NewArc MIG400 Quick start guide

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Newcastle UponTyne
Tel. [phone]
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Operational Manual
Newarc MIG400
NA9910208

MIG 400
2
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
Welding power source for MIG
Brand name or trade mark
Newarc
Type designation etc.
MIG 400
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.

MIG 400 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 off 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 different
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 off 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.

MIG 400
4
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 affect 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. Difficulties
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.

MIG 400 5
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 affect 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.

MIG 400
6
1. Preface 7
1.1 General 7
1.2 Introduction 8
1.3 Technical Specications 9
1.4 Overview of Machine 10
2. Installation 12
3. Operation 13
3.1 Start up Display 14
3.2 Standard Display Functions 14
3.3 Standard Display Functions MIG 15
3.4 Standard Display Functions User Menu 16
3.5 Standard Display Functions Errors 17
4. Fault Finding 18
4.1 Welding Problems 19
5. Maintenance 20
6. Warranty 21
7. Electrical Diagram 22
8. Parts 23
Contents

MIG 400 7
1. Preface
Congratulations on choosing your Newarc MIG400 inverter
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 effort 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

MIG 400
8
1.2 Introduction
These heavy duty D.C inverter power sources have been designed using the latest developments in
power electronics. Electronic parts are enclosed in a separate sealed compartment for protection from
the environment.
This portable, versatile inverter power source responds to changes in the welding arc much faster than
conventional machines resulting in a more stable and controllable weld pool.
Due to the high efficiency and power factor these units provide energy and cost saving solutions.
The MIG400 Power Source is capable of MIG welding when used with a peripheral wire feed unit.
Features
• Ecient 400 power source.
• 4 roll drive system.
• 70% duty cycle.
• Digital display.
• Choice of panels.
• Inductance and Arc trim.
• Consumes less energy.
• Fan assisted cooling.
• Safety circuits protecting against overloading.

MIG 400 9
Input Current
Recommended Mains Fuse
Mains Cable
Max Output Current
Duty Cycle at 40ºC
Voltage Control
Power Consumption
1.3 Technical Specications
Newarc
380-480 Volts 3 Phase
50/60Hz
Power voltage (V)
24A
18.5 KVA
32A slow blow or type C MCB
Variable
4 x 4.0mm² exible cable
0.95
400 amps
Power Factor
40V
2 - 40V Innitely Variable
400A @60%
350A @100%
MIG400
Open Circuit Voltage
Power Source (L x W x H) (mm)
Insulation Class
Weight (kg)
F
450 x 310 x 570
33

MIG 400
10
1. Mode Indication
LEDs to display welding mode (MIG 400 power source only
the MIG LED will function).
2. Rotary encoder
Adjusts the machines functional parameters and user
settings, as well as output current in CC mode or Voltage in
CV mode (when not controlled remotely).
3. O/On switch
Switches the machine on and off when the main 3 Phase
isolation switched is in the on position. Upon switching
on, the display will show the software version and the
machines output will be inhibited, after 4 seconds display
will clear and the machine is ready to use.
4. Digital Display
Indicates welding current in Amps,
welding voltage in Volts. The display also gives an indication
when the machine is over temperature (-OT -) , or the
optional cooling unit is turned off (-CU-).
1.4 Overview of Machine
Front View
Panel layout
1. Mode Indication
2. Rotary encoder
3. Off/On switch
4. Digital Display
5. Inductance control
6. Slope control
7. Remote control socket
8. -ve weld terminal
9. +ve weld terminal
10. Main 3P Isolation switch
MIG400
Power Source
7
SECTION 4 — OPERATION
4.1 Description of controls
1. Mode Indication - LEDs to display welding mode (MIG 400 power source only the MIG LED will function).
2. Rotary encoder - Adjusts the machines functional parameters and user settings, as well as output current in CC mode or Voltage in CV mode (when not controlled remotely).
3. Off/On switch - Switches the machine on and off when the main 3 Phase isolation switched is in the on position. Upon switching on, the display will show the software version and
the machines output will be inhibited, after 4 seconds display will clear and the machine is ready to use.
4. Digital Display - Indicates welding current in Amps, welding voltage in Volts. The display also gives an indication when the machine is over temperature (-OT -) , or the optional
cooling unit is turned off (-CU-).
5. Inductance control - Operates in MIG mode only. This control alters the response time of the power source and is generally used in short circuit dip transfer welding. Too little
inductance will result in excessive spatter and too much inductance will not allow the welding current to rise fast enough causing the electrode to stub into the base metal.
6. Slope control - Operates in MIG mode only. This control alters the output voltage(V) to output current(I) relationship. This control is sometimes know as ‘Arc Control’ or ‘Arc
Pinch Control’ as it regulates the pinch effect of the welding arc.
7. Remote control socket - For connection of external remote control or wire feed unit. There is no switch for remote operation, plugging an external unit into the socket automati-
cally selects remote operation
8. +ve weld terminal - Main welding power output connector, positive polarity.
9. -ve weld terminal - Main welding power output connector, negative polarity.
10. Main 3P Isolation switch - Switches the machine on and off.
11. Mains Input - Three phase mains cable.
12. Auxiliary transformer supply fuse - Fuse 3.15A slow blow, 32 x 6.3mm ceramic body.
13. Remote supply fuse - Protects the auxiliary supply from the remote control socket. Fuse type is 20 x 5mm glass body, 6.3A ‘slow blow’ rating
14. Main supply fuse to the cooling unit (Only fitted to cooling unit version) - Fuse 3.15A slow blow, 32 x 6.3mm ceramic body.
15. Auxiliary Cooling unit supply fuse (only fitted to cooling unit version) - protects the auxiliary supply to the cooling unit. Fuse type is 20 x 5mm glass body, 2A
‘slow blow’ rating.
3
7
6
2 10
11
12
13
1
8
9
15
MMA
TIG
MIG
4
5
14
Rear View
Panel layout
11. Mains Input
12. Auxiliary transformer supply fuse
13. Remote supply fuse se
14. Main supply fuse to the cooling unit
15. Auxiliary Cooling unit supply fuse

