Westweld NB-250LB User manual

１
NB-250/270/315LB
MIG/MAG/CO2WELDING MACHINE
MANUAL
INSTRUCTION

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Safety Depends on You
Huayuan arc welding and cutting equipments are designed and built with safety in mind. However, your overall safety
can be increased by proper installation.
DO NOT INSTALL, OPERATE OR REPAIR THIS EQUIPMENT WITHOUT READING THIS MANUAL AND THE SAFETY
PRECAUTIONS CONTAINED THROUGHOUT. And, most importantly, think before you act and be careful.
Special Attention (Very Important):
●AVOID FALLING DOWN WHEN THE WELDING MACHINE IS PLACED ON THE INCLINED PLANE.
●IT’S CAN NOT BE USED FOR UNFREEZING PIPELINES.
●THE SHIELD RANK OF THIS SERIES OF WELDING MACHINE IS IP21S, AND IT IS NOT SUTABLE FOR WORKING IN THE
RAIN.
Purchase Date：
Serial Number：
Machine Type：
Purchase Place：

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Cautions
Arc and arc rays may harm health.
Arc welding can be hazardous. All performing welding workers ought to have health qualification that provided
by authority organization. Protect yourself and others from possible serious injury or death. Keep children away.
Pacemaker wearers should consult with their doctor before operating. Be sure that all installation, operation,
maintenance and repair procedures are performed only by qualified individuals.
1 Electric shock can kill: 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. Users need to follow the below items to avoid electric
shocks:
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. Otherwise, use automatic or semiautomatic
welding machines, DC welding machines as possible as you can.
In semiautomatic or automatic wire welding, the electrode,electrode reel, welding head, nozzle or
semiautomatic welding gun are also electrically“hot”.
Always be sure the work cable makes a good electricalconnection with the metal being welded. The connection
should be as close as possible to the area being welded.
Ground the work or metal to be welded to a good electrical(earth) ground.
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, please do wear safety belt to avoid falling or losing balance on electric shock.
2 Arc rays can burn: Use a shield with the proper filter and cover plates to protect your eyes from
sparks and the rays of the arc when welding or observing open arc welding. Headshield and
filter lens should conform to nation standards.
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.
3 Fumes and Gases can be dangerous: Welding may produce fumes and gases hazardous to
health. Avoid breathing these fumes and gases. While working in limited room, use enough
ventilation and/or exhaust to keep fumes and gases away from the breathing zone, or use the
respirator.
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.
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.
Read and understand the manufacturer’s instructions for this equipment and the consumables to be used,
including the material safety data sheet (MSDS) and follow your employer’s safety practices. Make sure they

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are asepsis and innocuity.
4 Spatter: Welding or cutting spatter 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 in the field, special precautions should be used to prevent explosion.
When not welding, make certain that no electriferous part is touching the work piece or the work stage.
Accidental contact can create a fire hazard.
Do not weld containers or lines, which are not proved to be innocuity.
Do not heat, cut or weld tanks, drums or containers until the proper steps have been taken to insure that such
procedures will not cause flammable or toxic vapors from substances inside. They can cause an explosion even
though they have been“cleaned”.
Spatter might cause burn. Wear leather gloves, heavy shirt, cuffless trousers, high shoes and a cap over your
hair to prevent from burning by spatter. Wear the ear shield when performing sideways or face up welding.
Always wear safety glasses with side shields when being in a welding area.
The welding cables should be as close to the welding area as possible, and the short, the better. Avoid welding
cables going through the building framework, lifting chains, AC or DC cables of other welding machines and
appliances. The welding current is strong enough to damage them while having short circuit with them.
5 Cylinder may explode if damaged.
Make sure that the gas in the storage cylinder is qualified for welding, and the decompression
flowmeter, the adapter and the pipe are all in good condition.
Always keep cylinders in an upright position securely chained to an undercarriage or fixed support.
Be sure to put the cylinder in the working space with no crash or shake, and far from welding area.
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.
6 Power: (For electrically powered welding and cutting equipment) Turn off input power before
installation, maintenance and repair to avoid accidents.
Huanyuan welding equipment is Ι class safeguard equipment; please install the equipment in
accordance with the manufacturer’s recommendations by specific persons.
Ground the equipment perfectly in accordance with the manufacturer’s recommendations.
7 Power:(For engine driven welding and cutting equipment)
Work in ventilated place or outdoors.
Do not add fuel near to fire or during engine starting or welding. When not working, add fuel after
engine is cooling down; otherwise, the evaporation of hot fuel would result in dangers. Do not
splash fuel out of the fuel tank, and do not start the engine until complete evaporation of the
outside fuel.
Make sure that all the safeguard equipments, machine cover and devices are all in a good
condition. Be sure that arms, clothes and all the tools do not touch all the moving and rotating
components including V belt, gear and fan etc.
Sometimes some parts of the equipment have to be dismantled during maintenance, but you still have to keep
the strongest safety awareness .

