Jasic MIG250P User manual

3
CONTENTS
1. SAFETY ---------------------------------------------------------------------------------------------------------------------------5
2. PRODUCT OVERVIEW -------------------------------------------------------------------------------------------------------6
3. SCHEMATIC BLOCK DIAGRAM-------------------------------------------------------------------------------------------7
4. MAIN WELDER TECHNICAL PARAMETERS--------------------------------------------------------------------------8
5. EXTERNAL CHARACTERISTIC CURVE--------------------------------------------------------------------------------9
6. PANEL STRUCTURE AND DESCRIPTION---------------------------------------------------------------------------10
7. MIG INSTALLTION, DEBUGGING AND OPERATION-------------------------------------------------------------14
8. MMA INSTALLATION, DEBUGGING AND OPERATION ---------------------------------------------------------23
9. DESCRIPTION OF FAULT ALARM AND FAULT CODE ON FRONT PANEL-------------------------------26
10. ATTENTION --------------------------------------------------------------------------------------------------------------------26
11. REPAIR AND MAINTENANCE--------------------------------------------------------------------------------------------27
12. CARRY AND STORAGE----------------------------------------------------------------------------------------------------27
13. FAILURE AND MAINTENANCE------------------------------------------------------------------------------------------28
14. MAIN CIRCUIT SCHEMATIC DIAGRAM AND WIRING DIAGRAM FOR CONTROL WIRE OF WIRE
FEEDER----------------------------------------------------------------------------------------------------------------------------------30

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DECLARATION
Hereby we declare that the product is designed according to domestic and international standards so
that it meets relevant standards such as GB/T 15579-1、IEC60974-1、EN60974-1、AS60974-1、UL60974-1.
Relevant design plans and manufacturing technologies of this product are patented.
Free warranty is provided by Shenzhen Jasic Technology Co., Ltd for products purchased for three
years date from being purchased.
Please read this manual carefully before operation.
1. This manual can be revised at any time without prior notice.
2. This manual has been checked carefully, but should you find any inaccuracy, please contact us.
3. This manual was released in May, 2019.
SHENZHEN JASIC TECHNOLOGY CO., LTD
Address: No. 3, Qinglan 1st Road, Pingshan District, Shenzhen Postcode：518118
Tel：[phone] Fax：[phone]
Website: Http://www.jasictech.com E-mail：[e-mail]

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1. SAFETY
Welding may result in injury to you and others, so please implement protection during welding. See more
details in Safety Protection Guidebook for Operator which meets the requirements to manufacturers on
accident prevention.
Operate this equipment by trained professional only!
·Use welding labor protection supplies with approval of safety
supervisory authority!
·Operators must be the special workers with valid work permits of “Metal
Welding (Gas Cutting) Operation”!
·Do not maintain and repair welder with power.
Electric shock-may result in serious injury or even death!
·Install grounding device according to application standard.
·Do not touch live parts with naked skin, wet gloves or wet clothes.
·Be sure you are insulated from ground and workpiece.
·Confirm the safety of your working position.
Smoke-may be harmful to your health!
·Keep your head away from the smoke to avoid inhalation of waste gas
in welding.
·Keep the working environment well ventilated with exhaust or ventilation
equipment when welding.
Arc radiation-may hurt your eyes and burn your skin!
·Use proper welding mask and wear protective clothing to protect your
eyes and body.
·Use proper mask or curtain to protect onlooker from being injured.
Improper use and operation may result in fire or explosion
·Welding spark may result in fire, so please make ensure there are no
inflammables near the welding position, and pay attention to fire
safety.
·Ensure there is fire extinguisher nearby, and make sure someone has
been trained to operate the fire extinguisher.
·Do not weld closed container.
·Do not use this machine for pipe thawing.

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Hot workpiece can cause severe scald.
·Do not touch hot workpiece with bare hands.
·Cool the welding torch for a while after continuously working.
Excessive noise does great harm to people’s hearing.
·Wear ear covers or other hearing protectors when welding.
·Give warning to onlooker that noise may be potentially hazardous to
hearing.
Magnetic field can make cardiac pacemaker a bit wonky.
·People with cardiac pacemaker should stay away from the welding spot
without first talking to a doctor.
Moving parts may injure your body.
·Please keep away from moving parts (like fan).
·Each door, panel, cover, baffle plate, and protective device the like
should be closed and located correctly.
Failure-seek professional support when trouble strikes.
·When trouble strikes in installation and operation, please inspect
according to related contents in this manual.
·If you still cannot understand fully, or you still cannot solve the problem,
please contact the dealer or the service center of JASIC to obtain
professional support.
2. PRODUCT OVERVIEW
2.1. Advanced IGBT inverter technology
2.1.1. Inverting frequency of 26.5KHz greatly reduces the volume and weight of the welder.
2.1.2. Great reduction in copper and iron loss obviously enhances the welding efficiency and energy saving
effect.
2.1.3. Switching frequency is beyond audiorange, which almost eliminates noise pollution.
2.2. Leading control mode
2.2.1. Closed loop feedback control, stable output voltage, strong ability to resist network voltage fluctuation.

