GWS MIG200 User manual

INSTRUCTION MANUAL
IMPORTANT: Read This Instruction Manual Completely before operating this equipment. Save this
manual and keep it handy for quick reference. Pay particular attention to the hazards and safety
precautions provided for your protection and for the protection of those in the immediate vicinity
where this device is to be used. Contact your distributor if you do not fully understand this
manual or require additional information.

1
Contents
Features
1.0 Recommended Safety Precautions ................. 2
1.1 Personal Safety Warning Signs .............................. 2
1.2 Safety Precautions Preface .................................... 2
1.3 Electrical Shocks ..................................................... 4
1.4 User Responsibilities .............................................. 4
2.0 Introduction ......................................................... 4
2.1 Working Principle ................................................... 5
2.2 Volt-Ampere Characteristics .................................. 5
3.0 Installation and Adjustment ............................ 6
3.1 Parameters............................................................... 6
3.2 Duty Cycle & Over Heating..................................... 6
3.3 Movement and Placement ..................................... 7
3.4 Power supply input connection.............................. 7
3.5 Polarity Connection (MMA).................................... 7
3.6 Assembling the equipment (TIG) ........................... 7
5.0 Troubleshooting................................................. 16
4.0 Operation ............................................................. 8
4.1 Lay out For Front And Rear Panel........................... 8
4.2 Control Panel............................................................ 9
4.3 Argon ARC Welding Operation............................. 11
4.3.1 TIG Welding (4T Operation) ............................... 11
4.3.2 TIG Welding (2T operation)................................ 12
4.4 Welding Parameters............................................... 13
4.4.1 Joint form in TIG/MMA....................................... 13
4.4.2 The Explanation of Welding Quality ................ 13
4.4.3 TIG Parameters .................................................... 13
4.7 Operation Environment........................................ 15
4.8 Operation Notices .................................................. 15
PLEASE NOTE that under no circumstances should your
MIG200/250 be altered or changed in any way from
standard factory configuration. Doing so, will void the
machine warranty.
• Fan on demand
• True Multi-process MIG/Stick/2T/4T DC TIG in one machine
• Large 4.3 inch color screen
• Memory function that can hold up to 9
custom weld programs
• Power Factor Correction (PFC)
• Optional remote up/down mig torch
• Optional Spool Gun
• The MIG250 runs 2X Drive Rollers & 2X Pressure Rollers
• The MIG200 is a light weight, portable 17.6kg design
• Excellent results on MG-11 Gasless wires

1.1 Personal Safety Warning Signs
2
1.0 Recommended Safety Precautions
The above safety warning signs indicate the risk of personal
injury or even death. IMPORTANT! Hot or moving parts can
cause serious injury and electric shock can kill. Use the
following MIG200/250 operation guidelines to insure your
own personal safety and for those in the immediate vicinity
of your work area.
1.2 Safety Precautions Preface
• The following are explanations of dangers present while
operating the machine. Please remind yourself and others of
these dangers.
• Only people who are trained professionally can install,
debug, operate, maintain and repair the equipment.
• NEVER TOUCH electrical parts
• Use dry, hole-free gloves and other protective safety gear
• Protect yourself from work and ground using dry
insulation. Make sure inulation is sufficiently covering
the working area.
• Use caution when working in confined spaces, in wet
environments or where falling is a risk
CLOTHING:
Suitable clothing must be worn to prevent excessive skin
exposure to UV radiation, sparks and molten metal. Flame-
proof, loose fitting cotton clothing buttoned to the neck,
protective leather gloves, spats, apron and steel toe safety
boots are also highly recommended. In addition, use a
helmet with the recommended shade lens for amperage
listed in the shade chart below.
FUMES AND GASES CAN BE DANGEROUS:
• Welding may produce fumes and gases hazardous to
health. Avoid breathing these fumes and gases. When
welding, keep your head out of the fume. Use enough
ventilation and/or exhaust at the arc to keep fumes and
gases away from the breathing zone. When welding with
electrodes which require special ventilation such as stainless
or hard facing or on lead or cadmium plated steel and other
metals or coatings which produce highly toxic fumes, keep
exposure as low as possible and below Threshold Limit
Values using local exhaust or mechanical ventilation. In
confined spaces or in some circumstances, outdoors, a
respirator may be required. Additional precautions are also
required when welding on galvanized steel.
• Do not weld in locations near chlorinated hydrocarbon
vapors coming from degreasing, cleaning or spraying
operations. The heat and rays of the arc can react with
solvent vapors to form phosgene, a highly toxic gas, and
other irritating products.
• Shielding gases used for arc welding can displace air and
cause injury or death. Always use enough ventilation,
especially in confined areas, to insure breathing air is safe.
• Read and understand the manufacturer’s instructions for
this equipment and the consumables to be used, including
the material safety data sheet and follow your employer’s
safety practices.
ARC RAYS CAN BURN:
• Use a shield with the proper filter and cover plates to
protect your eyes from sparks and the rays of the arc when
welding or observing open arc welding.
Less than 150 amps
150 to 250 amps
250 to 300
300 to 350
Over 350 amps
Use one shade darker for aluminium welding
Shade 9
Shade 10
Shade 11/12
Shade 13
Shade 14
ELECTRIC SHOCK CAN KILL!

