WIA Weldmatic 256 User manual

Weldmatic 256 (480 V) MIG welder
With Four Roll Drive
Enclosed Wirefeeder
Model No. CP124-3, Iss B
05/09
®
CP124-41 Rev C
Weldmatic 256 [external wirefeeder]
Operators Manual

Quality •Reliability •Performance
Welding Industries of Australia
An ITW Company
ABN 18 004 547 111
Telephone: [phone]
Facsimile: 1300 301 884
Email: [email protected]
www.welding.com.au

Weldmatic 256
Model No CP124-3, Iss B 05/09 1
Quality •Reliability •Performance
Contents
Section General Information Page
Safe Practices 2
1 Introduction 5
2 Receiving 5
3 Specifications 6
4 Controls
4.1 Power Source 7
4.2 Wirefeeder 8
5 Installation 10
6 Normal Welding Sequence 12
7 Basic Welding Information 13
8 General Maintenance 14
9 Trouble Shooting 15
10 Service Information 17
11 Assembly and Parts Lists
11.1 Power Source 20
11.2 Wirefeeder 22
11.3 Wirefeed Assembly 24
11.4 Gun and Cable Assembly 25
11.5 Interconnecting Lead Kit 27
12 Warranty information 28

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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
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 wirefeeder 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.
Handle on Wirefeeder
Please note that the handle fitted
to the Weldmatic 256 wirefeeder is
intended for carrying the equipment by
hand only.
DO NOT use this handle for
suspending or mounting the
wirefeeder in any other manner.

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Weldmatic 256
Model No CP124-3, Iss B 05/09 3
Quality •Reliability •Performance
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-toe 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.

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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oors
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-lling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.
If the supply cable is damaged
it must be replaced by the
manufacturer’s service agent or a
similarly qualified person.

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Weldmatic 256
Model No CP124-3, Iss B 05/09 5
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1 Introduction
Gas Metal Arc Welding (G.M.A.W.) 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 256 has been designed to
be used with consumable wires in the range
from 0.6mm to 1.2mm 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 G.M.A.W. 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 G.M.A.W. using the correct consumable
wire and shielding gas.
The Weldmatic 256 wirefeeder has been
designed to feed a range of hard, soft, and
flux-cored wires for the G.M.A.W. process.
A compact motor with integral gear box is
coupled to a four roll drive assembly forming
the basic component of the wirefeeder. The
motor is controlled by an electronic speed
control which provides speed regulation and
compensation for supply voltage variations.
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 CP124-3 package contains;
• Weldmatic256(480V)Powersource
CP124-4
• Weldmatic256EnclosedWirefeeder
W60-0
• 8minterconnectingleads
• 3mBernardgunandcableassembly
• 5mworklead
• Gashose
• Argon/mixedgasregulator
• (This)OperatingManualCP124-41.

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Wirefeeder
Supply Voltage
30 volts AC, (from welding power source)
Rated Supply Current
5 Amps
Circuit Breaker
5 Amps
Spot Weld Time
0 - 5 seconds
Pre/Post Gas Range
0 - 2 seconds
Spool Sizes
5 kg, 15 kg
Wirespeed Range
0 - 172 RPM (0 - 20 metres per min.)
Wire Size Range
0.6mm - 1.2mm diameter (solid wire)
0.8mm - 1.2mm diameter (cored wire)
3 Specifications
Power Source
Manufactured to Australian Standard
AS60974-1.
Primary Voltage
480 Vac, 50Hz
Rated Primary Current
12 Amps
Maximum Primary Current
25 Amps
Recommended Generator kVA
12 kVA
Rated Output @ 40oC
Duty cycle based on 10min cycle time
255 Amp, 27 V, 25% duty
100 Amp, 19 V, 100% duty
Welding Current
30-255 Amps
Open Circuit Voltage
20-42 V
Shipping weight
104 kg (inc wirefeeder and lead kit)
Mains Circuit Breaker Rating
15 Amps
Fitted Supply Cable
30/0.25 Three Core, Heavy Duty PVC
Cooling
Fan on demand, fan operates only as
required to cool internal components
Insulation
Class H, 140°C Rise.

