Stealth DIGI-ARC 160PFC MV User manual

Part No. 9022H
DIGI-ARC 160PFC MV
OPERATOR’S
MANUAL

STEALTH DIGI-ARC 160PFC MV
IMPORTANT
Read this Owner’s Manual completely before attempting to use this equipment.
Save this manual and keep it handy for quick reference. Pay particular attention
to the safety instructions provided for your protection. Contact your distributor if
you do not fully understand this manual.

CONTENTS
1. SAFETY 4
1.1 SIGNAL EXPLANATION 4
1.2 ARC WELDING DAMAGE 4
1.3 ELECTRIC AND MAGNETIC FIELDS INFORMATION 7
2. SUMMARY 8
2.1 BRIEF INTRODUCTION 8
2.2 WORKING PRINCIPLE 9
2.3 VOLT-AMPERE CHARACTERISTIC 9
3. INSTALLATION AND ADJUSTMENT 11
3.1 PARAMETERS 10
3.2 DUTY CYCLE AND OVER-HEATING 11
3.3 WELDING POLARITY CONNECTION 12
3.3.1 MMA 11
3.3.2 TIG 12
4. OPERATION – CONTROL AND CONNECTORS 13
4.1 MACHINE CONTROLS 13
4.2 WELDING CURENT ADJUSTMENT 14
4.3 WELDING OPERATION 14
4.3.1 STRIKING ARC 14
4.3.2 MANIPULATION OF ELECTRODE 14
4.4 WELDING PARAMETERS 14
4.4.1 JOINT FORM IN MMA 14
4.4.2 ELECTRODE SELECTION 15
4.5 ARC WELDING DEFECT AND PREVENT METHOD 15
4.6 OPERATION ENVIRONMENT 17
4.7 OPERATION NOTICES 17
5. MAINTENANCE & TROUBLESHOOTING 18
5.1 MAINTENANCE 18
5.2 TROUBLESHOOTING 19
5.3 MAIN ELECTRICAL DIAGRAM 21
STEALTH DIGI-ARC 160PFC MV

STEALTH DIGI-ARC 160PFC MV
1. SAFETY
1.1 Signal Explanation
• The above icons mean Warning! Notice! Running and thermal parts or receiving an
electric shock may harm you or others. The following precautions apply as a guide
to working safely.
1.2 Arc Welding Damage
• The following icons explanations are to prevent accidents to you or others during
the welding process.
• Only experienced personell can install, operate, maintain and repair the equipment.
• During the operation make sure those around you are properly protected.
• After turning off the machine power, please maintain and examine the equipment
according to 5due to DC voltage existing in the electrolytic capacitors.
ELECTRIC SHOCK CAN KILL
• Never touch live electrical parts.
• Wear dry, hole-free gloves and clothes to insulate yourself.
• Insulate yourself from work and ground using dry insulation. Make certain the
insulation is large enough to cover your full area of physical contact with work and
ground.
• Take care when using the equipment in a confined space, on uneven surfaces and
in damp conditions.
• Never close the machine power before installation and adjustment.
• Ensure the equipment is installed correctly and the work or metal is earthed
according to the operation manual.
• The electrode and work (or ground) circuits are ‘hot’ when the machine is on. Do not
touch these electrically ‘hot’ parts with your bare skin or wet clothing. Wear dry,
hole-free gloves to insulate hands.
• In semiautomatic or automatic wire welding, the electrode, electrode reel, welding
head, nozzle or semiautomatic welding gun are also electrically ‘hot’.
• Always ensure the work cable makes a good electrical connection and is as close as
possible to the metal being welded.
• Ensure the electrode holder, work clamp, welding cable and welding machine are
in good, safe operating condition. Replace any damaged insulation.
• Never dip the electrode in water for cooling.
• Never simultaneously touch electrically ‘hot’ parts of electrode holders connected to
two machines as voltage between the two can be the total of the open circuit voltage
of both welders.
• When working above floor level, use a safety belt to protect yourself from a fall
should you receive an electric shock.
FUMES AND GASES CAN BE DANGEROUS
• Welding may produce fumes and gases hazardous to health. Avoid breathing these
fumes and gases.
SAFETY
1
§1 SAFETY
§1.1 Signal Explanation
The above signals mean warning! Notice! Running parts and getting an electric shock or thermal parts
will take damage for your body or others. The corresponding notices are as follows. It is quite a safe
operation after taking several necessary protection measures.
§1.2 Arc Welding Damage
The following signals and word explanations are to some damages for your body or others happening
on the welding operation. While seeing these, please remind of yourself or others to be dangerous.
Only ones who are trained professionally can install, debug, operate, maintain and repair the
equipment.
During the operation, non-concerned people should be lift, especially for children.
After shut off the machine power, please maintain and examine the equipment according to §5
because of the DC voltage existing in the electrolytic capacitors.
ELECTRIC SHOCK CAN KILL.
Never touch electrical parts.
Wear dry, hole-free gloves and clothes to insulate yourself.
Insulate yourself from work and ground using dry insulation. Make certain the insulation is large
enough to cover your full area of physical contact with work and ground.
Take carefully when using the equipment in small place, falling-off and wet circumstance.
Never close the machine power before installation and adjustment.
Ensure to install the equipment correctly and ground the work or metal to be welded to a good
electrical (earth) ground according to the operation manual.
The electrode and work (or ground) circuits are electrically “hot” when the welder is on. Do not touch
these “hot” parts with your bare skin or wet clothing. Wear dry, hole-free gloves to insulate hands.
In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or
SAFETY
1
§1 SAFETY
§1.1 Signal Explanation
The above signals mean warning! Notice! Running parts and getting an electric shock or thermal parts
will take damage for your body or others. The corresponding notices are as follows. It is quite a safe
operation after taking several necessary protection measures.
§1.2 Arc Welding Damage
The following signals and word explanations are to some damages for your body or others happening
on the welding operation. While seeing these, please remind of yourself or others to be dangerous.
Only ones who are trained professionally can install, debug, operate, maintain and repair the
equipment.
During the operation, non-concerned people should be lift, especially for children.
After shut off the machine power, please maintain and examine the equipment according to §5
because of the DC voltage existing in the electrolytic capacitors.
ELECTRIC SHOCK CAN KILL.
Never touch electrical parts.
Wear dry, hole-free gloves and clothes to insulate yourself.
Insulate yourself from work and ground using dry insulation. Make certain the insulation is large
enough to cover your full area of physical contact with work and ground.
Take carefully when using the equipment in small place, falling-off and wet circumstance.
Never close the machine power before installation and adjustment.
Ensure to install the equipment correctly and ground the work or metal to be welded to a good
electrical (earth) ground according to the operation manual.
The electrode and work (or ground) circuits are electrically “hot” when the welder is on. Do not touch
these “hot” parts with your bare skin or wet clothing. Wear dry, hole-free gloves to insulate hands.
In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or
SAFETY
2
semiautomatic welding gun are also electrically “hot”.
Always be sure the work cable makes a good electrical connection with the metal being welded. The
connection should be as close as possible to the area being welded.
Maintain the electrode holder, work clamp, welding cable and welding machine in good, safe
operating condition. Replace damaged insulation.
Never dip the electrode in water for cooling.
Never simultaneously touch electrically “hot” parts of electrode holders connected to two welders
because voltage between the two can be the total of the open circuit voltage of both welders.
When working above floor level, use a safety belt to protect yourself from a fall should you get a
shock.
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
4

