Taurus MIG 280 PLUS User manual

Digital Inverter Pulsed Gas Metal
Arc Welding Machine
MIG 280 PLUS
Operation Manual
Read this manual carefully before installing,
operating and maintaining the machine.

- 1 -
Description: This machine is designed and built to weld ferrous and non-ferrous metals.
Disclaimer: The information, illustrations and instructions described in this manual
are based on the latest product information available at the time of publication. The
manufacturer and distributors reserve the right to modify the contents of this manual
at any time. Modifications may result following product modifications and the
manufacturer and distributors are not obliged to notify any organization or individual
of such modifications. Welding work must be executed only by professionally trained
and qualified individuals. Therefore, the manufacturer and distributors will only
accept responsibility for product quality. No liability, joint or several, shall be
accepted for incidents including but not limited to loss of profit resulting from
omissions or misdirection that may be printed in this operation manual. This manual
will contain as far as possible preventive and safe operation measures related to the
equipment but cannot exclude the occurrence of accidents. Therefore, the
manufacturer and distributors shall not be liable for any direct or indirect, joint or
several liability for any incidental or consequential damages which may occur. For
detailed health and safety information, the relevant professional agencies and
manufacturers of consumables such as welding materials and flux should be
contacted.
Warranty Exclusions:
✓Consumable items such as welding wires, welding flux, fuses, quick
connectors, drive rollers, tension rollers, etc.
✓Machine damages caused by incorrect voltage input or power surges.
✓Machine or parts malfunction owing to incorrect connections or user operation.
✓Illegal disassembly or re-fitment of the machine without permission of the
manufacturer, resulting in damage or malfunction.
✓Accidental damage during shipment, transportation and storage.
✓Damage owing to incorrect handling, natural disaster and other force majeure
occurrences.

- 2 -
CONTENTS
Safety Precautions .........................................................................3
Warnings ........................................................................................4
Packaging and Transportation ...............................................................7
Parameters .............................................................................................8
Product Description ................................................................................8
Working Principle.................................................................................. 16
Installation and Wiring..........................................................................17
Brief Procedure for Welding Operation ................................................27
Maintenance .........................................................................................30
Common Machine Malfunctions and Solutions....................................30

- 3 -
Safety Precautions
The equipment is designed for use by qualified personnel who have completed
professional training and have obtained a qualification certificate as a welder/cutter.
The operator shall have sufficient professional knowledge of welding, cutting and
circuitry. The machine should be operated only after having read and fully
understood all the safety precautions and warnings contained in this manual and
those generally applicable to welding operations. The risk of personal injury and
damage to equipment is reduced by safety precautions being followed when using
tools and equipment. This machine is easy to operate and the selection of its
functions is straight forward. Improper use and maintenance will reduce the safe
operation of the machine and the following safety precautions must be followed:
1. The operator must be suitably qualified and certificated before operating the
equipment.
2. A qualified professional should be employed to ensure that the machine and all
cables are properly connected, grounded and installed.
3. Personal protective equipment approved by the local safety authority must be
used. All relevant safety procedures must be adhered to.
4. Before operation, insulation layers on wires and cables as well as connection
sequences should be inspected and corrected if required.
5. Repairs and maintenance should be carried out by qualified technicians only
after the machine has been disconnected from the electricity supply.
6. Operating the machine in a humid environment may result in a short circuit or
may cause an electric shock to the operator.
7. Modifications to the machine or equipment are not allowed.
8. The disposal of scrap machine parts and equipment must comply with local
regulations.

