Welding Industries MC105-0 Operator's Manual

Weldarc 200i AC/DC

Weldarc 200i AC/DC Arc/TIG Welder
Model No. MC105-0

Iss A

Operators Manual

02/16

MC105-40 Rev A

Welding Industries of Australia

A division of ITW Australia Pty Ltd

1300 300 884
[e-mail]

welding.com.au

Weldmatic 200i AC/DC

Contents

Section General Information Page

Safe Practices 2

1 Introduction 5

2 Receiving 6

3 Operation 6

4 Specifications 7

5 Controls 9

6 Installation 14

7 Basic Welding Information 15

8 External Trouble Shooting 19

9 Service Information 20

9.1 Circuit Diagram 21

10 Assembly and Parts Lists

Power Source 22

11 Warranty Information 26

Model No MC105, Iss A 02/16 1

Operators Manual

Read First

Safe Practices When Using
Welding Equipment

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 handle fitted to
the Weldarc 200i inverter is intended
for carrying the equipment by hand
only.

DO NOT use this handle for
suspending or mounting the Weldarc
in any other manner.

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

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

Pulsed

MIG

2

Trusted by the best

Weldmatic 200i AC/DC

Burn Protection

The welding arc is intense and visibly bright.
Its radiation can damage eyes, penetrate
light-weight clothing, reflect from light­coloured 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 cuffless 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
perchlorethylene 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
percholorethylene.

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.

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.

Model No MC105, Iss A 02/16 3

Operators Manual

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.

4

Trusted by the best

1 Introduction

Weldmatic 200i AC/DC

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 Weldarc 200i has been designed to
be used with 2.0mm, 2.5mm, 3.2mm and

4.0mm 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.

Austarc 13S, Classification E4313-A

A smooth running electrode with a soft arc,
particularly suited to light sheetmetal 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.

Austarc 11, Classification E4311-A

A high cellulose electrode for all positional
welding, AC or DC. Particularly suited for
vertical and incline pipe welding where
complete root penetration is required.

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 Weldarc inverter is suitable for welding
most ferrous and non-ferrous metals. The AC
current output is for welding Aluminium.

Model No MC105, Iss A 02/16 5

Operators Manual

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 Weldarc inverter package contains;

• Weldarc Inverter Power Source

• Twist-lock Electrode Holder

• Work Clamp 3m

• (This) Operating Manual MC105-40.

• TIG Torch Complete WP17V121625
with valve, 5m cable with twist-lock
connection and fitted with 2.4mm collet
and ceriated tungsten

• TIG Consumable KIT

• Argon flow gauge regulator REG003

3 Operation

VRD Function - Only active during

MMA

Whenever the welding output of the Weldarc
inverter is open circuit (ie not arcing), the
voltage across the welding leads is reduced
to a safe level. This provides an increased
level of safety to the welding operator during
operations such as changing the electrode.
The “VRD SAFE” indicator on the front
panel is on to confirm the output is in the
safe condition.

The term VRD refers to a “Voltage Reducing
Device”which complies with AS1674.2 for
Category “C” conditions.

If the supply cable is damaged it
must be replaced by the manufacturer,
their service agent or a similarly
qualified person.

IMPORTANT NOTICE: Warranty may
be voided if equipment is powered
from an unsuitable engine driven
generator.

Generators used to power this equipment
must have a minimum capacity of 10 kW
continuous 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.

6

Trusted by the best

Weldmatic 200i AC/DC

4 Specifications

Manufactured to Australian Standard
IEC60974-10 6.3.2 6.3.3.

