Wholesale Digi-Multi 250 ACDC User manual

THANKS FOR PURCHASING OUR PRODUCT
OPERATION INSTRUCTIONS
（BE SUITABLE FOR 1x220V~240V）
DC INVERTER
WELDING MACHINE
AC TIG/DC TIG
DC MMA/CUT

SAFETY PRECAUTIONS
Follow these precautions carefully. Improper use of any welder can
result in injury or death.
1. ONLY CONNECT WELDER TO A POWER SOURCE FOR WHICH IT WAS DESIGEND.
The specification plate on the welder lists this information. When welding outdoors only use an
extension cord intended for such use.
2. ONLY OPERATE WELDER IN DRY LOCATIONS and on cement or masonry floor. Keep area
clean and uncluttered.
3. KEEP ALL COMBUSTIBLES AWAY FROM WORK SITE.
4. DO NOT WEAR CLOTHING THAT HAS BEEN CONTAMINATED with grease or oil.
5. KEEP CABLES DRY AND FREE FROM OIL AND GREASE and never coil around shoulders.
6. SECURE WORK WITH CLAMPS or other means; don't overreach when working.
7. NEVER STRIKE AN ARC ON A COMPRESSED GAS CYLINDER
8. DON'T ALLOW THE INSULATED PORTION OF THE ELECTRODE HOLDER TO TOUCH
THE WELDING GROUND WHILE CURRENT IS FLOWING.
9. SHUT OFF POWER AND UNPLUG MACHINE WHEN REPAIRING OR ADJUSTING. Inspect
before every use. Only use identical replacement parl.
10. FOLLOW ALL MANUFACTURER'S RULES on operating switches and making adjustments.
11. ALWAYS WEAR PROTECTIVE CLOTHING when welding . This includes: long sleeved shirt
(leather sleeves), protective apron without pockets, long protective pants and boots. When handing
hot materials, wear asbestos gloves.
12. ALWAYS WEAR A WELDER'S HELMET WITH PROTECTIVE EYE PIECE when welding.
Arcs may cause blindness. Wear a protective cap underneath the helmet.
13. WHEN WELDING OVERHEAD, BEWARE OF HOT METAL DROPPINGS. Always protect
the head, hand, feet and body.
14. KEEP A FIRE EXTINGUISHER CLOSE BY AT ALL TIMES.
15. DO NOT EXCEED THE DUTY CYCLE OF THE MACHINE. The rated cycle of a welding
machine is the percentage of a ten minute period that the machine can operate safely at a given output
setting.
16. KEEP ALL CHILDREN AWAY FROM WORK AREA. When storing equipment, make sure it
is out of reach of children.
17. GUARD AGAINST ELECTRIC SHOCK. DO not work when tired. Do not let body come In'
contact with grounded surfaces.

I.
MAIN USAGE AND THE RANGE OF USAGE
，
Digi-Multi 250 ACDC Welder is triple functional machine used as DC MMA/CUT AC TIG,
DC/PULSE TIG Welder. All ferrous metals copper, Aluminium ,titanium and stainless steel
material can be omnibearing welding in all position.The welding current is stable and stepless
adjustable.The welding seam is nice. few spatter and low noise occurs during welding.The welder
is small volume,light in weight and easy to move.It is particularly suitable for enterprise of
pressure vessel,building,shipping and petrochemical works. It is the priority product to replace
the NSA series welding machine.
Ⅱ. MAIN TECHNICAL SPECIFICATIONS
MODEL Digi-Multi 250 ACDC
INPUT Voltage 1 xAC220V~240V 50Hz
DC
MMA
No-load Voltage
70V
Base current Adjusting Range 10~200A
Rated Output Current 200A
Rated Duty Cycle 60%
AC
TIG
No-load Voltage
70V
Current Adjusting Range 5~250A
SP %
(
AC balance
)
10~70
AC S
q
uare Wave Fre
q
uenc
y
30~250Hz
Rated Duty Cycle 60%
DC
TIG
Current Adjusting Range 5~250A
Rated Duty Cycle 60%
Standard
PULSE
TIG
Peak Current
5~250A
Base/peak Current ratio 5~95%
Rated Duty Cycle 60%
Pulse width 5%~95%
pulse Freq.
0.1~500Hz@DC
0.1~250Hz@AC ADV.SQUARE
0.1~10Hz@AC SOFT.SQUARE&TRIANGULAR&SINE WAVE
Advanced
PULSE
TIG
(MIX)
AC peak Current
5~200A
DC(base)/AC peak Current Ratio 5~95%
Rated Duty Cycle 60%
Pulse width 5%~95%
pulse (AC to DC-) Freq. 0.1~10Hz
Current UP/Down-slope Time 0~10S
Initial current/weldingcurrent 5~150%
crater-fill current/welding current 5~95%
Pre gas Flow Time 0~25s
Post gas Flow Time 0~25s
Arc starting Mode HF/LIFT TIG
CUT current Adjusting Range
15~60A
Rated Duty Cycle 60%
Post gas Flow Time 20~60s
Efficiency
≥80%
Mass 26k
g
Protection Class of enclosure IP21S
Outline Dimensions mm
3430x200x290