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Weldmatic 256
Model No CP124-3, Iss B 05/09 7
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Fig 1 Power Source Controls
1 Circuit Breaker
This circuit breaker protects the 30 Vac
wirefeeder supply circuit.
2 Wirefeeder Control Socket
Connector for control cable from remote
wirefeeder.
3 Coarse Voltage, On/Off Control
This switch provides mains power ON/OFF
andCoarseadjustmentoftheoutputwelding
voltage over three ranges.
4.1 Power Source Controls
3
4 Gas Outlet
Connector for shielding gas hose from
remote wirefeeder.
5 Negative Welding Output Terminal
6 Positive Welding Output Terminal
1
2
6
5
4

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4.2 Wirefeeder Controls
Fig 2 Controls on front face of wirefeeder
1 Power On Indicator
This indicator is illuminated when wirefeeder
is connected to a power source and the
power source is switched on.
2 Fine Voltage Control
The Fine Voltage Control provides variable fine
adjustmentoftheoutputweldingvoltage.
3 Arc Start
This control can be set to modify arc starting
conditions. For many applications the control
can be set at the mid point.
Rotating the knob towards ‘FAST’ will
provide faster wire acceleration at arc start
giving quicker starts, suitable for applications
such as rapid tack welding.
Rotating the knob towards ‘SOFT’ will slow
wire acceleration, providing a softer start
suitable for larger diameter and aluminium
wires.
4 Wire Speed Control
This control sets the speed of the wire drive
motor within the range of 0 - 172 RPM,
equivalent to 0 - 20 metres per minute of
welding electrode wire. Rotate the control
clockwise to increase the feed speed. This
controlisusedinconjunctionwiththeWire
Speed Range Select Switch. Switch to low for
slower wirespeed control and switch to high
for higher wire speeds.
5 Wire Speed Range Indicator Light
This indicator is illuminated when speed
range is set to High speed range (8-20
metres/min).
6 Wire Speed Range Select Switch
Press to change from Low wire speed range
to High wire speed range.
5
4
6
2
1
8
7
9
3
10

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Model No CP124-3, Iss B 05/09 9
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7 Purge Button
Press to open the gas solenoid valve without
energising the welding power source.
8 Inch Button
Press to feed wire without energising the
welding power source. The wire will feed at
the current wirespeed setting.
9 Latch Select Button and Indicator
Press to select and deselect ‘Latch’ mode.
When ‘Latch’ mode is selected, the operator
need close the gun switch momentarily only to
commence welding, and again momentarily
to end welding. This can help to reduce
operator fatigue during long welding runs.
10 Creep Select Button and Indicator
‘Creep’ is selected when welding more
difficult materials such as aluminium or
stainless steel. In ‘Creep’ mode, the wire is
fed slowly until contact is detected and then
accelerated to full speed. Because the wire
comes into contact with the work slowly the
arc establishes smoothly.
This is followed by rapid acceleration so that
the arc does not flare up and damage the tip.
Even if an arc is not established, within one
second of the gun switch being operated
the wire feed accelerates to selected welding
speed.
Wirefeeder Controls on Inside Panel
Pre Gas Control
Sets the time period of gas flow before welding
commences, and can be set for 0 - 2 seconds.
Post Gas Control
This sets the time period of gas flow after
welding ceases, and can be set for 0 - 2 seconds.
Spot Time Control
When the setting is other than fully anti
clockwise, the welder will operate for a short
time after each trigger press. Turn clockwise
to increase the weld duration up to a
maximum of 5 seconds.
Rotating the dial in a clockwise direction will
increase the spot weld time.
Burnback Control
This control sets the time period that welding
voltage continues after the gun switch is
released, and wirefeed ceases.
When set correctly ‘Burnback’ prevents the
welding wire freezing in the weld pool at the
end of a weld.
Fig 3 Controls on inside panel of wirefeeder

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5 Installation
Connection to Electrical Mains Power
Supply
NOTE. All electrical work shall only be
undertaken by a qualified electrician.
The Weldmatic 256 (480 V) is factory fitted
with a 3 metre, 3 core 30/0.25 Heavy Duty
PVC mains power supply cable.
The minimum capacity of the mains wiring
and power outlet supplying a welder is
selected according to the effective primary
current of the equipment. The effective
primary current for the Weldmatic 256 is
12 Amps.
To obtain full rated output current from the
Weldmatic 256, the 15 Amp flexible supply
cable must be fitted with a 3 pin plug that
is rated for greater than 15 Amps, and
connected to a correctly installed power outlet
of at least 15 Amps, 480 V supply capacity.
The minimum recommended mains circuit
breaker rating for a Weldmatic 256 is
15 Amps. Note: Due to normal variations
of sensitivity, the tripping time of some 15A
circuit breakers may limit the duty cycle
available from the Weldmatic 256. A higher
rated circuit breaker can be selected, but
the mains wiring capacity must be increased
to suit.
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. Access to the supply
terminals is gained by removing the power
source side panels.
The replacement cable must be fitted and
retained in the same manner as the original.
Fig 4 Positive Wire
Output Voltage Polarity
The design of the Weldmatic 256 allows
selection of the output voltage polarity.
Positive Wire
G.M.A.W. with solid consumable wires 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 socket
on the Power Source, and the ‘WELDING’
lead from the wirefeeder into the (+) socket
on the Power Source, as in Figure 4.
To wirefeeder
To work clamp