STEALTH DIGI-ARC 160PFC MV
• When welding, keep your head out of fumes. 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
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 vapours coming from
degreasing, cleaning or spraying operations. The heat and rays of the arc can react
with solvent vapours 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 ensure 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 correct filter and cover plates to protect your eyes from sparks
and the rays of the arc when welding or observing open arc welding.
• Use suitable clothing made from durable flame-resistant material to protect your
skin and that of your helpers from the arc rays.
• Protect nearby personnel with suitable, non-flammable screening and/or warn them
to avert their eyes from the arc rays or expose themselves to hot spatter or metal.
SELF-PROTECTION
• Keep all equipment safety guards, covers and devices in position and in good repair.
Keep hands, hair, clothing and tools away from V-belts, gears, fans and all other
moving parts when starting, operating or repairing equipment.
• Do not put your hands near the engine fan. Do not attempt to override the governor
or idler by pushing on the throttle control rods while the engine is running.
DO NOT add fuel near an open flame welding arc or when the
engine is running. Stop the machine and allow it to cool before refuelling to prevent
spilled fuel from vapourising on contact with hot engine parts and igniting. Do not
spill fuel when filling tank. If fuel is spilled, wipe it up and do not start engine until
fumes have been eliminated.
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
SAFETY
3
arc when welding or observing open arc welding.
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-flammable screening and /or warn them not to
watch the arc nor expose themselves to the arc rays or to hot spatter or metal.
SELF-PROTECTION
Keep all equipment safety guards, covers and devices in position and in good repair. Keep hands, hair,
clothing and tools away from V-belts, gears, fans and all other moving parts when starting, operating or
repairing equipment.
Do not put your hands near the engine fan. Do not attempt to override the governor or idler by
pushing on the throttle control rods while the engine is running.
DO NOT adds the fuel near an open flame welding arc or when the engine is
running. Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on
contact with hot engine parts and igniting. Do not spill fuel when filling tank. If fuel is spilled, wipe it
up and do not start engine until fumes have been eliminated.
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 hydraulic 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 situation.
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
SAFETY
2
semiautomatic welding gun are also electrically “hot”.
Always be sure the work cable makes a good electrical connection with the metal being welded. The
connection should be as close as possible to the area being welded.
Maintain the electrode holder, work clamp, welding cable and welding machine in good, safe
operating condition. Replace damaged insulation.
Never dip the electrode in water for cooling.
Never simultaneously touch electrically “hot” parts of electrode holders connected to two welders
because voltage between the two can be the total of the open circuit voltage of both welders.
When working above floor level, use a safety belt to protect yourself from a fall should you get a
shock.
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
SAFETY
3
arc when welding or observing open arc welding.
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-flammable screening and /or warn them not to
watch the arc nor expose themselves to the arc rays or to hot spatter or metal.
SELF-PROTECTION
Keep all equipment safety guards, covers and devices in position and in good repair. Keep hands, hair,
clothing and tools away from V-belts, gears, fans and all other moving parts when starting, operating or
repairing equipment.
Do not put your hands near the engine fan. Do not attempt to override the governor or idler by
pushing on the throttle control rods while the engine is running.
DO NOT adds the fuel near an open flame welding arc or when the engine is
running. Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on
contact with hot engine parts and igniting. Do not spill fuel when filling tank. If fuel is spilled, wipe it
up and do not start engine until fumes have been eliminated.
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 hydraulic 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 situation.
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
SAFETY
3
arc when welding or observing open arc welding.
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-flammable screening and /or warn them not to
watch the arc nor expose themselves to the arc rays or to hot spatter or metal.
SELF-PROTECTION
Keep all equipment safety guards, covers and devices in position and in good repair. Keep hands, hair,
clothing and tools away from V-belts, gears, fans and all other moving parts when starting, operating or
repairing equipment.
Do not put your hands near the engine fan. Do not attempt to override the governor or idler by
pushing on the throttle control rods while the engine is running.
DO NOT adds the fuel near an open flame welding arc or when the engine is
running. Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on
contact with hot engine parts and igniting. Do not spill fuel when filling tank. If fuel is spilled, wipe it
up and do not start engine until fumes have been eliminated.
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 hydraulic 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 situation.
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
5