Ⅲ. OPERATING CONDITION AND WORK SURROUNDING
1. Operating condition:
。
Voltage of power source: 1 xAC 220~240 V
Frequency: 50/60Hz
Reliable grounding protection
2.Work surrounding
① ℃
. relative humidity: not more than 90 %( average monthly temperature not more than 20 )
②℃℃
. ambient temperature:-10 ~ 40
③. The welding site should have no harmful gas, Chemicals, molds and inflammable matter,
explosive and corrosive medium, no big vibration and bump to the welder.
④. Avoiding rain water. Operating in rain is not allowed.
Ⅳ. DESCRIPTION OF THE ERECTION
1. Before welding, the operator should read the operation instructions.
2.Check the welder appearance for deformation and damage.
3.For the safety of the equipment and the persons, the customer must correctly make grounding
or protection according to the power supply system:using 4mm2lead to connect the protection
grounding of the welder
4. Welding operation should be carried out in dry and good ventilating area.The surrounding
objects should be not less than 0. 5m away from the welder.
5.Checking the welder output connector for tightness.
6.The welder can not be moved and the cover can not be opened during the power is on and
welding operation is carried out.
7.The welder should be cared, used and managed by specialized person.
8.Current of the distribution board:not less than 40A
Ⅴ.SKETCH SKETCH THE PANEL FUNCTION
1. FRONT PANEL 2. BACK PANEL
20
24
21 22
7 8
4
910
1113
3
5
615
15
16
17 18 16
112
19
26
23
14
Digi-Multi250 ACDC

1.Memory chanel LED 2. Data Display meter 3. Parameter Select function 4.indicating light of power
5. S -- unit of up & downslope time & pre& post flow time
% -- unit of AC balance &peak time on
Hz-- unit of pulse freq.&AC freq.
（（6. indicating light of Parameter Select function Pre-flow /Start current/Up slope/Welding Amps Pulse peak
）amps /peak time on/ pulse freq./base Amps/down slope/end current/post flow/AC freq./ AC balance/)
7.AC
slector
AC WAVE FORM: advanced square/soft square/triangular square / sine square
8.warning indicating light
9. MMA slector
DC-/DC+
10.TIG PULSE slector
11.TIG slector
DC TIG/AC TIG/MIX TIG
12. 2 T/ 4 T slector
（）13. Data Display Adjustment Knob 14.pilotarc15. output"+" Welding holder
（）16. output"-" Ground clamp
17.argon out 18.argon arc control (or remote control)
19.Amp Adjustment slector (remote control)
panel/ pedal /finger torch
20. power switch
21.argon inlet 22.power supply 23.safety earthing column 24.fan
25.HF/Lift TIG slector
26.CUT slector
1
2
3
43
7
10
11
12
85
25
13
9
6
619
26
Digi-Multi 250 ACDC