TERM VALUE UNIT

Rated Input Voltage 220 - 240 V

Power Frequency 50/60 Hz

Rated Input Capacity 7.9 KVA

Generator Capacity 10 KVA

Rated Maximum Supply Current Imax 34 A

Maximum Effective Supply Current Ieff 13 A

Output No Load Voltage 71 V

Supply Main Circuit Breaker 25 A

Supply Cable 2.5mm2 & Plug Rating 15 A

Extension Lead Rating 15 A

VRD Safe 13.5 V

Rated Output 240 ° C

Stick MMA 170 Amps @26.8 Volts 15% Duty

Stick MMA 66 Amps @22.6 Volts 100% Duty

TIG 200 Amps 18 Volts 15% Duty

TIG 77 Amps 13.1 Volts 100% Duty

Current Up Slope Time 0 ~ 15 S

Current Down slope Time 0 ~ 25 S

Pulse Frequency 0.5 ~ 200 Hz

Pulse Width Adjustment (DC) 15 ~ 85 %

AC Balance Control, Negative 15 ~ 65 %

Arc Force Control MMA 0 -100 %

Arc Start MMA 0 - 70 A

Arc Start MMA 0.2 S

Post Gas Time 0 ~ 30 S

Pre Gas Time 0 ~ 5 S

Cooling Type Fan on Demand

Efficiency ≥ 85% n

Power Factor 0.92 Cos§

Model No MC105, Iss A 02/16 7

Operators Manual

4 Specifications (cont)

Insulation Degree H

Cover Protection Degree IP21S IP

Weight 19.5 kg

Shipping Weight 25 kg

Dimension L × W × H 530 x 240 x 420 mm

Shipping Dimension L × W × H 770 x 335 x 460 mm

8

Trusted by the best

5 Controls

Weldmatic 200i AC/DC

10

Power Switch

14

Located on the rear panel

CRATER
CURRENT

PRESS

GAS PURGE

1

2

3

4

5

WIN567B

WELDING
CURRENT

13

PEAK
CURRENT

PULSE
RATIO

HERTZ

12

BASE
CURRENT

DOWN
SLOPE

11

Welding Industries of Australia

welding.com.au

AMPS

AC/DC

HOT

IGNITION

STAR T

CURRENTUPSLOPE

9

HF

PULSE

MODE GAS

Fig 1 Weldarc 200i AC/DC Controls

1 VRD Safe Mode Indicator

When the machine is in MMA stick mode
the light will be on when the voltage across
the output terminals is reduced to safe level.
The VRD will operate in accordance the
requirements of AS1672.2 2007 Category C
Environment.

66 78

2 Over Temperature Indicator

This light will come on if any internal thermal
protection devices have operated due to
overheating, caused by the duty cycle
being exceeded.

The machine will not weld but the fan will
continue to operate to cool the machine.
When a safe temperature has been reached,
the thermal protection device will reset and
welding can continue.

Model No MC105, Iss A 02/16 9

Operators Manual

5 Controls

3 Voltage Range Indicator

This light will be on when the input supply
voltage is too high or too low. There will be
no output.

Low voltage can occur on a weak power
supply, or if the machine is operated from a
long power cable from a weak supply, or an
under rated generator.

High voltage can occur on some rural power
supplies and lightly loaded generators.

4 Latch Mode 2T/4T

Latch mode provides a 2 STEP or 4 STEP
trigger control while in TIG mode:

4.1 2 STEP

In this mode the torch trigger must be
pressed on to initiate welding and held
on till welding is finished.

Up slope and down slope, ignition

current and crater current cannot
used in the 2 STEP.

Press + Hold
Torc h Tr igger

4.2 4 STEP

In this mode the torch trigger switch is
pressed to start the arc.

The current will stay at the ARC IGNITION

setting.

When trigger is released the current

will increase to the WELDING CURRENT
setting, according to the UP SLOPE time.

Output will continue at WELDING

CURRENT setting.

When torch trigger is pressed again then

the weld output will decrease down to
CRATER CURRENT setting, according to the
DOWN SLOPE time.

Weld output will remain at CRATER

CURRENT until torch trigger is released,
then gas will flow for POST GAS time.

