NewArc WFU12-4C Quick start guide

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Operational Manual
Newarc WFU12-4C
NA9910616
Newcastle UponTyne
Tel. [phone]
[e-mail]

WFU12-4C
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2WFU12-4C
WEEE Directive & Product Disposal
At the end of its serviceable life, this product should not be treated as household
or general waste. It should be handed over to the applicable collection point for
the recycling of electrical and electronic equipment, or returned to the supplier for
disposal.
Place and Date
Newcastle upon Tyne, UK
14/06/2016
DECLARATION OF CONFORMITY
The Low voltage Directive 2014/35/EU
The EMC Directive 2004/108/EC, entering into force 20 July 2007
The RoHS Directive 2011/65/EU, entering into force 2 January 2013
Type of Equipment
Wire feeder
Brand name or trade mark
Newarc
Type designation etc.
WFU12-4C
Manufacturer or his authorised representative established within the EEA
Name, address, telephone no
Newarc
Newcastle upon Tyne
Phone: [phone]
The product has been designed to comply with the following harmonised standards:
IEC 60974-1 - Arc welding Equipment Arc striking and stabilizing devices
EN 60974-10 - Arc Welding Equipment Electromagnetic compatibility
Additional information: restrictive use, Class A equipment, intended for use in locations other than residential
We declare that the equipment named above has been designed to comply with the relevant sections of the
above referenced specications. The unit complies with applicable essential requirements of the directives.

WFU12-4C 3
Safety Guidelines
These general safety guides cover both arc welding machines and plasma cutting machines unless
otherwise noted. The equipment must only be used for the purpose it was designed for. Using it in any
other way could result in damage or injury and in breach of the safety rules. Only suitably trained and
competent persons should use the equipment. Operators should respect the safety of other persons.
Prevention against electric shock
The equipment should be installed by a qualified person and in accordance with current standards in
operation. It is the user’s responsibility to ensure that the equipment is connected to a suitable power
supply. Consult with your utility supplier if required. If earth grounding of the work piece is required,
ground it directly with a separate cable. Do not use the equipment with the covers removed. Do not
touch live electrical parts or parts which are electrically charged. Turn o all equipment when not in use.
Cables (both primary supply and welding) should be regularly checked for damage and overheating.
Do not use worn, damaged, under sized or poorly jointed cables. Ensure that you wear the correct
protective clothing, gloves, head and eye protection. Insulate yourself from work and ground using
dry insulating mats or covers big enough to prevent any physical contact with the work ground. Never
touch the electrode if you are in contact with the work ground, or another electrode from a dierent
machine.
Do not wrap cables over your body. Ensure that you take additional safety precautions when you are
welding in electrically hazardous conditions such as damp environments, wearing wet clothing, and
metal structures. Try to avoid welding in cramped or restricted positions. Ensure that the equipment
is well maintained. Repair or replace damaged or defective parts immediately. Carry out any regular
maintenance in accordance with the manufacturer’s instructions.
Safety against fumes and welding gases
Locate the equipment in a well-ventilated position. Keep your head out of the fumes. Do not breathe
the fumes. Ensure the welding zone is in a well-ventilated area. If this is not possible, provision should
be made for suitable fume extraction. If ventilation is poor, wear an approved respirator. Read and
understand the Material Safety Data Sheets (MSDS’s) and the manufacturer’s instructions for metals,
consumable, coatings, cleaners, and de-greasers. Do not weld in locations near any de-greasing,
cleaning, or spraying operations. Be aware that heat and rays of the arc can react with vapours to form
highly toxic and irritating gases. Do not weld on coated metals, unless the coating is removed from the
weld area, the area is well ventilated, and while wearing an air-supplied respirator. The coatings on many
metals can give o toxic fumes if welded.
Prevention against burns and radiation
Arc rays from the welding process produce intense, visible and invisible (ultraviolet and infrared) rays
that can burn eyes and skin. Wear an approved welding helmet fitted with a proper shade of filter lens
to protect your face and eyes when welding or watching. Wear approved safety glasses with side shields
under your helmet. Never use broken or faulty welding helmets. Always ensure there are adequate
protective screens or barriers to protect others from flash, glare and sparks from the welding area. Ensure
that there are adequate warnings that welding or cutting is taking place.
3
WFU12-4C