Ⅵ.METHOD OF THE OPERATION
1.ARGON ARC WELDING(TIG)
a. FRONT OF WELDER b. BACK OF WELDER
1.1 CLEARING BEFORE WELDING
Tungsten argon an welding is very sensitive to surface contamination of filled metal.
Therefore before welding is carried out, grease, paint and coating on the surface,lubricant for
machining and oxidized film should be removed.
1.2 DC ARGON ARC WELDING
①
.selector "11" onto the position " DC TIG "or "AC TIG" or"MIX TIG", selector "10" onto the
position " pulse off " ,Connecting the gas inlet pipe to inlet "21" of the welding.
②
.Connecting gas inlet pipe of the welding torch to argon output of welder "17".
③
.Putting the aerial plug of the welding torch in the argon arc control socket "18".
④
.Testing gas: get the power of the welder ready and switch on the power "2", open the argon
bottle switch and switch on the flow meter, press the torch switch, select suitable argon flow.
⑤
. .Regulating the knob " 3 &13". Selecting suitable welding current according to thickness
of the workpiece to be welded.. Selecting suitable current down slope time and post flow
time according to the current.
Notice 1: The current indicating meter on the front panel is used to display the preset output
current level before welding, and actual output level while welding: A lit display indicates input
power is turned on.
Notice 2:
When using
'Adjustable foot control '.regulating the current with sole. selector "12" onto
the position " PEDAL "welding current will increase gradually when you step at full tilt the 'Adjus
table foot control
' with sole.
Notice 3:
When using
' Adjustable finger control torch '.regulating the current with finger.
selector "19" onto the position " Panel " or " PEDAL "or"
finger torch",, then begin to weld.
oo
workpiece
torch
21
argon
bottle
switch
flow meter
gas inlet pipe
20
24
23 22
7 8
4
910
1113
3
5
615
16
112
19
26
15 17 18 16
14
Digi-Multi250 ACDC

⑥
. Tungsten electrode end is 2-3mm away from the welding workpiece. Press the torch
switch,arc striking will occur.
Notice: During welding, when the" 12. 2T/4Tswitch"on "2T", switch of the torch must be
pressed and can not be released.otherwise the arc will be broken.
⑦
.Releasing the switch of the torch, welding current will reduce gradually (time is adjustive)
and arc extinguishes.The welding torch can not be removed as soon as the arc extinguishing. Let
the protection gas cooling down for the welding seam not to be oxidized.
⑧
.When the welding operation is finished, turn off argon bottle switch and cut off input power
of the welder.
1.3 PULSE ARGON ARC WELDING
①
. Selection of peak current and base current:
②
. selector "11" onto the position " DC TIG " or "AC TIG "and selector "10" onto the position
" on",
③
.select peak time on ratio: It can be selected between 5%-95%.
④
.select up-slope&down slope time: It can be selected between 0-10S.
⑤
.Gas connecting and testing,are generating and are blowing off etc. are all the same as DC
are welding.
1.4 PULSE ARGON TUNGSTEN WElDING PROCESS (only for reference)
①.Features and application scope of the process .
The pulse type argon tungsten are welding is different from the continuous(DC) argon are
welding.The welding current is pulsed.The wave form of the current is shown in the following
sketch.Ip and Ib and their continuous time tp and tb can be regulated according to
requirements of the process. The amplitude value of electric current changes periodically with
certain frequency in case of the pulse current, molten base will be formed in the workpiece and
the molten bath will be solidified in care of base current.The welding seam is formed by
reciprocal overlaps. Welding heat input can be controlled by regulating pulse frequency, pulse
current amplitude, size of base current,continuous time of pulse current and base current and
therefore the welding seam,size and quality of the zone influenced from heat can be controlled.
②
.Advantages and application scope of pulse argon gas tungsten arc welding
a. Precisely control the size of the bath inputting heat to workpiece to increase penetration
tp--width time of pulse current
width time of base current
tb--
tp+tb=T
tb
--- = D pulse width
CUR.
(A)
T (s)
t1
gas pre flow
arcing
up-slope
welding process
down-slope
arcing off
post Flow
tp tb
T
Ip
Ib
Ip--pulse current
Ib--base current
tp
Start Amps End Amps

