SWP Stealth 9020H User manual

Part No. 9020H
DIGI-ARC 140LT DV
OPERATOR’S
MANUAL

STEALTH DIGI-ARC 140LT DV

CONTENTS
1 SAFETY 4
2 SUMMARY 5
3 MAIN ELECTRICAL DIAGRAM 5
4 OPERATION CONTROL AND CONNECTORS 6
5 INSTALLATION & ADJUSTMENT 6
5.1 INSTALLATION 7
5.2 OPERATION 7
5.3 WELDING TABLE 8
6 OPERATION NOTICES 8
6.1 INSTALLATION 8
6.2 SAFETY 8
7 MAINTENANCE 9
8 TROUBLESHOOTING AND SERVICE 10
9 PARTS LIST 11
STEALTH DIGI-ARC 140LT DV

Welding may damage your body or others. Take protection during operation.
Only professionally trained technicians should install, set-up, operate,
maintain and repair the equipment.
Do not maintain or repair the machine when the machine is connected to
power.
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 earth.
Ensure equipment is correctly installed. Earth the work or metal to be
welded according the operation manual.
Ensure equipment is operated in a safe position.
Fumes and gases can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid breathing
these fumes and gases.
Use sufficient ventilation and/or exhaust at the arc to keep fumes and gases
away from the breathing zone.
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 welding material can easily go through small cracks
and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Have a fire extinguisher readily available.
Hot parts can cause burns.
Do not touch hot parts.
Use torch after cooling or use the welding blow lamp.
Personnel with a heart-pacemaker should keep away from the welding arc.
Rotating parts may be dangerous.
Keep clear of rotating parts (eg fan).
Keep machine parts in a safe position.
STEALTH DIGI-ARC 140LT DV
1 SAFETY
4
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.
3
1. SAFETY
Welding may damage your body or others, so please take protection measure in
operation.
Only ones who are trained professionally can install , debug, operate,
maintain and repair the equipment.
Do not maintain and repair the machine when the machine is connected
with power.
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.
Ensure to install the equipment correctly and ground the work or metal to be welded to a
good electrical(earth) ground according the operation manual.
Ensure to operate the equipment in safe position.
Fumes and gasses can be dangerous!
Welding may produce fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When welding, keep your head out the
fume.
Using enough ventilation and/or exhaust at the arc to keep fumes and gases away from
the breathing zone.
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 not materials from welding can easily go through small
cracks and openings to adjacent areas.
Do not weld enclosed tanks or containers.
Prohibit to use welder to unfrozen.
Have a fire extinguisher readily available.
Hot parts can lead to burn.
Do not touch the hot parts.
Please use the torch after cooling or use the welding blow lamp.
The people with heart-pacemaker should be away from the welding arc.
Rotating parts may be dangerous.
Far away from rotating parts. (like fan)
Keep the parts of machine in the safe position.

The DIGI-ARC 140LT DV is a MMA arc welding machine featuring the Insulated Gate Bipolar
Transistor (IGBT) power module. Its medium frequency transformer makes it portable,
compact, light weight and with low consumption and noise.
The DIGI-ARC 140LT DV offers excellent performance. Constant current output makes the
welding arc more stable and a fast dynamic response speed reduces the impact from the arc
length current fluctuation.
Other automatic functions protect from under voltage, over current, over heat, etc.
An alarm on the front panel lights, at the same time the output current cuts off. This can
prolong production use and greatly improve the reliability of the machine.
The machine can be easily ignited with little splash and good weld bead.
The DIGI-ARC 140LT DV has a high duty cycle – even at 40ºC – for continuous operation.
The machine is very stable and keeps working under high temperature and
corrosive environments.
STEALTH DIGI-ARC 140LT DV
2 SUMMARY
3 MAIN ELECTRICAL DIAGRAM
5
4
2. Summary
ARC-series(discrete)welder is a MMA arc welder which adopts the insulated gate
bipolar transistor(IGBT)power module.
It can change work frequency to medium frequency so as to replace the traditional
hulking work frequency transformer with the cabinet medium frequency transformer.
Thus, it is characterized with portable, small size, light weight, low consumption and
noise etc.
ARC-series(discrete) has excellent performance: constant current output makes
welding arc more stable; fast dynamic response speed reduces the impact form the arc
length fluctuation to the current.
There are also some automatic protection functions for under voltage, over current,
over heat, etc. inside the welders, when the problems listed before occurred, the alarm on
the front panel is light and at the same time the output current will be cut off. It can
self-protect and prolong the using life and greatly improved the reliability of the welders.
ARC-series can be ignited easily, also with little splash and good weld bead.
ARC-series(discrete) is widely used in Petroleum, chemical, mechanical,
shipbuilding, architecture, boiler, pressure container, war industry and installation and so
on. This machine has high duty cycle even in the 40℃, which can keep the continuous
operation. The frame is Stability of the machine, which can keep working under high
temperature and corrosion environment.
3. Electrical principle drawing