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Wear suitable protective flame resistant clothing. The sparks and spatter from welding, hot work pieces,
and hot equipment can cause fires and burns. Welding on closed containers, such as tanks, drums, or
pipes, can cause them to explode. Accidental contact of electrode to metal objects can cause arcs,
explosion, overheating, or fire. Check and be sure the area is safe and clear of inflammable material
before carrying out any welding.
Protection against noise
Some welding and cutting operations may produce noise. Wear safety ear protection to protect your
hearing.
Protection from moving parts
When the machine is in operation, keep away from moving parts such as motors and fans. Moving
parts, such as the fan, may cut fingers and hands and snag garments. Protections and coverings may
be removed for maintenance and controls only by qualified personnel, after first disconnecting the
power supply cable. Replace the coverings and protections and close all doors when the intervention
is finished, and before starting the equipment. Take care to avoid getting fingers trapped when loading
and feeding wire during set up and operation. When feeding wire be careful to avoid pointing it at other
people or toward your body. Always ensure machine covers and protective devices are in operation.
Precautions against fire and explosion
Avoid causing fires due to sparks and hot waste or molten metal. Ensure that appropriate fire safety
devices are available near the cutting / welding area. Remove all flammable and combustible materials
from the cutting / welding zone and surrounding areas. Do not cut/weld fuel and lubricant containers,
even if empty. These must be carefully cleaned before they can be cut/welded. Always allow the cut/
welded material to cool before touching it or placing it in contact with combustible or flammable
material. Do not work in atmospheres with high concentrations of combustible fumes, flammable gases
and dust. Always check the work area half an hour after cutting to make sure that no fires have begun.
Risks due to magnetic fields
The magnetic fields created by high currents may aect the operation of pacemakers or electronically
controlled medical equipment. Wearers of vital electronic equipment should consult their physician
before beginning any arc welding, cutting, gouging or spot welding operations. Do not go near welding
equipment with any sensitive electronic equipment as the magnetic fields may cause damage.
RF Declaration
Equipment that complies with directive 2004/108/EC concerning electromagnetic compatibility (EMC)
and the technical requirements of EN60974-10 is designed for use in industrial buildings and not those
for domestic use where electricity is provided via the low voltage public distribution system. Diculties
may arise in assuring class A electromagnetic compatibility for systems installed in domestic locations
due to conducted and radiated emissions. In the case of electromagnetic problems, it is the
responsibility of the user to resolve the situation. It may be necessary to shield the equipment and fit
suitable filters on the mains supply.

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LF Declaration
Consult the data plate on the equipment for the power supply requirements. Due to the elevated
absorbency of the primary current from the power supply network, high power systems aect the
quality of power provided by the network. Consequently, connection restrictions or maximum
impedance requirements permitted by the network at the public network connection point must be
applied to these systems. In this case the installer or the user is responsible for ensuring the equipment
can be connected, consulting the electricity provider if necessary.
Materials and their disposal
The equipment is manufactured with materials, which do not contain any toxic or poisonous
materials dangerous to the operator. When the equipment is scrapped, it should be dismantled
separating components according to the type of materials. Do not dispose of the equipment with
normal waste. The European Directive 2002/96/EC on Waste Electrical and Electronic Equipment states
the electrical equipment that has reached its end of life must be collected separately and returned to an
environmentally compatible recycling facility.
Handling of compressed gas cylinders and regulators
All cylinders and pressure regulators used in welding operations should be handled with care.
Never allow the electrode, electrode holder or any other electrically “hot” parts to touch a cylinder.
Keep your head and face away from the cylinder valve outlet when opening the cylinder valve.
Always secure the cylinder safely. Never deface or alter any cylinder.
The following signs and explanations are to remind the user of the potential
risks involved and the dangers of misuse or mistreatment of the welding
machine.
!
RUNNING PARTS MAY BE DANGEROUS!
Keep away from running components,
including the fan.
BE AWARE OF SPARKS AND SPATTER
Wear protective clothing, such as leather
gloves, Flame retardant overalls, boots and
eyewear.
DO NOT TOUCH THERMAL COMPONENTS!
Thermal components may cause severe burns
when in contact with unprotected skin.
ELECTRIC SHOCKS CAN KILL!
Never touch electrical parts. Keep the
equipment in good condition, replace
damaged parts, undertake regular
maintenance according to the instructions.