- 4 -
Warnings
Welding and cutting operations are specialised operations which present a certain
degree of risk. Professional training, correct operating procedures and protective
measures reduce the accident risk and damage to equipment.
Personal Safety Protection
Welding and cutting operations generate noise, bright light and
high-temperature sparks which will cause harm to human hearing,
eyes and skin unless personal protective measures are
implemented and proper operational instructions are adhered to.
1
Wear flame retardant personal protective equipment (PPE) such as gloves,
overalls, welding/cutting helmets, shoes and aprons to protect against
thermal radiation, sparks and hot metal particles.
2
Hot sparks and metal fragments can cause skin damage. Avoid clothes with
front pockets and button-up sleeves and collars.
3
Use appropriate flame-retardant shields or curtains to protect bystanders
from arc radiation and high temperature sparks. Bystanders also need to
wear a protective helmet fitted with a shading filter to protect face and eyes
or a pair of spectacles fitted with shading filters.
4
Avoid burns and scalds by not touching a welded work piece with bare
hands.
Fire and Explosion Hazards
Welding and cutting operations generate high-temperature flames
and arc which can cause fires and explosions. The same applies to
welding slag and sparks.
1
Operators and bystanders must be protected from arc, sparks and metal
fragments.
2
The welding/cutting area should be free from flammable and explosive
materials. Should these materials be required in the welding/cutting process,
flame retardant covers should be applied.
3
Care should be taken to avoid fire hazards from cracked floors and walls.

- 5 -
4
Welding and cutting on sealed gas tanks will cause explosions. These
operations are prohibited.
5
Welding and cutting areas must be provided with adequate fire extinguishing
equipment. Regular testing for efficiency of this equipment is compulsory as
is training of staff in the use of the equipment.
6
Once the welding/cutting operation is completed, check for any high
temperature spark or metal which might cause a fire and immediately
dispose of it. If necessary, employ the assistance of a firefighter.
Electricity Hazards
Electric shock can cause serious injury or even death to the
individual when contact is made with live wires. Humid conditions
can add to the risk and great care should be taken when welding or
cutting machines are used in these conditions.
1
Reliable grounding of machine and work piece as well as a secure ground
clamp, is important.
2
Insulation layers of electric wires and cables must be checked regularly for
wear and replaced if necessary.
3
All equipment used and clothing worn during the welding/cutting operation
should be free from moist and kept dry.
4
Do not make direct body contact with any live electrical parts.
5
Wearing rubber-insulated shoes and standing on an insulated platform
greatly reduce the risk of accidental shock.
6
Refrain from replacing the ground cable on the machine with wires not
suitable for the task.
7
The machine operates on high voltage and capacitors remain charged even
after power is switched off. Removing covers for maintenance procedures
must only be executed by qualified professionals.
Effects of Electromagnetic Fields
Electric current flowing through a conductor produces magnetic
fields (EMF). The discussion on the topic of the effects of EMF on
the human body is ongoing worldwide and up to the present no
evidence has been forthcoming proving negative effects on health.

- 6 -
However, it would be wise to limit exposure to EMF as far as
possible and the following procedures are suggested:
1
Welders and cutters with cardiac pacemaker implants should obtain medical
advice on the effects of EMF on the implant.
2
Welders should minimise the possibility of electromagnetic field damage
through the following methods.
2.1
Route the electrode and ground cables together and, where possible, secure
them with tape.
2.2
Do not wrap wires and cables around arms or coil power cables around body
parts. If possible, keep cables away from the body.
2.3
Keep the distance between the ground clamp to the workpiece and the
electrode as short as possible.
2.4
Keep a safe distance between the operator and the welding/cutting machine.
Protection from Fumes and Gases
During the welding or cutting process, fumes can be produced
which may be detrimental to health.
1
The working area should be well ventilated and welding/cutting activities
should not be executed in confined spaces. Eye, nose or throat discomfort
can be the result of inadequate ventilation.
2
Welding and cutting in or near locations where chlorinated hydrocarbon
vapours are produced such as degreasing, cleaning and spraying
operations, should not be undertaken since phosgene, a highly toxic gas as
well as other irritants can be reaction products.
3
The industry offers a variety of respiratory masks and must be used in
conditions where clean breathing air is required.
Gas Cylinder Safety
Gas leaks can occur on cylinders connected to welding/cutting
operations if the system is not properly managed and maintained.
A ruptured cylinder or relief valve can cause serious injury or can
even be fatal.
1
Gas cylinders should be kept away from extreme temperatures and fire
sources. Scratching on cylinder walls with hard objects should be avoided.