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Model No CP124-3, Iss B 05/09 11
Quality •Reliability •Performance
Fitting the gas cylinder
Place the gas cylinder on the tray at the rear
of the welder. 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.
Fig 5 Negative Wire
Negative Wire
Some ‘self-shielded’ flux cored 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 socket
on the Power Source, and the ‘WELDING’
lead from the wirefeeder into the (-) socket
on the Power Source, as in Figure 5.
Remote Wirefeeder
The remote wirefeeder is connected to the
Weldmatic 256 power source using 8m
composite cable interconnecting lead. Check
all connections are firmly made to ensure good
electrical contact, and to prevent gas leaks.
The Weldmatic 256 wirefeeder is supplied
fitted with WF027 bottom rollers which
are suitable for both 0.9mm and 1.2mm
diameter steel wire.
Fitting The Gun and Cable Assembly
The supplied BERNARD gun/cable assembly is
equipped with a ‘Euro’ wirefeeder connector
which incorporates all required connection
points for welding current, shielding gas and
gun switch control.
To attach the gun/cable assembly to
the wirefeeder mechanism, engage the
mating parts of the male and female
Euro connectors, then rotate the locking
ring clockwise to firmly secure the
connection.
Fitting the Consumable Wire
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.
Place the spool of welding wire onto the
spool holder. The location pin should mate
with a hole provided on the wire spool body.
Fit the spool retaining ‘R’ clip supplied.
To wirefeeder
To work clamp

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6 Normal Welding Sequence
Weld Start
Closing the welding gun switch initiates this
sequence of events:
• Thegasvalveisenergisedandgasow
commences;
• Thepowersourcecontactorfunction
is initiated. 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;
• Afterashortpre-setperiod,knownas
the ‘burn-back’ time, the Power-source
contactor function is released. This period
ensures that the consumable wire does
not ‘freeze’ in the weld pool.
• Thegasvalveisde-energisedandtheow
of shielding gas ceases.
Checktheadjustmentofthespoolbrake,
which should be set to prevent over run of
the wire spool at the end of a weld, without
unduly loading the wirefeed motor. The
brakingcanbeadjustedbytheNylocnut
using a 15/16” AF or 24mm socket wrench.
Compression screw
Top roller arms
Feeding the Consumable Wire
At the wirefeeder, release the compression
screw and rotate the top roller arms to
the open position. The end of the welding
wire can now be passed through the inlet
guide, over the first lower roller, through
the intermediate guide, over the second
lower roller and into the output wire guide
tube. Check that the drive roll grooves are
correct for the wire in use. The appropriate
size is stamped on the visible side of the
installed rollers. Check also that the correct
size contact tip is fitted at the gun end. Feed
roller and tip details are shown in Section 11
of this manual.
Return the top roller arms to the closed
positionandadjustthecompressionscrew
to provide sufficient clamping of the drive
rollers to achieve constant wirefeed. Do not
over tighten.
With the equipment energised, operate the
gun switch to feed wire through the gun
cable.
Fig 6 WF024 Four Roll Drive
Inlet guide
Drive rollers

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Model No CP124-3, Iss B 05/09 13
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7 Basic Welding Information
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.
The recommended shielding gases for use
with the Weldmatic 256 are:
• MildSteel Argon+
5 to 25% Carbon Dioxide;
100% CO2
• Aluminium Argon
• StainlessSteelArgon+1to2%Oxygen.
Consult your gas supplier if more specific
information is required.
Shielding Gas Flow Rate
In G.M.A. welding, one function of the
shielding gas is to protect the molten 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 workpiece preparation in
order to avoid weld porosity.
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.
Important: Do not operate the Voltage
Control switch during welding.
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 7. 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 8. 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.

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Gun Position
For “down hand” fillet welding, the gun is
normally positioned as shown in Figure 9
below with the nozzle end pointing in the
direction of travel.
Fig 9 Gun Position
Fig 8 “Bad” WeldFig 7 “Good” Weld
8 General Maintenance
Before removing the power source
or wirefeeder covers, 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 dry, low pressure compressed air, or a
vacuum cleaner.
Wirefeed
In order to obtain the most satisfactory
welding results from the G.M.A.W. 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 there
is correct alignment along the complete
wirefeed path 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 (see
page 28). 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;
3 Welding 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;