3
ROTATING PARTS MAY BE DANGEOUS:
• Use only compressed gas cylinders containing the correct
shielding gas for the process used and properly operating
regulators designed for the gas and pressure used. All hoses,
fittings, etc. should be suitable for the application and
maintained in good condition.
• Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.
• Cylinders should be located:
- Away from areas where they may be struck or subjected
to physical damage.
- A safe distance from arc welding or cutting operations
and any other source of heat, sparks, or flame.
• 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.
• Valve protection caps should always be in place and hand
tight except when the cylinder is in use or connected for
use.
ELECTRIC AND MAGNETIC FIELDS:
Electric current flowing through any conductor causes
localized Electric and Magnetic Fields (EMF). The discussion
on the effect of EMF is ongoing all around the world. Until
now, no material evidences show that EMF may have effects
on health. However, the research on damage of EMF is still
ongoing. Before any conclusions are made, we should
minimize exposure to EMF as much as possible.
In order to minimize EMF, we should use the following
procedures:
• Route the electrode and work cables together – Secure
them with tape when possible.
• All cables should be put away and far from the operator.
• Never coil the power cable around your body.
• Make sure the welding machine and power cable are as
far away from the operator as possible.
• Connect the work cable to the workpiece as close as
possible to the area being welded.
• People with heart pacemakers should stay away from the
welding area.
The equipment complies with electromagnetic compatibility
on the class A which is intended for users in any locations
other than residential locations where the electrical power is
provided by public low-voltage supply system.
• Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
the arc rays.
• Protect other nearby personnel with suitable, non-flam-
mable screening and /or warn them not to watch the arc nor
expose themselves to the arc rays or to hot spatter or metal.
WELDING SPARKS CAN CAUSE FIRE OR EXPLOSION.
• Remove fire hazards from the welding area. If this is not
possible, cover them to prevent the welding sparks from
starting a fire. Remember that welding sparks and hot
materials from welding can easily go through small cracks
and openings to adjacent areas. Avoid welding near hydrau-
lic lines. Have a fire extinguisher readily available.
• Where compressed gases are to be used at the job site,
special precautions should be used to prevent hazardous
situations.
• When not welding, make certain no part of the electrode
circuit is touching the work or ground. Accidental contact
can cause overheating and create a fire hazard.
• Do not heat, cut or weld tanks, drums or containers until
the proper steps have been taken to insure that such
procedures will not cause flammable or toxic vapors from
substances inside. They can cause an explosion even though
they have been “cleaned”.
• Vent hollow castings or containers before heating, cutting
or welding. They may explode.
• Connect the work cable to the work as close to the
welding area as practical. Work cables connected to the
building framework or other locations away from the
welding area increase the possibility of the welding current
passing through lifting chains, crane cables or other alter-
nate circuits. This can create fire hazards or overheat lifting
chains or cables until they fail.

