zika TIG160S User manual

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
1
TABLE OF CONTENTS
1. SAFETY...........................................................................................................................................................................2
2. GENERAL DESCRIPTION...........................................................................................................................................3
3. MAIN PARAMETER.......................................................................................................................................................4
4. INSTALLTION & OPERATION....................................................................................................................................6
5. WELDING PARAMETERS TABLE...........................................................................................................................10
6. FAQ.................................................................................................................................................................................11
7. CAUTION.......................................................................................................................................................................11
8. MAINTENANCE............................................................................................................................................................12
9. TROUBLESHOOTING.................................................................................................................................................13
This welding machine for industrial and professional use is in the conformity with IEC 60974 International
Safety Standard.
Please read and understand this operator’s manual carefully before the installation and operation of this
machine.
The contents of this manual may be revised without prior notice.
This operator’s manual is issued in November 2015.

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
2
1. SAFETY
Welding is dangerous, and may cause damage to you and others, so take good protection when welding. For
details, please refer to the operator safety guidelines in conformity with the accident prevention requirements of
the manufacturer.
Professional training is needed before operating the machine.
Use labor protection welding supplies authorized by national
security supervision department.
Operators should be with valid work permits for metal welding
(cutting) operations.
Cut off power before maintenance or repair.
Electric shock—may lead to serious injury or even death.
Install earth device according to the application criteria.
Never touch the live parts when skin bared or wearing wet
gloves/clothes.
Make sure that you are insulated from the ground and workpiece.
Make sure that your working position is safe.
Smoke & gas—may be harmful to health.
Keep your head away from smoke and gas to avoid inhalation of
exhaust gas from welding.
Keep the working environment well ventilated with exhaust or
ventilation equipment when welding.
Arc radiation—may damage eyes or burn skin.
Wear suitable welding masks and protective clothing to protect your
eyes and body.
Use suitable masks or screens to protect spectators from harm.
Improper operation may cause fire or explosion.
Welding sparks may result in a fire, so please make sure no
combustible materials nearby and pay attention to fire hazard.
Have a fire extinguisher nearby, and have a trained person to use it.
Airtight container welding is forbidden
Do not use this machine for pipe thawing.
Hot workpiece may cause severe scalding.
Do not touch hot workpiece with bare hands.
Cooling is needed during continuous use of the welding torch.
Noise may be harmful to people’s hearing.
Wear approved ear protection when welding.
Warn spectators that noise may be harmful to their hearing.
Magnetic fields affect cardiac pacemaker.
Pacemaker users should be away from the welding spot before
medical consultation.

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
3
Moving parts may lead to personal injury.
Keep yourself away from moving parts such as fan.
All doors, panels, covers and other protective devices should be
closed during operation.
Please seek professional help when encountering machine failure.
Consult the relevant contents of this manual if you encounter any
difficulties in installation and operation.
Contact the service center of your supplier to seek professional help
if you still can not fully understand after reading the manual or still
can not solve the problem according to the manual.
2. GENERAL DESCRIPTION
This welding machine is manufactured with advanced inverter technology. With PWM technology and power
MOSFET, it converts the DC voltage, which is rectified from 50Hz/60Hz input AC voltage, to 100KHz AC high
voltage. Then the voltage is dropped and rectified. For adopting switch power supply inverter technology, the
machine is much smaller and lighter.
TIG welding function is available on TIG160S, TIG160SII and TIG200S,TIG200SII.
MMA and TIG welding functions are available on TIG180A, TIG200A, TIG300 and TIG400.
TIG160SⅡ, TIG200SⅡ, TIG180PⅡ, TIG180AⅡand TIG200AⅡare models of new products with plastic
enclosure. The enclosure is made of non-flammable ABS material. Compared to the machines of metal
enclosure, it has more advantages, such as beautiful appearance, excellent insulation, waterproof, antistatic
and anticorrosion.
In MMA welding, the external characteristic of the machine is constant current with arc force control. When the
arc voltage is normal, the welding current does not vary with the arc length, ensuring stable welding and elastic
arc. When the arc length is overly short and the arc voltage is overly low, the current increases correspondingly
to make the arc length recover automatically, ensuring stable arc and adjustable arc force. When the arc
voltage is too low to maintain arc, the external characteristic of the machine turns to drooping, avoiding spatters
due to the high current when short-circuited.
In TIG welding, the external characteristic of the machine is constant current. The welding current is very stable,
and does not vary with the arc length.
Block Diagram

