WIA WELDMATIC 350 User manual

WELDING.COM.AU
From serial numbers C1442A*/C1452A*
MIG &
Multi-Process
Welders
OPERATORS MANUAL
CP144-1, CP145-1

32
WELDING INDUSTRIES
AUSTRALIA
A Division of ITW Australia Pty Ltd
ABN: 63 004 235 063
1300 300 884
Email: [e-mail]
welding.com.au
WELDWELL
NEW ZEALAND
A Division of ITW New Zealand
NZBN: 9 429 039 833 129
GST NO: 080177186
0800 9353 9355
Email: [e-mail]
weldwell.co.nz

32
CONTENTS
Section General Information Page
Safe Practices 4
1 Introduction 7
2 Receiving 8
3 Specifications 9
4 Controls 10
5 Installation 12
6 Normal Welding Sequence 14
7 Basic Welding Information 14
8 General Maintenance 20
9 External Trouble Shooting 21
10 Trouble Shooting Chart 22
11 Service Information 25
11.1 Circuit Diagram 26
12 Assembly & Parts Lists
12.1 Power Source 27
12.2 Welding Torch 350 29
12.3 Welding Torch 500 30
13 Australian Warranty
Information 32
14 New Zealand Warranty
Information 34

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
54
READ FIRST
The information contained in this
manual is set out to enable you
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 ordering spare parts, please
quote the model and serial number
of the power source and part number
of the item required. All relevant
numbers are shown in lists contained
in this manual. Failure to supply this
information may result in unnecessary
delays in supplying the correct parts.
SAFETY
Before this equipment is put into
operation, please read the Safe
Practices section of this manual.
This will help to avoid possible injury
due to misuse or improper welding
applications.
PLASTIC HANDLES ON
POWER SOURCE
Please note that the handles fitted
to the Weldmatic power source are
intended for carrying the equipment
by hand only.
DO NOT use these handles for
suspending or mounting the power
source in any other manner.
SAFE PRACTICES WHEN USING
WELDING EQUIPMENT
These notes are provided in the interests
of improving operator safety. They should
be considered 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 State Electricity Authorities,
Departments of Labour and Industry or
Mines Department and other Local Health
or Safety Inspection Authorities may have
additional requirements. Australian Standard
AS1674.2 provides a comprehensive guide
to safe practices in welding.
Eye Protection
NEVER LOOK AT AN ARC WITHOUT
PROTECTION. Wear a helmet with safety
goggles or glasses with side shields
underneath, with appropriate filter lenses
protected by clear cover 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 10 9 10 12-13
100-150 11 10 10 12-13
150-200 12 10-11 11-12 12-13
200-300 13 11 12-13 12-13
300-400 14 12 13 14
400-500 — 13 14 14
500 + — — 14 14

54
Burn Protection
The welding arc is intense and visibly bright.
Its radiation can damage eyes, penetrate
light-weight clothing, reflect from light-
coloured surfaces, and burn the skin and
eyes. Burns resulting from gas-shielded
arcs resemble acute sunburn, but can be
more severe and painful.
Wear protective clothing – leather or heat
resistant gloves, hat, and safety-toed boots.
Button shirt collar and pocket flaps, and
wear cuff less trousers to avoid entry of
sparks and slag.
Avoid oily or greasy clothing. A spark may
ignite them. Hot metal such as electrode
stubs and work pieces should never be
handled without gloves.
Ear plugs should be worn when welding in
overhead positions or in a confined space.
A hard hat should be worn when others are
working overhead.
Flammable hair preparations should 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 welding or cutting may
produce. NEVER ventilate with oxygen.
Lead, cadmium, zinc, mercury, and
beryllium bearing and similar materials
when welded or cut may produce harmful
concentrations of toxic fumes. Adequate
local exhaust ventilation must be used,
or each person in the area as well as
the operator must wear an air-supplied
respirator. For beryllium, both must be used.
Metals coated with or containing materials
that emit fumes should not be heated
unless coating is removed from the work
surface, the area is well ventilated, or the
operator wears an air-supplied respirator.
Work in a confined space only while it is
being ventilated and, if necessary, while
wearing air-supplied respirator.
Vapours from chlorinated solvents can
be decomposed by the heat of the arc (or
flame) to form phosgene, a highly toxic
gas, and lung and eye irritating products.
The ultra-violet (radiant) energy of the arc
can also decompose trichlorethylene
and perchloroethylene vapours to form
phosgene. Do not weld or cut where solvent
vapours can be drawn into the welding or
cutting atmosphere or where the radiant
energy can penetrate to atmospheres
containing even minute amounts of
trichlorethylene or perchloroethylene.
Fire and Explosion Prevention
Be aware that flying sparks or falling slag
can pass through cracks, along pipes,
through windows or doors, and through
wall or floor openings, out of sight of the
operator. Sparks and slag can travel up to
10 metres from the arc.
Keep equipment clean and operable, free of
oil, grease, and (in electrical parts) of metallic
particles that can cause short circuits.
If combustibles are present in the work
area, do NOT weld or cut. Move the
work if practicable, to an area free of
combustibles. Avoid paint spray rooms, dip
tanks, storage areas, ventilators. If the work
can not be moved, move combustibles at
least 10metres away out of reach of sparks
and heat; or protect against ignition with
suitable and snug-fitting fire-resistant
covers or shields.