STEALTH DIGI-ARC 160PFC MV
adjacent areas. Avoid welding near hydraulic lines. Have a fire extinguisher readily
available.
• Where compressed gases are to be used at the job site, special precautions should
be taken to prevent a hazardous situation.
• 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 ensure that any flammable or toxic vapours have been eliminated from
within. They can cause an explosion even though they have been ‘cleaned’.
• Vent hollow castings or containers before heating, cutting or welding. They may
ignite.
• Sparks and spatter are thrown from the welding arc. Wear oil free protective
garments such as leather gloves, heavy shirt, cuff less trousers, protective shoes and
a cap over your hair. Wear ear plugs when welding out of position or in confined
space. Always wear safety glasses with side shields when in a welding area.
• Connect the work cable to the work as close to the welding area as practical. Keep
work cables connected to the building framework or other locations away from the
welding area.
Rotating parts may be dangerous
• 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.
SAFETY
4
an explosion even though they have been “cleaned”.
Vent hollow castings or containers before heating, cutting or welding. They may explode.
Sparks and spatter are thrown from the welding arc. Wear oil free protective garments such as leather
gloves, heavy shirt, cuff less trousers, high shoes and a cap over your hair. Wear ear plugs when
welding out of position or in confined places. Always wear safety glasses with side shields when in a
welding area.
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 alternate circuits. This can create
fire hazards or overheat lifting chains or cables until they fail.
Rotating parts may be dangerous.
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.
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STEALTH DIGI-ARC 160PFC MV
1.3 Electric and Magnetic Fields
• Electric current flowing through any conductor causes localised Electric and
Magnetic Fields (EMF). The discussions of the effect of EMF is ongoing globally.
Up to now, there is no material evidence that EMF has any adverse effects on
health.
Minimise exposure to EMF as far as possible by applying the following procedures:
– Route the electrode and work cables together. Secure them with tape when
possible.
– All cables should be stored away from the operator.
– Never coil the power cable around your body.
– Make sure welding machine and power cable are far enough away from the
operator according to the working environment.
– Connect the work cable to the workpiece as close as possible to the area being
welded.
– Personnel fitted with a heart-pacemaker should keep their distance from the
welding area.
7

STEALTH DIGI-ARC 160PFC MV
2 SUMMARY
2.1 Brief Introduction
The DIGI-ARC 160PFC MV welding machine features the latest Pulse Width
Modulation (PWM) technology and Insulated Gate Bipolar Transistor (IGBT) power
module, which can change work frequency to medium frequency so as to replace the
traditional large transformer with a medium frequency transformer – making it smaller,
portable lightweight and low consumption.
The DIGI-ARC 160PFC MV offers excellent performance with: constant current output
for a stable welding arc; fast dynamic response speed to reduce impact from the arc
length fluctuation to the current; accurate stepless current adjustment and pre-setting
function.
There are further automatic protection functions for under voltage, over-current,
over-heat, etc. In the event of any failure, the alarm on the front panel lights and the
output current is simultaneously cut off. This function provides for safe operation and
can extend the working life of the machine.
In MMA operation, if the electrode touches a workpiece for over two seconds the
welding current will automatically drop to the minimum current to protect the electrode.
While in TIG operation, the minimum current will be output initially until the arc is
ignited by lifting method. The output current rises to the preset value to protect the
electrode. At the same time, the arc force and hot start will be provided with MMA
operation.
MMA Manual Metal Arc welding
PWM Pulse-Width Modulation
IGBT Insulated Gate Bipolar Transistor
TIG Tungsten Insert Gas welding
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STEALTH DIGI-ARC 160PFC MV
2.2 Working Principle
The working principle of the DIGI-ARC 160PFC welding machines is shown as follows:
Single phase work frequency 110/220V (50/60 Hz) is converted to DC, then by PFC
circuit DC (approx. 155/312V), then is converted to medium frequency AC (approx
50/40KHz) by inverter device (IGBT). After reducing voltage by medium transformer
(the main transformer) and rectifying by medium frequency rectifier (fast recovery
diode). The circuit adopts current feedback control technology to ensure a stable
current output. Meanwhile, the welding current parameter can be adjusted
continuously and steplessly to meet with the requirements of the welding craft.
2.3 Volt-Ampere Characteristic
The DIGI-ARC 160PFC welding machine has an excellent volt-ampere characteristic,
as shown as the following graph. In MMA welding the relation between the rated
loading voltage U2and the conventional welding current I2is as follows:
When I2 ≤600A, U2 = 20+0.04 I2 (V); When I2 >600A, U2 = 44 (V).
9
SUMMARY
6
§2.2 Working Principle
The working principle of ARC160/200 PFC MV welder is shown as the following figure.
Single phase 110V/220Vwork frequency (50/60 Hz) AC is rectified into DC, then by PFC circuit,
DC(about155/312V)is converted to medium frequency AC (about 50/40KHz) by inverter device
(IGBT module), after reducing voltage by medium transformer (the main transformer) and
rectified by medium frequency rectifier (fast recovery diodes), The circuit adopts current
feedback control technology to insure current output stably. Meanwhile, the welding current
parameter can be adjusted continuously and steplessly to meet with the requirements of welding
craft.
§2.3 Volt-Ampere Characteristic
ARC160/200 PFC MV welders have excellent volt-ampere characteristic, seeing the
following graph. In MMA welding, the relation between the rated loading voltage U2and
welding current I2 is as follows:
When I2 ≤600A，U2＝20＋0.04 I2（V）； When I2＞600A，U2＝44（V）.
64
44
20
0600 I
2
（A）
U
2
（V）
Working
point
Volt-ampere characteristic
The relation of the rated loading
voltage&welding current
SUMMARY
6
§2.2 Working Principle
The working principle of ARC160/200 PFC MV welder is shown as the following figure.
Single phase 110V/220Vwork frequency (50/60 Hz) AC is rectified into DC, then by PFC circuit,
DC(about155/312V)is converted to medium frequency AC (about 50/40KHz) by inverter device
(IGBT module), after reducing voltage by medium transformer (the main transformer) and
rectified by medium frequency rectifier (fast recovery diodes), The circuit adopts current
feedback control technology to insure current output stably. Meanwhile, the welding current
parameter can be adjusted continuously and steplessly to meet with the requirements of welding
craft.
§2.3 Volt-Ampere Characteristic
ARC160/200 PFC MV welders have excellent volt-ampere characteristic, seeing the
following graph. In MMA welding, the relation between the rated loading voltage U2and
welding current I2 is as follows:
When I2 ≤600A，U2＝20＋0.04 I2（V）； When I2＞600A，U2＝44（V）.
64
44
20
0600 I
2
（A）
U
2
（V）
Working
point
Volt-ampere characteristic
The relation of the rated loading
voltage&welding current