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
4
3. MAIN PARAMETER
MODEL
TIG160S
TIG200S
TIG180A
TIG200A
TIG180P
TIG200P
Input voltage (V)
Single-phase AC230V/AC230V 15%
Frequency (Hz)
50/60
Input current (A)
15
21
18
21
27
30
No-load voltage (V)
42
42
56
56
56
56
Output current range
10～160A
10～200A
10～180A
10-200A
10-180A
10-200A
Rated voltage (V)
16.4V
18V
17V
18V
17V
18V
Post-flow time (S)
2.5, 5
2.5, 5
2.5, 5
2.5, 5
5
5
Arc force range
--
--
--
Automatic
Automatic
Automatic
Duty cycle
60%
40%
No-load loss (W)
35
35
40
40
40
40
Arc ignition
HF
Pulse frequency (Hz)
--
--
--
---
LF: 2.5
MF: 200
LF: 2.5
MF: 200
Efficiency
85%
Power factor
0.7
Insulation class
F
Protection class
IP21
Weight (kg)
8
9
8
8
9
9
Schematic block diagram (single-phase input)

 
 

  
 










R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
5
MODEL
TIG250/
(TIG250 single-phase)
TIG300S/
(TIG300S single-phase)
TIG300
TIG400
Input voltage (V)
3-phase AC380V15%
(Single-phase AC200V15% for TIG250 single-phase and TIG300S single-phase)
Frequency (Hz)
50/60
50/60
50/60
50/60
Input current (A)
9.5/29
12.5/38
12.5
19.8
No-load voltage (V)
70/62
42
70
80
Output current range
10~250A
10～300A
10~300A
25~400A
Rated voltage (V)
20V
22V
22V
26V
Arc force range (A)
0~100/0~60
--
0~100
0~100
Post-flow time (S)
10 (Adjustable)
5
10 (Adjustable)
5
Duty cycle
60%
60%
60%
60%
No-load loss (W)
40
40
60
100
Arc ignition
HF
HF
HF
HF
Efficiency
85%
85%
85%
85%
Power factor
0.93
0.93
0.93
0.93
Insulation class
F
F
F
F
Protection class
IP23
IP23
IP23
IP23
Weight (kg)
19
19
21.5
27
Note: Single-phase 230V type and 3-phase 380V type are available on TIG250 and TIG300S.
Schematic block diagram (3-phase input)






 

 
 



  
 

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
6
4. INSTALLTION & OPERATION
To reduce voltage drop, it is suggested to use cable of bigger cross section if the output cable is relatively long.
If the torch cable is too long, the performance of this welding machine such as arc ignition will be possibly
affected due to the fact that the inner resistance of the cable will reduce the output voltage.


 
s
2.5s
TIG
5s
ON
OFF 
 
   
 
OFF
ON
TIG
 

A

 
4.1 Connection of input cable
1) A primary power supply cable is available for this welding machine. Connect the power supply cable to the
rated input power. (Ground connection is needed for safety purpose.)
The input voltage of TIG160 /180/200 is single-phase 230V, and that of TIG250/300/400 is 3-phase 380V.
2) The primary cable should be tightly connected to the correct socket to avoid oxidization.
3) Check whether the voltage value varies in acceptable range with a multi-meter.
4.2 Connection of output cable
◆TIG: Applicable to TIG160S/TIG200S
1) Correctly connect the TIG torch according to the above drawing. Connect the gas-electric connector of the
TIG torch to the corresponding connector (2a) on the machine panel, and tighten it clockwise.
2) Connect the aviation plug on the TIG torch to the corresponding socket (2b) on the machine panel, and
tighten it clockwise.
3) Insert the quick plug on the earth cable into the “+” quick socket (2c) on the machine panel, and tighten it
clockwise. Clamp the workpiece with the earth clamp at the other end of the earth cable.
4) Tightly connect the gas hose to the gas inlet on the back panel of the machine. The gas path should include
the cylinder, gas regulator and gas hose. The joint with the hose should be tightened with a hoop to prevent
gas leakage and air mixing. Otherwise, weld bead cannot be well protected.
5) The enclosure of the machine must be grounded with a lead (cross section≥4mm2) to avoid static and
electric shock. A ground terminal marked with the symbol is located on the back panel of the machine for this
purpose.
◆MMA & TIG: Applicable to TIG180A/TIG200A/TIG180P/TIG20P/TIG300/TIG400
Refer to the above steps for output cable connection when you use the machine for TIG welding.When you use
the machine for MMA welding, Please note:
1) Two quick plugs are available for this welding machine. Insert the quick plugs into the quick sockets on the
front panel of the machine, and tighten them with an inner hexagon spanner to ensure good contact.
Otherwise, the plugs and sockets will be burned if the working time is long and the working current is high.
2) Insert the cable plug with electrode holder into the “＋” socket (2c) on the front panel of the welding machine,
and tighten it clockwise. Insert the cable plug with work clamp into the “－” socket (2d) on the front panel of
the welding machine, and tighten it clockwise.
3) Generally, DCEP polarity and DCEN polarity are available in MMA.
DCEP: Connect the electrode holder to “＋” output terminal, and the work clamp to “－”output terminal.