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
76
Walls touching combustibles on opposite
sides should not be welded on or cut. Walls,
ceilings, and floor near work should be
protected by heat-resistant covers or shields.
A person acting as Fire Watcher must be
standing by with suitable fire extinguishing
equipment during and for some time after
welding or cutting if;
– Combustibles (including building
construction) are within 10 metres.
– Combustibles are further than 10
metres but can be ignited by sparks.
– Openings (concealed or visible) in
floors or walls within 10 metres may
expose combustibles to sparks.
– Combustibles adjacent to walls,
ceilings, roofs, or metal partitions can
be ignited by radiant or conducted heat.
After work is done, check that area is free
of sparks, glowing embers, and flames.
A tank or drum which has contained
combustibles can produce flammable
vapours when heated. Such a container
must never be welded on or cut, unless
it has first been cleaned as described in
AS.1674-2. This includes a thorough steam
or caustic cleaning (or a solvent or water
washing, depending on the combustible’s
solubility), followed by purging and inerting
with nitrogen or carbon dioxide, and using
protective equipment as recommended in
AS.1674-2. Water-filling just below working
level may substitute for inerting.
Hollow castings or containers must be vented
before welding or cutting. They can explode.
Never weld or cut where the air may contain
flammable dust, gas, or liquid vapours.
Shock Prevention
Exposed conductors or other bare metal
in the welding circuit, or ungrounded
electrically alive equipment can fatally
shock a person whose body becomes
a conductor. Ensure that the equipment
is correctly connected and earthed. If
unsure have the equipment installed by a
qualified electrician. On mobile or portable
equipment, regularly inspect condition of
trailing power leads and connecting plugs.
Repair or replace damaged leads.
Fully insulated electrode holders should be
used. Do not use holders with protruding
screws. Fully insulated lock-type connectors
should be used to join welding cable lengths.
Terminals and other exposed parts of
electrical units should have insulated knobs
or covers secured before operation.
IMPORTANT NOTICE: Warranty may
be voided if equipment is powered
from an unsuitable engine driven
generator.
Generators used to power
this equipment must have the
recommended minimum capacity and
incorporate output voltage regulation.
Due to variation between generators
by different manufacturers, it is
impossible for WIA to validate
operation from all generators.
Therefore, we recommend that
operation of equipment on the
generator is received from the
manufacturer before purchasing the
generator.