MIG 400 11
5. Inductance control
Operates in MIG mode only. This control alters the response time of the power source and is generally used in short
circuit dip transfer welding. Too little inductance will result in excessive spatter and too much inductance will not allow
the welding current to rise fast enough causing the electrode to stub into the base metal.
6. Slope control
Operates in MIG mode only. This control alters the output voltage(V) to output current(I) relationship. This control is
sometimes know as‘Arc Control’or‘Arc Pinch Control’as it regulates the pinch effect of the welding arc.
7. Remote control socket
For connection of external remote control or wire feed unit.There is no switch for remote operation, plugging an
external unit into the socket automatically selects remote operation
8. +ve weld terminal
Main welding power output connector, positive polarity.
9. -ve weld terminal
Main welding power output connector, negative polarity.
10. Main 3P Isolation switch
Switches the machine on and off.
11. Mains Input
Three phase mains cable.
12. Auxiliary transformer supply fuse
Fuse 3.15A slow blow, 32 x 6.3mm ceramic body.
13. Remote supply fuse
Protects the auxiliary supply from the remote control socket. Fuse type is 20 x 5mm glass body, 6.3A‘slow blow’rating
14. Main supply fuse to the cooling unit (Only tted to cooling unit version)
Fuse 3.15A slow blow, 32 x 6.3mm ceramic body.
15. Auxiliary Cooling unit (only tted to cooling unit version)
Protects the auxiliary supply to the cooling unit. Fuse type is 20 x 5mm glass body, 2A‘slow blow’rating.

MIG 400
12
2. Installation
Unpacking
Check the packaging for any signs of damage. Carefully remove the machine and retain the packaging until the
installation is complete.
Positioning of the machine
Place the machine on a rm, dry and level surface. Where possible, do not allow dust or other impurities to enter
the machines cooling air ow. Preferably site the machine above oor level; fsuch as a suitable carriage unit.
Notes for positioning the machine
• Make sure there is at least 20cm clearance at the front, rear and sides of the machine to allow good circulation
of the cooling air.
•Ensure that the machine is positioned in such a way that particles created by grinding and cutting operations
do not enter the machine.
NOTE! Damage caused by metal particles and water entering the machine will not be covered under warranty.
WARNING! All electric shocks are potentially fatal, a competent electrician should under-take the tting of the
mains plug.
Connecting to mains supply
• Make sure that the mains supply is of the correct voltage and current
capability for the machine.
• Make sure that any extension cables used are of sufficient current
carrying capacity.
• Make sure that the mains plug and socket (if tted) are in good
condition and are of the correct current carrying capacity. If the machine
is wired directly to the mains supply then an isolator switch must be
tted.
NOTE! See technical specications page for correct supply information
Primary cable length
Long extension cable lengths may reduce the performance of the machine, the welding arc may become
unstable especially at higher currents. Ensure the mains cable is not coiled up when you are welding as this will
reduce the input voltage to the machine and may cause overheating and degradation of the cable.
Setting supply voltage tapping
WARNING! All electric shocks are potentially fatal, a competent electrician should carry out any supply voltage
tapping adjustments required.
• To enable the setting of the supply voltage tapping, the front panel display cover of the R4000/R5000 has to be
removed.
• The photograph above shows the voltage tapping set to 415V, with the red wire from the fuse holder connect-
ed to the 415 terminal.
• This connector can be moved to the required voltage terminal to select the desired input voltage.