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Do not put your hand close to fans and do not move the brake handle while operating.
Please remove the connection between the engine and the welding equipment to avoid sudden starting during
maintenances.
When engine is hot, it is forbidden to open the airtight cover of the radiator water tank to avoid hurt by the hot
vapor.
8 Electromagnetic: Welding current going though any area can generate electromagnetic, as well
as the welding equipment itself.
Electromagnetic would affect cardiac pacemaker, the cardiac pacemaker users should consult
one’s doctor first.
The effect of electromagnetic to one’s health is not confirmed, and it might have some negative effect to one’s
health.
Welders may use following method to reduce the hazardous of electromagnetic:
a. Bundle the cable connected to the work piece and the welding cable together.
b. Do not enwind partially or entirely your body with the cable.
c. Do not place yourself between the welding cable and the ground (work piece) cable, if the welding cable is by
your left side, then the ground cable should be by your left side too.
d. The Welding cable and the ground cable are as short as possible.
e. D e. Do not work near to the welding power source.
9 Lifting equipment: carton or wooden boxes package the welding machines supplied by
Huayuan. There is no lifting equipment in its wrapper. Users can move it to the prospective area
by a fork-lift truck, then open the box.
If there are rings, the machine can be transited by rings. While Huayuan Welding Machine
Manufacture reminds users, there is potential risk to damage the welding machine. So it is better
to push the welding machine by its rollers unless special situations.
Be sure that the appurtenances are all removed off when lifting.
When lifting, make sure that there is no person below the welding machine, and remind people
passing by at any moment.
Do not move the hoist too fast.
10 Noise: Huayuan Welding Machine Manufacture reminds users: Noise beyond the limit (over 80
db) can cause injury to vision, heart and audition depending on oneself. Please consult local
medical institution. Use the equipment after doctor’s permission would help to keep healthy.

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Content
一、 Summary..................................................................................................................................................................７
1. Model introduction................................................................................................................................................７
2. Features..................................................................................................................................................................７
3. Usage......................................................................................................................................................................７
4. Symbols Introduction.............................................................................................................................................７
5. Safety attentions ....................................................................................................................................................７
二、 Working condition and environment.......................................................................................................................８
1. Operation place......................................................................................................................................................８
2. Power supply..........................................................................................................................................................８
三、 Technical Parameters ...............................................................................................................................................８
四、 Products system introduction ..................................................................................................................................９
1. Summarize of working principles ...........................................................................................................................９
2. Main electric diagram ............................................................................................................................................９
3. Block schematic diagram........................................................................................................................................９
五、 Panel function introduction .....................................................................................................................................９
2. Rear Panel Function Drawing.............................................................................................................................１１
3. Gas bottle bracket(Optional)introduction and installation drawing...............................................................１１
六、 Installation............................................................................................................................................................１３
1. Power supply:.....................................................................................................................................................１３
2. Installation (please refer to figure 8)..................................................................................................................１３
七、 Operation .............................................................................................................................................................１４
1. Operating instructions........................................................................................................................................１４
2. Matters need attention ......................................................................................................................................１５
八、 Maintenance and repairing..................................................................................................................................１５
1. Matters need attention ......................................................................................................................................１５
2. Maintenance ......................................................................................................................................................１５
3. Trouble shooting ................................................................................................................................................１５
九、 Complete sets.......................................................................................................................................................１７
十、Drawing..................................................................................................................................................................１８