76
1 INTRODUCTION
The Weldmatic is a multi-process welding
machine capable of Gas Metal Arc Welding
(GMAW or MIG), Manual Metal Arc Welding
(MMAW or Stick) and Gas Tungsten Arc
Welding (GTAW or TIG).
GMAW (MIG Welding)
Gas Metal Arc Welding (GMAW) is an arc
welding process where a consumable wire
is fed by motor driven feed rolls to a welding
gun, and where welding current is supplied
from the welding power source. The welding
arc is struck between the work piece and
the end of the wire, which melts into the
weld pool. The arc and the weld pool are
both shielded by gas flow from the gun, or
in the case of self-shielded wires, by gases
generated by the wire core.
The process is very versatile in that by
selection of the correct wire composition,
diameter and shielding gas, it can be used
for applications ranging from sheet-metal
to heavy plate, and metals ranging from
carbon steel to aluminium alloys.
The Weldmatic has been designed to be
used with consumable wires of different
diameter. The smaller wire sizes are used
when welding at lower currents, such as
sheet-metal applications. Increasing the
wire diameter permits higher welding
currents to be selected.
A common application of GMAW is for
welding Mild Steel. In this application, a
Mild Steel solid consumable wire such as
AUSTMIG ES6 is used with a shielding gas
of Carbon Dioxide, or Argon mixed with
Carbon Dioxide. Alternatively, Flux-cored
consumable wires are available in both gas
shielded, and ‘gasless’ self shielding types.
Stainless steel and Aluminium can be
welded with GMAW using the correct
consumable wire and shielding gas.
The Weldmatic wirefeeder has been
designed to feed a range of hard, soft, and
flux-cored wires for the GMAW process.
A compact motor with integral gear box is
coupled to a two roll drive assembly forming
the basic component of the wirefeeder. The
motor is controlled by an electronic speed
control which provides speed regulation.
MMAW (Stick Welding)
Manual Metal Arc Welding (MMAW) is a
process where an arc is struck between a
flux-coated consumable electrode and the
work piece. The arc and the weld pool are
both shielded by gases generated by the
flux coating of the electrode.
The Weldmatic 350/500 has been
designed to be used with 2.0mm, 2.5mm,
3.2mm, 4.0mm and 5.0mm diameter
electrodes. The smaller electrodes are
used when welding at lower currents, such
as sheet metal applications. Increasing the
electrode diameter permits higher welding
currents to be selected.
WIA supplies a wide range of mild steel and
special purpose electrodes which cater
for home workshop, rural, and industrial
requirements. Some popular AUSTARC
electrodes are listed below. The correctly
selected AUSTARC electrode will influence
the quality of the weld, and the stability
of the arc.
Austarc 12P, Classification E4313-A
A popular general purpose electrode
used with ease in all positions, vertical up
or down. The smooth forceful arc makes it
an ideal electrode for all general mild
steel applications.

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
98
Austarc 13S, Classification E4313-A
A smooth running electrode with a soft arc,
particularly suited to light sheet metal and
smooth mitre fillet welds.
Austarc 16TC, Classification E4916-A
A low hydrogen electrode with good
arc stability and out-of-position welding
characteristics. This electrode is ideal
for medium carbon steels, or steels of
unknown analysis.
Unicord 312, Classification ES312-16
A high tensile (50tsi), chromium nickel
electrode specially formulated for joining
all alloy steels and irons, and for tool and
die maintenance.
GTAW (TIG Welding)
Gas Tungsten Arc Welding (GTAW) is a
welding process where the arc is struck
between a non-consumable tungsten
electrode and the work piece. A ceramic
nozzle surrounds the tungsten electrode
and directs a flow of inert gas, usually Argon,
over the electrode and the weld zone. If
filler metal is required, it is hand fed into
the welding arc. The DC current output of
the Weldmaticis suitable for welding most
ferrous and non-ferrous metals, but is not
suitable for welding Aluminium for which an
AC machine is required.
2 RECEIVING
Check the equipment received against the
shipping invoice to make sure the shipment
is complete and undamaged. If any damage
has occurred in transit, please immediately
notify your supplier.
The Weldmatic 350 package contains:
– CP144-2 Weldmatic 350 power source.
– Argon gas regulator.
– Gas Hose
– Welding torch – 300 AMP fitted with
Bernard 0.9 centre fire tip
– Work lead and spring clamp - 10m
x 35mm2 cable with large twist lock
connector.
– W67-0 wire feeder with 4 roll drive.
– Feed roller V0.9/1.2mm with V groove
quantity 2 fitted
– Feed roller V0.9/1.2mm with teeth
(knurled) quantity 2 spare
– Composite lead 35mm2 10m
– AM358 trolley with drawers
– Owners Manual CP145-40
The Weldmatic 500 package contains:
– CP145-2 Weldmatic 500 power source.
– Argon gas regulator
– Gas Hose
– Welding torch - 400amp fitted with
0.9mm Bernard centre fire tip
– Work lead and clamp - 10m x 50mm2
cable terminated with G clamp
– W67-0 wire feeder with heavy duty
4 roll drive
– Feed roller V0.9/1.2mm with V groove
quantity 2 fitted
– Feed roller V0.9/1.2mm with teeth
(knurled) quantity 2 spare
– COMPOSITE LEAD 50mm2 10m
– AM358 Trolley with drawers
– Owners Manual CP145-40
Optionally available
– TIG Torch Complete TIG002, 4m cable
with twist-lock connection and fitted
with 2.4mm collet. Manual Gas valve on
hand piece

