rear panel, justabovethe Supply Flexible Cable entry.
If equipment failure is suspected, forward the unit to yournearest WIA Sales
and Service Branch, orquaiifiedservice agent.

TIGARC 150DC MANUAL Page 9
7. SERVICE INFORMATION.
The electrical components of the TIGARC 150DC areshown 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 inductancecoil.
Primary voltage to the Welding Transformer is controlled by means
of a Triac
based phase shift circuit. Adjustment
of the front panel potentiometerwill vary the
open circuit output voltage of theWeldingTransformer.
-
-
-
ACTIVE
-
NEUTRAL
AUXILLIARY
TRANSFORMER
CPlO2-0116
AUXILLIARY
RECTIFIER
.
!I l- l
I L
L-J 'il""""" BTA40-6008 MC86-11 -
OVERLOADDEVICE
PRIMARY
MC84-013
PRlMARY
I
-VE
GTAW
INDUCTANCE
MC86-20
I SECONDARY I ,
MAIN
RECTIFIER
CPlO4-012
+VE
CURRENTLIMITINGRESISTORS
~~82-15110
FIGURE 5. TfGARC 150DC CIRCUIT DIAGRAM

page 10
TIGARC J50DC MANUAL
The TIGARC 150DC also includes an auxilliary transformer, rectifier,and
current limiting resistors.The current from these components maintainsthe GTAW
are during periods when the triac
is not conducting. The printedcircuitboard
assembly provides
the appropriate trigger pulses to the Triac. AS this circuit
incorporates specialized components,
it is not intendedto be repaired in the field.
Replacement assemblies obtained from WIA are supplied complete with Triac
and
Potentiometer.
Replacingthe Triac requires removal of the original part by first drilling out the
retaining pop-rivets. Clean the mounting surface to removeswarf and any
remaining heat-sink compound.Always apply clean heat-sink compound to the
new triac prior toassembly.
To correctlyadjustthe phase-shift rangeof a replacementcircuit board:
m Rotate the Current Control potentiometer knob to the minimum current
II Disconnect the red wire from the positive terminal of the auxilliary rectifier
U Connecta DC Voltmeter to the welding output terminals "+VB WORK" and
"-veMMAW".
P With the PIGARC energised, but not welding, adjust the potentiometer RV2
on the printed circuit boardto obtain a voltmeter reading of 12 volts.
U Reconnectthe redwire to the positive terminal of the auxilliaryrectifier.
position, (fully anti-clockwise).
(CP38-31/5).
8. PARTS LISTS
TlGARC 150DC POWER SOURCE
ITEM -#........PART# ......................
DESeRIFSPION
1 .................. MC864 1 ...................
PrintedCircuitAssembly
CP101-11/8 ..............
Potentiometer
CPlO1-11/2 .............. Triac
Includes
2..................MC86-23...................Transformer Assembly (220J240V)
4 .................. MC84-14 ................... Cover
6 .................. MC84-16 ................... TerminalAssembly
3 .................. MC86-13 ................... Base
5..................SA140-0/1 ................ Handle
Includes
MCI1-41/1 ............... TerminalKnob
7 .................. MC66-Q/8 ................. Primary Flex and Plug
8..................CP27-0/15 ................ Fan and Motor
9..................CP101-0/17 .............. Fan Finger Guard
10 ................. W1 1-0/16 .................. PotentiometerKnob
11 ................. MK6/4 ...................... TerminalBlock
12 ................. H390W ...................... CupTerminaland Washer
13 ................. H285 ......................... EarthTab
15 ................. CP102-0/18 .............. Circuit Board Support
17 ................. WIN199 labe^ labe^ be^ Set
I8 ................. HF200-1 75 .............. Foot
19 ................. MC84-0 / 3 ................. OverloadDevice
21 ................. MC&4-0/4 .................
CableGland Nut
24 ................. CP102-0/16 ..............
AuxilliaryTransformer
26 ................. MC82-15/10 .............
Resistor
31 ................. MC84-24 ...................
Heatsinkto suit 220/240V
20 ................. MC84-0/2 ................. CableGland
22 ................. MC86-20 ...................
InductanceAssembly
23 ................. CP104-0/2 ................
RectifierAssembly
25 ................. eP38-31/5 ................
Diode Bridge