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
7
DCEN: Connect the electrode holder to “－” output terminal, and the work clamp to “＋”output terminal.
4.3 Operation
Main switch (3): Switch the power switch on the back panel to “ON”, the machine is started with the power LED
on and the fan working.
/ switch (4): Toggle between TIG and MMA.
◆TIG operation
1) Switch the
/ switch to “
”.
2) Open the gas valve of the cylinder, and adjust the gas regulator to the desired value.
3) Switch the power switch on the back panel to “ON”, the machine is started with the power LED on and the fan
working. Press the torch trigger, the solenoid valve works and there is gas output.
4) Adjust the welding current according to the thickness of the workpiece.
5) Keep the torch 2~4mm away from the workpiece, and then press the torch trigger. After arc is ignited, the HF
discharge rustling disappears, and welding can be carried out.
◆MMA operation
1) Switch the
/ switch to “ ”.
2) Adjust the welding current according to the thickness of workpiece.

 





 






 
 









Welding current knob (5): to adjust the output current.
Overheating LED (6): to indicate overheating. Overheating LED on indicates that the temperature inside the
machine is too high and the machine is under overheating protection status.
Digital meter (7): to display the welding current value. (Applicable to TIG300S/TIG250/TIG300/ only)
Pulse selecting switch (8): Switch the
/ switch to “
”, and then set . Note: “ ” -- no pulse;
“” -- medium frequency; “ ” -- low frequency. (Applicable to TIG180P/200P only)
2T/4T switch（9）: This function can be added upon customers’ request.
Select proper welding mode 2T or 4T. Note: 2T –General pulsed TIG welding; 4T –Multifunctional welding.
The operation in 4T is as follows: Adjust the arc ignition current, upslope time, welding current, base current,
downslope time, crater current and post-flow time according to the welding application requirement. Keep the
torch 2~4mm away from the workpiece, and then press the torch trigger. After arc is ignited, release the torch
trigger, and current will slowly increase to the peak current value. Then, normal welding can be carried out.

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
8
After the welding is completed, press the torch trigger again, and current will slowly drop to the crater current
value. Release the torch trigger after the crater is well filled, and the machine will stop working.
Downslope time control (10): The downslope time can be adjusted between 0 to 10 seconds.
Post-flow time control (11): The post-flow time is the period from the time when arc goes out to the time when
gas supply stops, and it can be adjusted between 1 to 10 seconds.

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
9
Arc force current control (12): Applicable to TIG250/TIG400 only.
You may adjust the arc force upon your requirement in MMA welding. This arc force control knob is used to
control welding performance. Especially, it can be used together with the welding current control knob under
low current to adjust the arc ignition current conveniently, not controlled by the welding current control knob.
Thus, big arc force can be obtained in low current welding.
Pulsed frequency control (13): See the waveform characteristic below.
Base current control (14): Applicable to TIG180P/TIG200P（R21）only.
It is not applicable in MMA welding. Switch the pulse selecting switch to “ ” or “ ”, and adjust the base
current according to the thickness of workpiece.
Peak current control (15): Applicable to TIG180P/TIG200P only.
It is not applicable in MMA welding. Switch the pulse selecting switch to “ ” or “ ”, and adjust the peak
current according to the thickness of workpiece.
Waveform characteristic
ReleasePress
Release
Press
Base current
Peak current