98
3 SPECIFICATIONS
350 500
Manufactured to Standards AS60974.1 IEC60974.10 AS60974.1 IEC60974.10
Rated Input Voltage 380 – 415V 3 Phase 380 – 415V 3 Phase
Power Frequency 50/60 Hz 50/60 Hz
Generator Three Phase Capacity 32KVA 47KVA
Rated Maximum
Supply Current Imax
26A 42A
Maximum Effective
Supply Current Ieff
20A 32.5A
Output No Load Voltage 66V 75V
VRD Safe 7. 5 V 7. 5 V
MIG GMAW
350Amp @ 31.5V 60% Duty 500Amp @ 39V 60% Duty
271Amp @ 27.6V 100% Duty 387Amp @ 33.4V 100% Duty
Stick MMA
350Amp @ 34V 60% Duty 500Amp @ 40V 60% Duty
271Amp @ 30.8V 100% Duty 387Amp @ 35.5V 100% Duty
TIG
350Amp @ 24V 60% Duty 500Amp @ 30V 60% Duty
271Amp @ 20.8V 100% Duty 387Amp @ 25.5V 100% Duty
Spool Size ES6 – 5kg & 15kg ES6 – 5kg & 15kg
Supply Plug 32A 32A
Supply Cable 2.5mm2 3 Core + E Heavy
Duty PVC
4.0mm2 3 Core + E Heavy
Duty PVC
Mains Circuit Breaker Rating 25A 32A
Wire Speed Range 2-22 Metre/min 2-22 Metre/min
Wire Size 0.9, 1.2, 1.6 mm Solid Wire
0.9 - 1.6 mm Cored Wire
0.9, 1.2, 1.6 mm Solid Wire
0.9 - 1.6 mm Cored Wire
Cooling Type Fan on Demand Fan On Demand
Efficiency ≥ 85% ≥ 85%
Power Factor 0.92 0.92
Insulation H 140°C Rise H 140°C Rise
Protection IP21S IP21S
Weight 97kg 105kg
Shipping Weight 143kg 148kg
Dimension L × W × H 940 x 485 x 880mm 940 x 485 x 880mm
Shipping Dimension L × W × H 1080 x 500 x 980mm 1080 x 500 x 980mm

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
1110
Fig 1 Weldmatic 350 + 500 Controls
1 Control Panel
2 Remote Connector
Connect the wire feeder control cable to
this connection.
3 Positive Welding Output Terminal
4 Negative Welding Output Terminal
5 Power On Indicator
6 VRD Safe Light
VRD safe light is on when the open circuit
output voltage is reduced to a safe level.
7 Over Temperature Warning
If an over temperature condition is reached
the machine will prevent weld output and
wait until machine has cooled down, before
welding output can commence.
8 Digital Display Amps
If Weld Mode is stick MMA Mode or TIG
mode the display will indicate the selected
welding Amps when adjusted with knob,
item (9).
During welding in any mode, the display will
show actual welding Amps. At the end of
welding, the display will hold the actual weld
amps for 10 seconds.
4 CONTROLS
PANTONE 432 C
WHITE
PANTONE 426 C
PANTONE 116 C
WIRE
0.9
1.2
1.6
CORED WIRE
- Self/Gas Shielded
- All Sizes
MIG
STICK
TIG
MIG VS
(Hold 3 Sec.)
PROCESS
WIN649A
Design WIN649A
ON VRD
MIG ARC CONTROL
STICK ARC FORCE
AMPS
VOLTS
Proof with knob and push button design in place
11856 7 910
12 13
1
2 43