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1. Preface 7
1.1 General 7
1.2 Introduction 8
1.3 Technical Specications 9
1.4 Overview of Panel MF34 10
1.5 Overview of Panel MF37 12
1.6 Overview of Panel MF34 14
2. Installation 16
3. Operation 18
4. Fault Finding 19
4.1 MF34/MF34P Fault Codes 20
4.2 MF37/MF37P Fault Codes 20
4.3 MF33 Fault Codes 21
5. Maintenance 22
6. Warranty 23
7. Electrical Diagram
8. Parts 25
Contents

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1. Preface
Congratulations on choosing your Newarc WFU 12-4C wire feeder.
Used correctly, our products can signicantly increase the productivity of your welding, and provide
years of economical service. This operating manual contains important information on the use,
maintenance and safety of your Newarc product. Please read the manual carefully before using the
equipment for the rst time. For your own safety and that of your working environment, pay particular
attention to the safety instructions in the manual.
For more information on Newarc products, contact an authorised Newarc dealer, or visit the Newarc
website at www.newarc.co.uk. The specications presented in this manual are subject to change without
prior notice.
Important notes
Items in the manual that require particular attention in order to minimise damage and personal harm
are indicated with the ’NOTE!’ notation. Read these sections carefully and follow the instructions.
Disclaimer
While every eort has been made to ensure that the information contained in this guide is accurate and
complete, no liability can be accepted for any errors or omissions. We reserve the right to change the
specication of the product described at any time without prior notice. Do not copy, record, reproduce
or transmit the contents of this guide without prior permission.
1.1 General

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1.2 Introduction
The WFU12-4C wire feed unit is designed to work in conjunction with the Newarc range of inverter
based power sources. This powerful four roll drive wire feed system boasts electronic stabilization for
precise wire speed control. The large digital display allows for easy reading in low and high ambient light
conditions; and displays voltage and wire feed speed in either inches or meters per minute.
The simple front panel layout allows for ease of set up and all functions are directly accessible by the
multi function control knob and water proof push buttons.
Common functions such as wire feed speed and voltage adjustment have priority over other functions.
Features
• Powerful 4 roll wire drive system with electronic feed-back to provide
accurate and stable wire feed
• Digital display of wire feed speed and voltage, wire speed may be set
in either inches or meters per minute.
• Set burn back time.
• Set slow start time.
• Set initial start voltage.
• Set pre-gas and post-gas time.
• 2T or 4T gun switch latching.
• Wire inch and gas purge buttons.
• Display activity, (displays how many hours the wire feeder has been in use)

WFU12-4C 9
0 - 23 m/min
24 - 36V AC
450 amps @ 60%
Weight (kg)
Digital Display
Voltage Control
Wire Speed Range
Wire Diameter
1.3 Technical Specications
Newarc WFU12-4C
Current Rating
350 amps @ 100%
0.8mm - 2.0mm
Max Wire Spool Size 30cm / 12”
Input Voltage
Yes
Yes
Dimensions (L x W x H) (mm) 640 x 235 x 440
13

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1.4 Overview of Panel MF34
*(Only available on programmable version)
** (Only available on Vref version)
1. Adjustment knob
On initial power up the display will display if the optional
Voltage reference PCB is tted (Activ UI)
• Press the control knob once to alternate between
Voltage (U) and Wire speed (WS). Turn the knob to
adjust the parameter.
• Double press the control knob to access the additional
parameters. Then a single press to select the
options below. Turn the knob to adjust the parameter.
1:1 Program Mode (Prg) *
1:2 Burn Back (Bur)
1:3 Start Voltage (SV)
1:4 Slow Start (Slo)
1:5 Pre Gas (Pre)
1:6 Post Gas (Pos)
1:7 Crater Fill (CrF) *
• Once these settings have been adjusted, wait for 3
seconds and a beep will indicate that they have been
saved.
• Any settings which have been adjusted during the
welding process will automatically be saved after
welding has nished and the 3 seconds has elapsed.
• Press and hold the control knob to access the advanced
menu.
2:1 Wire feed scale (WS scale)
2.2 Auto arc voltage correction (AutoDem) **
2:3 Version (Version)
2:4 Overload Level (OvrldLvl)
2:5 Overload delay (OvrldDel)
2:6 Activity Counter (ActivCnt)
2:7 Programs locked (PrgLock) *
• To exit the menu select exit or press and hold
adjustment knob(1)
2. Wire Inch button
Initiates wire-feed without having to press the MIG torch
switch, Used when feeding the wire
through the torch when changing wire spools.
3. Gas Test button
Press to test gas ow.
4. Torch latch button
Changes the mode of operation of the MIG torch switch
between 2T, 4T & 4D. In 2T, the MIG torch switch is
pressed to start welding and released to stop. In 4T, the
torch switch is pressed and released to start welding and
pressed and released again to stop welding. 4D is similar
to 4T but with a delay time of 1 second before it latches
on allowing a quick tack feature.
Front View
Panel layout
1. Adjustment Control knob
2. Wire inch button
3. Gas Test button
4. Torch latch button