Release
Torc h Tr igger

Amps

Amps

10

Press + Hold
Torc h Tr igger

PRE GAS

IGNITION
CURRENT

PRE GAS

Release
Torc h Tr igger

UP SLOPE

WELDING CURRENT

Time

Fig 2 Latch Mode–2 STEP

WELDING CURRENT

DOWN SLOPE

Time

Fig 3 Latch Mode–4 STEP

POST GAS

Press + Hold
Torc h Tr igger

CRATER
CURRENT

Release
Torc h Tr igger

POST GAS

Trusted by the best

Weldmatic 200i AC/DC

5 Gas Purge

Press and hold the gas purge button to allow
gas to flow without output weld voltage or
current. This feature can be used when a gas
bottle is connected and air can be purged
from the gas line and torch. It can also be
used to safely set shielding gas flow rate
at the gas flowmeter, without the welding
current outputs being live.

6 Parameter Select

Use these buttons to cycle through the
Welding parameters, which can then be
adjusted by knob 7. If no adjustment is made
after 4 seconds the parameter will change
back to WELDING CURRENT.

7 Adjustment Knob

This knob is used to adjust the parameter of
the weld function, as selected by button 6.

8 Weld Mode Selection

The Weld Mode can select between the three
mode of operation.

8.1 Stick MMA Mode

In this mode the machine performs as

a DC stick MMA welding machine. The
HOT START and ARC FORCE parameters
can be adjusted on the front panel.

8.2 Lift Arc TIG

In this mode the machine will perform as

a AC or DC TIG machine. The arc start is
by Lift Arc technique.

8.3 High Frequency Start TIG

In this mode the machine will perform as

AC or DC machine with High Frequency
(HF) arc start. When the tungsten is near
the work piece and the torch trigger

is pressed, then a high energy spark is
created to jump from the tungsten to
work piece and initiate an Arc.

9 Pulse Mode

When in LIFT-ARC TIG or HF TIG mode, then
Pulse TIG can be selected and the parameters
for adjusting the pulse shape will be available
for adjustment.

Peak Current, Pulse Ratio, Frequency Hertz,
and Base Current.

10 AC/DC Mode

The polarity of the output current can be
selected between Alternating Current (AC)
or Direct Current (DC).

AC mode can only be selected in TIG mode.
The alternating current arc can be used
specifically for welding aluminium.

11 AMPS Display

The Left hand digital display will show
Amps while adjusting current with knob 7,
and then display weld Amps while welding
is in progress.

12 Multi Parameter Display

The right hand display will show the value
of a parameter being adjusted. The type of
parameter will be indicated by one of the 4
indicators next to the display.

For example if the AC Frequency is being
adjusted then Hz indicator will be on and the
display will show the frequency that is being
adjusted by knob 7.

Model No MC105, Iss A 02/16 11

Operators Manual

5 Controls

13 Welding Parameters

13.1 Pre Gas

Pre gas flow can be set to a maximum

of 5 seconds, to allow gas flow before
Arc Start.

13.2 Hot Start

Only available in Stick MMA mode, Hot

Start will provide a current boost at the
start of the arc. The parameter can be
adjusted up to 70Amps which will add
to the preset welding current.

13.3 Ignition Current

While in 4 STEP latch mode the arc will

start and maintain the Ignition current
output until the trigger torch is released.

The IGNITION CURRENT can be more or

less than the WELD CURRENT setting.

Setting the IGNITION CURRENT high

can be useful for joint preheat.

13.4 Up Slope

The UP SLOPE time is the time taken

for the weld current to transition from
the IGNITION CURRENT value to WELD
CURRENT value. The time can be
adjusted from 0 to 15 seconds.

13.5 Welding Current

The setting for actual weld current.

13.6 Pulse Welding

Pulse welding allows the current to

be pulsed between two different
values, the frequency and ratio can be
adjusted. This feature can be used on
thin material.

13.6.1 Peak Current

Set the Peak current Amps.

13.6.2 Pulse Ratio

Set the ratio in % for the peak

current compared to the back
ground current. Range is 15%
to 85%.

13.6.3 Hertz

The frequency of the pulse can be

set, as number of pulses for second
(HERTZ) 0.5Hz to 200Hz.