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2.2.2. Unique control circuit of welding dynamic characteristic, stable welding arc, excellent spot welding, less
spatter, nice shape, high welding efficiency.
2.2.3. Molten globule can be removed after welding. With high no-load voltage and slow wire feeding on
striking arc, arc striking success rate can be increased.
2.3. Perfect function design
2.3.1. With synergic MIG, welding parameters can be automatically selected based on wire feed speed.
2.3.2. Four welding modes include MMA, lift TIG, DC MIG/MAG, digital control and humanized operation
panel is available.
2.3.3. Functions such as accurate preset current/voltage, 2T/4T operation mode, synergic, gas selection, wire
diameter selection, electronic inductance adjustment, and on-demand fan and so on are available.
2.3.4. Effective protective functions including over-current, overload, current sharing, etc are available.
3. SCHEMATIC BLOCK DIAGRAM
Single-phase rectifying
Filter board
Auxiliary power
Full-bridge
inverter
Rectifying output
ARM
processor
Single-phase AC power
Panel display
Voltage
Current
Drive circuit of
wire feeder
Mutual inductor
PWM
流环
Drive board

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4. MAIN WELDER TECHNICAL PARAMETERS
Model
MIG250P(N24901)
Input
Input power
AC230V single-phase ±15% 50/60Hz
Rated input capacity
9.13KVA
Power factor
0.76
Output
Rated no-load voltage
75V
Rated maximum output
MMA 250A/30V
Lift TIG 250/20V
MIG 250A/26.5V
Rated duty cycle
40%@AC230V Single-phase
Welding voltage
13.5V～36V@AC230V Single-phase
Welding current
MMA 15A/20.6V～250A/30V
Lift TIG 15A/10.6V～250A/20V
MIG/pulsed MIG 40A/16V～250A/26.5V
Output characteristic
MIG/MAG: CV MMA: CC
Ambient
Operation temperature
-10～+40℃
Storage temperature
-25～+55℃
Protection class
IP21S
Insulation class
F
Cooling method
Air cooling
Others
Rated efficiency
82%
Dimension of bare welding
source
895*445*760 mm
Dimension of packaged
welding source
1010*585*840 mm
Weight of bare welding
source
49.7kg
Weight of complete welding
source
64.4kg

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5. EXTERNAL CHARACTERISTIC CURVE
External characteristic for MMA External characteristic for MIG/MAG
Welding current I/A
Welding current I/A
Welding
voltage
U/V
Welding
voltage
U/V

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6. PANEL STRUCTURE AND DESCRIPTION
6.1. Panel structure and
description
Picture 1 Front panel
No.
Component
name
Component function
1
Segment display
Display welding current and
welding function
2
Adjusting knob
Welding function selection
and welding parameters
setting
3
Gas check
button
Welder gas check
4
Welding mode
button
MMA, TIG, MIG and pulse
MIG selection
5
Welding material
button
Carbon steel/stainless steel/
aluminum-silicon/
aluminum-magnesium
selection
6
Euro output
connector
Euro torch connector for
MIG
7
Polarity adapter
Euro output socket for
polarity selection
8
Segment display
Display welding voltage and
welding parameters setting
9
Adjusting knob
Setting for welding
parameters and board
thickness
10
Synergic button
Synergic/separated
selection
11
Welding function
button
Parameters setting for
pre-flow, post-flow, striking
arc, stopping arc, upslope
and downslope
12
Welding method
button
Spot/2T/4T selection
13
Wire diameter
button
Wire diameter selection
14
Welder output
socket
“+ ”output
15
Welder output
socket
“-”output