MIG 400 13
3. Operation
Front panel operation
This design is based on microprocessor technology and allows to implement set of functions previously not
available in Newarc inverters:
• Encoder based function control - digital settings
• Hot start control
• Operation time control
• Welding duration (resettable user counter available as an optional extra)
• Error identication and counter
• Mode changing
• Cooling unit control
• Improved remote control
Conguration
Front Panel is factory calibrated and in most cases doesn’t need additional adjusting. If any problem occurs
please contact service for advice.To check set maximum parameters and mode access use function“Settings
Check”(Start-up Display)
Software
By default both the current and voltage displays show four dashes when not welding. When current ows, panel
shows actual current and voltage on display.
Every other function is accessible by short pressing encoder down and turning encoder anti- or clockwise for the
correct value.

MIG 400
14
3.1 Start up Display
MIG400
Power Source
8
SECTION 4 — OPERATION
4.2 - Front panel operation
4.2.1 Description
This design is based on microprocessor technology and allows to implement set of functions
previously not available in Newarc
inverters like:
encoder based function control - digital settings
operation time control,
welding duration (resettable user counter available as an optional extra)
error identification and counter
mode changing
cooling unit control
improved remote control
4.2.2 Configuration
Front Panel is factory calibrated and in most cases doesn’t need additional adjusting. If
any problem occurs
please contact service for advice.
To check set maximum parameters and mode access use function "Settings Check" (3.1
Start-up Display)
4.2.3 Software
By default both the current and voltage displays show four dashes when not welding. When
current flows, panel shows actual current and voltage on display.
Every other function is accessible by short pressing encoder down and turning encoder anti- or
clockwise for the correct value.
4.2.4 Start-up Display
1 P.5.9.8.
8.1.0.0. Program no. and version display Only during display start
2 L.S.-. 1.
8.5.0.0.
Settings Check
Maximum current set for MMA mode
(This mode not available on MIG 400)
Function accessible when encoder button
press long during start-up.
This is info only, no changes are possible.
LED4 (bottom) is flashing when mode is
available (mode availability is specified by
software version)
Restart is necessary to stop display
3 L.S.-.2.
8.3.0.0.
Settings Check
Maximum current set for MIG mode
4 L.S.-.3.
8.4.0.0.
Settings Check
Maximum current set for TIG mode
(This mode not available on MIG 400)
3.2 Standard Display Functions
MIG400
Power Source
9
SECTION 4 — OPERATION
4.2.5 Standard display functions
5 8.8.8.8
•
8.8.8.8. Top, right decimal point constantly ON Remote control detected
6 8.8.8.8
*
8.8.8.8. Top, right decimal point flashing Output voltage detected (when output volt-
age >5V and no remote connected)
7 8.8.8.8.
8.8.8.8
*
Bottom, right decimal point flashing Current flow detected (when current flow
>5A)
8 _._._.U.
8.3.3.A
*
Dashes on the bottom of the voltage display and
current flow diode flashing
Current flow and output voltage too low
(<5V)
9 ~.~.~.U.
8.3.3.A
*
Dashes on the top of the voltage display and cur-
rent flow diode flashing
Current flow and output voltage too high
(>50V)
10
1.0.0.U
*
8.3.3.A
*
Voltage and current display with
U and A characters Actual current and voltage readings
11
1.0.0.U.
8.3.3.A.
Voltage and current display with flashing U and A
characters
Average welding conditions from the last
job. That function is automatically displayed
after stop current flow but is also accessible
as a menu function.
Minimum current flow time to activate func-
tion is 5s
12 -.-.-.-.
-.-.-.-. Change mode
Mode is selected by turning encoder. Cur-
rently selected mode is indicated by one of
the LED diodes
13 d.u.r.8.
8. 1. 1.3. Welding time duration
Personal time counter in minutes.
Every decimal point = 6min
Maximum value 999.9min
Long press to reset value
14 d.u.r.8.
C.L.r.8.
After long press counter is resetting and mes-
sage "dur.clr" displayed for short time