13.6.4 Base Current

Set the Base current Amps.

12

HOT
STA RT

IGNITION
CURRENTUPSLOPE

Fig 4 Weldarc 200i AC/DC Welding Parameters

WELDING
CURRENT

PEAK
CURRENT

PULSE
RATIO

HERTZ

BASE
CURRENT

DOWN
SLOPE

Trusted by the best

CRATER
CURRENT

Weldmatic 200i AC/DC

−%

13.6.5 Down Slope

The DOWN SLOPE time is the

time taken for the weld current
to transition from the WELDING
CURRENT value to CRATER
CURRENT value. The time can be
adjusted from 0 to 25 seconds.

13.6.6 Crater Current

The current at the end of WELD

can be adjusted to a value which
will allow controlled finish of the
weld. The end of weld pool (Crater)
can be filled.

13.6.7 Post Gas

The Post Gas time can be adjusted

to allow gas to flow after weld has
stopped. This feature can be used to
provide a gas shield to the cooling
weld pool. Adjustable from 0 to 30
seconds.

13.7 AC Frequency

When AC mode is selected by button

(10) then actual AC frequency can be
adjusted from 20 to 200Hz.

Increasing the frequency makes the

welding current change direction at a
faster rate. The arc becomes constricted,
more stable and directional, providing
deep penetrating narrow welds.

When the frequency is lower the arc is

wide with shallow penetration, suitable
for butt or edge welds on thin material.

13.8 AC Balance Or Arc Force

13.8.1 AC Balance

When AC TIG mode is selected

then the proportion of positive
and negative in the cycle can be
adjusted. This is referred to as the
BALANCE and is expressed as a
% of the time that the polarity
is negative. Adjustment is from
15% - 65%.

Arc Welding of aluminium is difficult

because the metal readily forms an
oxide layer, which is an electrical
insulator, and inhibits arc formation.
The Oxide needs to be “cleaned
off”. Electrode positive will remove
the oxide off the surface as the
electrons flow off the aluminium to
the tungsten electrode. Continuous
electrode positive will burn the
tip away, so the current has to be
reversed to electrode negative, for
some of the time.

For new clean aluminium an

AC BALANCE of 65% is a good
starting point.

++

%

Fig 5 AC Balance

−

Model No MC105, Iss A 02/16 13

Operators Manual

5 Controls

13.8.1.1 Low % Balance

› Less time negative

› More time positive

› More cleaning action

› More heat in the tungsten

› Wider weld with shallower

penetration

13.8.1.2 High % Balance

› More time negative

› Less time positive

› Less cleaning action

› Less heat in the tungsten,

higher current for smaller
electrode

› Narrow weld beads with

deeper penetration

› Smaller heat affected zone

13.8.2 Arc Force

When machine is in Stick MMA

mode, selecting the ARC FORCE
allows adjustment of the % increase
in current that will occur when the
arc starts to short circuit, or snap out.
Adjusting this value can be useful
when using cellulose electrodes.

14 Power On/Off Switch

In the OFF position, this switch isolates the
power source from mains power supply.
The switch is located on the rear panel.

6 Installation

Connection to Electrical Mains Power
Supply

The Weldarc 200i AC/DC is fitted with a
15 Amp plug and socket, recognisable by
a wide Earth pin. Power Supply authorities
require that equipment fitted with a 15 Amp
plug shall ONLY be connected to a 240 Volt,
15 Amp power point. DO NOT modify
the plug.

The minimum capacity of the main power
supply wiring and power outlet supplying a
welder is selected according to the Effective
Primary Current of the equipment. Refer to
Section 4.

The minimum recommended main power
supply circuit breaker rating for Weldarc
inverter are listed in Section 4.

The current rating of the mains cable
depends on cable size and method of
installation. Refer to AS/NZS 3008.1, Table 9.

If it becomes necessary to replace the mains
flexible supply cable, use only cable with
correct current rating. See Section 4.