STEALTH DIGI-ARC 140LT DV
6
4 OPERATION CONTROL AND CONNECTORS
6
(1) Welding current adjustment knob: Turn this knob to adjust the output current size.
(2) Alarm light: alarm indicator, lights that occurred over voltage, over current, or
overheating inside the machine, is protected.
(3) Power indicator: power indicator, power on light on.
(4) Current display: Welding Current display when machine is working.
(5) Conversion switch: choose (up),MMA; choose (down),TIG.
(6) MMA light: When choose (up)MMA, this light on.
(7) TIG light: When choose (down)TIG, this light on.
(8) Negative output: Connect to pliers.
(9) positive output: Connect the welding the clamp.
(10)Cable clamp: Fastened the mains cable
(11)Power switch: Choose “ON”, power through; Choose “OFF”, power cut off.
6. Installation & Adjustment
Note: Please follow steps in strictly accordance with installation!
Electrical connection operation must be shut after power distribution box power
switch!
The equipment protection level is IP23. Do not use it in the rain!
6.1 Installation
(1) Each machine is equipped with a power cable should be based on the input
voltage welding power cable connected to the appropriate position, not to pick the wrong
voltage.
1 Welding current adjustment knob. Turn to adjust output current size.
2 Alarm lights: alarm indicator; over voltage; over current; machine overheating.
3 Power indicator: power indicator; power on light.
4 Current display: welding current display when machine is in operation.
5 Conversion switch: choose (up), MMA; choose (down), TIG.
6 MMA light: choose (up) MMA light on.
7 TIG light: choose (down) TIG light on.
8 Negative output: connect to pliers.
9 Positive output: connect the welding the clamp.
10 Cable clamp: secures the mains cable
11 Power switch: choose ‘ON’, power on; choose ‘OFF’, power off

STEALTH DIGI-ARC 140LT DV
7
6
(1) Welding current adjustment knob: Turn this knob to adjust the output current size.
(2) Alarm light: alarm indicator, lights that occurred over voltage, over current, or
overheating inside the machine, is protected.
(3) Power indicator: power indicator, power on light on.
(4) Current display: Welding Current display when machine is working.
(5) Conversion switch: choose (up),MMA; choose (down),TIG.
(6) MMA light: When choose (up)MMA, this light on.
(7) TIG light: When choose (down)TIG, this light on.
(8) Negative output: Connect to pliers.
(9) positive output: Connect the welding the clamp.
(10)Cable clamp: Fastened the mains cable
(11)Power switch: Choose “ON”, power through; Choose “OFF”, power cut off.
6. Installation & Adjustment
Note: Please follow steps in strictly accordance with installation!
Electrical connection operation must be shut after power distribution box power
switch!
The equipment protection level is IP23. Do not use it in the rain!
6.1 Installation
(1) Each machine is equipped with a power cable should be based on the input
voltage welding power cable connected to the appropriate position, not to pick the wrong
voltage.
5 INSTALLATION & ADJUSTMENT
Note: Please follow steps in strict accordance with installation instructions!
Electrical connection must be disconnected after power is switched off!
Equipment protection level is IP23. Do not use in the rain!
5.1 Installation
6.1.1 Each machine is fitted with a power cable based on the input voltage connected
to the appropriate selection. Do not select the wrong voltage.
6.1.2 With the corresponding input power supply terminal or socket, ensure good
contact and prevent oxidation.
6.1.3 A multi meter measures the input voltage is within the fluctuation range.
6.1.4 Clamp the front panel connector into the jack at the bottom of the cathode and
tighten clockwise.
6.1.5 Clamp the cable plug into the front panel below the negative welding socket and
tighten clockwise.
6.1.6 Ensure a good earth.
See above (4) and (5) for DC reverse operation.
Select DCSP operation when using base metals and welding rods.
In general, the basic electrode reverse method is recommended (ie, connected to a
positive electrode). When using acid electrodes take extra care.
5.2 Operation
6.2.1 Use the above method for correct installation. Turn the power switch to ‘ON’
and the power indicator light and fan come on – the device is working correctly.
6.2.2 Note the polarity of wiring. Generally DC welding wires are connected in two
ways – positive and reverse polarity.
Positive Connection: Welding clamp then negative, then positive, then positive
work piece; reverse law contrary. Select according to technical requirements.
An incorrect selection can result in arc instability and spatter etc.
6.2.3 If the work piece distance from the welding machine to the second line
(electrode holder and ground) is longer, choose the appropriate conductor.
A cross-sectional area should be larger to reduce cable voltage drop.
6.2.4 According to the standard pre-set welding electrode current, the electrode clip
will be sufficient and you can use short-circuit arc welding. For welding
parameters refer to 6.3.