- 7 -
2
A pressure regulator should be installed on the gas cylinder in use in
accordance with the manufacturer's operating instructions. Quick-coupling
connectors must not be used and gas hose fitting should be tested for leaks.
3
Gas cylinders must always be kept upright and chained or belted to a
cylinder trolley, base, wall, post or shelf. Never fix a gas cylinder to a
worktable or machine: It can become party to an electrical circuit and
explode.
4
Ensure that the cylinder valve is closed when not in use. If there is no hose
connected to the cylinder regulator then cover the outlet with a dust cap.
Protection Against Moving and Rotating Parts
Moving parts, such as fans, rotors and belts, can be
hazardous.
1
Ensure that all protective covers, doors and panels on the machine are
closed or securely intact before starting an operation.
2
Ensure that maintenance on machines are only carried out by qualified
technicians.
3
Ensure that hands, hair, clothing and tools are safely out of range from
moving and rotating parts.
Packaging, Transportation and Handling
1. Pay attention to and comply with packaging, storage and transportation
instructions which are clearly identified on the containers.
2. Always handle all containers with care.
3. Equipment must be stored in waterproof, moisture proof and well-ventilated
facilities within the temperature range -25°C - 55°C.

- 8 -
Parameters
Model
MIG-280
MIG-280PLUS
Parameters name
Value
Rated input voltage:
AC380V±10% 50Hz 3PH
Rated input power:
9.2kVA
9.2kVA
Rated input current:
14A
14A
Output current range:
10A~280A
10A~280A
Open circuit voltage:
70V
70V
Rated duty cycle:
60%
60%
Efficiency:
≥85%
≥85%
Wire diameter(mm):
Φ0.8~1.6
Φ0.8~1.6
Gas flow rate(l/min):
5~15
5~15
Insulation grade:
F
F
IP grade:
IP21S
IP21S
Package
dimensions(mm):
980×540×790
980×540×1020
N.W.:
48kg
59kg
Product Description
The welding machine in this series inverts the 50Hz power supply to a high-
frequency, high-voltage power supply. The inversion process is facilitated by a
powerful IGBT device followed by step-down rectification and pulse-width modulation
(PWM) technology producing a high-power DC output suitable for welding. The
advanced inverter technology allows for the construction of a smaller volume and
light-weight, stable and reliable transformer with a 30% improved efficiency.
Added to the advantages of the inverted power supply, the machine has good
dynamic characteristics, and offers a stable arc, good welding quality and ease of
control.
This semi-automatic, high-performance machine is designed for argon or carbon
dioxide and mixed-gas welding on aluminium, aluminium alloys, low-carbon steel,

- 9 -
low-alloy steel, stainless steel and copper. Aluminium welding wire (4043/5356) and
0.8mm - 1.6mm diameter steel and stainless-steel wire as well as other solid or flux-
cored wires can be used.
The inverter welding machines in this series are manufactured in accordance with
IEC60974-1 <Arc Welding Equipment - Part 1: Welding Power Sources >, Safety
Requirements for Arc Welding Equipment.
1. Product Functions and Features:
1.1. All-in-one multiple welding functions served by a digital CPU control system
delivering a precise digital output.
1.2. A reliable work performance and fast dynamic response is ensured by the IGBT
high-frequency, soft-switching inverter technology.
1.3. A stable welding process and excellent arc self-regulation is ensured by the
closed-loop control system regulating a stable voltage in cases of grid-voltage
fluctuation.
1.4. Less spatter and a high metal-deposition rate.
1.5. Excellent weld-seam appearance and low heat-input distortion.
1.6. An excellent arc start resulting from an intense pulse-to-strike arc.
1.7. A wire feeding circuit which adopts a stable power supply ensuring smooth wire
feeding.
1.8. Troubleshooting is minimised by the protection circuit ensuring safety and
reliability.
1.9. Small size, light weight, high efficiency and reliable duty cycle as well as a
noiseless arc produced by the rectifier.
1.10.Good structure, simple layout and ease of maintenance.