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
10
5. WELDING PARAMETERS TABLE
Table 1- Parameters for TIG welding on stainless steel sheet (for reference only)
Plate
Thickness
(mm)
Welding joint
Electrode
diameter
(mm)
Wire
diameter
(mm)
Current
type
Welding
current
(A)
Gas flow
(L/min)
Welding
speed
(cm/min)
1.0
1.2
1.5
Butt Joint
2
2
2
1.6
1.6
1.6
DCEN
7～28
15
5～19
3～4
3～4
3～4
12～47
25
8～32
Table 2- Parameters for TIG welding on titanium and its alloy (for reference only)
Plate
thickness
(mm)
Groove
type
Welding
layers
Electrode
diameter
(mm)
Wire
diameter
(mm)
Welding
current
(A)
Gas flow (L/min)
Nozzle
diameter
(mm)
0.5
1.0
1.5
2.0
2.5
Square
groove
1
1
1
1
1
1.5
2.0
2.0
2.0～3.0
2.0～3.0
1.0
1.0～2.0
1.0～2.0
1.0～2.0
2.0
30～50
40～60
60～80
80～110
110～120
8～10
8～10
10～12
12～14
12～14
6～8
6～8
8～10
10～12
10～12
14～16
14～16
14～16
16～20
16～20
10
10
10～12
12～14
12～14
3.0
4.0
5.0
6.0
7.0
8.0
Single V
groove
with root
face
1～2
2
2～3
2～3
2～3
3～4
3.0
3.0～4.0
4.0
4.0
4.0
4.0
2.0～3.0
2.0～3.0
3.0
3.0～4.0
3.0～4.0
3.0～4.0
120～140
130～150
130～150
140～180
140～180
140～180
12～14
14～16
14～16
14～16
14～16
14～16
10～12
12～14
12～14
12～14
12～14
12～14
16～20
20～25
20～25
25～28
25～28
25～28
14～18
18～20
18～20
18～20
20～22
20～22
10
20
22
25
30
Double V
groove
with root
face
4～6
12
12
15～16
17～18
4.0
4.0
4.0
4.0
4.0
3.0～4.0
4.0
4.0～5.0
3.0～4.0
3.0～4.0
160～200
200～240
230～250
200～220
200～220
14～16
12～14
15～18
16～18
16～18
12～14
10～12
18～20
20～26
20～26
25～28
20
18～20
26～30
26～30
20～22
18
20
22
22
Table 3- Parameters for pulsed TIG welding on stainless steel sheet (for reference only)
Table 4- Parameters for TIG welding on aluminum and its alloy (for reference only)
Plate
thickness
(mm)
Groove
type
Welding
layers
Electrode
diameter
(mm)
Wire
diameter
(mm)
preheat
temperature
(℃)
Welding
current
(A)
Gas flow
(L/min)
Nozzle
diameter
(mm)
1.5
2
Square
groove
1/0
1/0
2
2～3
1.6～2.0
2～2.5
--
--
50～80
50～80
7～9
8～12
8
8～12
3
4
5
8
10
12
16
20
Single V
groove
with root
face
1/0
1～2/1
1～2/1
2/1
3～4/1～2
3～4/1～2
4～5/1～2
4～5/1～2
3
4
4
5
5
5～6
6
6
2～3
3
3～4
4～5
4～5
4～5
5～6
5～6
--
--
--
100
100～150
150～200
200～220
200～260
15～180
180～200
180～240
260～320
280～340
300～360
340～380
360～400
8～12
10～15
10～15
16～20
16～20
18～22
20～24
25～30
8
8～12
8～12
10～12
14～16
14～16
16～20
20～22
16～20
22～25
Double V
groove
with root
face
2～3/2～3
2～3/2～3
6
6～7
5～6
5～6
200～260
200～260
300～380
360～400
25～30
30～35
16～20
20～22
Plate thickness
(mm)
Current (A)
Duration (s)
Pulse
frequency
(Hz)
Welding speed
(cm/min)
Pulse
Base value
Pulse
Base value
0.3
0.5
0.8
20～22
55～60
85
5～8
10
10
0.06～0.08
0.08
0.12
0.06
0.06
0.08
8
7
5
50～60
55～60
80～100