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ADDITIONAL PARAMETERS MENU
1.1 Program mode (Prg) Program save
• Set the wire feed unit up ensuring all required settings
have been adjusted.
• Double press the control knob(1) to enter addition
parameters menu then select program mode (Prg).
• Turn the control knob(1) to select a program number to
save too.
• Press and hold the control knob until SAVED is displayed.
NOTE!A total of 9 programs can been saved.
1.2 Program Load & Program Exit
The program that is currently loaded is displayed on the
far right of the display. 0 indicated no program is currently
loaded.
• Double press the control knob(1) to enter program
mode (Prg).
• Turn knob(1) to select the desired program.
• Press the adjustment knob(1)once to load.
• To exit a program, enter program mode, select program
dash(-) and press and hold the adjustment knob(1) for 3
seconds, END will be displayed.
1.3 Burn-back (Bur)
This determines how much of the wire is left sticking out
of the contact tip when welding is stopped. Too much
wire and there is a chance of it‘freezing’in the weld pool
as it cools, too little and there is a chance that the wire will
burn back into the contact tip, necessitating changing of
the tip.
1.4 Start Voltage (SV)
Allows an increase in the start voltage for 1 second at the
start of welding. It is adjustable between 0-10 volts.
1.5 Slow-Start (Slo)
The length of time up to 1 second for the wire speed to
be at 50% of the set wire speed value at the start of
welding.
1.6 Pre Gas (Pre)
The time in seconds after the torch switch is pressed that
the gas ows before welding starts .
1.7 Post Gas (Pos)
The time in seconds that the gas remains on after
welding has stopped.
Crater Fill (CrF)
This option allows you to setup one of the programs as a
selectable program to be recalled at the end of a 4T latch
operation for crater lling.
• Program one of the programs 1-9 with the parameters
to be used for the crater ll operation
• Select crater ll (CrF) option then select the correct
program (1-9) the number selected is the program
parameters to be used as crater ll.
• Select 4T mode. Press-release the torch switch to start
welding. To crater ll at the end of a weld, press and hold
the torch switch button. Release the button to stop the
crater ll process. An addition crater ll option is available
with the 4D latch mode of operation. Repeat the steps
above but select 4D mode.
• Press (hold for 1 second) then release latches on
the standard welding settings.
• Press (hold for 1 second) then release latches on
the crater ll program.
• Press (Hold for 1 second) then release latches on
the standard program again. This cycle can be
repeated as much as required.
• Press (Quick press) then release ends the cycle.
ADVANCED MENU
2:1 Wire feed scale (WS scale)
Selectable between Meters/Inches.
2:2 Auto arc voltage correction (AutoDem)
Auto corrects the arc voltage to be the same as the
set voltage (See Sec 4.5 voltage reference) Options of
(AV ON) Auto correction turned on or (AV OFF) Auto
correction disabled.
2:3 Version (Version)
Indicates the computer program version.
2:4 Overload Level (OvrldLvl)
Dictates the sensitivity of the overload function.
2:5 Overload delay (OvrldDel)
Dictates the length of time it takes before displaying
a fault condition when the motor is being overloaded.
2:6 Activity Counter (ActivCnt)
This is a log, in hours, of how long the unit has been in
operation. Turn the knob to view the total hours.
2:7 Programs locked (PrgLock)
Allows programs set in program mode to be locked (PLck
ON) therefore wire speed is a locked value and it only
allowing the voltage (U) to be adjusted by +-1V.
Or (PLck OFF) allows programs to be fully adjustable
once loaded.
Front View
Panel layout
1. Adjustment Control knob
2. Wire inch button
3. Gas Test button
4. Torch latch button