STEALTH DIGI-ARC 140LT DV
8
5.3 Welding Table
Note: The following table applies to low-carbon steel. For other materials, please refer
to related information.
Electrode diameter Recommended welding Recommended welding
(mm) current (A) voltage (V)
1.0 20~60 20.8~22.4
1.6 44~84 21.76~23.36
2.0 60~100 22.4~24
2.5 80~120 23.2~24.8
3.2 108~148 23.32~24.92
6 OPERATION NOTICES
6.1 Installation
6.1.1 Welding environmental temperature should be between –10ºC to 40ºC.
6.1.2 Welding should be completed in relatively dry environments with air humidity of
not more than 90%.
6.1.3 Avoid environments containing dust or corrosive gases.
6.1.4 Avoid sunlight or rain. Do not allow water or rain water to infiltrated the welding
machine.
6.1.5 Avoid a strong air flow environment when gas welding.
6.2 Safety
This welding machine has been installed with a over-voltage, over-current and
over-temperature protection circuit. When the grid voltage, output current and internal
temperatures exceed the set temperature, the welding machine will automatically
cease working. Excessive use will result in welding damage, so please note:
6.2.1 Ensure good ventilation
The Digi-Arc 140LT DV is equipped with cooling fans. Before use, please check
the vents are clear and the distance surrounding welding is not be less than 0.3
metres.
6.2.2 Prevent overload
The welder should ensure that the duty cycle current is kept within the standard
range (see technical data table). Any current overload will shorten the life of
the machine welding machine and may even ignite.
6.2.3 Prevent over-voltage
The welding voltage within the circuit will automatically compensate to ensure
the welding current is in the permitted range. If the voltage exceeds the

STEALTH DIGI-ARC 140LT DV
9
allowable value it can damage the machine. The welder should be fully aware of
this and take appropriate preventive measures.
6.2.4 Each welding machine comes with a grounding screw. Use a 2.5mm earthing
cable to be connected to the chassis to discharge any static electricity.
6.2.5 If the welding work exceeds the standard loading time, the machine may
suddenly cease working safely and the front panel alarm indicator lights up.
In this event do not unplug the power, to ensure the cooling fan rotates and the
red light goes out. When the temperature has dropped to a reasonable extent,
welding can recommence.
7 MAINTENANCE
The following operations require the welder has sufficient electrical expertise and can
demonstrate a comprehensive knowledge of working safely with valid qualifications and
documents. Check to make sure the welding power input cable is not broken.
7.1 Periodically inspect the internal circuit connections are intact and reliable (especially
the joints or components). If any rust and debris is found, sand off, clean, reconnect
and tighten.
7.2 Do not allow hands, hair and tools near live components or fans inside the machine.
7.3 Regularly clean machine with dry compressed air. Compressed air pressure should be
at a reasonable level in order to avoid damage to the welding of small internal
components. Dust the machine regularly.
7.4 Avoid water or water vapour getting inside the welding machine inside. In the event of
accidental ingress, the machine should be thoroughly dried. Only when you are sure
that any moisture or water has been thoroughly dried from inside may you use the
machine. Suitable tools for checking the moisture content within are advised.
7.5 Regularly inspect the cable insulation for damage. In the event of any damage wrap or
replace the cable.
7.6 When not using the machine, place back in the case and keep in a dry environment.

STEALTH DIGI-ARC 140LT DV
8 TROUBLESHOOTING AND SERVICE
Common faults and solutions:
Symptom Solution
Power indicator does not light, fan does not – Make sure the power switch is turned on.
turn, no welding output – Confirm that the power input cable is
connected to electricity.
Fan switch not working – Assess any damage and replace where
Fluctuation in current High / Low necessary.
– Check for poor connections (eg plug-ins).
– Check all connectors inside the machine.
– Check circuit output connections.
– If the alarm indicator light is on check:
That the machine is not overheating.
Power indicator light shows fan rotating If so maintain power, so that the fan
normally but no welding output continues and the temperature drops.
When the light goes out continue working.
– Check if the thermal switch is damaged
and replace if necessary.
Hot welding clamp – Welding clamp current is too small.
Replace with larger clamp.
Welding arc flares – Check +/– polarity is correct for welding
process.
10

STEALTH DIGI-ARC 140LT DV
11
9 PARTS LIST
9020H-02 COVER
9020H-05 ROCKER SWITCH – USE 9000H-07
9020H-07 REAR PANEL
9020H-08 FAN
9020H-13 BASE
9020H-15 CURRENT TRANSFORMER – USE 9012-36
9020H-17 FRONT PANEL
9020H-21 KNOB – USE 9000H-33
9020H-22 FRONT PCB
9020H-24 MAIN PCB ASSEMBLY
9020H-25 CONTROL PCB

Specialised Welding Products Ltd
Unit 1, Farringdon Industrial Centre, Farringdon, Nr Alton, Hampshire GU34 3DD, UK
tel: [phone] • fax: [phone] • email: [email protected]
STEALTH DIGI-ARC 140LT DV