1.3 Electrical Shock
• Never touch ‘live’ electrical parts
• Earth clamp all work materials
• Never work in wet or damp environments
Avoid electric shock by:
• Wearing dry, insulated boots
• Using dry, leather gloves
• Never changing electrodes with bare hands or wet gloves
• Never cool electrode holders in water
• Work on a dry, insulated floor where possible
• Never hold the electrode or holder under your arm
1.4 User Responsibilities
• Read the Instructional Manual prior to using your
MIG200/250
• Unauthorised repairs to this equipment may endanger
the technician and operator and will void your Warranty.
Only qualified personnel should perform repairs
• Always disconnect mains power before investigating
equipment malfunctions
• Replace broken, damaged, missing or worn parts & hoses
immediately.
• Equipment should be cleaned & serviced periodically
4
2.0 Introduction
The MIG200/250 welders are general MIG welders which
adopt the latest pulse width modulation (PWM) technology
and the insulated gate bipolar transistor (IGBT) power
module.
The MIG200/250 welders adopt ZVS and PFC(MIG200 only)
full bridge inverter technology. Single phase alternating
current (AC) after full bridge rectifier, after PFC for power
factor correction，adopting the boost booster technology ,
and then through filter, the whole bridge rectifier．
In order to improve the efficiency of the power supply，this
machine uses ZVS technology and phase-shifting to control
the average current control mode, which results with a more
efficient power factor of the power supply for a remarkable
improvement. At the same time, this machine is capable of
three welding patterns, such as MMA, MIG & TIG, so it can
satisfy all kinds of welding.
The MIG200/250 are suitable for all positions welding for
various plates made of stainless steel, carbon steel, alloyed
steel, aluminium, etc, which is also applied to pipe install-
ment, mould mend, petrochemical, architecture decoration,
car repairs, handicraft and common manufacture.
• The ZVS soft switch technology reduces the IGBT switching
loss.
• The efficiency of the machine has a lot of improvement, in
the state of MMA, it can reach nearly 84%
• MIG200/250 machines use the average current control
mode. They also have built in general protection functions
for:
Pulse width (PWM) limit
Over-voltage/over-current/over-heating
• MCU control system
• Reduced weight of the machine improves portability
MMA——Manual Metal Arc welding
PWM——Pulse-Width Modulation
IGBT——Insulation Gate Bipolar Transistor
TIG——Tungsten Insert Gas welding

5
2.1 Working Principle
The working principle of MIG200/250 welders is shown as
the following figure.
Single phase work frequency AC 220V (50 Hz) AC is rectified
into DC (about 310V), then is converted to medium frequen-
cy AC (about 44KHz) by inverter device (IGBT), after reduc-
ing voltage by medium transformer (the main transformer)
and rectified by medium frequency rectifier (fast recovery
diodes), and is output by inductance filtering. The circuit
adopts current feedback control technology to ensure
current output stability. The welding current parameter can
also be adjusted continuously to meet welding require-
ments.
Single Phase, AC
220V, 50HZ Rectify
DC
DC
AC
AC
DC
Inverter
Medium
frequency
transformer
Medium
frequency
rectify
Hall device
Current positive-
feedback control
2.2 Volt-Ampere Characteristic
MIG200/250 Series welders have an excellent volt-ampere
characteristic, displayed in the following graph. The relation
between the conventional rated loading voltage U2and
welding current I2is as follows:
When I2 ≤ 600A，U2＝14＋0.05I2
（V)；
When I2 ＞600A2，U2＝44（V）.
67
0 600 I
2
（A）
U
2
（V）
Working
point
Volt-ampere characteristic The relation between the
conventional loading
voltage and welding current
14
44