STEALTH DIGI-ARC 160PFC MV
10
DIGI-ARC 160 PFC MV
TIG
3 INSTALLATION AND ADJUSTMENT
3.1 Parameters
110
10~90
Power Supply Voltage (V)
10~160
50/60
H
IP23
6
390 × 146 × 278
14.5
≥85
TIG
15.8
2.0
40%
90A
60%
75A
100%
60A
40%
90A
60%
75A
100%
60A
40%
160A
60%
135A
100%
105A
40%
160A
60%
135A
100%
105A
0.99
MMA
24.4
2.9
15.7
3.6
MMA
22.9
5
230
Frequency (Hz)
Rated Input Current (A)
Rated Input Power (Kw)
Power Factor
Welding Current Adjustment Range (A)
Maximum No Load Voltage (V)
Efficiency (%)
Duty Cycle (40ºC / 10 min)
Insulation Class
Protection Class
Net Weight (Kg)
Dimensions (mm) L × W × H

STEALTH DIGI-ARC 160PFC MV
11
3.2 Duty Cycle and 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 figure on the right.
If the welder is over-heating, the IGBT over-heating protection unit inside will send a
message to cut output welding current and illuminate the pilot lamp on the front
panel.
At this point, the machine should be turned off for 15 minutes to cool the fan. When
operating the machine again, the welding output current or the duty cycle should be
reduced.
3.3 Welding polarity connection
3.3.1 MMA
INSTALLATION AND ADJUSTMENT
8
§3.2 Duty cycle & Over heat
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 is over-heat, the IGBT over-heat protection unit inside it will output an
instruction to cut output welding current, and brighten the over-heat pilot lamp on the front panel.
At this time, 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.
§3.3 Welding polarity connection way
§3.3.1 MMA
Choosing the connection of DCEN or DCEP is based on the arc stable burning condition.
The different electrodes need different connection way. Please refer to the electrode manual.
workpiece
Welding holder
electrode
DCEP
GM-2000
workpiece
electrode
DCEN
Welding holder
GM-2000
ARC160
ARC160
INSTALLATION AND ADJUSTMENT
8
§3.2 Duty cycle & Over heat
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 is over-heat, the IGBT over-heat protection unit inside it will output an
instruction to cut output welding current, and brighten the over-heat pilot lamp on the front panel.
At this time, 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.
§3.3 Welding polarity connection way
§3.3.1 MMA
Choosing the connection of DCEN or DCEP is based on the arc stable burning condition.
The different electrodes need different connection way. Please refer to the electrode manual.
workpiece
Welding holder
electrode
DCEP
GM-2000
workpiece
electrode
DCEN
Welding holder
GM-2000
ARC160
ARC160
DCEN DCEP
Choosing the connection of DCEN or DCEP is based on the arc stable burning
condition. The different electrodes need different connections. Please refer to the
electrode manual.

STEALTH DIGI-ARC 160PFC MV
12
3.3.2 TIG
INSTALLATION AND ADJUSTMENT
9
§3.3.2 TIG
Ar
Workpiece
DCEN
Welding gun
GM-2000
2 ～ 4mm
1、Place the welding
gun aslant.
2、Scrape the electrode
with the workpiece.
3、Lift arc.
Steps of scraping arc
Steps of scraping arc
Stricking arc of TIG operation：when tungsten electrode touches the workpiece，the
short-circuit current is only 28A . After generating arc, current can rise to the setting welding
current.If the tungesten electrode touches the workpiece when welding, the current will drop to
5A within 2s, which can reduce the tungsten spoilage farthestly，prolong the using life of the
tungsten electrode，and prevent tungsten clipping.
●
When TIG operation,
the shielded gas is inputted
to welding gun directly,
and the method of lifting
arc is scraping arc.
ARC160
When in TIG operation, the
shielded gas is fed directly into
to the welding gun in readiness
for the lift arc process.
1. Place welding gun
at an angle
2. Scrape the electrode
with the workpiece
3. Lift arc
Steps of scraping arc
Striking arc of TIG operation:
When tungsten electrode touches the workpiece, the short-circuit current is only 28A.
After generating arc, current can rise to the setting welding current. If the tungsten
electrode touches the workpiece when welding, the current will drop to 5A within 2
seconds, which can further reduce the tungsten spoilage and extend the life of the
tungsten electrode and prevent clipping.