- 10 -
2. Appearance Diagram:
MIG-280PLUS
1
Control panel：Welding parameter settings and display.
2
Euro standard torch connector：Connecting the welding torch.
3
Gas cylinder fixed base：Accommodating the gas cylinder.
4
+
6
Terminal sockets - positive pole (+) and negative pole (-): In MMA mode
the electrode holder cable is connected to the positive terminal and the earth
cable is connected to the negative terminal and should be reversed when
using scratch start DC TIG in MMA mode. In MIG mode the polarity cable is
connected to the positive terminal and the earth cable is connected to the
negative terminal for all MIG welding applications, except for gasless flux-
core welding where the polarity cable is reversed and connected to the
negative terminal and the earth cable is connected to the positive terminal.
5
Polarity conversion plug：When using flux-cored wires the coupling device
is connected to the negative pole.
1
2
3
6
4
5

- 11 -
Panel:
1
Push-button - Welding Material：Select between AlSi, AlMg, CrNi, Fe, Cu
or SP and the selected material light will be turned on.
2
Save-button：Saves the completed welding parameters.
3
Memory-button：Ten sets (0 - 9) of adjusted welding parameters can be
recalled and saved during each operation.
4
Wire-feed-button: Press and hold the feed button to start the wire feed.
Releasing the button will stop the wire feed.
5
Gas：Press and hold the gas button to start the gas flow inspection.
Releasing the button will stop the gas flow.
6
Resume-button: After holding this button depressed for 3 seconds, all
parameters will be restored to factory values.
7
Voltage-adjusting Dial: Turning the dial will adjust the voltage output.
8
Push-button - Left Menu: Tapping this button will allow setting voltage, arc
voltage and induction when the corresponding light is lit.
9
Push-button - Right Menu: Tapping this button will allow setting current,
wire-feed speed, thickness and time when the corresponding light is lit.
10
Current-adjustment dial: Turn the dial to adjust the current output..
11
Push-button - Select from parameters：Tapping this button will allow
setting values of pre-flow, ignition current, up slope, down slope, finish
current and post-flow when the corresponding light is lit.
4
12
1
2
7
8
9
10
3
5
6
11
13
14
15

- 12 -
12
Push-button - Select from parameters：When welding type is selected
as double pulse, selected as 'double pulse', short-pressing this key will
adjust the corresponding value of frequency/ duty cycle/ amplitude when
the relevant light is lit.
When Spot is selected under mode operation short-pressing this key will
adjust the welding time.
When spot continuous is selected under mode operation short-pressing
this key will adjust welding and interval time.
13
Push-button - Operation Mode Selection: Switch trigger modes between
2T (without arc stopping), repeat 2T, 4T (with arc stopping), spot, continuous
spot and communicate with the robot. When the corresponding light is lit, the
selected mode is operational.
14
Push-button - Welding Type Selection: Select between pulse MIG, double
pulse MIG, standard MIG and MMA welding. When the corresponding light is
lit, the selected mode is operational.
15
Push-button - Wire Diameter Selection：Wire diameter 0.8mm, 1.0mm or
1.2mm is selected when corresponding light is lit.
3. Setting the Trigger Mode
3.1. 2T Mode
This setting applies for short-spell welds and the responding current curve is depicted
below:
0~t1: Press torch trigger. Gas pre-flow starts.
t1~t2: Wire feed starts. Gas flows.
t2: Welding operation starts and current reaches preset value.