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
11
6. FAQ
The phenomena listed below may be caused by the accessory you use, the working environment or the power
supply condition. Try to improve the working environment to avoid such occurrence.
◆Black weld bead
This indicates that the weld bead is not well protected and is oxidized. Please check the following points.
1) Make sure the gas valve of the cylinder is open and the pressure inside the cylinder is sufficient. Generally,
it is necessary to refill the cylinder when the pressure is lower than 0.5MPa.
2) Check if the gas flow is normal. You may select different gas flow according to welding current value.
However low the current is, the gas flow is recommended to be not less than 5L/min. Otherwise, the weld
bead may not be fully covered for lack of shielded gas.
3) Make sure the gas path is not blocked. Check if there is gas output from the nozzle of the welding torch with
your hand.
4) Check if the gas path is airproof and if the gas is pure enough.
5) Check if the environment is with strong wind.
6) Check if the pulse duration ratio is too low.
◆Arc is hard to start but easy to break.
1) Make sure the electrode you use is of good quality, because the electrode of bad quality may not meet the
discharge requirement.
2) Make sure the electrode is sharpened, because arc is hard to ignite and unstable when using the
unsharpened electrode.
◆Unstable current during welding
This may be caused by the following:
1) Mains voltage fluctuates badly.
2) There is serious interference from other electric appliances.
7. CAUTION
7.1 Working environment
1) Welding should be carried out in dry environment with its humidity not greater than 90%.
2) The temperature of the working environment should be between -10℃to 40℃.
3) Avoid welding in the open air unless sheltered from sunlight and rain. Keep it dry anytime and do not place
it on wet ground or in puddles.
4) Avoid welding in dusty area or environment with corrosive chemical gas.
5) Gas shielded arc welding should be operated in environment without strong wind.
7.2 Safety tips
Overvoltage, overcurrent and overheating protection circuit are installed in this machine. If the output current or
the temperature inside the machine is too high, the machine will stop automatically. However, excessive use
(e.g. too high voltage) of machine may also damage the machine, so please note:
1) Ventilation
This welder can create powerful welding current that has strict cooling requirements that cannot be met with
natural ventilation. Therefore the two built-in fans are very important in enabling the machine to work stable with
effective cooling. The operator should make sure that the louvers be uncovered and unblocked. The minimum
distance between the machine and nearby objects should be 30cm. Good ventilation is of critical importance to
the normal performance and lifespan of the machine.
2) Overload is forbidden.
Remember to observe the max load current at any moment (refer to the corresponding duty cycle). Make sure
that the welding current should not exceed the max load current. Overload could obviously shorten the
machine's lifespan, or even damage the machine.

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
12
3) Overvoltage is forbidden.
Regarding the power supply voltage range of the machine, please refer to “Main Parameters”table. This
machine is of automatic mains voltage compensation, which ensures that the welding current varies within the
given range. In case that the input mains voltage exceeds the tolerance value, it would possibly damage the
components of the machine.
4) The enclosure of the machine must be grounded.Aground terminal marked with the symbol is located on the
back panel for this purpose.
5) A sudden halt may occur with the overheating LED on while the machine is of over-load status. Under this
circumstance, it is unnecessary to restart the machine. Keep the built-in fan working to lower the temperature
inside the machine. Welding can be continued after the inner temperature falls into the standard range and the
overheating LED is off.
8. MAINTENANCE
●Warning: Cut off the power before maintenance and repair.
Make sure the power supply is cut off before uncovering
the machine.
●Check periodically whether inner circuit connection is in
good condition (esp. plugs). Tighten the loose connection.
If there is oxidization, remove it with sandpaper and then
reconnect.
●Keep hands, hair and tools away from the moving parts
such as the fan to avoid personal injury or machine
damage.
●Clean the dust periodically with dry and clean compressed
air. If cutting in environment with heavy smoke and
pollution, the machine should be cleaned daily.
●The pressure of compressed air should be at a proper level
in order to avoid the small parts inside the machine to be
damaged.
●Avoid rain, water and vapor infiltrating the machine. If there
is, dry it and check the insulation with equipment (including
that between the connections and that between the
connection and the enclosure). Only when there are no
abnormal phenomena any more, then the machine can be
used.
●Put the machine into the original packing in dry location if it
is not used for a long time.