1110
9 Weld Current Adjustment
Weld Current Adjustment Knob for Stick
MMA or TIG Mode.
10 Digital Display Volts
MIG Mode (GMAW): The display will
indicate Actual weld volts as measured at
output terminals. At the end of welding, the
display will hold the actual weld volts for 10
seconds. The display will indicate the MIG
Arc Control 0-10 setting by knob (11).
Stick Mode (MMA): The display will
indicate the amount of Arc Force 0-10 set
by Knob (11). During welding, the display
will show actual weld volts. At the end of
welding, the display will hold the actual weld
volts for 10 seconds.
Voltage Sensing (VS): The display will
indicate the weld volts setting set by Knob
(9). During welding, the display will show
actual weld volts. At the end of welding, the
display will hold the actual weld volts for
10 seconds.
TIG Mode (GTAW): During welding, the
display will show actual weld volts. At the
end of welding, the display will hold the
actual weld volts for 10 seconds.
11 Voltage Adjustment Knob
11.1 Stick Mode
When in Stick MMA Mode the knob will
adjust Arc force 0-10.
When the welding machine detects a
sudden drop in the weld arc voltage, the
machine will compensate momentarily
by increasing the weld current and
weld voltage.
A higher arc force might be useful for
difficult electrodes such as Cellulose.
11.2 Voltage Sensing
If Weld Mode is Voltage Sensing VS the
knob will adjust the weld volts setting
11.3 MIG Arc Control
When in MIG GMAW mode the harshness
of the arc can be adjusted. For example
aluminium welding would require a different
setting to steel welding. The display (10) will
indicate the MIG Arc Control value 0-10.
12 Process Selection Button
Pressing the button will cycle through each
of the four welding processes as indicated
by the four lights. The Four Processes are:
12.1 GMAW MIG using remote wire
feeder: The weld voltage is controlled
from the wire feeder and the set value is
displayed on (10). The output voltage is only
active when signaled from the wire feeder.
12.2 Stick electrode welding MMA, with
LOCAL control: Knob (9) will adjust the
weld current which is displayed on (8). Knob
(11) will adjust arc force displayed on (10).
12.3 TIG GTAW welding, LOCAL control:
Lift arc start, using TIG welding torch with
separate gas supply.
Knob (9) will adjust the weld current which is
displayed on (8).
12.4 MIG Process Voltage Sensing VS:
The Knob (11) will adjust the weld volts
setting, which is displayed on (10).
The output terminals are at full OCV.
This process requires a special wire feeder
that is capable of operating from output
live terminals.
Note: Process selection switch must
be pressed for 3 seconds, to lock into
VS Process.
13 Wire select Button and Indicator
Use this button to select the wire size
being used. For 350, sizes 0.9, 1.2, 1.6mm
can be used. For 500, sizes 0.9, 1.2, 1.6mm
can be used.
When wire setting is set to Gasless then
there is no need to select wire size.

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
1312
5 INSTALLATION
Connection to Electrical Mains
Power Supply
Note: All electrical work shall only be
undertaken by a qualified electrician.
350
The Weldmatic 350 is factory fitted with a
3 metre, 3 core+ earth 2.5mm2 Heavy Duty
PVC mains power supply cable.
The power cable is fitted with a 32 amp
3 phase plug.
Maximum rated output
To achieve the rated output of 350A 60%
the machine requires maximum primary
current Imax 26A and Effective primary
current Ieff 20 Amps.
The machine needs to be fitted with a
plug capacity 20A or greater, and a supply
capacity 25A or greater.
The minimum recommended supply
circuit breaker rating for a Weldmatic 350
is 25 Amps.
500
The Weldmatic 500 is factory fitted with a
3 metre, 3 core+ earth 4.0mm2 Heavy Duty
PVC mains power supply cable.
The power cable is fitted with a 32 amp
3 phase plug.
Maximum rated output
To achieve the rated output of 500A 60%
the machine requires maximum primary
current Imax 42A and Effective primary
current Ieff 32.5 Amps.
The machine needs to be fitted with a
plug capacity 32A or greater, and a supply
capacity 31A or greater.
The minimum recommended supply
circuit breaker rating for a Weldmatic 500
is 32 Amps.