- 13 -
t3~t4: Trigger released. Wire feeding stops and current drops to zero. Post-
flow gas will continue for a short period. Note: the gas pre-flow and post-flow
not adjustable in T2 mode.
3.2. 4T Mode
This mode is suited for longer spell welding operations and entail the following:
arc start current, preset current, arc-stop current. The following represents the
current, gas-flow and wire-feed curve when the 4T mode is selected:
0~t1: Press torch trigger. Gas pre-flow starts.
t1~t2: Wire feed starts and gas flows.
t2~t3: Welding operation starts and welding current reaches the arc-start
current. If the trigger is not released, the operation will continue with the start
current.
t3~t4: Trigger released and the welding current will reach the preset current in
the upslope time.
t5~t7: Trigger pressed again. Welding current will drop to the arc-ending value
in preset downslope time. If the trigger is not released, the operation will
continue on the arc-ending current value.
t7~t8: Trigger released. Wire feed stops, current drops to zero. Post gas flow
will continue for a short period of time.
In the 4T mode pre-flow time, arc-start current, upslope time, downslope time,
arc-ending current and post-flow time are adjustable individually.

- 14 -
3.3. Spot-welding Mode
In this mode, welding time can be preset and the diagram below depicts the
activity:
0~t1: Press torch trigger. Gas pre-flow starts.
t1~t2: Wire feed starts and gas flows.
t2: Welding starts and the welding current reaches the preset value.
t3: Trigger released within the preset welding time, wire feed stops
immediately and the current drops to zero. Gas post flow will continue for a
short period of time. Note: The pre-flow and post-flow times not adjustable in
the spot-welding mode.
t4/t5: Trigger released after the preset welding time, the operation will stop
when the preset time has elapsed and the current drops to zero as post-flow
will continue for a short period of time. Note: The pre-flow and post-flow times
not adjustable in the spot-welding mode.
3.4. Continuous Spot-welding Mode
Select the Spot Continuous mode, press and hold the torch trigger for welding at the
preset current for the duration of the operation. Spot time and spot interval work in a
cycle and the welding operation stops when the trigger is released.
3.5. Robot Mode
Select the robot mode to allow communication between the welding machine and the
welding robot.

- 15 -
4. Auxiliary Welding Parameter Settings
Moving the menu button will allow selection of different parameters when the relevant
light is lit.
Parameters
Default
Adjustable range
Pre-flow
0.1s
0.1s~5s
Ignition current
100A
20A~280A
Up slope
0.1s
0s~14.9s
Down slope
0.1s
0s~14.9s
Finish current
100A
20A~280A
Post-flow
1s
0.1s~5s
5. Selection of Welding Wires
A variety of welding wires in a range of diameters can be selected. As a general rule
Ø1.0mm or Ø1.2mm wire is used for welding aluminium and Ø1.2mm is the
recommended diameter. For copper, stainless steel and carbon steel material Ø0.8mm
or Ø1.0mm wire can be used.
Welding
process
Wire type
Diameter
(mm)
Work piece
material
Shielding gas
Pulsed
MIG/MAG
Aluminum-silicon
alloy
Ø 0.8
Ø 1.0
Ø 1.2
Soft aluminum:
4043,4047
≥99.99%Ar
Aluminum
magnesium alloy
Hard aluminum:
5356,5183,MgAl5
≥99.99%Ar
Copper
Ø 0.8
Ø 1.0
Ø 1.2
Cu18,Cu19,CuSi3,
CuAl9
≥99.99%Ar
Stainless steel
304,316,312,308
98%Ar+2%CO2
Carbon steel
80%Ar+20%CO2
Synergic
MIG/MAG
Carbon steel
Ø0.8
Ø 1.0
100%CO2