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一、 Summary
1. Model introduction
NB —□□□ LT
Product series
Rated welding current(A)
Semi-automatic welding
Gas shield welding machine
2. Features
Striking arc under high voltage and slow wire feed. Smooth and stable arc striking with high success rate;
Adopting unique feedback control circuit of arc voltage and current, stable welding process, little spatter,
strong adaptability of wire extension change, wide adjusting range for matching current and voltage,
well-shape weld appearance;
Adopting high performance ball-eliminating circuit, the diameter of ball on wire end almost the same as wire
diameter, high success rate at arc striking;
3. Usage
Widely applied in the fields of automobile, steel furniture, filing cabinet, security door, guard railing, and building
decoration, suitable for all position welding on the mild carbon steel in thickness 0.8～6mm;
Ф0.8、Ф1.0 solid wire is suitable.
4. Symbols Introduction
Please read
manual
Connect earth
cable
Positive
negative
Up/down
current
Input voltage
voltage
MIG/MAG
Over heat
Connection with
workpiece
Dangerous
voltage
Remote control
Clear air
（check-air）
Self-lock
non self-lock
5. Safety attentions
To you and others safety, please do abide by the below items:
The welding machine should be grounded reliably:

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To prevent electric shock, please do ground the green-yellow wire well;
Wear protective equipments
To prevent the hurt of welding gas, dust, arc, spatter and noise, please do wear some protective equipments and
install necessary ventilation devices. Keep kids away from the dangerous area;
The cylinder of shielding gas should be fixed well to ensure there is no shock;
Welding machines and procedure should be away from combustible and explosive material, do not weld
closed container. It is dangerous to weld the hand-hole of container, please make sure there is no combustible
and toxic gas on the weld before operation;
Keep sharp objects and other wastes away from the inner machine;
If dropping or cracking, the welding machine can not be used again without checking by qualified individuals.
二、 Working condition and environment
1. Operation place
If machine is not operated according to the below items, the welding performance should be poor even damage
the machine!
The machine should be placed in where there is no sunshine shooting, rain, dust, etchant gas and
combustibles, the environment temperature is to be in the range of -10℃～40℃.
The machine should be placed in where there is no metal waste;
Keep the welding power source away from wall or other closed objects at least 30cm, the distance between
two welding machine is also said to more than 30cm;
Operate this machine in where there is no wind.
Operate this machine in where the altitude is lower than 1000m.
2. Power supply
Power：3～50Hz380VAC
Fluctuation range of distribution voltage：＜±15%
Fluctuation range of frequency：＜±1%
Unbalance ratio of three phase voltage：＜±5%
When engine generator is used: make sure the output power of the generator is 2 times larger than the rated
input power of welding power source, compensating coil is also needed.
三、 Technical Parameters
Item
Unit
Model
NB-250LT
NB-315LT
Input power
V／Hz
3～380±15％50／60
Rated input capacity
KVA
10.3
14.6
Rated input current
A
15.7
22.1
rated output current
A
250
315
rated output voltage
V
26.5
29.8
Rated open voltage
V
64
Duty rated
-
35%（40℃）
efficiency
-
85％
86%
efficiency factor
-
0.74
0.75
Output Voltage adjustment
V
15～32
Wire feeding speed
m/min
1.5～28
Suited wire diameter
mm
Φ0.8、Φ1.0
Cooling mode
-
Air cooling