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1.5 Overview of Panel MF37
Front View
Panel layout
1. Adjustment Control for left display
2. Adjustment Control for right display
3. Mode select push button
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SECTION 4 — OPERATION
4.2 - Operational Controls for MF37 Front Panel
1:1 Program Mode (Pr)
Program Save
• Set the wire feed unit up ensuring all required set-
tings have been adjusted.
• Press the mode select button once to enter pro-
gram mode (PR).
• Turn Knob 1 to select a program number.
• Press and hold the mode select button until SAVE is
displayed.
Note: A total of 9 programs can been saved.
Program Load & Program Exit
The program that is currently loaded is displayed on dis-
play2’s right most digit. 0 indicated no program is cur-
rently loaded.
• Press the mode select button once to enter pro-
gram mode.
• Turn knob 1 to select the desired program.
• Press the mode select button once to load.
• To exit a program select PR , program dash (-) and
press and hold the mode button (3) for 3 seconds,
END will be displayed.
Note: In a loaded program: Wire speed(o), Demand off-
set (D) are non adjustable, voltage (U) only has a +- 1V
adjustment available.
1. Adjustment Control for left display
2. Adjustment Control for right display
3. Mode select push button
On initial power up the display will give the option to
select Welding arc voltage correction (Auto) (if the
optional Voltage reference PCB is fitted).
Turn the left hand knob(1) to select YES or NO. The
Auto led on the front panel will light when auto mode
is selected.
After initial power up the following options are shown
and can be adjusted with the corresponding knob:
Display1/knob1 Display2/knob2
Voltage (U) Wire-speed (o)
Pressing the mode button (3) allows other options to
be displayed on the two displays. These options are
adjusted using the knob below the corresponding
display.
Display1/knob1 Display2/knob2
1. Program Mode (Pr)
2. Burn-back (B) Latch (L)
3. Slow-Start (S) Post Gas (P)
4. Crater Fill (C)NO/1-9 Demand offset (D)
Last welding results display: voltage (U) current (A)
The last digit of the display indicates a letter to show
the option mode selected.
Note: Any settings that are changed are saved after a
3 second period.
1 2
3
Display 1 Display 2
On initial power up the display will give the option to select Welding arc voltage correction (Auto) (if the
optional Voltage reference PCB is tted). Turn the left hand knob(1) to select YES or NO. The Auto led on the front
panel will light when auto mode is selected.
Display1/knob1 Display2/knob2
Voltage (U) Wire-speed (o)
Pressing the mode button (3) allows other options to be displayed on the two displays. These options are
adjusted using the knob below the corresponding display.
Display1/knob1 Display2/knob2
1. Program Mode (Pr)
2. Burn-back (B) Latch (L)
3. Slow-Start (S) Post Gas (P)
4. Crater Fill (C)NO/1-9 Demand oset (D)
Last welding results display: voltage (U) current (A)
The last digit of the display indicates a letter to show the option mode selected.
NOTE! Any settings that are changed are saved after a 3 second period.