- 16 -
Working Principle
1. Three Ways to Connect the Polarity Reversal Cable
1.1. General Connection（Welding Mode: Pulse/double pulse)
1.2. Flux-cored Welding（Welding Mode: MIG/MAG）：
1.3. MMA Welding（Welding Mode: MMA）：
2. Diagram Explaining Working Principle
2.1. A bridge rectifier converts AC to DC;
2.2. Controlled by PWM, the IGBT inverts the DC to 33Khz AC and transmits it
through a high-frequency transformer;
2.3. After secondary rectification and reactor filtering, the output current is sufficient to

- 17 -
meet the welding requirements;
2.4. The in-time protection circuit provides signals to the PWM warning for overheat
and over-current situations;
2.5. The closed-loop control method is adopted to make the welding power source
have good anti-grid fluctuation ability and excellent welding performance.
Installation and Wiring
1. Location Requirements
1.1. The machine should not be installed in an area where it is exposed to direct
sunlight or rain but where the humidity is as low as possible and the ambient
temperature is within the range of -10 °C - 40 °C.
1.2. The machine should be installed on a flat, preferable level surface but, in any
case not on a surface with an inclination of more than 10 degrees.
1.3. The machine should not be operated in a work station exposed to wind. Should
a windy environment be unavoidable, suitable screening should be installed.
1.4. In order to allow for efficient ventilation, a clear space of at least 20cm should be
allowed in front of and behind the machine as well as at least 10cm at each
side.
2. Power Input Requirements
The power supply waveform should be the standard sin wave, the rated voltage
380V±10% 50/60Hz. Three phase voltage unbalance should be ≤5%.
Parameters
Value
Input power
AC380V±10% 50/60Hz 3PH
Min. grid capacity
6.2kVA
Min. electric generator capacity
10kVA
Fuse:
10A
Circuit breaker：
20A
Input cable：
≥3mm2
Output cable：
35mm2
Ground cable：
≥1.5mm2
Note: The specifications of fuse and circuit breaker in the above table are for reference
only.

- 18 -
3. Main Power Supply Connection
Pay attention to prevent electric
shock
Wear goggles
Warning: Take note of the following when the welding machine is connected to
the main power supply:
3.1. The connection must be carried out by a qualified electrician or technician.
3.2. The connection must be in compliance with national and local regulations.
3.3. Before the connection is carried out, the main power supply to the control box
must be switched off.
3.4. An earth cable set must be securely connected from the machine to the work-
piece. The machine must be earthed.
3.5. Ensure that the required power supply of the machine (as printed on its
nameplate) corresponds to the main power supply.
3.6. The connection screws on the terminal block must be tight ensuring a solid
connection between the machine cable wires and the main power supply.
3.7. The correct wiring procedure is explained in the following diagram:
Wiring of Three Phase AC, 50/60Hz Welding Machine
2b
3
7
6
4
5
1
2c
2d
2a

- 19 -
No.
Item
No.
Item
1
Power cord
3
Terminal block
2a
Live wire L1
4
Overcurrent protection device
2b
Live wire L2
5
GND
2c
Live wire L3
6
Earth wire terminal block
2d
Earth wire
7
Electric control box
4. Gas-cylinder Connection
Explosion hazard
Prevent gas
inhalation
Wear goggles
Warning: The following safety instructions are important when connecting a gas
cylinder to the welding machine.
4.1. The cylinder must be fixed upright to a wall, cylinder rack or support. Its centre
of gravity can cause the cylinder to topple resulting in injury and material
damage.
4.2. The cylinder must be placed out of reach of the operator and not in contact with
the work table, work-piece or the welding machine.
4.3. Position yourself beside the valve and remove the air valve cover. ①Carefully
open the valve slowly. ②slightly allow the gas flow to clear the valve outlet from
dust and dirt ②.
4.4. Mount the flowmeter ④to the cylinder ③.
4.5. Connect the gas hose firmly from the flowmeter outlet ⑤to the gas inlet ⑥
situated at the back of the welding machine. Gas leakage is not allowed.
4.6. Adjust the flowrate in accordance with the manufacturer's recommendation.
Generally, 15 -20 litres/min.