6
3. Installation & Adjustment
3.1Parameters
Note: The above parameters are subject to change with the improvement of machines.
3.2 Duty cycle & Over heating
The letter “X” stands for duty cycle, which is defined as the
proportion of the time that a machine can work continuously
within a certain time (10 minutes).
The rated duty cycle means the proportion of the time that a
machine can work continuously within 10 minutes when it outputs
the rated welding current.
The relation between the duty cycle “X” and the output welding
current “I” is shown as the right figure.
If the welder overheats, the IGBT over-heat protection unit inside
it will output an instruction to cut the output welding current, and
will light up the over-heat pilot lamp on the front panel. In the
even this occurs, the machine should be relaxed for 15 minutes to
cool the fan. When operating the machine again, the welding
output current or the duty cycle should be reduced.
x
I(A)
100%
60%
25%
The relation of the welding current and
duty cycle for MIG200
130 150 200
Power Supply Voltage (V) 220 50/60Hz
Duty Cycle @ (40°C 10min) 35% 250A
Power Factor
0.99
Protection Class IP23
Insulation Class F
469 x 223 x 421
Net Weight (kg) 17.6
MIG TIG MMA MIG TIG MMA
100% 170A
60% 195A 60% 195A
100% 170A
25% 200A
100% 105A
60% 140A
25% 200A
100% 105A
60% 140A
25% 200A
100% 105A
60% 140A
Effective Current (A) l1eff 21.4
15.51013 23.716
Welding Current Range (A) 10~250
10~20010~20010~200 10~25010~250
MIG 200 MIG 250
504 x 223 x 421
IP23
F
220 50/60Hz
0.99
35% 250A
60% 195A
100% 170A
35% 250A
Dimensions (LxWxHmm)
Rated Input Power (KW) 7.8
6.34.375.7 8.245.8
32
Machine

7
3.3 Movement and placement
Take care for the welder when moving it, ensure the machine is stood upright and refrain from sloping the machine.
It can also be moved by using the handle on top of the welder. When the machine gets to the destination, it needs to be securely
mounted to avoid sliding.
3.4 Power supply input connection
3.5 Polarity Connection (MMA)
Workpiece
-+-+
MIG200 MIG200
Holder
Workpiece
Holder
Electrode Electrode
DC POSITIVE CONNECTION DC NEGATIVE CONNECTION
MMA (DC): Choosing the connection of DCEN or DCEP according to the different electrodes. Please refer to the electrode
manual. (ie: MIG200)
3.6 Assembling the equipment (TIG)
-+
MIG200
Workpiece
Welding Torch
Ar
DC POSITIVE CONNECTION
MIG200
rear panel front panel
Gas Hose
Argon Gas
Cylinder
Pipe
Welding Cable
Control Cable of
torch switch
Shield gas
input joint
Shield gas
connector
Aero socket
(ie: MIG200)
The MIG200/250 welding machines’ power supply connects to 220V.
When the power supply voltage is over/under the safe work voltage, the over voltage or under voltage protection inside the
welder will trigger, turning the alarm light on and cutting the current output off.
If the power supply voltage continually goes beyond the safe work voltage range, it will shorten the machines life-span.
The below measures can be used:
• Change the power supply input net - connect the welder with the stable power supply voltage of the distributor
• Induce the machines current power supply at the same time
• Set the voltage stabilization device in the front of the power cable input

8
• The workpiece is connected to the positive electrode of the welding machine, with the welding torch connected to the
negative electrode, called the DC positive connection. Otherwise, it’s called the DC Negative connection. Generally it is usually
operated as a DC positive connection when TIG welding.
• The control cable of the torch switch consists of 2 wires, pedal control of 3 wires and the aero socket has 14 leads.
4. Operation
4.1 Layout For Front And Rear Panel
12
3
4
5
6
7
8
9
10
11
12
13
1. Current & wire knob Used to adjust the current and wire feeding speed
2. LCD Display Displays current working state and the related settings parameters
3. Voltage knob Used to adjust voltage downslope/arc force
4. Inductance adjusting knob Used for adjusting inductance
5. Main Control Knob Used for navigation and selection
6. MIG gun quick connector The MIG welders positive polarity output.
7.
8. Shield gas connector Is connected to the gas input pipe of torch.
9. Aero socket Is connected to torch switch control wire. (It has 14 leads and lead 8 - lead 9 are connected to
torch switch control wire
10. Negative output The welders negative polarity output
11. Shield gas input joint To connect one head of the gas hose while the other head is connected to the argon cylinder
12. Power source switch Turns the machine off and on.
13. Power source input To connect power source
14. Fan Triggers when the machine overheats, used for cooling components inside the welder.
Positive output The welders positive polarity output