MIG 400 15
3.3 Standard Display Functions MIG
MIG400
Power Source
10
SECTION 4 — OPERATION
Default function
Conditional function
Additional function
A or V letters are dimmed on display for better recognising read value of voltage and current
4.2.6 Standard display functions: MIG Mode
Actual Current and Voltage
(When welding)
Set Voltage
dur
Welding Time Duration
(Long press to reset. Optional
extra, not fitted as standard)
Mode Change
(Only when remote off)
Average Values
(After 5s of weld)
MIG
1.0.0.U.
8.8.8.8
.
Set Voltage

MIG 400
16
3.4 Standard Display Functions
MIG400
Power Source
11
SECTION 4 — OPERATION
4.2.7 Standard display functions: USER Configuration Menu
Reachable after long encoder button press (~3s) and indicated by flashing 3 LED diodes
To save changes, press long encoder button (~3s)
A
Activity Time
T
Total ON Time
C.U.
Cooling Unit Control
Er.
Errors Register
CodE
Service Code
drU
Control PCB Current Status
SERVICE Functions
USER
A.8.8.8.
8. 1.0.' . Activity time (hours)
Shows time how long current flow was detected
A.8.8.8.
8. 2.4.' '. Activity time (minutes)
t.8.8.8.
8. 1.0.' . Total ON time (hours)
Shows time how long device was ON
T.8.8.8.
8. 2.6.' '. Total ON time (minutes)
C.U.8.8.
8.o.F.F.
Cooling Unit
Error Register
Cooling unit disconnected or not active.
Signal from cooling unit is ignored.
C.U.8.8.
8.8.O.n.
Cooling unit is connected.
Stand-by function not active.
C.U.8.8.
8.6.O.n.
Cooling unit is connected.
Stand-by function active
Active only in communication mode
Set time range 2..30min
E.r.8.2.
8.8.8.4. Error Register
Display counter for each type of error
(during service mode long press will reset all counters
and display text ErCL)
C.O.d.E.
-.-.-.-. Service Code Enter
Function available only once correct start-up sequence
conducted (2).
Enter correct service code by turning encoder and press
button to access service functions
User Conguration Menu

MIG 400 17
User Conguration Menu 3.5 Standard Display Functions
R5/4000 CCCV
13
SECTION 4 — OPERATION
4.2.10 Standard display functions: Errors
Front Panel Errors
E.r.8.0.
-.o.t.-.
ERROR 0
-OT-
Over temperature fault Internal temperature too high
E.r.8. 1.
8.8.8.8. ERROR 1 Error 1
Microprocessor fault
Microprocessor internal reference volt-
age low - probably there is negative (<-
0.25V) or positive (>5.5V) voltage
connected to one of the microprocessor
pins
E.r.8. 2.
-.C.U.-.
ERROR 2
-CU-
Error 2
Cooling unit problem
Error signalled by Cooling Unit. Check
if water flow is correct
E.r.8.3.
c.o.n.t.
ERROR 3
CONT
Error 3
Wrong mode
Wrong mode demand from display
panel - check display panel available
modes
E.r.8.4.
c.u.r.r.
ERROR 4
CURR
Error 4
Inverter was switched off during current
flow
Error is displayed during start-up for 5s
Output current flow was noticed and
machine was switched off.
ERROR 5 Microprocessors restarts This is an errors counter visible during
configuration mode in Errors Register
E.r.8. 6.
-.C.U.-.
ERROR 6
-CU-
Error 6
Cooling unit communication problem
There is missing OK signal from cool-
ing unit. Check cooling unit for any
possible connection faults or discon-
nect it in configuration
E.r.8.7.
8.8.8.8. ERROR 7 Error 7
Control PCB communication problem
Communication with Control PCB is
down
(no data received from Control PCB by
at least 20sec)
TIPS
• during turning encoder fast, acceleration function is activated and for that time counter is increased
with x10 steps
• A or V letters are dimmed on display for better recognising read value of voltage and current
Errors
TIPS
• During turning encoder fast, acceleration function is activated and for that time counter is increased
with x10 steps
• A or V letters are dimmed on display for better recognising read value of voltage and current