If it is necessary to use an extension power
supply cable, ensure that it is rated as per
Section 4. Voltage drop which will occur over
long lengths of cable will reduce the quality
of welds and the maximum welding current
available from the equipment.

As noted previously, it is not recommended
that the Weldarc inverter be powered from
small engine-driven generator sets unless
they have adequate voltage regulation. Poor
regulation results in peaks of supply voltage
which can occur with some equipment
of this type. Excessive voltage peaks can
damage the circuits of the welder.

14

Trusted by the best

7 Basic Welding Information

Weldmatic 200i AC/DC

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, as illustrated in Figure 6.

Work

ClampElectrode

Fig 6 Connections for Stick Welding (MMAW)

Stick Welding

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.

Turn on the power switch located on the rear
panel. Wait approximately 5 seconds as the
unit goes through its initiation sequence.

Use the Weld Mode Selection button to
select Stick Mode.

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 3mm.

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 causes 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 molten 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

Model No MC105, Iss A 02/16 15

Operators Manual

7 Basic Welding Information

TIG Welding (GTAW)

Connection for TIG Welding

For TIG Welding, the TIG torch is connected
to the negative terminal. Figure 7 illustrates
the correct connection of the welding torch
and gas supply. Welding grade Argon is the
shielding gas most commonly used for AC/
DC GTAW welding. The torch will require a
tungsten electrode.

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 5-11 litres/min.

Work

Clamp

Fig 7 Connections for TIG Welding

TIG

Torch

Electrode TIG

Thoriated Tungsten electrodes are normally
used for DC welding current, and Zirconiated
Tungsten electrodes are normally used for AC
TIG welding.

For AC TIG welding a Thoritated tungsten
(red tip) can be used for low current AC TIG
but the tip does not ball well and the arc can
then wander.

Ceriated or Lanthinated are preferred for
advanced AC Welding with square wave
output. They can also be used on DC TIG,
so they are a good AC or DC electrode if
only one electrode type is to be used.

Tungsten Electrode Preperation

The tungstens needs to be ground to a point,
the grinding should only be in the direction
of the point and should be done on a fine
grit grinding wheel. The resulting grind
pattern will produce a sharp directed arc.
Poor tip preparation will result in arc wander.

A common practice is to grind the tip such
that the length of the points is approximately
2 times the diameter. The result will be an
included angle of 30 degrees.

For AC tip preparation, creating a blunt end
will assist a symmetrical and small ball to
develop at the tip.

It is important to maintain the electrode
point for DC or ball for AC. If the tip
accidently touches weld pool it will become
contaminated and the arc will become
erratic, and will need to be re ground.

Tungstens containing at least 2% lanthana
will hold a point when used with both DC
and AC welding currents

16

Trusted by the best

Tungsten Current Ranges

Weldmatic 200i AC/DC

Electrode
Diameter (mm)

Gas
Cup Size

DC
Current Amps

AC
Current Amps

Filler Wire
Diameter (mm)

1.0 6 15-80 20-60 1.6

1.6 6 70-150 50-100 1.6-2.4

2.4 8 150-250 100-160 2.4-3.2

30°

Safety Consideration Thoritated
Tungsten.

Thoriated Tungsten contains the element
Thorium (Th). Thorium is a radioactive
element which mainly emits alpha
particles. Alpha particles cannot penetrate

D

30° x

Fig 8 Tungsten Preparation

x = 1.5 to 4 times diameter

(2 x D = 30° included angle)

skin, or clothing, but can be a harmful
carcinogen if released inside the digestive
tract, or lungs.

D

There is almost no release of radioactive
material during arcing.

There is no significant hazard in handling

Fig 9 AC Advanced Preparation

x = 1.5 to 4 times diameter

and storage. The Thoria is inside the
tungsten electrode, it is enclosed in a
tungsten matrix and so there is little
radiation emitted externally.

The greatest risk of exposure is during
the grinding of the thoriated tungsten
electrodes. Care needs to be taken, to
control the dust. A dust mask should be

Fig 10 Correct Grind Direction

worn, and grinder area clean up should
be done with a vacuum cleaner.

x

Fig 11 Incorrect Grind Direction

Model No MC105, Iss A 02/16 17

Operators Manual

7 Basic Welding Information

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.