9
4.2 Control Panel
§4.2 Control panel
LCD Display
Current &
wire
feeding speed
adjusting knob
Main Control knob
Voltage/downslope
/arc force adjusting
knob
Inductance
adjusting knob
Overview
The key feature of the control panel is the logical way in
which the controls are arranged. All the main parameters
are needed for day-to-day working can easily be:
• Selected with the keys
• altered with the adjusting dial
• shown on the display during welding
The illustration below shows an overview of the main
settings needed for day-to-day working, the following
section is a detailed description of these settings.
(1) Current and wire feeding speed adjusting knob
In different modes of welding, this button
has diverse function. In the mode of
MMA, it is used to adjust the welding
current. In the state of MIG, it is used to
regulate wire feeding speed. The range of
the current and speed are displayed in the
table.
TYPE MIG 200
The range of adjusting
current (A)
The range of wire feeding
speed (m/s)
10~200
3.0~25
(2) The LCD Display
According to the different welding states, this display will
show the current working state and the related setting
parameters. ie: In the state of MMA, when the user sets the
relative MMA parameters, the current, ARC
force, welding-way, diameter, thickness and electrode etc
will be displayed. When in the state of welding, it will
display the setting parameters, current voltage and current.

10
ARC force
Diameter
Thickness
electrode
Display the setting
current
Setting arc
force
Setting welding
current
Weld Way
The actual current and voltage display
(3) The Control Knob
This knob is mainly used for navigating and confirming selections. When shifting the button left or right,
the corresponding page will navigate to the left or right. When pressing the knob, the page will be selected.
Navigation shifting the knob to the right

11
(4) The adjustment button for voltage, down slope and arc force
In different welding states, this knob has differing functions:
(1) In the mode of MMA, it can adjust the arc force, the range is 0~10;
(2) In the mode of TIG, it can adjust the time of down slope;
(3) In the mode of MIG, it can adjust the welding voltage, the range is 10~25V
(5) The knob of inductance
This button is used for adjusting the output inductance, the range is 1~10, used to make the
machines welding performance better.
NOTE:
Only “Parameter selection keys” and “Adjusting dial” can be used in the welding process.
Only “Rod electrode welding key”, and “Adjusting dial” can be used on MMA mode.
4.3 Argon ARC Welding Operation
4.3.1 TIG Welding (4T Operation)
The start current and crater current can be pre-set. This function can compensate the possible crater that appears at the
beginning and end of welding. Thus, 4T is suitable for the welding of medium thickness plates.
TIG long welding (4T):
Introduction:
• 0: Press and hold the gun switch, Electronmagnetic gas valve is turned on. The shielding gas starts to flow
• 0~t1: Pre flow time, adjustment range of pre flow time: 0.1~1.0S
• t1: Striking success, adjustment range of start current 10~200A
• t2: Loosen the gun switch, the output current slopes up from start current. If the output pulse function is turned on, the
output current is pulsed
• t2~t3 Output current slopes up to the setting current value; adjustment range of up slope time 0~10.0S

12
• t3~t4: Welding process. During this period, the gun switch is loosened
• t4: Repress down the gun switch, the output current slopes down to crater current
• t4~t5: Down slope time, adjustment range of down slope time: 0~10.0S
• t5~t6: Crater current holds time; adjustment range of crater current: 10~200A
• t6: Loosen the gun switch, stop arc, and keep on argon flowing
• t6~t7: Post flow time, adjustment range of post flow time: 0.1~10.0S
• t7: Electromagnetic valve is closed and stopped argon flowing. Welding is finished.
4.3.2 TIG Welding (2T operation)
TIG short welding (2T):
t（s）
0
I（A）
Loosen the
welding gun
switch
Press and hold the welding
gun switch
t1 t4 t5
Arc is
ignited
Arc is
turned off
t2 t3
Welding current Is
The setting base
current Ib
•0: Press and hold the gun switch, Electromagnetic gas valve is turned on. The shielding gas starts to flow.
• 0~t1: Pre flow time, adjustment rane of pre flow time: 0.1~1.0S
• t1~t2: Striking success, the output current slopes up to the setting current from minimum current (10A);
• t2~t3: During the whole welding process, the gun switch is pressed and held without releasing.
• t3: Loosen the gun switch, the output current slopes down
• t3~t4: The output current slopes down to minimum current (10A), stop arc; adjustment range of down slope time: 0~5S
• t4~t5: Post flow time, adjustment range of post flow time: 0.1~10.0S
• t5: Electromagnetic valve is closed and stopped argon flowing. Welding is finished.
Introduction:
Short circuit protection function:
1. TIG /DC/LIFT：If the tungesten electrode touches the workpiece when welding, the current will drop to 30A,
which can reduce tungsten spoilage，prolonging the life of the tungsten electrode，and prevent tungsten clipping.
2.TIG /DC/HF：If the tungesten electrode touches the workpiece when welding, the current will drop to 0 within 1s,
which can reduce tungsten spoilage，prolonging the life of the tungsten electrode，and prevent tungsten clipping.
3.MMA operation：if the electrode touches workpiece over two seconds, the welding current will drop to the 0
automatically to protect the electrode.
Prevent arc-break function：TIG operation，Avoid arc-break with special means, even if arc-break occurs the HF will
keep the arc stable.