resistance of molten seam and preservation of bath. It is easy to obtain even fusing deepness.
This process is specially applicable to omni-bearing welding of sheet and formation to be done
with both sides through one side welding.
b. Heating and cooling of each welding point is very fast,.Therefore,the process is applicable for
the workpiece with great difference of heat conductivity and thickness.
c. Pulse arc can obtain greater fusing deepness with lower heat input.Therefore under the
same condition, the zone influenced from welding heat and deformation from welding can be
reduced. This is very important for sheet and ultra-thin sheet welding.
d. Fast cooling of the bath metal and shot duration time of high temperature during welding
can reduce cracks caused to the thermo-sensitive materials during welding.
③
.Selection of welding parameters
Except for pulse current and the width time (width ratio) as well as pulse frequency ,welding
parameters of pulse argon gas tungsten arc welding are as same as general tungsten DC argon
are welding. Pulse current increasing means electric arc can obtain greater penetration ability.
But too much current can cause local melting of tungsten electrode.Generally,welding current
required for DC tungsten argon are welding or greater current is used. Arc holding current and
base current influences cooling and crystallizing of the metal in the bath. The range is
determined by performance of the welding materials. When sheet is welding,smaller arc holding
current (base current) is usually used in order to reduce welding through and deformation.When
pulse width ratio (holding time of pulse current and base current) is selected, both the heat input
％
and features of pulse welding should be considered. Usually, it can be selected between 10 - 90
％. Selection of pulse frequency (periodical change time of pulse current) mainly depends on
thickness of sheet and welding speed and operation custom of the operator should be also
considered.
1.4 AC ARGON ARC WELDING
1. selector "11" onto the position " AC TIG ",selector "25" onto the position "HF TIG",
selector "10" onto the position "off " or "Advanced AC",Connecting the gas inlet pipe to inlet "21"
of the welding.
2. The method of the connection same as 1.1
3. select right "sp(AC Balance)"
SP= *100%
tp:the time of I2at positive tn: the time of In at Negative
4. select right AC square wave frequency &AC balance.
tp
tn

5. The Method of the welding same as 1.1
2.Hand welding with electrode
①
.selector "9" onto the position " DC+ " or "DC-"
②
. select right welding current
select empiric formula:I=40d, d is dia. of the electrode.
③
.Notice positive and negative connection during welding.
④
.Connecting input power for the welder, then switch on the power and current indicating
light "2" is on .
⑤
.Pay attention to rated welding current and rated duty cycle of the welder. Overload is not
allowed.
⑥
.After the welding operation is finished, let the welder be ventilated for a few minutes and
then cut off the power switch.
3.Cutting with compressed air
Put switch"26" (CUT Slector) onto the position "CUT"
ELECTRODE
HOLDER
WORKPIECE
WELDER
ELECTRODE
HOLDER
WORKPIECE
WELDER
torch
workpiece
oo
13
4
5
6
7
8
91011
12
13
14
15
16
17 18
19
20
26
27
air compressor 13
4
5
6
7
8
91011
12
13
14
15
16
17 18
19
20
26
27
78
4
910
1113
3
5
615
14
16
17 18 20
112
19
26
14
Digi-Multi250 ACDC

(1). Connect the machine correctly according the sketch. And switch on the air compressor until to
its rated pressure. It will be turned off automatically to adjust the air pressure-reduced valve to the
proper value.(0.25-0.5MPa generally)
( 2). Join the power switch of the cutting machine. The power indication lamp lights.The cooling
fan begins working. Put the function switch in the position of "air testing" .Then the airspouts from
the cutting torch. put the function switch in the position of " cutting", and press the torch switch.
The air spouts from the torch also.
(3). Selecting suitable cutting current and air pressure according to the thickness and material of
the workpiece and the cutting speed.The selecting standard for the spray nozzle of the torch:
The spray nozzle not change color while cutting.
(4). CUTTING: Hold the cutting torch in the beginning position, and let the nozzle towards the
workpiece with 15 angle of inclination. The nozzle touches the workpiece, and press the torch
switch, Now flow the air first and high frequency arc generated.The high frequency can be cut
off automatically after the arc generation ,Begin to move the cutting torch after the workpiece is
pierced through. Loosen the switch after finish cutting.
Ⅶ.SYSTEMATIC BLOCK DIAGRAM
OUTPUT
AC/DC
Rectifier &
Filter
INPUT
Inverse
Circuit
25KHz
OUTPUT
Rectifier
Filter
220/230/240V
Control Circuit H.F.
+
TORCH
-