11
Picture 2 Back panel
6.2. Panel description
6.2.1. Button description
Picture 1-1 Welding modes selecting zone
Welding modes indicator and selection button are
included.
Four welding modes including lift TIG, MIG/MAG,
pulse MIG/MAG and MMA can be selected by
pressing the selection button. Corresponding
indicator will be on according to selected welding
mode.
Picture 1-2 Base metals selecting zone
Base metals indicator and selection button are
included.
Base metals including carbon steel, stainless steel,
aluminum-silicon alloy and aluminum-magnesium
alloy can be selected by pressing the selection
button. Corresponding indicator will be on
according to selected base metal.
Note: This function is unavailable for lift TIG
and MMA.
No.
Component
name
Component function
1
Power switch
Switch power on and off
2
Power cord
Connected to external
junction box
3
Heater power
socket
Connected to heating
plug of gas meter
4
Gas valve
To control gas input
5
Fan
Heat dissipation for
welder inside

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Picture 1-3 Welding operation selecting zone
Gas indicator and selection button are included.
Operation methods including spot, 2T and 4T can
be selected by pressing the button. Corresponding
indicator will be on according to selected operation
method.
Note: This function is unavailable for lift TIG
and MMA.
Picture 1-4 Welding wire diameter selecting
zone
Welding wire indicator and selection button are
included.
Welding wires including solidΦ0.8、Φ1.0、Φ1.2 and
SP can be selected by pressing the selection
button. Corresponding indicator will be on
according to selected welding wire.
Note: This function is unavailable for lift TIG
and MMA.
Picture 1-5 Welding procedure parameters selecting zone
Parts such as procedure parameters indicator, right cycle selection button, etc are included.
Procedure parameters including preset parameter (pre-flow time), initial parameters (speed, current and
voltage), upslope parameter (time), downslope parameter (time), arc stopping parameters (current,
speed and voltage) and post-set parameter (post-flow time) can be selected by pressing right selection
button. Corresponding indicator will be on according to selected parameters. Welding indicator will be on
at the beginning of welding and off at the end of welding for instruction.

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Picture 1-6 Current parameters selecting zone
There are current parameters display and
indicator. Current parameters including current (A),
wire feed speed (m/min) and secondary menu can
be selected by rotating the encoder. System
information, actual welding current and functions
classification can be displayed. Corresponding
indicator will be on and information will be
displayed according to selected parameters. When
there is welding current, actual welding current
value will be displayed.
Picture 1-7 Voltage parameters selecting zone
There are voltage parameters display and
indicator. System information and actual welding
voltage can be displayed. Voltage parameters
including voltage (V), time(S), duty ratio (%),
frequency (Hz) and function parameters can be
selected by rotating the encoder, while relevant
information will be displayed based on selected
parameters. When there is welding current, actual
voltage value will be displayed.
Picture 1-8 Operation modes selecting zone
Operation encoder and selection button are
included.
Current setting or secondary menu can be
adjusted by rotating the encoder. Selection button
is pressed to open secondary menu in which
options can be switched by rotating the encoder.
Picture 1-9 Parameters adjusting knob
zone
Operation encoder and selection button are
included.
Voltage setting or plate thickness parameter
(effective only under synergic) can be adjusted by
rotating the encoder. Selection button is pressed to
adjust plate thickness. When plate thickness is
displayed, selection button is pressed again to
switch display.
Picture 1-10 Gas check
There are gas check button and gas check
indicator. Gas check button is pressed to open gas
channel or is released to close the gas channel
indicated by gas check indicator.
Picture 1-11 Synergic
There are synergic button and synergic indicator.
Synergic button is pressed to make synergic
effective and is pressed again to make synergic
ineffective indicated by synergic indicator.

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6.2.2. Description of welding function and secondary menu
6.2.2.1. MMA mode
1）VRD is on or off by welding operation button corresponding to VRD indicator (VRD is off by
default);
2）Secondary menu includes hot start current and arc-force current;
It indicates 123A hot start current
It indicates 123A arc-force current
6.2.2.2. Lift TIG welding mode
Secondary menu is unavailable for this mode.
6.2.2.3. DC MIG mode
1）Left encoder is pressed to open the secondary menu and is rotated to switch menu mode, while
right encoder is to adjust voltage tuning and select workpiece thickness.
2）Secondary menu includes electronic inductance, burn-back time, burn-back voltage and spot time
(effective under spot mode );
It indicates 10 scale of electronic inductance
It indicates 123mS crater time
It indicates 12.3V crater voltage
It indicates 1.2S spot time
6.2.2.4. Pulse MIG mode
1）Left encoder is pressed to open the secondary menu and is rotated to switch menu mode, while
right encoder is to adjust voltage tuning and select board thickness.
2）Secondary menu includes frequency tuning, duty ratio tuning, electronic inductance and spot time
(effective under spot mode); It indicates frequency tuning scale of synergic (default is 0 under synergic)
It indicates 12% duty ratio or scale tuning (default is 0 under synergic)
It indicates 10 scale of electronic inductance (default is 0 under synergic)
It indicates 1.2S spot time
7. MIG INSTALLTION, DEBUGGING AND OPERATION
Attention: Please install and debug according to following steps!
Electrical connection cannot be conducted until distribution box is turned off.
Due to IP21S protection class, this machine should not be operated in the rain.
S-
123
F-
123
-L-
+10
Bt
123
Bv
12.3
F-
+0.3
D-
+0.2
-L-
+10
St
01.2
St
01.2