13
Notices:
•Check the condition of welding and connection units first, otherwise there may be malfunctions such as ignition
sparks, gas leakages, loss of control and so on.
•Check whether there is enough Argon gas in the shield gas cylinder, you can test the electromagnetic gas
valve via the switch on the front panel.
• Do not let the torch aim at your hand or other parts of your body. When you press the torch switch, the arc is ignited with
a high-frequency, high-voltage spark and the ignition spark can cause interferences in equipment.
• The flow rate is set according to the welding power used in the job. Turn the regulation screw to adjust the gas
flow which is shown on the gas hose pressure meter or the gas bottle pressure meter.
• The spark ignition works better if you keep the 3mm distance from the workpiece to the tungsten electrode during the ignition.
4.4 Welding Parameters
4.4.1 Joint form in TIG/MMA
Butt joint T jointCorner joint Lap joint
4.4.2 The Explanation of Welding Quality
The relation of welding area colour & the protection eect of stainless steel
Welding area
colour
Protect
effect
argent, golden blue red-grey grey black
best better good bad worst
The relation of welding area colour & the protection eect of Ti-alloy
Welding area
colour
Protect
effect
bright argent orange-yellow blue-purple caesious white powder of
titanium oxid
best better good bad worst
4.4.3 TIG Parameters
Gas Nozzle
diameter/mm
Electrode
diameter/mm
6.4 8 9.5 11.1
0.5 3.21.6 or 2.4 1.0
The corresponding relationship between gas nozzle diameter and electrode diameter

Welding current
range/A
DC Positive Connection
Gas Nozzle Diameter/mm Gas Flow Rate/L · min-1
10~100
101~150
151~200
201~300
4~9.5
4~9.5
6~13
8~13
4~5
4~7
6~8
8~9
Electrode Diameter Constant Included
Angle, Degrees
Current Range
A
1.0
1.6
1.6
2.3
2.3
3.2
3.2
.125
.250
.500
.800
.800
1.100
1.100
.500
12
20
25
30
35
45
60
90
2-15
5-30
8-50
10-70
12-90
15-150
20-200
25-250
MM IN
Diameter At Tip
MM IN
1.0
.040
1/16
1/16
3/32
3/32
1/8
1/8
.040
.005
.010
.020
.030
.030
.045
.045
.060
Workpiece
Thickness
/MM
0.8
1.5
1.5
2.4
2.4
3.2
3.2
1.0
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.0
Butt
Butt
Corner
Butt
Corner
Butt
Corner
Butt
Joint
Form
Tungsten
Electrode
Diameter/MM
Welding Wire
Diameter/MM
Argon Gas
Flow Rate/
L · min-1
Welding
Current
(DCEP)
Welding
Speed/
cm · min-1
4.8
4.8
Butt
Corner
2.4
3.2
1.6
1.6
1.6
1.6
2.4
2.4
2.4
2.4
3.2
3.2
5
5
7
7
7
7
7
7
8
9
20~50
50~80
65~105
75~125
85~125
95~135
100~135
115~145
150~225
175~250
66
56
30
25
30
25
30
25
25
20
14