STEALTH DIGI-ARC 160PFC MV
13
4 OPERATION – CONTROL AND CONNECTORS
4.1 Machine Controls
1 Conversion switch: Select (up) – MMA
Select (middle) – VRD MMA
Select (down) – TIG
2 Current display: Displays when machine is working.
3 Alarm pilot lamp: When the machine loses voltage, over-current, or over-heat, the
pilot light indicates that the protection of the machine has been activated.
4 Power pilot lamp: Lights when machine is on.
5 Welding current regulation: Set welding current.
6 Earth connection: Negative polarity output.
7 Welding connection: Positive polarity output.
8 Cable clamp: Connected to the mains cable.
9 Power switch: Select ‘ON’ for power on, select ‘OFF’ for power off.
10 MMA pilot lamp: Lights when MMA selected (up).
11 VRD MMA pilot lamp: Lights when VRD MMA selected (middle).
12 TIG pilot lamp: Lights when TIG selected (down).
OPERATION CONTROL AND CONNECTORS
10
§4 Operation control and connectors
§4.1 Layout for front & rear panel
1Conversion switch: Choose (up), MMA;
Choose (middle) , VRD MMA;
Choose (down) , TIG.
2Current display: Welding Current display when machine is working.
3Alarm pilot lamp: When the machine less voltage, over current, or over heat, This
pilot lamp indicates when lit that the protection of the machine has been activated
4Power pilot lamp: This pilot lamp when lit indicates that the machine is on.
5Welding current regulation: Set welding current.
6Earth connection: Negative polarity output.
7Welding connection: Positive polarity output.
8Cable clamp: Fastened the mains cable.
9Power switch: Choose “ON”, power through; Choose “OFF”, power cut off.
10 MMA pilot lamp: This pilot lamp lit When choose (up), MMA.
11 VRD MMA pilot lamp: This pilot lamp lit When choose (middle) , VRD MMA.
12 TIG pilot lamp: This pilot lamp lit When choose (down) , TIG.

STEALTH DIGI-ARC 160PFC MV
14
4.2 Welding current adjustment
Welding current range is 10~160/200A.
The DIGI-ARC 160PFC MV has a welding current pre-setting function that displays the
the amperage and allows for accurate parameters and adjustment.
4.3 Welding operation
4.3.1 Striking arc
Knocking arc: Hold the electrode upright to contact with the workpiece. After
forming a short circuit, quickly lift up about 2~4 mm, and arc will be ignited.
This method is ideal for welding brittle or hard steel.
The lift arc process is used by gently scraping the tungsten electrode onto the
work piece then lifting off once the arc is struck. Care should be taken not to put
too much pressure on the tungsten when operating in this process.
4.3.2 Manipulation of electrode
With MMA welding there are three operations:
1 The electrode moves to the molten pool
along axes
2 The electrode swings right and left
3 The electrode moves along welding way
The operator can select the appropriate
operation based on welding joint shape,
welding position, electrode spec welding
current and operational skills etc.
4.4 Welding parameters
4.4.1 Joint form in MMA
The common basic joint forms are: butt joint, lap joint, corner joint and T-joint.
OPERATION CONTROL AND CONNECTORS
11
§4.2 Welding current adjustment
Welding current range is 10～160/200A。
ARC series welder has the function of welding current pre-setting. Before
welding, adjusting welding current, the welding current display will show the ampere.
It is convenient to set parameters and adjust accurately.
§4.3 Welding operation
§4.3.1 Striking arc way
Knocking arc: take the electrode upright to touch the workpiece, after forming
short circuit, quickly lift up about 2~4 mm, and arc will be ignited. This method
is difficult to master. But in the welding for the brittle or hard steel, it is better to
use knocking way.
electrode
workpiece
electrode electrode
workpiece workpiece
Take the electrode upright The Electrode touch the workpiece Lift up for about 2-4mm
upright
up
touch
2～4mm
Lifting arc: take the electrode to scrape the workpiece for striking arc. But it may
cause the arc scratch, so must to lift arc in the groove.
§4.3.2 Manipulation of electrode
In MMA welding, there are three motions
to being matched in the end of electrode: the
electrode moving to the molten pool along
axes; the electrode swing right and left; the
electrode moving along welding way.
The operator can choose the manipulation
of electrode based on welding joint shape,
welding position, electrode spec, welding
electrode
workpiece
weld
1
2
3
2
1-electrode moving; 2-the electrode swing right & left; 3-the electrode move along weld
OPERATION CONTROL AND CONNECTORS
11
§4.2 Welding current adjustment
Welding current range is 10～160/200A。
ARC series welder has the function of welding current pre-setting. Before
welding, adjusting welding current, the welding current display will show the ampere.
It is convenient to set parameters and adjust accurately.
§4.3 Welding operation
§4.3.1 Striking arc way
Knocking arc: take the electrode upright to touch the workpiece, after forming
short circuit, quickly lift up about 2~4 mm, and arc will be ignited. This method
is difficult to master. But in the welding for the brittle or hard steel, it is better to
use knocking way.
electrode
workpiece
electrode electrode
workpiece workpiece
Take the electrode upright The Electrode touch the workpiece Lift up for about 2-4mm
upright
up
touch
2～4mm
Lifting arc: take the electrode to scrape the workpiece for striking arc. But it may
cause the arc scratch, so must to lift arc in the groove.
§4.3.2 Manipulation of electrode
In MMA welding, there are three motions
to being matched in the end of electrode: the
electrode moving to the molten pool along
axes; the electrode swing right and left; the
electrode moving along welding way.
The operator can choose the manipulation
of electrode based on welding joint shape,
welding position, electrode spec, welding
electrode
workpiece
weld
1
2
3
2
1-electrode moving; 2-the electrode swing right & left; 3-the electrode move along weld
Hold the electrode
upright
Electrode touches the
workpiece
Lift up approx 2-4mm
1 - Electrode movement.
2 - Electrode swings right and left.
3 - Electrode moves along weld.
OPERATION CONTROL AND CONNECTORS
12
current and operation skill, etc.
The details please refer to《Welding Dictionary》P69, Volume 1 of Edition 2.
§4.4 Welding parameters
§4.4.1 Joint form in MMA
In MMA welding, the common basic joint form: butt joint, lap joint, corner joint
& T joint.
§4.4.2 Electrode selection
The electrode diameter selection is based on the workpiece thickness, welding
position, joint form, welding layer, etc. Please refer to the following table.
The welding current reference for different electrode diameter
Electrode
diameter/mm
1.6
2.0
2.5
3.2
Welding current/A
25～40
40～60
50～80
100～130
The relation between the welding current(I)’ factor(K) & electrode diameter(d) (I＝K×d: Carbon electrode)
Electrode
diameter/mm
1.6
2～2.5
3.2
Factor/K
20～25
25～30
30～40
Notice: the above parameters originate from《Welding Dictionary》P66～P67, Volume
1 of Edition 2.
Electrode should be drying according to user manual before using. For reducing
the hydrogen of the molten pool and welding seam, and avoiding the blowhole
and cold crack.
In the welding process, the arc must not be too long; otherwise, it will cause
unstable arc burning, large spatter, light penetration, undercut, blowhole, etc. If
the arc is too short, it will cause electrode stick.
In MMA welding the arc length is usually equal to 0.5~1.0 time of the electrode
butt joint lap jointcorner joint T joint
Butt joint Corner joint Lap joint T-joint