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Diagram: Distribution box connection (for reference)
Wiring diagram of distribution box
1 Power switch of distribution box
2 Fuse of 60A or more.
3 Welder cable: Single-phase 230V, copper cable of
3*4
2
mm
or more is adopted.
4 Olivine ground wire (connected to GND! instead of null
line), copper cable of 4
2
mm
or more is adopted;
Wiring should be conducted with main power off as shown in
the diagram or in other correct ways.
Attention: Do not operate with power!
Connection to be done by professional electrician.
Do not connect two welders to the same fuse box.
If enclosure is connected to GND, wire 4 is not
connected to GND!
7.1. Installation
7.1.1. Power cord installation：Welder power cord is connected to 50Hz/60Hz AC grid via fuse of 60A or
more.
7.1.2. Ground wire connection：Cable plug with earth clamp is inserted into the “-”socket at the bottom of
the front panel and is tightened.
7.1.3. Gas pipe connection：One end of gas pipe is connected to gas port on the back panel, while the
other is connected to gas cylinder through gas meter.
7.1.4. Heater power connection：Heater power plug on the gas cylinder is inserted into heater power
socket on the back panel.
7.2. Installation diagram and instruction

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7.2.1. After installation is finished without problems, welder can work when breaker on the back panel is
turned on. On-demand fan can work automatically when welding begins or temperature is too high; fan
stops working after 30S when there is no current and inverter temperature is lower than 40℃.
7.2.2. Two types of wire feeding modes for this machine：
1）Wire feeder will work at high speed when manual wire feeding button on median septum is
pressed, and it will stop working after the button is released.
2）Wire feeder will work at high speed when torch trigger is pressed without welding current for 4S
which automatically switches to quick wire feeding mode. Wire feeder will stop working after torch trigger
is released. (Wire feeding will stop after quick wire feeding lasts for 45S)
Attention：Be careful when sharp welding wire is fed from contact tip of torch during manual wire
feeding!
It is prohibited to eyeball welding wire by getting close to the contact tip!
7.2.3. According to requirement of welding process, wire feed speed knob and voltage setting knob on the
panel can be adjusted to select suitable welding current and voltage.
When synergic button is pressed, welding voltage will be automatically selected by adjusting wire feed
Weldment
Torch
Earth clamp
Cable
Distribution box
Gas cylinder

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speed. Under pulse MIG, welding voltage and pulse parameters can be also automatically selected by
adjusting wire feed speed.
7.2.4. “Inductance” button on the panel is adjusted to realize soft or hard welding arc characteristic; when it
is rotated anticlockwise, arc becomes hard with low inductance and explosive arc; when it is rotated
clockwise, arc becomes soft with high inductance and less spatter. In general, “inductance” button is
adjusted to the middle and then is trimmed according to welder process requirement. Under mini
current, hard characteristic will be favorable, while soft characteristic will be favorable under max
current.
7.2.5. “2T/4T”operation mode
7.2.5.1. 2T operation mode
Torch trigger is pressed to ignite arc, and is released to extinguish arc.
提前送气
空载电压
防粘时间
滞后送气时间
慢送丝
焊接中
焊接电流
送 丝
输出端子间电压
送 气
焊枪开关
ON
OFF
焊接过程中请将焊枪开关始终设为"ON"
7.2.5.2. 4T operation mode
When torch trigger is pressed to ignite arc, welding begins and continues to work even if torch trigger is
released (“current adjusting” and “voltage setting” knobs on wire feeder can adjust welding condition); When
torch trigger is pressed again, stopping arc is effective (“welding/crater current” and “arc-force/crater voltage”
knobs on the front panel can adjust welding condition). At this time, ammeter and voltmeter display actual
current and voltage respectively. Welding stops when torch trigger is released.
Torch trigger
Gas supply
Voltage between output terminals
Wire feeding
Welding current
Pre-flow
No-load voltage
Anti-stick time
Post-flow time
Slow wire feeding
During welding