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
13
9. TROUBLESHOOTING
Note：Only the qualified technicians are authorized to undertake the maintenance and repair task in case of
machine fault.
9.1 Troubleshooting for TIG160S/TIG200A/TIG 200S/TIG180A/TIG180P/TIG200P/single-phase TIG300S/
single-phase TIG250
Malfunction Phenomena
Cause and Solution
Turn on the machine, the
power LED is off, the fan
does not work, and no
welding output.
1. Check if the power switch is damaged.
2. No input power.
3. Check if the input cable is well connected.
Turn on the machine, the
power LED is on, but the fan
does not work or it stops
working after a few turns,
and there is no welding
output.
1. Overvoltage protection occurs because the machine is wrongly
connected to 380V power supply. Connect the machine to the 230V
power supply and restart the machine.
2. The 220V is unstable (The input cable is overly thin or overly long.) or the
input cable is not well connected to the mains power supply, which lead to
overvoltage protection. Replace with a cable of bigger cross section or
reconnect the input cable. Shut down the machine, and restart it after 2~3
minutes.
3. The power switch is switched too frequently in a short time, which lead to
overvoltage protection. Shut down the machine, and restart it after 2~3
minutes.
4. Check if the switch wire is loosely connected to the power PCB, and
reconnect it if necessary.
5. The 24V relay on the power PCB is not closed or is damaged. Check the
24V power supply and relay, and replace the relay if it is damaged.
Turn on the machine, the fan
works, the protection LED is
off, but there is no HF
discharge rustling, and arc
cannot be ignited even by
scraping.
1. Check if the voltage of the power PCB to the anode and cathode of VH-07
on the MOS board is about DC308V.
1) Check if the connecting wire of the rectifier bridge is not well
connected.
2) Check if creepage exists in some of the four electrolytic capacitors
(470UF/450V) on the power PCB, and replace them if necessary.
2. There is a LED for the auxiliary power supply on the MOS board. If the
LED is off and the auxiliary power supply does not work, find out the
solution.
3. Check if any loose contact exists inside the machine.
4. Check if the control circuit fails. Find out the solution or contact your
supplier.
5. Check if the control wire of the torch is broken.
Turn on the machine, the
protection LED is off, there
is HF discharge rustling, but
no welding output.
1. Check if the torch cable is broken.
2. Check if the earth cable is broken or is not connected to the workpiece.
3. Check if the “+” output terminal or gas-electric output terminal of the torch
is not well connected to the joint inside the machine.

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
14
Malfunction Phenomena
Cause and Solution
Turn on the machine, the
protection LED is off, but
there is no HF discharge
rustling, and arc can be
ignited by scraping.
1. The primary wire of the arc ignition transformer is not well connected to
the power PCB. Reconnect it.
2. The discharge nozzle is oxidized or the interelectrode distance of the
discharge nozzle is too long. Get rid of the oxidation film or adjust the
interelectrode distance of the discharge nozzle to about 1mm.
3. Check if the MMA/TIG switch is damaged, and replace it if necessary.
4. Check if there are some parts in the HF arc ignition circuit, and replace
them if necessary.
Turn on the machine, the
protection LED is on, and
there is no welding output.
1. Overcurrent protection: Shut down the machine, and restart it when the
protection LED is off.
2. Overheating protection: Wait for 2~3 minutes without shutting down the
machine, and it will recover automatically. (Machines for TIG welding only
are without overheating protection function.)
3. The inverter or arc ignition board fails. Pull out the power supply plug
(near VH-07 of the fan) of the main transformer on the MOS board, and
restart the machine.
1) If the protection LED is still on, shut down the machine, pull out the
power supply plug (near VH-03 of the fan) of the HF arc ignition
power supply, and restart the machine.
A. If the protection LED is still on, check if some of the MOSFET on
the MOS board are damaged, and replace them if necessary.
B. If the protection LED is off, check if the transformer booster in the
HF arc ignition circuit on the power PCB is damaged, and
replace it if necessary.
2) If the protection LED is off:
A. Check if the transformer on the center PCB is damaged, and
replace it if necessary.
B. Check if some secondary rectifier diode of the transformer is
broken down, and replace it if necessary.
4. The feedback circuit opens.
The output current is
unstable and cannot be
controlled by potentiometer
when welding.
1. Check if the potentiometer (1K) is damaged, and replace it if necessary.
2. Check if any loose contact exists inside the machine.
There is excessive spatter in
MMA welding, and it is hard
to ignite the basic electrode.
The output polarity is incorrect. Exchange the polarity.