MIG 400
18
4. Fault nding
Machine Operation Problems
Most problems with the MIG400 can be overcome by following the procedures below.
No Digital Display on switch on
• Check that the machine is attached to a working mains supply that it is correctly plugged in and any
isolator switches are closed.
• Check the condition of the 2A fuse on the rear panel of the machine and replace if necessary.
Note! Make sure the fuse is replaced with one of the correct type and rating. It should be a 32 x 6.3mm
(1¼”x ¼”) ceramic bodied type with a rating of 2A ‘slow blow’
• Have a competent electrician check that there are no mains fuses or overload devices interrupted, that
the mains plug is tted correctly and that there are no loose wires or connections, check that there are
no breaks in the mains cable.
Digital display lit but no output
• Make sure that the display is not reading‘OT’, if it is, it means that the R4000/R5000 has overheated,
normally by exceeding its ’Duty Cycle’, and the power stages of the machine have been shut down.
In this case, leave the machine switched on until it has cooled down, if you turn the machine off, the
cooling fans will be turned off also and the cooling down period will be lengthened considerably.
Note! If the R4000/R5000 is overheating on a regular basis or at current settings below the maximum,
this would usually indicate that the inside of the machine is choked with dust and therefore not being
cooled correctly. For information about cleaning the dust out of the R4000/R5000 please refer to the
three monthly service schedule.
MIG Unit is not working
• Check the condition of the 6.3A fuse on the rear panel of the machine and replace if necessary.
Note! Make sure the fuse is replaced with one of the correct type and rating. It should be a 20 x 5mm
glass bodied type with a rating of 6.3A ‘slow blow’. Any welding problems not covered above must be
brought to the attention of a qualied Welding Engineer, if the problem still persists have the R4000/
R5000 checked by a trained Newarc service engineer.

MIG 400 19
4.1 Welding problems
MIG
If problems are experienced whilst MIG welding, please consult the fault nding and maintenance
section of the WFU instruction manual.
Any welding problems not covered above must be brought to the attention of a qualied Welding
Engineer, if the problem still persists have the R4000/R5000 checked by a trained Newarc service
engineer.

MIG 400
20
5. Maintenance
Note!
All Electric shocks are potentially fatal, switch off the machine and unplug from the
mains supply before carrying out any maintenance work.
It is very important that the Wire feed unit is regularly maintained. The amount of use and the working
environment must be taken into account when scheduling the maintenance periods. Careful use and
regular preventative maintenance will prolong the life of the machine and ensure trouble free operation.
Weekly
• Clean the exterior of the machine and remove any dirt and pieces of MIG wire that may have collected
inside the wire spool compartment.
• Remove any build up of dirt from the wire feed rollers.
• The wire tension adjuster should be set so that when the wire is restricted at the welding torch the
drive rollers slip. Remember if the pressure is set too high the wire may pile up behind the front wire
guide and undue strain will be put on the wire feed system leading to a reduced duty cycle and lifespan.
• If necessary, adjust the brake tension on the spool holder so that the wire spool stops at the same time
as the feed rollers.
• Inspect the machines exterior for obvious signs of damage.
• Check the condition of the welding cable, earth clamp and welding connectors for damage and any
sign of over-heating.
• Check the gas hose and regulator for leaks, remember that air leaks can result in weld porosity.
• Check the condition of the MIG welding gun, check for cuts in the cable sheath, condition of the liner
and condition of the contact tip. Remove any build up of spatter from inside the gas nozzle.
Three monthly
As per the weekly schedule, plus:
• Remove the cover from the machine and remove the build up of dust and debris from inside the
machine. Either use compressed air at low pressure or an industrial vacuum cleaner.
• Make a thorough visual inspection of the interior of the machine, look particularly for pieces of welding
wire and other foreign matter.
• Check the condition of the weld current input connector and Euro socket, look for any signs of
discolouration due to overheating, this is generally caused by poor connection of the welding power
leads due to poor quality welding connectors and can be a common cause of welding set failure.
• Check that the gas solenoid retaining nut is secure and that the gas hose inside the machine is in good
conditio and shows no sign of kinking or of rubbing on any internal component.
Annually
As per the three monthly schedule, plus:
• Have the wire-feeder calibration checked, if necessary have the machine re-calibrated by a Newarc
trained technician.