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Insulation grade
-
F
Ingress protection
-
IP21S
Dimension(L×W×H)
mm
640×300×595
Power net weight
kg
38
39
The static external characteristic of this machine is dropping characteristic, it`s rated duty cycle is 35%, which
means in a 10 minutes work cycle, the welding machine can work 3.5 minutes(stop 6.5 minutes) under the rated
current. If it is forced to use over the rated duty cycle, the inner temperature will exceed the set temperature. To avoid
poor working or burning, a overheating protection function is set: when overheating, the indicator light lights and
there is no out-putting from the welding machine, it can work again after the temperature dropping.
When welding current is lower than 200A, the gas flow is 8-15L/min, when the welding current is larger than 200A,
the gas flow is 15-25L/min.
四、 Products system introduction
1.Summarize of working principles
This series of CO2/MIG/MAG inverter gas shield welding machine adopts the latest electron device----IGBT is the
key inverter device. The three phase AC power is transformer into 20KHz high frequency voltage after bridge rectified.
The high frequency voltage output welding voltage after transforming, rectifying and filtering.
2.Main electric diagram
Please refer to the attached figure
3.Block schematic diagram
五、 Panel function introduction
1.Front Panel function drawing

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Function of figures 2 as below:
1. Digital display meter of voltage：when machine is not working, it display preset voltage, when machine is
working, it display the actual welding voltage;
2. Digital display meter of current：to display the actual welding current；
3. Adjusting knob of welding voltage: to adjust the welding voltage;
4. Adjusting knob of welding current: to adjust the welding current;
5. Plug seat of welding torch: plug of welding torch, Europe type interface;
6. Over heating indicator light: when the welding machine is working in high temperature environment and
working overload, the temperature of radiator is higher than 75℃±5℃, the protection circuit begin to work, and
then output current will be cut. At the same time, the cooling fan go on working, after the temperature get down,
the welding machine will work normal again. The indicator light will also light when the air flue jammed or cooling
fan damaged.
7. Change-over switch of welding & gas checking: before welding, to adjust the shield gas flow, turn it on "gas
checking". Turn it on "welding" position when welding.
8. Change-over switch of self-lock & non-lock: when it is put on"self-lock", press the torch button and then the arc
can be stroke, loosen the button, welding will keep on normally, press the button again, welding finishes. When it is
put on "non-lock", press the button, welding begins, loosen the button, welding finishes.
9. Manual wire feeding button: press it and the wire feeder work. Wire feeding speed can be adjusted by welding
current. When wire diameter is small, the wire feeding speed should be slow to prevent bending the wire.
10. Arc characteristic adjust knob: Gas welding, use to adjust and control the different period current rate of
melting drop process, adjust the knob directly affect the arc soft/hard, spatter, welding shape and arc stability.
Recommend use standard characteristic.
Note: large spatter if arc hard, otherwise small.
11. -(power output negative): use to connect the earth cable;

１１
2. Rear Panel Function Drawing
1) Input cable of three phase power: connect to distribution box, connect the green-yellow wire to ground wire
reliably;
2) Heater power source interface: Heater connector, output voltage 36VAC;
3) Wire feeding fuse holder: Used for short connect and over current protection of Wire feeder power supply
circuit, inside Fuse 8A;
4) Control fuse holder: used for short connect protection of welding machine control circuit, inside fuse 1.5A;
5) Over current protection switch(Air switch):welding machine have abnormal, disconnect the power source
then protect. The switch only for protection, another power switch shall be configured during installation
welding machine.
6) Cooling fan: To cool power source;
3. Gas bottle bracket(Optional)introduction and installation drawing
1) Gas bottle bracket parts introduction as FIG4：
（FIG 4 Gas bottle bracket part drawing）
U-Style
bracket
Support
plate
Support
plate

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Note: Gas bottle bracket is the optional!!!
2) Gas bottle installation drawing：
（FIG 5 Gas bottle bracket installation drawing）
(FIG 6 Gas bottle U-Style bracket installation drawing)
Note: if buy gas bottle bracket together machine, please remove the two rear wheels and install them on the support
plate of bracket, Then install U-style bracket and done,refer to Fig 5 and 6.
Fig 7 is the comparison for the welding
machine which with and without bracket.
standard Power source Power source with gas bottle bracket(Optional)
（FIG 7）
M8 screw
（18pcs）
M6 screw
（6pcs）

１３
六、 Installation
1. Power supply:
Specification
NB-250LT
NB-315LT
Capacity of power
supply switch(A)
25
32
Capacity of fuse (A)
23
30
Sectional area of
power supply line
(mm2)
≥2.5
≥2.5
Sectional area of
ground wire(mm2)
≥4
≥4
2. Installation (please refer to figure 8)
Make sure the distribution switch is cut down, and then connect the welding machine. Do not operate with
wet hands. Do not put anything on the power cable. Connect all the parts well. Install according to the below
orders：
Connect the three phase power cable to the power switch of distribution box well, the green-yellow line of
welding machine should be reliably connected with ground wire in the distribution box.
Connect the quick coupling of ground wire with the socket of work-piece, tighten it by clockwise, connect the
other end of ground wire with work-piece reliably.
Insert the plug of torch into socket, fasten the ring nut and tighten the torch.

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Install the CO2 pressure flow regulator on the gas cylinder, fasten the nuts;
Connect the plug of CO2 pressure flow regulator heater to the socket in the back panel;
Connect the φ8 gas line to the output air cock of CO2 pressure flow regulator, and connect the other end of
gas line to input air cock, clamp it with hoop. Please use standard shield gas, or there will be welding defect.
七、 Operation
1.Operating instructions
A. Installation of electrode wire (see figure 9 as reference)
Open up the left upper panel of welding machine, stand the panel on it;
Adjust the catch of electrode wire reel, the stretch out direction of catch should be same as the axis direction
of wire reel shaft, put wire reel on the shaft. Adjust the catch of electrode wire reel, the stretch out direction
of catch should be vertical with axis direction of wire reel shaft, fast it to prevent rolling out.
Make sure the wire slot diameter of wire feeding wheel is same as the electrode wire diameter;
Loosen the clamp handle of wire feeder, put up the wire wheel, pull out the wire tip, cut off the deformation
part, insert the wire tip into the wire guide pipe, it reach torch connector through guide tube, press the wire
wheel and fasten it with suitable strength;
B. Make sure the diameter of contact tip is same as the used electrode wire;
C. Put three phase switch on, press the button of "Manual wire feed", adjust welding current to get suitable wire
feeding speed, loosen the button till 15---20mm electrode wire is sticked out.
D. Put the switch of "welding/gas checking" on "gas checking" position, unscrew the switch of gas cylinder with a
suitable speed till get the wanted gas flow value, and then put the switch on "welding" position;
E. Adjust the button of "welding current" by actual needed current;
F. If welding current is confirmed, the welding voltage can be figured out by the formula of U（welding voltage）
=14＋0.05×I(welding current), adjust the button of "welding voltage" and make it displayed on digital meter;
G. Change-over switch of self-lock & non-lock: when it is put on"self-lock", press the torch button and then the
arc can be stroke, loosen the button, welding will keep on normally, press the button again, welding finishes.
When it is put on "non-lock", press the button, welding begins, loosen the button, welding finishes;
H. After finishing the above adjustment, wear required safety equipments, then normal welding process can be
operated;

１５
I. To get excellent welding performance, the "welding current" and "welding voltage" should be adjusted when
welding.
2.Matters need attention
A. When welding, the cable of welding torch can not be bended too much, or it will affect normal wire feeding;
B. Lubricating grease or engine oil can not be used on wire feeding roll and wheel;
C. The contact tip of welding torch is consumable, after long time use, the welding current may unstable, please
replace it in time;
D. The nozzle of welding torch is consumable, please replace it in time. When clear the spatter on nozzle, please
take it down and clear lightly. A spatter prevent grease is recommended to use, which can clear spatter easily
and lengthen the service life of nozzle.
E. After long time use, dust get into the wire feeding pipe of welding torch, which may affect normal welding, so
please take the pipe out at fixed period and wash with kerosene or dry compressed air, shake the pipe before
cleaning;
F. When welding, please control the wire length between nozzle and work-piece. Generally, the length should be
10 times as wire diameter; If too long, there will be unstable welding current, more spatter and air hole; if
too short, the nozzle will be easily blocked by spatter;
八、 Maintenance and repairing
1.Matters need attention
A. When maintain or repair, the power must be cut off.
B. Since this machine is filtered by large capacity and high voltage electrolytic capacitor, it can not be opened and
repaired in 5 minutes after cutting off power.
2.Maintenance
A. Check connectors at fixed period to see if they become flexible or if there is poor contact;
B. Keep machine clean: the service life will be shorten because of dirty in the machine, so please open and clean
the machine at least half a year;
3.Trouble shooting
A. The three phase voltage should be 380±15%, check and make sure the voltage is in this range;
B. Make sure the power switch is not damaged, and the fuse and power cable are installed reliably, or there may
be open phase or poor contact;
C. Make sure the connection of welding cable is good.
D. Check if welding switch or cable is damaged, and if nozzle, contact tip, tip table and shunt are burned or
damaged;
Common faults and eliminating methods:(see below sheet)
Faults
Reasons
Eliminating methods
1.Put power on, the power
indicator do not light
1.Open phase of three
phase power;
2.The power switch is old
and damaged;
3.The 1.5A fuse of power
control is melt;
1.Check the three phase power
switch;
2.Replace power switch;
3.Replace the fuse;
2.Welding machine do not
work, under voltage
indicator light
1．Open phase on three
phase power;
2．Under voltage on three
phase power;
Check three phase supply power,
make sure supply voltage fit the
required voltage;
3.Press torch switch, wire
wheel moves, but there is
no wire sending out from
torch, or the wire feeding
is unstable
1.The wire wheel is not
tighten;
2.The diameter of wire slot
is not same as electrode
wire;
1.Fasten the wire wheel;
2.Replace wire slot;
3.Eliminate the spatter on contact
tip;
4.Replace wire feeding wheel;

１６
3.The contact tip is blocked
by spatter;
4.The wire reel slog is
abraded;
5.The wire feeding pipe of
torch is blocked;
6.The torch cable is
excessive bended;
5.Clean the dirty or dust in wire
feeding pipe by dry compressed air
or replace it with a new one;
6.Make the bending diameter of
torch cable larger than 300mm;
4.Welding machine do not
work, the over heating
indicator lights
1.The environment
temperature is too high;
2.There is something
wrong with the cooling
fan;
3.The temperature relay is
damaged;
1.Make welding machine rest for a
moment;
2.Check the power of cooling fan or
replace cooling fan;
3.Replace the temperature relay;
5.The gas heater frosts
1.Poor contact on heater
plug seat;
2.Open circuit on heater
resistance wire;
1.Check the plug and socket of
heater;
2.Repair or replace heater;
6.Press torch switch, the
wire feeding wheel do not
move or there is no
welding current
1.Open circuit on welding
torch cable;
2.The wire feeding motor
is damaged;
3.The PCB is damaged;
1.Check the control cable of welding
torch;
2.Repair the wire feeding motor or
replace it with a new one;
3.Repair or replace PCB;
7.There are too many air
holes on welding seam;
1.CO2 gas is not pure;
2.The gas flow is not
enough;
3.There is grease dirt or
rust on welding seam;
4.The wind in the welding
place is too heavy;
5.CO2 gas circuit is blocked
or blab;
6.Gas valve doesn’t
actuate;
7.Deformation on nozzle;
1.Use high purity CO2 gas;
2.Adjust the gas flow;
3.Eliminate the grease dirt or rust
on welding seam;
4.Do something to reduce the wind
in welding place;
5.Check the gas circuit, dredge it or
block it;
6.Replace the nozzle of welding
torch;
8.There is too much spatter
or the welding current is
not stable
1.Open circuit on three
phase power;
2.Wrong welding standard;
3.Bad electrode wire
quality;
4.There is grease dirt or
rust on work piece or
electrode wire;
5.The distribution voltage
fluctuates heavily;
6.The electrode wire sticks
out too long;
7.The diameter of wire slot
is not same as electrode
wire;
8.Something wrong with
1.Check three phase supply power,
make sure supply voltage fit the
required voltage;
2.Adjust the welding standard;
3.Replace electrode wire;
4.Clean the grease dirt or rust;
5.Make sure the fluctuation range of
distribution voltage is in 380
VAC±15%;
6.The stick out length should be 10
times more than wire diameter;
7.Replace the wire slot;
8.Use high purity gas;
9.Replace contact tip;
10.Clean the wire feeding pipe;
11.Fasten the ground wire;

１７
the shield gas;
9.Wrong model of contact
tip or the tip hole is
damaged;
10.Too much dirt in wire
feed pipe;
11.Ground wire gets
flexible;
9.Wire is feed without
pressing torch
1.Short circuit on switch;
2.Manual wire feeding
button is damaged;
1.Repair or replace welding torch;
2.Replace manual wire feeding
button;
10.Current and voltage can
not be adjusted
1.The potentiometer of
current and voltage is
damaged;
2.The PCB is damaged.
1.Replace potentiometer;
2.Repair or replace the PCB;
11.There is wire feeding,
but no current spark, or
there is noise in machine
1.The fast recovery diode
is damaged;
2.IGBT is damaged;
3.Circuit or other
components are damaged;
1.Check and replace the damaged
fast recovery diode;
2.Replace IGBT or PCB;
3.Check and replace the damaged
parts;
!SPECIAL ATTENTION: If there some problems that can not be judged or solved, please do not hesitate to contact our
company to get some technical assistance. Please do not repair or open the machine arbitrarily. There is high voltage
after cutting power for 10 minutes, only qualified electrician can operate!
九、 Complete sets
1. NB-LT welding machine 1set
2. Ground wire 1
3. Welding torch 1
4. Heater 1
5. Attached documents：Operation manual、Certificate、Warranty Each 1
★6.Gas bottle bracket 1set (Optional)

１８
十、Drawing
QF1
TM1
C2
C7
C1
C6
C3
L2
C4
L3
FU1 1.5A
D25
＋15V
1
O ut
3
-15V
2
0V
4
TA1
TC1
17V 17V
36V 17V
380V 220V
7980
93 92 94 85 87 90
66656867 PV1
64 63 61 62
G2 E2 G1E1G4 E4 G3E3 24 25
G1 G2
G3 G4
E1 E2
E3 E4
1 2 3 4
5 6 7
8
10
7
11
12
18
17
15
20 21
22
23 24
25
AP1
86 89 88 91
27V 27V 8V
26V
100
99
加热器电源
RT2
PA1
60 59 57 58
V1
L4
26
HL1
过热
7576 78
KT1
77
C5R1
7 8
EV1
C11
TA2
R6
C8
C12
V2
42444330 33
SA1
检气
53
31 31 30 56
SA2
自锁／非自锁
54 3435
焊接电流
3637
短接
4041
送丝
收弧电流
4947 48
4645
启动
SB4 SB3
RP4
3839
焊接电压
RP5
收弧电压
5250 51
83 84
27V
+5V DC
GND
IN +
IN -
+5V DC
GND
IN +
IN -
预留功能
72 71
7473
欠压指示灯
82 81
FU2
8A
55
32
电弧特性
RP3
101
RT1
AP2
AP2
V3
V4 V5
A
- +
MG1
YV1
送丝电机

１９
The final explanation rights reserved to Westweld /Huayuan Company!
If there is any changes in the user’s manual, forgive not to inform separately!
Westweld Ltd
4-23-4, No.51, Xuefu Avenue, Nanan, Chongqing, China
E-mail: [e-mail] [e-mail]
www.westweld.com