Ⅷ.This product is sold subject to the understanding that if any defect in manufacture or
material shall appear within 12 months from date of consumer sale, the manufacturer will
arrange for such defect to be rectified without charge on the sales invoice and warranty
card (except for any personal trouble).
General Troubles and Problem Solving:
Output current
decreased 1. Input Voltage is low 2. Input line is too thin 2. Power line is thickened
Current can not be
regulated
1.Connecting line of the potentiometer is of
f
2.Potentiometer for current regulation fail
1.Reconnecting the line
2.Replace potentiometer
High frequency are
can not be generated
1.The switch fails
2.Interval of high frequency discharging is t
oo big
3.Distance of the torch and workpieceis too far
high frequency arc generator fails
1.Replace torch switch
2.Regulating discharging interval
to 0.8-1.0mm
3.Put torch tungsten electrode close to wor
kpiece
4.Replace high frequency arc generator
Arc of argon welding
is broken or
tungsten electrode
is burnt
1.Argon gas flow is not regulated well
2.Tungsten electrode fails
3.Value of current does not match with dia.
of tungsten electrode
4.After flow time too short
1.Regulated well
2.Replace or sharpen
3.Select the electrode dia. and
current correctly
4.Enlarge the time
Welding torch
overheat
1.Not use the water cooling when the
current is more than 160A
2.The argon flow is the low current
1.Use water cooling
2.Enlarge the argon flow
Welding stops, and
warning light is on
Self-protection has engaged
1.Display "801"
2.Display "802"
3.Display "804"
4.Display "805"
5.Display "806"
or
6.Display "E01"
7.Display "E02"
8.Display "E03"
9.Display "E04"
1.over-voltage, lower-voltage
2. over-current,
3.over-temperature,
4.torch switch always close
5. lower air pressure
6. over-temperature,
7.over-current,
8. lower air pressure
9.torch switch always close
Trouble Causes Problem Solving
Power lamp not light 1.No electricity input
2.Switch of welder fails. 1.Check incoming line 2.Replace the switch
Fan not rotating 1.Fan poer line is off.
2.Enclosure blocks the fan due to deformation
3.The fan fails.
1.Reconnect the line
2.Reform the enclosure
3.Replace the fan
Warning lamp lights 1.Over heat(yellow lamp lights)
2.Oer current(Green lamp lights) 1.Welding after cooling. 2.Input voltage too low or the machine fails.
No output of welder 1.Over crrent protection
2. Welder fails
1. Over load using
2. Maintenance in manufacturer or service
center

Ⅸ.ACCESSORIES:SEE PACKING LIST,PLEASE
PACKING LIST
★★★★★★★★★★★★★★★★★★★★★★★★
No.
━━━━━━━━━━━━━━━━━━━━━━━
─────────────────────────────
Certificate of quality
Name of product: AC/DC/PULSE TIG WELDING
Type of product:Digi-Multi 250 ACDC
Packing No:
Test results of this welder fulfils_____________
_________technical requirements and its release
from the works is granted.
Inspector_________ Date___________
model quantity remark note
Digi-Multi 250 ACDC
Welding machine 1
Welding Holder 1
Ground clamp 1
TIG welding torch 1
CUT Torch 1
Adjustable foot control 1 optional accessory
Adjustable finger control torch 1 optional accessory
gas inlet pipe 1
Operation instructions 1
Certificate of quality 1