15
15
Piping
Diameter
Φ/MM
38
60
76
108
133
159
219
42
2.0
2.0
2.5
2.0
Tungsten
Electrode
Diameter/MM
Gaas Nozzle
Diameter/MM
Welding Wire
Diameter/MM
Welding
Current/A
Arc
Voltage/V
Welding
Rate/
cm · min-1
273
325
75~90
75~95
75~100
80~105
90~110
90~115
95~120
100~120
110~125
120~140
11~13
11~13
14~16
14~16
14~16
14~16
14~16
14~16
14~16
6~8
6~8
7~9
8~10
9~11
10~12
11~13
12~14
12~14
12~14
4~5
4~5
4~5
4~5
5~6
5~6
5~6
5~6
5~6
5~6
Argon
Flow Rate/
L · min-1
2.5
2.5
2.5
2.5
2.5
2.5
2
2
2.5
2
2.5
2.5
2.5
2.5
2.5
2.5
8
8
8~10
8
8~10
8~10
8~10
8~10
8~10
8~10
11~13
4.7 Operation Environment
• Height above sea level is below 1000m.
• Operation temperature range:-10°C~+40°C.
• Relative humidity is below 90 %(+20°C). relative humidity
is below 50% (40°C).
• The inclination of the power source does not exceed 10°.
• Protect the machine against heavy rain or in hot circum-
stance against direct sunshine.
• The content of dust, acid, corrosive gas in the surrounding
air or substance can not exceed normal standards.
• Take care that there is sufficient ventilation during
welding. There is at least 30cm free distance between the
machine and wall.
4.8 Operation Notices
• Read section 1 carefully before attempting to use this
equipment.
• Connect the ground wire with the machine directly, and
refer to section 3.
• In the case of closing the power switch, no-load voltage
may be exported. Do not touch the output electrode with
any part of your body.
• Do not watch the arc with no eye protection.
• Ensure good ventilation of the machine to improve duty
ratio.
• Turn off the engine when finished to save power.
• When power switch shuts off protectively because of
failure, don’t restart it until the problem is resolved.
Otherwise, the range of potential problems will be
exacerbated.

5.1 Troubleshooting
If there are simple troubles with your MIG200/250 welding machine, you can consult the following overhauling chart:
When the machine is powered
on, the fan works but the
power light is not on
Light damaged or has a bad
connection
Power PCB Failures
Test/repair the inside circuit of power
light
Repair or change control panel
When the machine is powered
on, the power light is on
but the fan doesn’t work
There is something in the fan
The fan motor is damaged
Clear out
Change fan motor
When the machine is powered
on, neither the fan or power
light work
No input voltage Check whether there is input voltage
Over Voltage (input voltage is
too much or too little)
Check input voltage
No no-load voltage output There is trouble inside
the machine
Check the main circuit, Pr1 & Pr2
The max and min value
displayed doesn’t match
the set value
No Gas Flow (TIG)
Something in the valve
Gas cylinder is closed or gas
pressure is low
Electromagnetic valve is
damaged
Remove it
Open or change the gas cylinder
Change it
The displayed current on the
screen doesnt match output The LCD screen is broken Change the LCD screen
The welding current can
not be adjusted
The welding current
potentionmeter in the front
panel has a bad connection
or is damaged
Repair or change the potentionmeter
The penetration of the molten
pool is not enough
The welding current is
adjusted too low
Increase the welding current
Gas always flows
Something in the valve
The gas test on front panel is on
Electromagnetic valve
is damaged
Remove it
Turn off
Repair or change it
Repair or change it
The alarm light is on
Over heat
protection
Over current
protection
Over welding
current
Working time
too long
Unusual current
in the main
circuit
Reduce the welding current output
Reduce the duty cycle (interval work)
Use a stable power supply/ ensure
not too many machines are using the
same power supply
1
2
3
4
5
6
7
8
9
10
11
S/N Troubles Reasons Solutions
The max value isn’t in
accordance
The min value isn’t in
accordance
Adjust potentiometer Imin on the power
board
Adjust potentiometer Imaxin the current
meter
The adjustment kob of pre-gas
timeon the front panel is
damaged
Low-Voltage
Protection
Over-Voltage
Protection
Power supply
fluctuates Use a stable power supply
16