Use the Weld Mode Selection Switch to
select LIFT TIG or HF TIG Mode.

Select an appropriate welding current for
the job by setting the knob on the machine
front panel.

HF Start

When HF Start TIG is selected then the
electrode tip is bought close to the work
piece, but not touching.

Pressing the trigger will produce a high
voltage spark that will jump to the work
piece and initiate an arc.

HF TIG can be used where work piece
contamination by the electrode is a
concern. Also where repetitive starts causes
contamination of the electrode, which
produces an unstable arc.

LIFT TIG Operation

When the Welding mode is set to LIFT TIG
then the arc start can be achieved with the
following procedure.

1 32 4

Fig 12 Lift TIG Operation Procedure

1 Touch the electrode lightly against the

work piece.

2 Press the torch trigger switch. The

shielding gas will start to flow and a
small current will pass through the
electrode.

3 While 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.

4 Immediately lift the cup of the work

piece, the current will rise to the welding
level within the up-slope time.

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.

18

Trusted by the best

8 External Trouble Shooting

If the following checks do not identify
the fault condition, the equipment
should be returned to a WIA Service
agent. Phone [phone] for details
of your nearest service agent.

No Welding Current

Check:

1 Check that mains supply is available

at the Weldarc inverter power source.
The display panel lights should be
on. If not, test outlet using a known
working appliance.

2 Check that the welding and work leads

are connected securely to the output
sockets at the front of the machine.

3 Check for continuity of the work lead,

work clamp and electrode holder. Loose
connections can prevent proper flow of
the welding current.

4 The Weldarc inverter welding power

source incorporates an in built protection
device which will operate if the unit is
overloaded. In this event, the machine
will not deliver welding current, and the
Over Temp light will be on. Leave the
machine energised with the fan running
to achieve the maximum cooling rate.

5 If the supply voltage is too high or too

low then the Voltage Range Indicator
light will be on and the machine will not
deliver welding current.

Check the mains voltage supply. Long

extension cords can cause low voltage.
A generator can cause high voltage.

Weldmatic 200i AC/DC

Model No MC105, Iss A 02/16 19

Operators Manual

9 Service Information

CAUTION: The following
information is intended for use
by qualified service personnel.
When the unit is energised
LETHAL VOLTAGES are present
on the electrical and electronic
components. It is not intended that
persons without suitable training
and knowledge attempt to perform
service tasks on the components of
this welder.

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.

The electrical components of the equipment
are shown in the circuit diagram below.
The Weldarc inverter is an inverter type
design, where the mains supply is first
rectified, filtered then chopped to a high
frequency before being applied to the
welding transformer. The output of this
transformer is rectified to form the welding
output of the machine.