WFU12-4C 13
1:1 Program Mode (Pr)
Program Save
• Set the wire feed unit up ensuring all required
settings have been adjusted.
• Press the mode select button once to enter program
mode (PR).
• Turn Knob 1 to select a program number.
• Press and hold the mode select button until SAVE is
displayed. Note! A total of 9 programs can been saved.
Program Load & Program Exit
The program that is currently loaded is displayed on
display2’s right most digit. 0 indicated no program is
currently loaded.
• Press the mode select button once to enter program
mode.
• Turn knob 1 to select the desired program.
• Press the mode select button once to load.
• To exit a program select PR , program dash (-) and
press and hold the mode button (3) for 3 seconds,
END will be displayed.
NOTE! In a loaded program: Wire speed (o), Demand
oset (D) are non adjustable, voltage (U) only has a +-
1V adjustment available.
2:1 Burn-back (B)
This determines how much of the wire is left sticking
out of the contact tip when welding is stopped. Too
much
wire and there is a chance of it‘freezing’in the weld
pool as it cools, too little and there is a chance that the
wire will burn back into the contact tip, necessitating
changing of the tip.
2:2 Latch (L)
2T, 4T & 4D. In 2T, the MIG torch switch is pressed to
start welding and released to stop. In 4T, the torch
switch is pressed and released to start welding and
pressed and released again to stop welding. 4D is
similar to 4T but with a delay time of 1 seconds before
it latches on allowing a quick tack feature.
3:1 Slow-Start (S)
The length of time up to 1 second for the wire speed
to be at 50% of the set wire speed value at the start of
welding.
3:2 Post Gas (P)
The time in seconds that the gas remains on after
welding has stopped.
4:1 Crater Fill (C)
This option allows you to setup one of the programs
as a selectable program to be recalled at the end of a
4T or 4D latch operation for crater lling.
• Program one of the programs 1-9 with the
parameters to be used for the crater ll operation. (See
program mode on how to save a program (1:1)
• Select crater ll (C) option then select the correct
program (1-9) the number selected is the program
parameters to be used as crater ll.
• Select 4T or 4D mode. Press-release the torch switch
to start welding. To crater ll at the end of a weld press
and hold the torch switch button. Release the button
to stop the crater ll process.
4:2 Demand oset (D)
This option can be used when the Auto function is not
available. This allows a small voltage compensation to
help compensate for voltage drop of long welding
cables
NOTE!
1: If the MF37 is left idling for more than 4 minutes the
panel goes into standby made. This is indicated by a
small red LED in display2 pulsing on and o. To
reactivate the panel press or turn anything on the
MF37 panel or press the MIG torch switch.
2: During welding the MF37 displays the voltage (U)
(If the optional voltage ref PCB is tted) and the
current (A) of the welding arc (if the optional Current
transducer LEM circuit is tted).

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1.6 Overview of Panel MF33
WFU12-4C
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1. Burn back adjustment - This determines how much of the wire is left sticking out of the contact tip
when welding is stopped. Too much wire and there is a chance of it 'freezing' in the weld pool as
it cools, too little and there is a chance that the wire will burn back into the contact tip, necessi-
tating changing of the tip. Adjusting the control anti-clockwise increases the amount of wire stick-
ing out of the tip and adjusting it clockwise reduces it.
2. Wire speed control - Adjusts the speed of the wire feed system up to a maximum of 23m/min.
3. Voltage control - Controls the welding voltage when used in conjunction with a Newarc R4/5000
multi-process or constant voltage power source.
4. Latch - Changes the mode of operation of the MIG torch switch between 2T and 4T. In 2T, the
MIG torch switch is pressed to start welding and released to stop. In 4T, the torch switch is pressed
and released to start welding and pressed and released again to stop welding.
4.4 - MIG Welding
• It is assumed that the wire and welding torch have been fitted as per the installation part of this
manual.
• Set the Voltage control and wire speed controls proportional to the thickness of metal to be
welded.
• Select the welding torch mode required.
• Ensure the gas cylinder is turned on and the flow-meter or regulator is set to give approximately 15
to 20 Litres per minute. (30 to 40 cubic feet per hour).
• Until you are familiar with the machine it is preferable to start welding on a piece of waste material
the same type and thickness as the work-piece, adjust the voltage control (if fitted), wire feed and
gas flow until the required welding condition is achieved.
When used with the Newarc power sources all the controls can be adjusted whilst welding without dam-
aging the machine.
4.3 - Operational Controls for MF33 Front Panel
3
1
2
4
SECTION 4 — OPERATION
Front View
Panel layout
1. Burn back adjustment
2. Wire speed control
3. Voltage control
4. Latch