STEALTH DIGI-ARC 160PFC MV
15
4.4.2 Electrode selection
Electrode diameter selection is based on the workpiece thickness, welding
position, joint form, welding layer, etc. Please refer to the following table.
• Electrode should be drying according to user manual before using. For reducing
the hydrogen of the molten pool and welding seam, and avoiding the blowhole and
cold crack.
• In the welding process, the arc must not be too long otherwise it will cause
unstable arc burning, large spatter, light penetration, undercut, blowhole, etc.
If the arc is too short, it will cause electrode stick.
• In MMA welding the arc length is usually equal to 0.5~1.0 times of the electrode
diameter. The basic electrode’s arc length is not beyond the electrode diameter, it’s
better to choose the short arc welding; the acid electrode’s arc length is equal to the
electrode diameter.
OPERATION CONTROL AND CONNECTORS
12
current and operation skill, etc.
The details please refer to《Welding Dictionary》P69, Volume 1 of Edition 2.
§4.4 Welding parameters
§4.4.1 Joint form in MMA
In MMA welding, the common basic joint form: butt joint, lap joint, corner joint
& T joint.
§4.4.2 Electrode selection
The electrode diameter selection is based on the workpiece thickness, welding
position, joint form, welding layer, etc. Please refer to the following table.
The welding current reference for different electrode diameter
Electrode
diameter/mm 1.6 2.0 2.5 3.2
Welding current/A 25～40 40～60 50～80 100～130
The relation between the welding current(I)’ factor(K) & electrode diameter(d) (I＝K×d: Carbon electrode)
Electrode
diameter/mm
1.6 2～2.5 3.2
Factor/K 20～25 25～30 30～40
Notice: the above parameters originate from《Welding Dictionary》P66～P67, Volume
1 of Edition 2.
Electrode should be drying according to user manual before using. For reducing
the hydrogen of the molten pool and welding seam, and avoiding the blowhole
and cold crack.
In the welding process, the arc must not be too long; otherwise, it will cause
unstable arc burning, large spatter, light penetration, undercut, blowhole, etc. If
the arc is too short, it will cause electrode stick.
In MMA welding the arc length is usually equal to 0.5~1.0 time of the electrode
butt joint lap jointcorner joint T joint
4.5 Arc Welding Defect and Prevent Method
OPERATION CONTROL AND CONNECTORS
13
diameter. The basic electrode’s arc length is not beyond the electrode diameter,
it’s better to choose the short arc welding; the acid electrode’s arc length is equal
to the electrode diameter.
§4.5 Arc Welding Defect and Prevent Method
Defect name
Caused reasons
Prevent methods
Welding seam
doesn’t meet
the requirement
The groove angle is not proper
The root face and assembly gap is not equal
Welding technics parameters are unreasonable
The welder’s operation skill is lower
Choosing the proper groove angle & assembly
gap, improve the assembly quality
Choosing the proper welding parameters
Improve the operation skill of welders
Undercut
Over current
Arc length is too long
The electrode angle is wrong
Manipulation of electrode is not proper
Choosing the proper welding current & speed
The arc can’t be drawn too long
The electrode angle should be proper
Manipulation of electrode should be correct
Incomplete
penetration
The groove angle or gap is too small, the root
face is too big
Welding parameters are not suitable, or the
assembly is not good
The welder’s operation skill is lower
Correctly to choose and process the groove size
Correctly to assemble and ensure clearance
Choosing the suitable welding current & speed
Improve the operation skill of welders
Incomplete
fusion
The welding thermal input is too low
The arc direction is lean
There are rust & dust on the side of groove
The slag between the layers is not cleared well
Correctly to choose the welding parameters
Operation seriously
Enhance the clearness of layers
Overlap
The temperature of molten pool is too high
The liquid metal concretes slowly
Choosing parameters based on the welding
different position
Strictly to control the molten hole size
Crater
The crater time lasts too short
Over current in the welding of thin plate
In the crater, electrode should be stayed for a
short time or round to manipulate electrode
after the molten pool is filled in by metal, take
to the side for crater
Blowhole
There are some dust like oil, rust or water on
the work piece surface and groove
The coating of electrode is damped& is not
drying
Under current or over speed in the welding
The arc is too long or lean burning, the molten
pool protection is not good
Over current, the coating of electrode falls off
and lose protection
Manipulation of electrode is not proper
Clear out the dust around groove for about 20～
30mm
Strictly to dry the electrode according to manual
Correctly to choose parameters and to operate
Using the short arc operation
Welding operation in the field should have
anti-wind protection
Don’t use the invalid electrode
Inclusion &
slag inclusion
The slag clears bad in the middle layer in the
welding process
Choosing the electrode of good slag
detachability