20

Trusted by the best

A

A

9.1 Circuit Diagrams – Power Source

Weldmatic 200i AC/DC

-

CN6

T002

L001

CN1CN4

CN3

CN5

HVPulse

CN2

CN3

CN201

CN200 CN100

DigiWave-Panel

CN1

CN2

6R 60W 6R 60W

+

I

-­O
G
+

200A:4V

X8

E2

E1

G1

G2

CN4CN5CN1CN2

t

WJ1

t

WJ1

D1

X3

X1

X2

TR1

TR2

TRM

T1

G3

G4

E4

E3

X30 BUS-

D2

TR1 TR2 DC+DC-

DigiWave-MtArc

DigiWave-MtArc

CN400 CN202 CN300

CN4

CN600

CN601

CN401

CN500

CN402

3

21

5

Air valve

4

Remote

E1

E2

G2

G1

-

+

t

CN5

AC

WJ1

AC

J1

RH1

AC_N

AC_L

CN2

12

34

CN1

CN1

CN2

SMPS_ISO24V

CN3

Fan

CN2

ECONOWAVE200 SEMI

CN3CN1

Torch switch

EMI

SW1

C_N

GND

C_L

Fig 13 Weldarc 200i Circuit Diagram

Model No MC105, Iss A 02/16 21

Operators Manual

10 Assembly and Parts List - Weldarc 200i AC/DC Power Source

22

3

1

2

6

23

21

20

19

16

13

7

4

18

24

5

8

10

22

12

15

1714

Fig 14 Weldarc 200i AC/DC Power Source Assembly

11

Trusted by the best

9

Weldmatic 200i AC/DC

Item # Part # Description Qty

1 M0067 HANDLE 1

2 PAN160 ENCLOSURE 1

3 PWA024 PCB ASSY SECONDARY INVERTER ARC 1

4 E0089 SWITCH ON OFF 1

5 FAN013 FAN 240V 1

6 PWA025 PCB ASSY POWER SUPPLY 24V 1

7 PWA026 PCB ASSY HV PULSE 1

8 D0036 DIODE BRIDGE 35A 1000V 2

9 PWA027 PCB ASSY PRIMARY INVERTER MC105 1

10 D0038 IGBT 12

11 M0068 FOOT PLASTIC 4

12 L0026 COUPLING TRANSFORMER 1

13 M0069 GAS CONNECTION FRONT M10 1

14 E0079 PLUG 5 PIN MC105 1

15 M0070 FRONT PANEL PLASTIC MC105 1

16 M0058 KNOB , BLACK 200I 200i 1

17 CX58 PANEL MOUNT DINSE SOCKET 2

18 M0074 BACK PANEL 1

19 PWA028 PCB ASSY FRONT PANEL MC105 1

20 E0080 HALL EFFECT TRANSDUCER MC105 1

21 D0039 FAST RECOVERY DIODE 2

22 PWA029 PCB ASSY TRIGGER ISOLATION 1

23 PWA030 PCB ASSY MAIN CONTROL MC105 1

24 E0041 GAS VALVE 1

??? R0032 THERMISTOR 1

26 REG003 ARGON REGULATOR 1

27 CLA002 WORK CLAMP 1

Not Shown MC105-40 OPERATING MANUAL 1

Not Shown DGT26FX8M200 TIG TORCH 1

26

27

Model No MC105, Iss A 02/16 23

Operators Manual

10 Assembly and Parts List (Cont)

Item # Part # Description Qty

10N31 COLLET BODY 1.6mm 1

10N32 COLLET BODY 2.4mm 1

10N28 COLLET BODY 3.2mm 1

10N23 COLLET 1.6mm 1

10N24 COLLET 2.4mm 1

10N25 COLLET 3.2mm 1

10N50 CERAMIC NOZZLE SIZE 4 (6mm) 1

10N49 CERAMIC NOZZLE SIZE 5 (8mm) 1

10N48 CERAMIC NOZZLE SIZE 6 (10mm) 1

10N47 CERAMIC NOZZLE SIZE 7 (11mm) 1

10N46 CERAMIC NOZZLE SIZE 8 (12.5mm) 1

57Y04 SHORT BACK CAP 1

57Y03 MEDIUM BACK CAP 1

57Y02 LONG BACK CAP 1

24

Trusted by the best

Weldmatic 200i AC/DC

Model No MC105, Iss A 02/16 25

Operators Manual

11 Warranty Information

WIA Weldmatic MIG &
Weldarc MMA Equipment

2 Year Warranty Statement

Welding Industries of Australia (WIA)
warrants to the original retail purchaser
that the Weldmatic welding machine
purchased (Product) will be free from defects
in materials and workmanship for a period
of 2 years from the date of purchase of
the Product by the customer. If a defect in
material or workmanship becomes evident
during that period, Welding Industries of
Australia will, at its option, either:

• Repair the Product (or pay for the costs
of repair of the Product); or

• Replace the Product.

In the event of such a defect, the customer
should return the product to the original
place of purchase, with proof of purchase,
or contact Welding Industries of Australia
on 1300 300 884 to locate an authorised
service agent.