1312
Successful operation
Successful operation will depend on a
number of factors:
– Variation in circuit breaker thresholds.
– Ambient temperature.
– Number of previous circuit breaker
operations.
– Actual weld conditions, resulting in
higher weld currents.
– Repeated starts can result in
repeated in-rush currents raising
circuit breaker threshold.
Repeated circuit breaker operation at weld
start can sometimes be overcome by using
a “D” curve circuit breaker.
To reduce nuisance tripping, a higher
rated circuit breaker can be selected, but
the supply circuit wiring capacity must be
increased to suit.
Supply Cable
If it becomes necessary to replace the
mains flexible supply cable, use only cable
with correct current rating.
The replacement cable must be fitted and
retained in the same manner as the original.
Output Voltage Polarity
The design of the Weldmatic allows
selection of the output voltage polarity.
Positive Wire
MIG welding (GMAW), with solid
consumable wires and gas shielding, is
carried out with the work piece Negative
and the welding wire Positive.
To setup for this condition, connect the
‘WORK’ lead plug into the (-) output terminal
on the power source, and the wirefeeder
weld cable into the (+) output terminal.
Negative Wire
Some ‘self-shielded’ flux cored gasless
consumable wires are operated with the
work piece Positive and the consumable
wire Negative. Refer to the manufacturers
data for the particular consumable wire to
be used.
To setup for this condition, connect the
‘WORK’ lead plug into the (+) output terminal
on the power source, and the wirefeeder
weld cable into the (-) output terminal.
Fitting the Gas Cylinder
Place the gas cylinder on the tray at the
rear of the optional welder trolley (if using).
Retain the cylinder with the chain provided.
Fit the gas regulator to the cylinder. DO NOT
apply grease or oil to these joints.
Fit the end of the gas inlet hose from the
back of the power source to the connector
supplied with the gas regulator, and secure
with the clamp also supplied.

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
1514
7 BASIC WELDING INFORMATION
MIG Welding (GMAW)
Choice of Shielding Gas
The choice of shielding gas is largely
determined by the consumable wire to
be used. Many proprietary shielding gas
mixtures are available.
Some recommended shielding gases are:
– Mild Steel: Argon + 18% Oxygen;
Argon + 2% Oxygen +
5% Carbon dioxide;
– Aluminium: Argon;
– Stainless Steel: Argon + 1 to 2% Oxygen.
Argon + Helium
Consult your gas supplier if more specific
information is required.
Shielding Gas Flow Rate
In GMAW, one function of the shielding gas
is to protect the moulten weld pool from
the effects of oxygen in the atmosphere.
Without this protection the weld deposit
becomes ‘honeycombed’ in appearance, an
effect which is described as weld porosity.
In draft-free conditions the gas flow rate
required to give adequate protection is
typically 10-12 litres/min. In situations
where drafts cannot be avoided, it may be
necessary to increase this rate up to 20
litres/min, and/or to provide screening of
the work area.
Weld porosity can also be caused by
air entering the gas stream through a
damaged hose, loose gas connection, or
from restriction in the nozzle, such as from
excess build-up of spatter.
When welding aluminium, particular care
must be taken with all aspects of shielding
gas delivery and work piece preparation in
order to avoid weld porosity.
6 NORMAL WELDING
SEQUENCE
Weld Start
Closing the welding gun switch initiates
this sequence of events:
– The gas valve is energised and gas
flow commences;
– Welding voltage is applied between
the work piece and the consumable
wire.
– The wire drive motor is energised.
– The wire touches the work piece, and
the arc is established.
Weld End
Releasing the gun switch initiates this
sequence of events:
– The wire drive motor is de-energised,
and is dynamically braked to a stop;
– The welding current stops.
– The gas valve is de-energised and the
flow of shielding gas ceases.
The quality of the consumable wire
greatly affects how reliably a gas
metal arc welder will operate. For
best results when welding mild
steel, we recommend quality WIA
AUSTMIG ES6. Dirty, rusty or kinked
wire will not feed smoothly through
the gun cable and will cause erratic
welding. Deposits from the wire will
clog the gun cable liner requiring it
to be replaced prematurely.