STEALTH DIGI-ARC 160PFC MV
16
OPERATION CONTROL AND CONNECTORS
13
diameter. The basic electrode’s arc length is not beyond the electrode diameter,
it’s better to choose the short arc welding; the acid electrode’s arc length is equal
to the electrode diameter.
§4.5 Arc Welding Defect and Prevent Method
Defect name
Caused reasons
Prevent methods
Welding seam
doesn’t meet
the requirement
The groove angle is not proper
The root face and assembly gap is not equal
Welding technics parameters are unreasonable
The welder’s operation skill is lower
Choosing the proper groove angle & assembly
gap, improve the assembly quality
Choosing the proper welding parameters
Improve the operation skill of welders
Undercut
Over current
Arc length is too long
The electrode angle is wrong
Manipulation of electrode is not proper
Choosing the proper welding current & speed
The arc can’t be drawn too long
The electrode angle should be proper
Manipulation of electrode should be correct
Incomplete
penetration
The groove angle or gap is too small, the root
face is too big
Welding parameters are not suitable, or the
assembly is not good
The welder’s operation skill is lower
Correctly to choose and process the groove size
Correctly to assemble and ensure clearance
Choosing the suitable welding current & speed
Improve the operation skill of welders
Incomplete
fusion
The welding thermal input is too low
The arc direction is lean
There are rust & dust on the side of groove
The slag between the layers is not cleared well
Correctly to choose the welding parameters
Operation seriously
Enhance the clearness of layers
Overlap The temperature of molten pool is too high
The liquid metal concretes slowly
Choosing parameters based on the welding
different position
Strictly to control the molten hole size
Crater The crater time lasts too short
Over current in the welding of thin plate
In the crater, electrode should be stayed for a
short time or round to manipulate electrode
after the molten pool is filled in by metal, take
to the side for crater
Blowhole
There are some dust like oil, rust or water on
the work piece surface and groove
The coating of electrode is damped& is not
drying
Under current or over speed in the welding
The arc is too long or lean burning, the molten
pool protection is not good
Over current, the coating of electrode falls off
and lose protection
Manipulation of electrode is not proper
Clear out the dust around groove for about 20～
30mm
Strictly to dry the electrode according to manual
Correctly to choose parameters and to operate
Using the short arc operation
Welding operation in the field sho
uld have
anti-wind protection
Don’t use the invalid electrode
Inclusion &
slag inclusion
The slag clears bad in the middle layer in the
welding process
Choosing the electrode of good slag
detachability
OPERATION CONTROL AND CONNECTORS
14
Under current or over speed in the welding
Welding operation is not proper
The welding material can not match the work
piece
The groove design & processing are not
proper
Strictly to clear the slag in the layers
Correctly to choose the welding parameters
Adjusting the electrode angle and manipulation
way
Hot crack
In the process of solidification, the inter
crystal segregation is seriously caused. At the
same time, with the effect of welding stress,
the hot crack is formed.
Strictly control the percentage of S and P in
welding material.
Adjust the structure of welding material.
Adopt the basic electrode.
Cold crack
Three reasons will cause cold crack:
The structure turned from the marten site
The residual stress caused by big restraint
intensity
The residual hydrogen in welding gap.
Adopt low hydrogen type basic electrode.
Bake under the instruction before use.
Remove the feculence before use, reduce the
percentage of hydrogen
Adopt appropriate parameters and heat input
After welding, do dehydrogenation at once.
§4.6 Operation Environment
●Height above sea level is below 1000m.
●Operation temperature range:-100C～+400C.
●Relative humidity is below 90 %(+200C).
●Preferably site the machine some angles above the floor level, the maximum angle
does not exceed 150.
●Protect the machine against heavy rain or in hot circumstance against direct
sunshine.
●The content of dust, acid, corrosive gas in the surrounding air or substance can not
exceed normal standard.
●Take care that there is sufficient ventilation during welding. There is at least 30cm
free distance between the machine and wall.
§4.7 Operation Notices
●Read §1 carefully before attempting to use this equipment.
●Connect the ground wire with the machine directly
●In case closing the power switch, no-load voltage may be exported. Do not touch
the output electrode with any part of your body.
●Before operation, no concerned people should be left. Do not watch the arc in

STEALTH DIGI-ARC 160PFC MV
17
4.6 Operation Environment
• Height above sea level below 1000m
• Operation temperature range: –10ºC~+40ºC
• Relative humidity below 90% (+20ºC)
• Preferably site the machine above floor level with the maximum angle not exceeding
15º.
• Protect the machine against heavy rain, hot environments and direct sunshine
• The content of dust, acid, corrosive gas in the surrounding air or substance should
not exceed normal standards
• Take care that there is sufficient ventilation during welding and there is at least
30cm free distance between the machine and wall
4.7 Operation Notices
• Read all notes carefully before attempting to use this equipment
• Connect the ground wire with the machine directly
• If the power switch is accidentally closed, no-load voltage may be exported. Do not
touch the output electrode with any part of your body
• Before operation ensure no other presonnnel is present without proper eye
protection
• Ensure good ventilation of the machine to improve duty ratio.
• Turn off the engine when the operation finished to economize energy source.
• If the power switch shuts off accidentally, do not restart until the problem is
resolved.
• If problems persist, contact your authorised supplier.