WARNING
AVISO DE
PRECAUCION
ATTENTION
WARNUNG
ATENÇÃO
Spanish
French
German
Portuguese
Japanese
Chinese
Korean
Arabic
READ AND UNDERSTAND THE MANUFACTURER’S INSTRUCTION FOR THIS EQUIPMENT AND THE CONSUMABLES TO BE
USED AND FOLLOW YOUR EMPLOYER’S SAFETY PRACTICES.
SE RECOMIENDA LEER Y ENTENDER LAS INSTRUCCIONES DEL FABRICANTE PARA EL USO DE ESTE EQUIPO Y LOS
CONSUMIBLES QUE VA A UTILIZAR, SIGA LAS MEDIDAS DE SEGURIDAD DE SU SUPERVISOR.
LISEZ ET COMPRENEZ LES INSTRUCTIONS DU FABRICANT EN CE QUI REGARDE CET EQUIPMENT ET LES PRODUITS A
ETRE EMPLOYES ET SUIVEZ LES PROCEDURES DE SECURITE DE VOTRE EMPLOYEUR.
LESEN SIE UND BEFOLGEN SIE DIE BETRIEBSANLEITUNG DER ANLAGE UND DEN ELEKTRODENEINSATZ DES HER-
STELLERS. DIE UNFALLVERHÜTUNGSVORSCHRIFTEN DES ARBEITGEBERS SIND EBENFALLS ZU BEACHTEN.
●Do not touch electrically live parts or
electrode with skin or wet clothing.
●Insulate yourself from work and
ground.
●No toque las partes o los electrodos
bajo carga con la piel o ropa moja-
da.
●Aislese del trabajo y de la tierra.
●Ne laissez ni la peau ni des vête-
ments mouillés entrer en contact
avec des pièces sous tension.
●Isolez-vous du travail et de la terre.
●Berühren Sie keine stromführenden
Teile oder Elektroden mit Ihrem
Körper oder feuchter Kleidung!
●Isolieren Sie sich von den
Elektroden und dem Erdboden!
●Não toque partes elétricas e elec-
trodos com a pele ou roupa molha-
da.
●Isole-se da peça e terra.
●Keep flammable materials away.
●Mantenga el material combustible
fuera del área de trabajo.
●Gardez à l’écart de tout matériel
inflammable.
●Entfernen Sie brennbarres Material!
●Mantenha inflamáveis bem guarda-
dos.
●Wear eye, ear and body protection.
●Protéjase los ojos, los oídos y el
cuerpo.
●Protégez vos yeux, vos oreilles et
votre corps.
●Tragen Sie Augen-, Ohren- und Kör-
perschutz!
●Use proteção para a vista, ouvido e
corpo.

WARNING
AVISO DE
PRECAUCION
ATTENTION
WARNUNG
ATENÇÃO
Spanish
French
German
Portuguese
Japanese
Chinese
Korean
Arabic
LEIA E COMPREENDA AS INSTRUÇÕES DO FABRICANTE PARA ESTE EQUIPAMENTO E AS PARTES DE USO, E SIGA AS
PRÁTICAS DE SEGURANÇA DO EMPREGADOR.
●Keep your head out of fumes.
●Use ventilation or exhaust to
remove fumes from breathing zone.
●Los humos fuera de la zona de res-
piración.
●Mantenga la cabeza fuera de los
humos. Utilice ventilación o
aspiración para gases.
●Gardez la tête à l’écart des fumées.
●Utilisez un ventilateur ou un aspira-
teur pour ôter les fumées des zones
de travail.
●Vermeiden Sie das Einatmen von
Schweibrauch!
●Sorgen Sie für gute Be- und
Entlüftung des Arbeitsplatzes!
●Mantenha seu rosto da fumaça.
●Use ventilação e exhaustão para
remover fumo da zona respiratória.
●Turn power off before servicing.
●Desconectar el cable de ali-
mentación de poder de la máquina
antes de iniciar cualquier servicio.
●Débranchez le courant avant l’entre-
tien.
●Strom vor Wartungsarbeiten
abschalten! (Netzstrom völlig öff-
nen; Maschine anhalten!)
●Não opere com as tampas removidas.
●Desligue a corrente antes de fazer
serviço.
●Não toque as partes elétricas nuas.
●Do not operate with panel open or
guards off.
●No operar con panel abierto o
guardas quitadas.
●N’opérez pas avec les panneaux
ouverts ou avec les dispositifs de
protection enlevés.
●Anlage nie ohne Schutzgehäuse
oder Innenschutzverkleidung in
Betrieb setzen!
●Mantenha-se afastado das partes
moventes.
●Não opere com os paineis abertos
ou guardas removidas.