1514
Establishing a Weld Setting
Once the consumable wire type, wire size
and shielding gas have been chosen, the
two variables that are adjusted in order to
obtain a the desired weld setting are;
– Wirefeed speed,
– Welding arc voltage.
The wirefeed speed determines the welding
current; increasing the speed increases
the current, and decreasing it decreases
current.
The selected wirefeed speed must be
matched with sufficient arc voltage; a
speed increase requires an increase of arc
voltage.
If the voltage is too low the wire will stub
and stutter, and there will not be a steady
arc. If the voltage is too high the arc will
be long with metal transfer occurring as a
series of large droplets.
The weld setting should be chosen to suit
the application and the thickness of the
metal to be welded. It is important to check
that the deposited weld provides sufficient
strength to suit the application.
A “good” weld will have the characteristics
illustrated in Figure 2. The weld has penetrated
into the parent metal, fusing the root of the
joint where the two plates meet, and the
weld blends smoothly into the side walls.
A “bad” weld is shown in Figure 3. The weld
has not penetrated the joint root, and there
is poor side wall fusion. This lack of fusion
would normally be corrected by increasing
the arc voltage, or by increasing both
wirefeed speed and arc voltage to achieve
a higher current weld setting.
Fig 2 “Good” Weld
Fig 3 “Bad” Weld

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
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10-
Fig 4b Gas Shielded Solid Wires
Fig 4c Gasless Flux Cored Wires
Fig 4a Wire Stickout for Gasless Welding
Gun Position
For “down hand” fillet welding with gas
shielded solid wires, the gun is normally
positioned as shown in Figure 4a below,
with the nozzle end pointing in the direction
of travel.
For “down hand” fillet welding with gasless
flux cored wires, the gun is normally
positioned as shown in Figure 4b, with the
nozzle end pointing away from the direction
of travel, referred to as ‘dragging’ the
weld. Gasless flux cored wires should be
operated with approximately 10-15mm of
wire ‘stick-out’ from the welding contact tip
as shown in Figure 4c.

1716
Stick Welding (MMAW)
Connection for Stick Welding
It is important to select the electrode
polarity in accordance with the
manufacturers recommendations for that
electrode. Most common electrodes,
including cellulose types, are operated with
the electrode at positive polarity.
Stick Welding Operation
Be certain that you are wearing suitable
protective clothing, gloves etc and that
you are working in a non-hazardous area. If
necessary, refer again to Section 1 - Safe
Practices in this manual.
Connect the work clamp to the work piece.
Place the desired electrode in the electrode
holder (electrode holder optional extra).
Turn on the power switch located on the rear
panel. Wait approximately 5 seconds as the
unit goes through its initiation sequence.
Press the Weld Process button until the
Stick Process light is on.
Select an appropriate welding current for
the electrode diameter by setting the knob
on the machine front panel. WIA Austarc
electrodes will give the best results.
To strike the arc, drag the end of the
electrode along the work piece as if
striking a match. As the arc initiates, lift the
electrode slightly away, aiming to establish
an arc length of approximately 3mm.
As the electrode end is consumed, feed the
electrode into the arc in order to maintain
arc length. As a general rule, 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 cause
an unwieldy flow of metal with a rough weld
appearance and reduced penetration.
An arc too short leads to a narrow weld
deposit and “stuttery” arc characteristics,
and the electrode is liable to freeze onto
the work piece.
As the solidified weld deposit forms, move
the end of the electrode slowly along
the weld path, aiming to maintain a pool
of moulten weld 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 fill the crater which tends to form
at the end of a weld deposit, by pausing
momentarily before withdrawing the
electrode to break the arc. Unfilled craters
are a point of weakness, and can lead to
weld cracking.
Current Range for General Purpose
Electrodes
Diameter (mm) Current (Amps)
2.0 40 - 60
2.5 60 - 85
3.2 90 - 130
4.0 130 - 180

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
1918
TIG Welding (GTAW)
Connection for TIG Welding
For TIG welding, the torch is connected to
the negative terminal. Welding grade Argon
is the shielding gas most commonly used
for DCGTAW welding. The machine does
not have an internal gas valve. The gas is
connected directly to the torch.
Before first use of the welding torch, allow
gas to purge the torch and hoses for
1minutes at approximately 10 litres/min. For
welding purposes, the gas flow rate should
be set in the range 2-5 litres/min.
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. For
welding currents less than 20 amps, the
included angle of the point should be 30o,
for currents greater than 20 amps, the
recommended angle is 60o. When set in the
torch, the tungsten should protrude 6 mm
from the ceramic gas nozzle.
TIG Welding Operation
Connect the Work Clamp to the work piece.
Turn on the power switch located on the rear
panel. Wait approximately 5 seconds as the
unit goes through its initiation sequence.
Press the Weld Process button until the
TIG Process light is on. The Weldmatic
keeps the last process used in memory, so
this step is only necessary when using a
different process to that used last.
Select an appropriate welding current for
the job by setting the knob on the machine
front panel.
Use of a copper striking plate can be used
to avoid electrode contamination. The
electrode can also be contaminated by
contact with the filler rod. A contaminated
electrode produces an unstable arc. If this
occurs regrind the electrode tip.
When in TIG the output is turned on and the
LIFT-ARC voltage is present at the electrode.