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OFF
焊枪开关
送 气
输出端子间电压
送 丝
焊接电流
焊接中
慢送丝
滞后送气时间
防粘时间
空载电压
提前送气
收弧
ON ON
OFF
焊接电流
收弧电流
7.3. Shielding gas selection
7.3.1. Metal Active Gas Welding（MAG welding）
It adds a certain amount of oxidizing gas to Argon and usually adopts short circuiting transfer and spray
transfer to conduct downward welding, vertical welding, overhead welding and all-position welding. Besides, it
is mainly applied to carbon steel, low-alloy and high-strength steel and stainless steel.
7.3.2. CO
2
MIG（CO2 welding）
With CO2 as the shielding gas, it usually applies globular transfer and short circuiting transfer to conduct
all position welding. Although it has more spatters compared with other welding modes, this welding mode is
cost-effective which can be widely applicable in common metals.
7.4. WELDING PROCESS REFERENCE
7.4.1. Welding current selection
After preparation, welding current setting can begin. Short circuiting transfer which occurs under thin wire,
low voltage and mini current is suitable to thin wire with diameter less than φ1.6mm. Under this circumstance,
welding is stable with less spatter and nice shape of weld bead. In order to ensure that welding wire matches
welding current, below is reference for current setting. But as for particular materials, please refer to appendix
“welding process table”.
Acceptable current and optimum current during short circuiting transfer welding
Welding wire diameter φ(mm)
Acceptable current（A）
Optimum current（A）
Welding current
Wire feeding
Gas supply
Torch trigger
During welding
Stopping
arc
Crater current
Welding current
Slow wire feeding
Post-flow time
Pre-flow
No-load voltage
Anti-stick time
Voltage between output terminals

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0.8
40～200
60～100
1.0
70～250
80～120
7.4.2. Welding speed selection
Welding quality and productivity are main consideration. If welding speed is too fast with poor protective
effect which accelerates cooling speed, welding toughness is lowered which is not good for weld shaping; if
welding speed is too slow, it is easy to burn through weldment that results in large welding bead. Welding
speed is usually 50cm/min or less in actual production.
7.4.3. Welding wire extension selection
With increasing welding wire extension and shallow penetration, welding wire fusion is accelerated which
improves the productivity; but if extension is too long, welding wire is easily broken with large spatter, causing
unstable welding. Thus, it is generally 10~15 times of wire diameter.
7.4.4. Gas flow selection
Protective effect is main consideration. Because inside corner weld is better protected than outside
corner weld, flow should be low. As for solid wire welding, shielding gas should be reduced or removed. Below
is figure.
Welding method
Φ0.8
Φ1.0
φ1.2
Thick wire with max
current welding
Gas flow (L/min)
5～10
5～12
15～20
20～25
7.4.5. Extension cord modification
Synergic voltage of this welder is stipulated based on standardized 3m welding cable (25mm²). When
extension cord is applied, welding voltage becomes low and unstable caused by low arc voltage due to line
impedance. Here is extension cord modification. For instance, if 25mm² copper cable of welding loop
(resistance: 0.868Ω/km@20℃) lengthens every 5m and increases every 100A welding current, synergic
voltage should increase every 0.45V.
7.5. Welding process quick search for MIG (for reference)
Welding stability, welding quality and productivity depend on welding current and voltage which are
selected according to the requirement of welding wire diameter, needed droplet transfer form and
manufacturing technique with purpose of ensuring welding quality.
7.5.1. Common welding current and voltage application under CO2 MIG for reference
7.5.1.1. I type butt welding parameters

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Board
thickness
t（mm）
Gap
g(mm)
Welding
wire
diameter
φ(mm)
Welding
current
（A）
Welding
voltage
（V）
Welding
speed
（cm/min）
Gas flow
（L/min）
Number of
layers
0.8
0
0.8
60～70
17～18
45～55
8
1
1.0
0
0.8
70～90
18～19
45～55
8
1
1.2
0
0.8
80～90
18～19
45～55
8～10
1
1.6
0
0.8
90～110
19～20
45～55
8～10
1
2.0
0～0.5
1.0
80～90
18～19
40～55
8～10
1
2.3
0.5～1.0
1.0
90～100
19～19.5
50～55
10～15
1
3.2
1.0～1.2
1.0
100～120
20～21
40～50
10～15
1
4.5
1.2～1.5
1.0
120～150
21～22
40～50
10～15
1
7.5.1.2. Parameters of fillet welding in the flat position