R160A SC-A5 OPERATORS’ MANUAL · TIG SERIES
15
9.2 Troubleshooting for TIG250/TIG400
Malfunction Phenomena
Cause and Solution
Turn on the machine, the fan
does not work, and there is
no display on the digital
meter and no welding
output.
1. Make sure the air switch is not damaged and is closed.
2. No input power.
3. Check if the four thermal resistors on the power PCB are damaged. (This
is mainly caused by the bad contact of the DC24V relay or that the relay is
not closed.)
4. The power PCB fails, and there is no DC537V output.
1) The rectifier bridge opens or it is not well connected.
2) Some parts on the power PCB are burned.
3) Check if the air switch is well connected to the power PCB and if the
power PCB is well connected to the MOS board (inverter PCB).
5. The auxiliary power supply on the control PCB fails.
Turn on the machine, the fan
works, the protection LED is
off, but there is no HF
discharge rustling, and arc
cannot be ignited even by
scraping.
1. Check if any loose contact exists inside the machine
2. Check if the control circuit fails. Find out the solution or contact your
supplier.
3. Check if the control wire of the torch is broken.
Turn on the machine, the
protection LED is off, there
is HF discharge rustling, but
no welding output.
1. Check if the torch cable is broken.
2. Check if the earth cable is broken or is not connected to the workpiece.
3. Check if the “+” output terminal or gas-electric output terminal of the torch
is not well connected to the joint inside the machine.
Turn on the machine, the
protection LED is off, but
there is no HF discharge
rustling, and arc can be
ignited by scraping.
1. The primary wire of the arc ignition transformer is not well connected to
the arc ignition board. Reconnect it.
2. The discharge nozzle is oxidized or the interelectrode distance of the
discharge nozzle is too long. Get rid of the oxidation film or adjust the
interelectrode distance of the discharge nozzle to about 1mm.
3. Check if the MMA/TIG switch is damaged, and replace it if necessary.
4. Check if there are some parts in the HF arc ignition circuit, and replace
them if necessary.

OPERATORS’ MANUAL · TIG SERIES R160A SC-A5
16
Malfunction Phenomena
Cause and Solution
Turn on the machine, the
protection LED is on, and
there is no welding output.
1. Overcurrent protection: Shut down the machine, and restart it when the
protection LED is off.
2. Overheating protection: Wait for 2~3 minutes without shutting down the
machine, and it will recover automatically.
3. The inverter or arc ignition board fails. For double-inverter machine, pull
out the power supply plug (near -07 of the panel) of one inverter, and
restart the machine. If the protection LED is off, it indicates that this
inverter fails. Otherwise, the other inverter fails. Follow the below steps to
eliminate this problem for both single-inverter machine and
double-inverter machine.
1) If the protection LED is still on, shut down the machine, pull out the
power supply plug (near VH-03 of the fan) of the arc ignition power
supply, and restart the machine.
A. If the protection LED is still on, check if some of the MOSFET
on the MOS board are damaged, and replace them if
necessary.
B. If the protection LED is off, check the arc ignition board and
transformer booster for damage, and replace the transformer
booster if necessary.
2) Connect the power supply of the failed inverter, and restart the
machine with the power cord of the main transformer unconnected.
A. If the protection LED is off, check if the transformer on the
center PCB is damaged, and replace it if necessary.
B. Check if some rectifier diode on the center PCB is damaged,
and replace it if necessary
4. The feedback circuit opens.
The output current is not
high enough and cannot be
controlled by potentiometer
when welding.
1. The secondary cable is overly long or thin. Shorten the secondary cable
or replace with one of bigger cross section.
2. Check if the machine is in remote control mode.
3. Check if the current potentiometer is damaged.