Quality •Reliability •Performance
Weldmatic 256
Model No CP124-3, Iss B 05/09 15
Quality •Reliability •Performance
4 Feed roll pressure is not excessive. The
pressureshouldbejustsufcienttofeed
the wire evenly. Excessive pressure will
deform the electrode wire and make
feeding more difficult;
5 Consumable 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;
7 Welding 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;
8 Welding wire is free of surface rust.
Replace if rust is evident.
9 External Trouble Shooting
If the following checks do not
identify the fault condition, the
equipment should be returned to
a WIA Service agent. Phone 1300
300 884 for details of your nearest
service agent.
Power source has no output and no
wirefeed when gun switch is closed :
Power light on wirefeeder is off
1 Check equipment is connected to a
functional mains power outlet. Test outlet
using a known working appliance
2 Check the equipment is switched on, ie
‘Coarse’ switch is in position A, B or C.
3 Check the circuit breaker at the front of
the power source (press to reset)
4 Check the interconnecting lead is securely
plugged in at the welder and that the
lead is not damaged.
Power light on wirefeeder is on
1 The gun switch circuit is incomplete.
• Checkthegunswitchforcontinuity
with an ohm meter when the switch is
pressed. Replace if faulty
• Checkthe2pinreceptaclesintheMIG
gun adaptor are making contact with
the mating pins from the gun end.
There is wirefeed but no output
voltage when gun switch is closed:
1 Power source may have overheated.
• TheWeldmatic256weldingpower
source incorporates an in-built over-
temperature thermostat which will

16
Operators Manual
Quality •Reliability •Performance
Quality •Reliability •Performance
trip if the welding load exceeds the
operating duty cycle. The thermostat
will reset automatically - do not switch
the equipment off as the cooling
fan will assist the resetting of the
thermostat
• Ifproblempersistsafterthecooldown
period, call your WIA service agent.
2 There may be broken wires in the control
cables between the power source and the
wirefeeder.
Power source has low weld output
1 Check all electrical connections in
the welding current circuit, including
weld cable, work clamp and gun/cable
assembly.
Circuit breaker trips instantly when
mains voltage is applied
1 Check the rating of the mains supply
circuit breaker. The Weldmatic 256 should
be supplied from a 25 Amp or larger circuit
breaker.
Unsatisfactory Welding Performance
and Results
Erratic arc characteristics caused by poor
wirefeed
Erratic wirefeed is the MOST LIKELY cause of
failure in all Gas Metal Arc Welding. It should
therefore be the first point checked when
problems occur.
1 Refer to the points in ‘Wirefeed’ in
Section 8
2 Check if the consumable wire is slipping
in the drive rolls. Replace the feed roll if it
is the incorrect size or is worn
3 Check that gun cable liner is not too short
and is fitted correctly. Refer to page 28
for fitting instructions.
Constant poor arc characteristics
Check that the:
1 Correct polarity has been selected for
work and weld cables (refer page 10)
2 Shielding gas is correct for the
consumable wire in use (refer page 13)
3 Welding circuit is making good electrical
connection. Ensure that the work clamp is
securely tightened onto the work piece so
that good electrical contact is achieved
4 All connections in the external welding
circuit are clean and tight. Problems may
show as hot spots
5 Work piece surface is not contaminated.
Water, oil, grease, galvanising, paint,
or oxide layers can severely disturb the
welding arc and result in a poor weld.
Porosity (honeycomb appearance) in
weld
1 Check the gun nozzle and gas diffuser
holes are free from spatter and firmly
attached to the welding gun to ensure
that no air is being drawn into the
shielded area.
2 Check that the correct gas flow rate has
been set (refer page 13)
3 Check for leaks in the gas hose. Replace if
leaking
4 Check for leaks in gun/cable assembly, eg.
fractured gas hose, broken or missing ‘O’
rings. Replace as required
5 Check the work piece surface and MIG
wire for contamination. Water, oil, grease
or paint can result in porosity in the weld.

Quality •Reliability •Performance
Weldmatic 256
Model No CP124-3, Iss B 05/09 17
Quality •Reliability •Performance
10.1 Service Information - Solid State Relay Control Board CP107-10
CAUTION: Mains voltage is present
on this control board whenever the
power source is energised.
This control board provides the following
functions:
• WeldingtransformerON/OFFcontrolin
response to an output from the wirefeed
control board (the contactor function).
• OutputvoltagecontrolbymeansofPhase-
shifting of the welding transformer primary
voltage,asadjustedbythewirefeeder
front panel ‘Fine’ voltage selection knob.
Connections to the board are detailed in the
drawing below.
Fig 10 CP107-10 Control Board

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Operators Manual
Quality •Reliability •Performance
Quality •Reliability •Performance
Fig 11 Power Source Circuit Diagram
10.2 Circuit Diagram - Power Source