WFU12-4C 15
1. Burn back adjustment
This determines how much of the wire is left sticking out of the contact tip when welding is stopped.
Too much wire and there is a chance of it ‘freezing’in the weld pool as it cools, too little and there is a
chance that the wire will burn back into the contact tip, necessitating changing of the tip. Adjusting the
control anti-clockwise increases the amount of wire sticking out of the tip and adjusting it clockwise
reduces it.
2. Wire speed control
Adjusts the speed of the wire feed system up to a maximum of 23m/min.
3. Voltage control
Controls the welding voltage when used in conjunction with a Newarc R4/5000 multi-process or
constant voltage power source.
4. Latch
Changes the mode of operation of the MIG torch switch between 2T and 4T. In 2T, the MIG torch switch
is pressed to start welding and released to stop. In 4T, the torch switch is pressed and released to start
welding and pressed and released again to stop welding.
MIG Welding
• It is assumed that the wire and welding torch have been tted as per the installation part of this
manual.
• Set the Voltage control and wire speed controls proportional to the thickness of metal to be
welded.
• Select the welding torch mode required.
• Ensure the gas cylinder is turned on and the ow-meter or regulator is set to give approximately 15
to 20 Litres per minute. (30 to 40 cubic feet per hour).
• Until you are familiar with the machine it is preferable to start welding on a piece of waste material
the same type and thickness as the work-piece, adjust the voltage control (if tted), wire feed and
gas ow until the required welding condition is achieved.
When used with the Newarc power sources all the controls can be adjusted whilst welding without
damaging the machine.

WFU12-4C
16
2. Installation
Connection to Power Source
Only use copper welding cables with a cross sectional area
of 35mm2or more. Use the graph below to calculate the
cable size suitable for the required welding distance.
NOTE! The gures on the graph are for a duty cycle rating
of 60%. The total welding circuit includes the power and
the earth leads.
• For straight polarity welding, connect the power in
connector on the rear of the wire-feeder to the +ve
connector on the power source.
• Connect the welding earth lead to the -ve connector
onthe power source and attach the earth clamp to the
workpiece.

WFU12-4C 17
Fitting wire spool
The feed rollers must always be selected to match the size of the electrode wire being used. The feed
rollers tted to the wire-feeders normally have two dierent sized grooves.
• Make sure that the outlet wire guide located inside the torch adapter is of the correct size for the wire
being used.
• Open the pressure lever on the wire drive assembly.
• Remove the retaining nut on the spool holder and t wire spool so that the locating pin on the spool
holder ts into corresponding hole in the wire reel.
• Replace the retaining nut on the spool holder.
• Release the end of the wire from the spool and cut o the bent length, take care that the wire does not
spill o the spool
• Insert the wire through the rear wire guide, over the drive rollers and through the outlet wire guide so
that approximately 5cm of wire is protruding from the torch adapter.
• Close the pressure roller ensuring that the wire lays in the drive roll groove.
Connecting the Welding Torch
• Make sure that the liner and contact tip tted to the torch are of the correct size for the wire being used.
• Attach the welding torch to the torch adapter on the wire feed, making sure that the torch liner
retaining nut goes over the wire protruding from the torch adapter.
• Line all the connections on the torch up with their relevant sockets in the torch adapter and screw the
torch onto the wire feeder.
NOTE! The torch should screw easily onto the wire feeder, if any resistance is felt - do not force the torch
onto the wire feeder.
Feeding the Wire through the torch
• Set the wire feed speed control to about half way.
• Keeping the welding torch as straight as possible press the wire inch button until the wire is fed
through the torch and out through the contact tip.
• The wire pressure lever adjuster should be set so that when the wire is restricted at the welding torch
the drive rollers will slip. Setting the tension too high may cause the wire to build up inside the wire
drive assembly as well as cause excessive loading of the motor which will result in a reduced duty cycle.
Adjusting Brake Tension
• Remove the spool-retaining nut.
• The head of the brake adjusting screw is now visible in the centre of the spool holder.
• Turn the screw clockwise to tighten the brake and anti-clockwise to slacken it.
• It is advisable to check the tension every time a new spool of wire is tted as it is the extra weight of a
full spool that generally causes problems with the spool over-running and wire spilling o the spool.
Connecting the Gas Hose
A Gas hose suitable for use with Argon or CO2 up to a pressure of 10 bar (150 psi) should be connected
between the pressure regulator on the gas cylinder and the gas connection on the rear of the wire feed
unit. Do not over-tighten this connection.
NOTE! The pressure regulator should be set between approximately 3 and 5 bar for normal use.