STEALTH DIGI-ARC 160PFC MV
5 MAINTENANCE & TROUBLESHOOTING
5.1 Maintenance
In order to guarantee that an arc welding machine works efficiently and safely, it must
be maintained regularly. Read and understand the maintenance methods and regularly
carry out safety checks. Make any repairs as required in order to extend the service life
of the welding machine. Maintenance items are detailed in the following tables.
• Warning: Safely maintain the machine by shutting off the power supply and waiting
for 5 minutes until the capacity voltage drops to a safe voltage of 36V.
DATE MAINTENANCE CHECKS
Daily Observe whether panel knob and switch in the front and at the back of arc
examination welding machine are flexible and placed correctly. If the knob has not been
correctly installed, please correct. If this is not possible, replace immediately,
If the switch is not flexible or it cannot be correctly installed, please replace
immediately. Contact your distributor if there are no parts to hand.
After switching on power, watch and listen to check the arc welding machine is
not shaking, whistling or giving out an unusual odour. If so, investigate and
eliminate. If any problem persists please contact your distributor.
Observe the LED is working correctly. If the number is not displayed, replace the
LED. If it still does not work, maintain or replace the display PCB.
Observe whether the min/max value on LED accords with the set value. If there
is any difference and it has affected the normal welding process, adjust
accordingly.
Check fan for damage and correct rotation. If damaged, change immediately.
If the fan does not rotate after the arc welding machine is overheated, check
the blade is not obstructed. If the fan still does not rotate after eliminating the
above, push the blade in the direction the fan rotates. If the fan rotates
normally, the start capacity should be replaced. If not, change the fan.
Check whether the fast connector is loose or overheated. If so, it should be
fastened or changed.
Check the current output cable is not damaged. If so, it should be securely
insulated or replaced.
18

STEALTH DIGI-ARC 160PFC MV
DATE MAINTENANCE CHECKS
Monthly Use dry compressed air to clear the inside of arc welding machine. Pay
examination particular attention to clear any dust on radiator, main voltage transformer,
inductance, IGBT module, the fast recover diode and PCB, etc.
Check the arc welding machine bolt. If loose, tighten. Replace if worn. Scrape
off any rust to ensure it works efficiently.
Quarterly Check the actual current accords with the displaying value. If not, they should
examination be reconfigured. The actual current value can be measured by the adjusted
plier-type ampere meter.
Annual Measure the insulating impedance among the main circuit, PCB and case.
examination If it is below 1MΩ, insulation may be damaged and should be repaired or
replaced.
5.2 Troubleshooting
• Before arc welding machines are dispatched from the factory, they have already been
carefully checked. Do not allow anyone unauthorised to make any alterations to the
equipment.
• Maintenance work must be carefully undertaken. If any wire becomes loose or
misplaced, it may be a potential danger to the user.
• Only authorised professional maintenance personnel should overhaul the machine.
• If a problem persists and no authorised professional maintenance personnel is
available, contact your authorised supplier.
If there are minor problems with the DIGI-ARC160PFC MV welding machine, consult
the following chart:
19

STEALTH DIGI-ARC 160PFC MV
20
MAINTENANCE AND TROUBLESHOOTING
18
If there are some simple troubles of ARC 160/200 PFC MV welding machines, you can consult the
following overhauling chart:
S/N
Troubles
Reasons
Solutions
1
Turn on the power source, and fan
works, but the power light is not
on.
The power light damaged or connection is
not good
Test and repair the inside circuit of
power light Pr3
Power PCB failures Repair or change power PCB Pr2
2
Turn on the power source, and the
power light is on, but fan doesn’t
work
There is something in the fan Clear out
The fan motor damaged Change fan motor
3
Turn on the power source, and the
power light is not on, and fan
doesn’t work
No input voltage
Check whether there is input voltage
Overvoltage (Input voltage is too much or
not)
Check input voltage
4 No no-load voltage output There is trouble inside the machine Check the main circuit, Pr1 and Pr2
5 No current output in the welding
Welding cable is not connected with the two
output of the welder.
Connect the welding cable to the
welder’s output
Welding cable is broken
Wrap, repair or change the welding
cable
Earth cable is not connected or loosen
Check the earth clamp
6 Not easy to start arc in the welding,
or easy to cause sticking
The plug loosen or connect not well Check and tighten the plug
Oil or dust covered the workpiece
Check and clear out
MMA/TIG welding selection is wrong
Selecting the MMA welding
7
The arc is not stable in the welding
process
The arc force is too small Increase the arc force
8
The welding current can not be
adjusted
The welding current potentiometer in the
front panel connection not so good or
damaged
Repair or change the potentiometer
9
The penetration of molten pool is
not enough(MMA)
The welding current adjusted too low Increase the welding current
The arc force adjusted too small
Increase the arc force
10 Arc blow
Airflow disturbance Use the shelter from airflow
The electrode eccentricity
Adjust the electrode angle
Change the electrode
Magnetic effect
Incline the electrode to the opposite
way of the magnetic blow
Change the position of earth clamp or
add earth cable in the two side of
workpiece
Use the short arc operation
11 The alarm light is on
Over heat
protection
Over welding current
Induce the welding current output
Working time too long
Induce the duty cycle (interval work)
Over current
protection
Unusual current in the
main circuit
Test and repair the main circuit and
drive PCB (Pr1)
If there are minor problems with the DIGI-ARC160PFC MV welding machine, consult
the following chart: