Weiro WM250FI User manual

THANKS FOR PURCASHING OUR PRODUCT
WM –350FI
CO² / MIG / MAGAUTOMATIC WELDING MACHINE
W E I R O
OPERATION MANUAL
(Read the manual carefully before installation, operation and maintenace)
Safety Depends on You
WEIRO are welding and cutting equipment is designed and built with safety
in mind. However, your overall safety can be increased by proper
installation... and thoughtful operation in your part. 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.
C V. A N U G R A H D U TA N I A G A
Jln. Arief Rahman Hakim 51 Komplek Ruko 21 Klampis Blok D-1
Telp. 031 –5990089, 5997259 (Hunting)
Fax. [phone]
Email : [e-mail]

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Index
1. Principle &Technical data……………………………………….…(1)
2. Features & Applications……………………………………….…...(3)
3. Installation Guide…………………………………………….…….(5)
4. Operating Instruction…………...…………………………….….....(9)
5. Repair & Maintenance……………………………………….…….(13)
6. Error Code........................................................................................(16)
Appendix A: EMC Suggestion for installation and use of welder….….(17)
Appendix B: Feedback Form…………………………………………...(19)
This operating manual can be fit for MIG-FI (including WM250FI/350FI/500FI)
series welding machines. The technical data are measured with power supply 3
phase 380V, the data will be changed when you use different voltage or frequency.

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Principle & Technical data
MIG-FI Series Block diagram of principle shown as Figure 1
Input (3~380V/50Hz)
Output
Figure1: Block diagram of principle
This series welding machines apply IGBT soft switch inverter technology. 3-phase input volt
380V are rectified by rectifier, inverted into HF AC, reduced by HF transformer, rectified and
filtered by HF rectifier, then output DC power suitable for welding. After this process, the
welder’s dynamically responsive speed has been greatly increased, so the welder size and
weight are reduced noticeably. Power source enjoys good anti-fluctuating ability and
high-quality performance.
MIG-E Series Volt-Ampere Curve as shown in Figure 2:
Figure 2: MIG-FI Series Volt-Ampere Curve
U (V)
-
80
-
60
-
40
-
20
-
0
U2=14+0.05I2
I (A)
3 phase
Rectifier
HF
Inverter
HF
Transformer
Rectifier &
Filter
Control circuit
+
-

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1. Main technical parameters
Items
WM250FI
WM350FI
WM500FI
Rated input voltage (V)
/frequency (Hz)
3-phase 380±10% /50
Rated input capacity (KVA)
8
14
25
Rated input current (A)
12
21
38
Power factor
0.95
Rated duty cycle
60%
Open load voltage (V)
51
72
81
Welding current range (A)
40～250
60～350
60～500
Welding voltage range (V)
14～30
15～40
15～50
Wire diameter (mm)
0.8～1.0
0.8～1.2
1.0～1.6
Wire feeding type
Wire pushing
CO2gas flow rate (L/min)
10～20
15～25
15～25
Protection degree
IP21S
Insulation degree
H/B
Dimensions (mm3)
501×235×495
Weight (Kg)
20
26
28
Table 1: Parameter Specification

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2. Main Circuit diagram
Figure 3 : Main circuit diagram
2X2:11
2X2:4
1X3:2 1X3:3 1X3:4
1
-+
2X1:2 2X1:1 2X1:3
2X3:2
2X3:1
~27V
3X4:1 3X4:2
3X4:5
3X4:4
Drive board
FA1
BB1
N4
N3
N2 N1
C1
R1RE1
TB1
1
MIG350D Main Circuit Breaker
wi re fe ed e r
QB1
- +
T2
G1 G2
G3
G4
E1 E2
E3
E4
2XJ1 2XG1 2XJ22XG2 2XJ3 2XJ42XG3 2XG4
2
~10V ~22V ~22V
V+
RA1
Display Board
Front panel YKH
T1
1 2
Re ar pa ne l
BE1
M1
QN1
RA3
GQ1
3X5:3 3X5:1
1X2:1
1X3:1 1X2:3 3X1:2 3X1:3 3X1:1
3X4:5
3X4:6
RB1 RB2
R2 C6
C7R3
C10
6 5
4
3
2
1
7
3X3:8 3X3:7 3X3:6
3X3:2,3 3X3:4,5
3X3:1
7
3 4 5 6 7 10 8 9
Q1 A4 IGB T protection board Q2
A2
A3
X1
X2
RD2
3X2
C2 C3
C4 C5
C8
2 3
C9yellow
blue
red
V-
3X4:3
Power charging baord
A1
11
~10V
1X4
1
1X1:5,6 1X1:1,2 1X1:3,4
1X1:5,6 1X1:1,2 1X1:3,4
6
RA2

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Features & Applications
This inverter CO2/MAG welders are high-quality performers that can be used for all-purpose,
semi-automatic CO2 gas shield welding with solid or flux-cored wire (Ф0.8-Ф1.6mm)for
welding mild steel and low alloy steel work pieces. This series welder enjoys reasonable static
characteristic and sound dynamic characteristic.
Features and benefits:
◆Inverter technology can ensure fairly good stability of output volt when fluctuation occurs
in input primary volt or arc length changes, as well as startling arc self-adjustability and
stable welding process.
◆Less spatter, high deposit efficiency.
◆Less weld distortion, good weld formation.
◆High success rate of arc-starting due to stronger pulse strike.
◆Reducing molten ball while stopping arc.
◆Reducing labor intensity while welding long weld by using auto-lock function.
◆Stable wire feeding due to consistent output of power circuit.
◆Small, light and portable.
◆Digital control, with error code display functions.
◆Energy-saving, low expense and flexible to various input primary quality.
This series welding machine is strict in line with National standard GB15579.1-2004 <<”Arc
welding equipment” Chapter one: Welding Power Source>>.

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Installation Guide
1．Pre-installation
1.1 Installation Environment
The MIG-E series welding machines are designed for use in adverse environments.
Examples of environments with increased adverse conditions are
In locations in which freedom of movement is restricted, so that the operator is
forced to perform the work in a cramped (kneeling, sitting or lying) position with
physical contact with conductive parts;
In locations which are fully or partially limited by conductive elements, and in
which there is a high risk of unavoidable or accidental contact by the operator;
In wet or damp hot locations where humidity or perspiration considerably reduces
the skin resistance of the human body and the insulation properties of accessories.
Environments with adverse conditions do not include places where electrically
conductive parts, in the near vicinity of the operator, which can cause increased
hazard, have been insulated.
1.2. Installation Location
Be sure to locate the welder according to the following guidelines:
In areas, free from moisture and dust.
Ambient temperature between 0 degrees C to 40 degrees C.
In areas, free from oil, steam and corrosive gases.
In areas, not subjected to abnormal vibration or shock.
In areas, not exposed to direct sunlight or rain.
Place at a distance of 12" (304.79mm) or more from walls or similar boundaries
that could restrict natural airflow for cooling.
1.3 Power Source Connections
Warning _______
Thermal Arc advises that this equipment be electrically connected by a qualified
electrician.
ELECTRIC SHOCK can kill; SIGNIFICANT DC VOLTAGE is present after
removal of input power.
DO NOT TOUCH live electrical parts. _____________

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SHUT DOWN welding power source, disconnect input power employing
lockout/tagging procedures.
Lockout/tagging procedures consist of padlocking line disconnect switch in open
position.
Removing fuses from fuse box, or shutting off and red-tagging circuit breaker or
other disconnecting device.
1.4．Power Supplier Requirements
Input volt must be standard sine wave, effective value 380V±10%, frequency
50Hz.
Unbalance degree of 3-phase volt must be no more than 5%.
Power supply:
Table 3: Power supply connection
Note: The size of fuse and breaker in the table are for reference only.
Model
WM250FI
WM350FI
WM500FI
Power supply
3 phase AC 380V
Min. capacity
Power network
12KVA
26KVA
45KVA
Generator
16KVA
34KVA
60KVA
Input volt protection
Fuse
20A
30A
50A
Circuit breaker
20A
32A
63A
Cable size
(cross-section)
Input volt
≥1.5mm2
≥2.5mm2
≥4mm2
Output volt
25mm2
35mm2
50mm2
Ground lead
≥1.5mm2
≥2.5mm2
≥4mm2

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1.5. Machine Assembling Guide:
This series welder is small, light and portable. They will be more convenient if place
them on the trolleys. Ensure the location where to place the welder is even.
Figure 4: Connection Chart for MIG-E Series
Preparation prior to operation procedure:
(1) Connect the welder’s terminal plug (-) to the work piece by work lead.
(2) Connect the welder’s terminal plug (+) to the wire feeder by welding cable.
(3) Connect the welder’s control cable socket to the wire feeder by control cable.
(4) Connect feeder’s gas hose to the regulator.
(5) Connect the regulator’s heater cable to the welder’s “gas heater power “cable socket.
(on the rear panel).
(6) Connect the welder’s power cable to the disconnection switchboard, while grounds
the lead safely.
(7) Reset the circuit breaker on the welder’s rear panel.

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2. Operating procedure:
Reset the circuit breaker on the switchboard, then the welder’s indicator lamp will turn on,
and the cooling fan will spin. Press on the “Inch feeding” button on the feeder’s controller,
the feeder begin to feed wire. Preset the process parameters by regulating the controller,
tuning the knob, and flipping the switch to proper location on the front panel of the welder.
When the torch switch is pulled, the feeder start to feed wire, and CO2will blow out of the
nozzle, therefore it can be used for welding. Operators can select parameters from table
listed below. Be sure to turn off the valve of gas bottle and unplug the power cord while
stop welding.
Welding current (A)
Welding voltage (V)
Suitable wire (mm)
60~80
17～18
Ф1.0
80~130
18～21
Ф1.0、Ф1.2
130~200
20～24
Ф1.0、Ф1.2
200~250
24～27
Ф1.0、Ф1.2
250~350
26～32
Ф1.2、Ф1.6
350~500
31～39
Ф1.6
Table 4: Suggest welding parameters for selected wire

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Operating Instruction
1. Panel l illustration and parts number reference
1. 1 Front panel illustration and parts number reference
Front panel is illustrated below, other models are little different from this.
Figure 5: Front panel
(1) “Output Amp” meter
Display relative feeding speed while in open load, and display practical value of
current while in welding.
(2) “Output volt” meter
Display preset value of volt while in open load, and display practical value while in
welding.
(3) “Crater filler voltage” regulation knob
Adjusting crater filer voltage value in 4-step mode
(4) “Crater filler Current” regulation knob
Adjusting crater filler current value in 4-step mode
WM350FI

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(5) “Inductance” regulation knob
Altering welding stability, penetration and spatter volume. Recommend value is 5-7.
(6) “4-step /2-step” mode switch
Switch to “2-step”, perform welding when push torch switch, stop welding when
release the switch. This mode is suitable for short weld. To “4-step”, after
successfully starting arc by push torch switch, then you can perform welding by
release the switch, when you push torch switch again, torch will turn into
crater-filling situation which was preset by stop- arc knobs on the front panel. The
welder will stop welding when release the switch. This mode is suitable for welding
long weld.
(7) Gas Test button
Press this button, the gas flow will keep for 30s; while it will stop the gas if press it
during the 30s.
(8) Wire Test button
This button function is the same as torch switch. Press this button, the wire will
feeding; release the button, the wire feeding will stopped.
(9) Negative terminal (-)
Connect to the work lead by the ground cable.
(10) Wire feeder’s control cable socket
Connect to wire feeder’s control cable
(11) Positive terminal (+)
Connect to wire feeder’s welding cable

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2. The rear panel and parts number reference
Figure 6: Rear panel
(1) Circuit breaker
The function of circuit breaker is to protect welding machine by automatic trip to
turn-off power supply while in machine overload or failure. Normally, the switch
flipped to upward which means power-on. Use switch on the disconnected
switchboard or switchbox (customers prepare by them) to start or stop welding
machine, avoiding using the circuit breaker.
(2) Input power cable
The mixed-colored wire must be firmly grounded, the rest wires connect to 3-phase
power (380V/50Hz) respectively.
(3) Cooling fan
Cool down the heat components in the welding machine.
(4) Gas Heater power cable socket
Connect to CO2 regulator’s heating coil. The voltage is 10V in stand by mode (to
protect the gas meter).

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3. Controller
This controller is fixed on the panel of wire feeder.
Panel illustration and parts number reference
Figure 7: Controller Control panel
(1) Current regulation knob
Adjusting welding current
(2) Volt regulation knob
Adjusting welding volt
4. Sub-menu operation
Enter the Sub-menu by pressing “2 step /4 step”and “gas test”buttons together for 2 seconds.
Press “wire test”button will adjust and choose the sub-menu parameter.
Press “2 step /4 step”button to increase the parameters valve.
Press “gas test”button to reduce the parameter valve.
When in “P08”, press “gas test”or “2 step /4 step”will restore the factory setting.
The sub-menu parameters value will be saved automatically if there is none operation in 10s.
The illustration of sub-menu parameters is as chart below:
Code
Parameter
Valve Range
P02
Slower wire feeding speed
3～00
P03
Pre-gas time
0.10～9.90
P04
Post-gas time
0.10～9.90
P08
Restore factory setting
“FAC”～factory setting
“PRO”～sub-menu alternation
Table 5: Submenu illustration

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Repair & Maintenance
WARNING: Have a qualified electrician do the maintenance and trouble shooting work.
Turn the input power off, using the disconnect switch at the fuse box before working inside
the machine.
1. Cautions
Rivet equipment name tag on the specified area of the case, otherwise the inside parts
will possibly be damaged.
Connect welding cable to terminals firmly, otherwise the terminals will be burn out
which will cause the instability of welding process.
Avoid welding cable and control cable being broken, and prevent welding machine
from being short circuit.
Never let welding machine be bumped into or stacked up by heavy objects.
Ensure good ventilation.
Under high temperature, if work with large current for long period, welder may shut
down automatically due to thermal protection acts .At this point, let the machine runs
under open-load for a few minutes, and it will be automatically recover.
Under high temperature, if work with large current for long period, welder may shut
down automatically due to circuit breaker trips. Cut off the power supply to the
electricity switchboard on frame, and wait for 5 minutes to turn on the circuit breaker
on the power source fist then connect the power supply to the electricity switchboard on
frame. And leave the machine runs under open-load condition for a while.
After welding, cut off the gas supply and the power supply.
2. General maintenance
Remove dust from power resource with pressure air by qualified individuals every 3-6
months. Check if the jointers are loose.
Check regularly if cables are worn out, knobs are loose, and components of panel are
damaged.
Check regularly if cables are tightly connected to cable connecting terminals in case of
terminals being burnt out.
Clean and replace Contact Tip in time.

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3. Procedure for regular checking prior to maintenance
Check if all front panel switches are on the proper positions.
Check if the input volt has the phase missing, and range are between 340~420V.
Check if the input cable is connected correctly and firmly with the power source.
Check if the ground lead is connected correctly and firmly.
Check if the welding cables are connected correctly and firmly.
Check if gas regulator is in good situation and gas flows out normally.
WARNING: Have a qualified electrician do the maintenance and trouble shooting work.
Turn the input power off, using the disconnect switch at the fuse box before working inside
the machine. Don’t open up case uninstructed, the max volt inside machine is 600V. Never
discharge high voltage to welder case with welding torch! Shut down power source before
changing or repairing welding cable or torch.

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№
TROUBLE
CAUSES
WHAT TO DO
01
Indicator lamp does not light
on when machine switches
on.
(1)Phase missing
(2)Circuit breaker is damaged
(3)Fuse is broken
(1)Check power supply
(2)Replace
(3)Replace
02
Circuit breaker trips
immediately after the
machine is switched on.
(1)Circuit breaker is collapsed.
(2)IGBT module is damaged
(3)3-phase rectifier bridge is
damaged.
(4)Varistor is damaged
(5)Welder’s control board is
damaged
(1)Replace
(2)Replace IGBT module
and drive board
(3) Replace
(4) Replace
(5)Replace main control
board
03
Circuit breaker trips while in
welding
(1)Welding machine operates
in long term overload
(2)Circuit breaker is damaged
(1)Operating machine in
rated duty cycle
(2) Replace
04
Welding current can not be
adjusted
(1)Wire feeder’s control cable
is broken or controller is
damaged
(2)Control board is damaged
(3)Conductive wire connected
the rectifier is broken
(1)Change control cable or
controller
(2)Replace
(3)Reconnect the broken
wires
05
Instable arc welding, more
spatter
(1)Incorrect welding
parameters
(2)Contact tip is worn out
severely
(1)Fine tune parameters
(2)Replace
06
CO2gas regulator can’t heat
(1)CO2regulator is damaged
(2)Heater cable is broken or
shorten
(3)Thermistor in power source
is damaged
(1) Replace
(2) Check and repair
(3) Replace
07
Push welding torch switch,
wire feeding is normal but
airflow is blocked
(1)Control board is damaged
(2)Electromagnet valve is
damaged
(1)Replace
(2)Replace
08
Push welding torch switch,
wire feeder do not work and
there is no open load volt
display
(1)Torch switch is damaged
(2)Feeder’s control cable is
broken
(3)Control board is damaged
(1)Replace welding torch
(2)Repair control cable
(3)Replace main control
board
Table 6: Troubleshooting Table

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Error Code
During the event of failure, the welder will automatically display the error code:
CODE
DESCRIPTION
CAUSES
WHAT TO DO
E17
Over-current
protection
The output terminals (+)
and (-) is in short circuit
or exceed the rated
welding current
Check the output cables or
reduce the welding current value
E19
Over-heat
protection
Welding machine is too
hot or the thermal
switch is broken
Wait several minutes or replace
with new thermal switch
E24
Communication
is abnormal
Display board has fault.
Replace the display board
E34
Given is
abnormal
No given signal
Check the control circuit
E35
Wire feeding
motor has fault
Wire feeder motor
control cable has fault
or display board is
damaged
Check the wire feeding motor
circuit or replace display board,
power board.
Table 7: Error Code

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Appendix A
1. General
The user is responsible for installing and using the arc welding equipment according to the
manufacturer’s instructions. If electromagnetic disturbances are detected, then it shall be the
responsibility of the user of the arc welding equipment to resolve the situation with the
technical assistance of the manufacturer. In some cases this remedial action may be as
simple as earthling the welding circuit, see note. In other cases it could involve constructing
an electromagnetic screen enclosing the welding power source and the word complete with
associated input filters. In all cases electromagnetic disturbances shall be reduced to the
point, where they are no longer troublesome.
NOTE: The welding circuit may not be earthed for safety reasons. Changing the earthling
arrangements should only be authorized by a person who is competent to assess
whether the changes will increase the risk of injury.
2. Assessment of area
Before installing arc welding equipment the user shall make an assessment of potential
electromagnetic problems in the surrounding area. The following shall be taken into account:
1) Other supply cables, control cables, signaling and telephone cables, above, below and
adjacent to the arc welding equipment;
2) Radio and television transmitters and receivers;
3) Computer and other control equipment;
4) Safety critical equipment, for example guarding of industrial equipment;
5) The health of the people around, for example the use of pacemakers and hearing aids;
6) Equipment used for calibration or measurement;
7) The immunity of other equipment in the environment is compatible. The user shall ensure
that other equipment being used in the environment is compatible. This may require
additional protection measures;
8) The time of day that welding or other activities are to be carried out.
3. Methods of reducing emissions
1) Public supply system
Arc welding equipment should be connected to the public supply system according to the
manufacturer’s recommendations. If interference occurs, it may be necessary to take
additional precautions such as filtering of the public supply system. Consideration should
be given to shielding the supply cable of permanently installed arc welding equipment, in

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metallic conduit or equivalent. Shielding should be electrically continuous its length. The
shielding should be connected to the welding power source so that good electrical contact
is maintained between the conduit and the welding power source enclosure.
2) Maintenance of the arc welding equipment
The arc welding equipment should be routinely maintained according to the
manufacturer’s recommendations. All access and service doors and covers should be
closed and properly fastened when the arc welding equipment is in operation. The arc
welding equipment should not be modified in any way, except for those changes and
adjustments covered in the manufacturer’s instructions. In particular, the spark gaps of arc
striking and stabilizing devices should be adjusted and maintained according to the
manufacturer’s recommendations.
3) Welding cables
The welding cables should be kept as short as possible and should be positioned close
together, running at or close to the floor level.
4) Equipotent bonding
Bonding of all metallic components in the welding installation and adjacent to it should be
considered. However, metallic components bonded to the word piece will increase the risk
that the operator could receive an electric shock by touching these metallic components
and the electrode at the same time. The operator should be insulated from all such bonded
metallic components.
5) Earthling of the work piece
Where the work piece is nor bonded to earth for electrical safety, nor connected to earth
because of its size and position, for example ships hull or building steelwork, a connection
bonding the work piece to earth may reduce emissions in some, but not all instances. Care
should be taken to prevent the earthling of the work piece increasing the risk of injury to
users, or damage to other electrical equipment. Where necessary, the connection of the
work piece to earth should be made by a direct connection to the work piece, but in some
countries where direct connection is not permitted, the bonding should be achieved by
suitable capacitance, selected according to national regulations.
6) Screening and shielding
Selective screening and shielding of other cables and equipment in the surrounding area
may alleviate problems of interference. Screening of the entire welding installation may
be considered for special applications.