WFU12-4C
18
When welding in MIG mode there is always a voltage drop associated with the losses in the welding cables and
the operator must always set the power source output higher than the required arc voltage to overcome loss.
The WFU12-C wire feeders has an optional automatic voltage control system that automatically adjusts the
power source output to compensate for voltage drop caused by the welding cable losses.
The operator may set the voltage and wire feed speed on the front panel of the wire feeder before welding
with the knowledge that any losses in the interconnection cables and earth lead will be automatically
compensated for. It is possible to increase or decrease the welding interconnection length without any
change to the wire feeder settings and still maintain the set arc voltage.
The automatic voltage control system is ideal for welding applications where the point of welding is some
way from where the power source is sited.
For the automatic voltage control to work correctly the voltage reference lead must be connected directly to
the welding work and must remain connected in order to ensure an accurate reading of arc voltage.
3. Operation
WFU12-4C
13
SECTION 4 — OPERATION
4.5 - Voltage Reference
When welding in MIG mode there is always a voltage drop associated with the losses in
the welding cables and the operator must always set the power source output higher
than the required arc voltage to overcome loss.
The WFU12-C wire feeders has an optional automatic voltage control system that auto-
matically adjusts the power source output to compensate for voltage drop caused by
the welding cable losses.
The operator may set the voltage and wire feed speed on the front panel of the wire
feeder before welding with the knowledge that any losses in the interconnection cables
and earth lead will be automatically compensated for. It is possible to increase or de-
crease the welding interconnection length without any change to the wire feeder set-
tings and still maintain the set arc voltage.
The automatic voltage control system is ideal for welding applications where the point of
welding is some way from where the power source is sited.
For the automatic voltage control to work correctly the voltage reference lead must be
connected directly to the welding work and must remain connected in order to ensure
an accurate reading of arc voltage.

WFU12-4C 19
MIG Welding Problems
Porosity (holes) in weld - Has two common causes:-
1. Lack of shielding gas caused by the ow-meter not being set correctly, damage to any of the gas
hoses or MIG torch, a build up of spatter inside the MIG torch nozzle or dispersal of the gas shield by the
wind or fume extraction system.
2. Poor surface condition of the weld metal caused by inadequate surface preparation or contamination
by oil, grease or paint.
Wire burns back to contact tip
Caused by voltage being too high for wire feed speed, wire feed restricted by blocked tip or liner,
insucient tension on pressure roller or excessive brake tension on spool holder.
Cold arc with excessive spatter and weld bead too high (convex)
Caused by the voltage being too low for the wire feed speed or metal thickness, inductance control
on power source set too high, the power cables between the power source and wire-feed are either too
long or of inadequate cross section and are causing a volt drop or the MIG torch or earth lead are
damaged.
Hot arc with large irregular spatter and weld bead too at, or even concave
Wire feed too slow or voltage set too high.
Wire glows red hot and reluctant to arc
Power source set to MMA (constant current), either change power source to MIG (constant voltage) or set
wire-feeder to constant current setting. When using the Wire-feeder in constant current mode, especially
with ux-cored wires, it improves the welding characteristic if reverse polarity is used (torch -ve)
4. Fault nding

WFU12-4C
20
Torch
4.2 MF37 / MF37P Fault codes
Err 5
Err 4
DRUerr
Text on Display Panel Corrective Action
Beeps every second Display fault. Call service.
Torch is pressed during startup Release button, Reset machine
Temperature sensor fault
Check Overload setting value
Motor driver fault
Check wire tension
Motor overloaded
Call service
Motor jammed
Motor drive main supply error
Check wire tension and gearbox
Motor Driver over temperature
Short on torch switch socket
Check wire tension and gearbox
Motor drive aux supply error
Call service
Motor unit not detected
Call service
Temperature sensor supply
Check wiring to motor
Motor unit not working
Call service
Description
HOT
Err 3
No display
Err 6
Err 7
Err 8
Err 9
Check wiring to motor
Call service
Err 10
Torch
4.1 MF34 / MF34P Fault codes
Error 5
Error 4
Error 1
Text on Display Panel Corrective Action
Beeps every second LCD fault. Call service
Torch is pressed during startup Release button, Reset machine
Temperature sensor fault
Check Overload setting value
Motor driver fault
Check wire tension
Motor overloaded
Call service
Motor jammed
Motor drive main supply error
Check wire tension and gearbox
Motor Driver over temperature
Short on torch switch socket
Check wire tension and gearbox
Motor drive aux supply error
Call service
Motor unit not detected
Call service
Temperature sensor supply
Check wiring to motor
Motor unit not working
Call service
Description
OverTemp
Overload
MotorJAM
No display
Error 6
Error 7
Error 8
Error 9
Call service
Call service