1918
1 32 4
Fig 5 Lift TIG Operation Procedure
LIFT TIG Operation
LIFT TIG arc start can be achieved with the
following procedure.
1 Turn on the shielding gas.
2Touch the electrode lightly against the
work piece.
3While still holding the electrode against
the work piece, roll the hand piece over
until the cup rests on the work piece.
Use the cup as a pivot point to roll the
hand piece over allowing the electrode
to lift of the work piece.
The arc will ignite.
4Immediately lift the cup of the work
piece, the current will rise to the
welding level.
Duty Cycle
The term duty cycle indicates the percentage
welding time available at the rated output
current, for each 10 min period over 4 hours.
The Weldmatic 350 is rated at 350 Amps,
and the 500 at 500 Amps, 60%duty cycle.
If the machine is operated at a reduced
welding current, a higher duty cycle is
available. The diagram below illustrates the
appropriate duty cycle rating for the range
of welding currents available, and so allows
the maximum welding time per 10 minute
period to be determined.
The power source is protected by in built
over temperature protection devices. These
will operate if the machine is operated in
excess of its current and duty cycle rating.
If this occurs, the temperature warning
indicator will be on, the fan will continue to
run, but the machine will not deliver welding
current until the unit has cooled sufficiently.
Fig 6 Duty Cycle Rating
Maximum welding
time per 10 min
500
150 200 250 350300 400 450

Weldmatic 350 & 500 | Operator Manual | Model No CP144-2/CP145-2
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Before removing the equipment
cover, ENSURE that the equipment
is disconnected from the mains
power supply. When the equipment
is energised LETHAL VOLTAGES
are present on the electrical
components enclosed.
Dust
Care should be taken to prevent excessive
build-up of dust and dirt within the welding
power source. It is recommended that
at regular intervals, according to the
prevailing conditions, the equipment
covers be removed and any accumulated
dust be removed by the use of a dry, low
pressure compressed air, or a vacuum
cleaner. The machine should be blown
out with compressed air at least every 12
months as grinding dust can settle on PCB
componentry causing failure. Failure to
maintain machines may void warranty.
Wirefeed
In order to obtain the most satisfactory
welding results from the GMAW process,
the wirefeed must be smooth and constant.
Most causes of erratic wirefeed can be cured
by basic maintenance. Check that the:
1 Feed rolls are the correct size and type
for the wire in use. Check also that the
drive groove is aligned with the wire,
and that the groove is not worn;
2 Gun cable liner is clear of dust and
swarf build-up. When replacement
becomes necessary, fit only the correct
liner. The build-up of dust can be
minimised by regular purging of the
liner with dry compressed air. This may
be conveniently done each time the
wire spool is replaced;
3Welding tip is free of obstructions
such as spatter build-up. Ream out
the tip bore with a suitable size oxy-tip
cleaner. Replace the welding tip as it
becomes worn;
4Feed roll pressure is not excessive.
The pressure should be just sufficient
to feed the wire evenly. Excessive
pressure will deform the electrode wire
and make feeding more difficult;
5Consumable wire spool holder rotates
smoothly and that the braking action is
not excessive. The spool should only
have sufficient braking to prevent over
run when the motor stops. This also
may be conveniently checked each
time the wire is replenished;
7Welding wire is straight and free
of buckles or ‘waviness’. To check,
remove 2 or 3 metres of wire from
the spool. Clamp one end in a vice
or similar, then holding the other end
pull the wire out straight. Look down
the length of the wire, any buckles will
be obvious. Buckled wire is extremely
difficult to feed reliably and should be
replaced;
8Welding wire is free of surface rust.
Replace if rust is evident.
8 GENERAL MAINTENANCE