Any handling and transportation costs
(and other expenses) incurred in claiming
under this warranty are not covered by this
warranty and will not be borne by Welding
Industries of Australia. Welding Industries of
Australia will return the replacement product,
if original found to be faulty, freight free to
the customer.

This warranty covers the Weldarc power
source only, and does not extend to the
accessories included in the original purchase
package.

The obligation of Welding Industries of
Australia under this warranty is limited to the
circumstances set out above and is subject to:

• The customer being able to provide
proof of purchase of the Product and the
purchase price paid for the Product;

• The relevant defect in materials or
workmanship;

• The Product not having been altered,
tampered with or otherwise dealt with
by any person in a manner other than
as intended in respect of the relevant
Product; and

• The Product not having been used or
applied in a manner that is contrary to
customary usage or application for the
relevant Product or contrary to any stated
instructions or specification of Welding
Industries of Australia.

Our goods come with guarantees that
cannot be excluded under the Australian
Consumer Law. You are entitled to a
replacement or refund for a major failure and
for compensation for any other reasonably
foreseeable loss or damage. You are also
entitled to have the goods repaired or
replaced if the goods fail to be of acceptable
quality and the failure does not amount to
a major failure. The benefits given by this
warranty are in addition to other rights and
remedies which may be available to the
customer under any law in relation to goods
and services to which this warranty relates.

Warranty provided by:
Welding Industries of Australia
(ABN 63 004 235 063)
A Division of ITW Australia Pty Ltd
5 Allan Street, Melrose Park
South Australia 5039

Ph: 1300 300 884
Email: [e-mail]
Web: www.welding.com.au

26

Trusted by the best

High Performing
Austarc Electrodes

Austarc 16TC

• Smooth running, basic
low hydrogen electrode,
developed for all positional
(except vertical down)
welding, using AC or DC
power sources.

• Unique twin coating
delivers significantly
improved arc stability and
control of all applications.

Austarc 18TC

• An iron powder hydrogen
controlled electrode used
primarily on C-Mn and low
alloy structural steels.

• Unique twin coating
design offers excellent AC
tability and superb DC+
arc transfer.

Classification:

AS/NZS 4855-B –
E49 16 A U H10

AWS A5. 1: E7016 H8

Part Numbers:

16TC25 (2.5mm)

16TC32 (3.2mm)

16TC40 (4.0mm)

16TC50 (5.0mm)

16TC60 (6.0mm)

Classification:

AS/NZS 4855-B –
E49 18-1 A U H5

AWS A5.1: E7018-1

Part Numbers:

18TC25 (2.5mm)

18TC32 (3.2mm)

18TC40 (4.0mm)

Austarc 11

• High cellulose electrode
developed for all positional
welding on both AC and
DC current.

• It is particularly suited for
vertical and incline pipe
welding where complete
root penetration is required.

Classification:

AS/NZS 4855-B –
E43 11 A

AWS A5. 1: E6011

Part Numbers:

1125 (2.5mm)

1132 (3.2mm)

1140 (4.0mm)

1150 (5.0mm)

For more information call 1300 300 884 or visit welding.com.au

Miller Digital Elite Series

AUTO-DARKENING HELMETS

Inferno P/N - 257217 Joker P/N - 257218
Lucky’s Speed Shop P/N - 257214 Black P/N - 257213

FOUR MODES –

WELD, CUT, GRIND & X-MODE

Black

Lucky’s

Speed Shop

™

Joker

Inferno

• Lens and helmet comply with
Australian Standards AS/NZS

1338.1 (Auto-Darkening) and
AS/NZS 1337.1 B (High Impact)

• Lightweight at only 510g.

• Improved digital controls.

• Battery powered with solar assist.

For more information call 1300 300 884 or visit welding.com.au

• Lightweight headgear.

• Four independent arc sensors.

• Suits MIG, Stick, Flux-Cored
and Pulse.

• TIG rating 5 Amps.

• 3 year warranty (Auto-Darkening

lens only).