FRO­NIUS MTG 250i User manual

Fronius prints on elemental chlorine free paper (ECF) sourced from certified sustainable forests (FSC).
/ Perfect Charging / Perfect Welding / Solar Energy
42,0410,2067 012-29052020
MTG 250i, 320i, 400i, 550i
MTW 250i, 400i, 500i, 700i
MTB 250i, 320i, 330i, 400i, 550i G ML
MTB 250i, 330i, 400i, 500i W ML
MTB 700i W ML
MHP 250i, 400i, 550i G ML
MHP 500i, 700i W ML
Operating Instructions
MIG/MAG manual welding torch
Kasutusjuhend
Manuaalne MIG/MAG-keevituspõ-
leti
Uputstvo za upotrebu
Ručni gorionik za zavarivanje za
MIG/MAG
Kezelési útmutató
MIG/MAG kézi hegesztőpisztoly
Istruzioni per l'uso
Torcia per saldatura manuale MIG/
MAG
操作手順
MIG/MAG 手動溶接トーチ
ENETHRHUITJA

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EN
Dear reader,
Introduction Thank you for the trust you have placed in our company and congratulations on buying this
high-quality Fronius product. These instructions will help you familiarise yourself with the
product. Reading the instructions carefully will enable you to learn about the many different
features it has to offer. This will allow you to make full use of its advantages.
Please also note the safety rules to ensure greater safety when using the product. Careful
handling of the product will repay you with years of safe and reliable operation. These are
essential prerequisites for excellent results.

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Contents
Safety......................................................................................................................................................... 7
Proper use ............................................................................................................................................ 7
Safety.................................................................................................................................................... 7
General ...................................................................................................................................................... 9
General ................................................................................................................................................. 9
Up/Down function.................................................................................................................................. 9
JobMaster function................................................................................................................................ 9
Functions of the torch trigger ..................................................................................................................... 10
Functions of the two-stage torch trigger................................................................................................ 10
Installation and commissioning .................................................................................................................. 11
Fitting wearing parts to the torch body.................................................................................................. 11
Assembling Multilock welding torches .................................................................................................. 12
Note regarding the inner liner with gas-cooled welding torches ........................................................... 13
Fitting the inner liner inside the torch hosepack.................................................................................... 13
Connecting the welding torch to the wire-feed unit............................................................................... 15
Connecting the welding torch to the power source and the cooling unit............................................... 15
Twisting the Multilock welding torch body............................................................................................. 16
Changing the torch body on a Multilock welding torch.......................................................................... 17
Care, maintenance and disposal ............................................................................................................... 18
General ................................................................................................................................................. 18
Recognising faulty wearing parts.......................................................................................................... 18
Maintenance at every start-up .............................................................................................................. 19
Maintenance every time the wirespool/basket-type spool is changed:................................................. 19
Troubleshooting ......................................................................................................................................... 20
Troubleshooting .................................................................................................................................... 20
Technical data............................................................................................................................................ 25
General ................................................................................................................................................. 25
Gas-cooled welding torch - MTG 250i, 320i, 400i, 550i........................................................................ 25
Gas-cooled hosepack - MHP 250i, 400i, 550i G ML............................................................................. 26
Gas-cooled torch neck - MTB 250i, 320i, 330i, 400i, 550i G ML .......................................................... 26
Water-cooled welding torch - MTW 250i, 400i, 500i, 700i .................................................................... 27
Water-cooled hosepack - MHP 500i, 700i W ML.................................................................................. 27
Water-cooled torch neck - MTB 250i, 330i, 400i, 500i, 700i W ML....................................................... 28

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Safety
Proper use The MIG/MAG manual welding torch is intended solely for MIG/MAG welding in manual ap-
plications.
Any use above and beyond this purpose is deemed improper. The manufacturer shall not
be held liable for any damage arising from such usage.
Proper use includes:
- Carefully reading and following all the instructions given in the operating instructions
- Performing all stipulated inspection and maintenance work.
Safety WARNING!
Danger due to incorrect operation and incorrectly performed work.
This can result in serious injury and damage to property.
► All the work and functions described in this document must only be carried out by
trained and qualified personnel.
► Read and understand this document.
► Read and understand all the Operating Instructions for the system components, espe-
cially the safety rules.
WARNING!
Danger from electric current and risk of injury from the emerging wire electrode.
This can result in serious injury and damage to property.
► Turn the power source mains switch to the "O" position.
► Disconnect the power source from the mains.
► Ensure that the power source remains disconnected from the mains until all work has
been completed.
WARNING!
Danger from electric current.
This can result in serious injury and damage to property.
► All cables, lines and hosepacks must be properly connected, undamaged, correctly in-
sulated and adequately dimensioned at all times.
CAUTION!
Risk of burns from hot welding torch components and hot coolant.
This can result in severe scalds.
► Before commencing any of the work described in these Operating Instructions, allow
all welding torch components and the coolant to cool to room temperature (+25 °C, +77
°F).

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CAUTION!
Risk of damage due to operation without coolant.
This can result in serious damage to property.
► Never operate a water-cooled welding torch without coolant.
► Fronius shall not be liable for any damage resulting from such action. In addition, no
warranty claims will be entertained.
CAUTION!
Danger from coolant leakage.
This can result in serious injury and damage to property.
► Seal the coolant hoses on water-cooled welding torches with the plastic stoppers fitted
to them if the hoses are detached from the cooling unit or the wirefeeder.

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General
General MIG/MAG welding torches are particularly robust and reliable, with an ergonomic grip, ball
joint and perfect weight distribution for fatigue-free working. The welding torches are avail-
able as gas-cooled and water-cooled versions in different power categories and sizes, so
no weld seam is out of reach. The welding torches can be used in an extremely wide range
of applications. They are ideal for manual batch and single-piece production as well as jobs
in the workshop.
Up/Down function The Up/Down torch has the following func-
tions:
- Changes the welding power in Syner-
gic operation via the Up/Down buttons
- Error display:
- all the LEDs light up red if there is
a system fault
- all the LEDs flash red if there is a
data communication fault
- Self-test during the run-up sequence:
- all LEDs light up briefly one after
the other
JobMaster func-
tion The JobMaster welding torch has the follo-
wing functions:
- The desired welding parameter on the
power source can be selected using
the arrow buttons
- The parameter can be changed using
the +/- buttons
- The display shows the current parame-
ter and value

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Functions of the torch trigger
Functions of the
two-stage torch
trigger
Function of the torch trigger in switching po-
sition 1 (torch trigger half pressed):
- LED lights up.
Function of the torch trigger in switching po-
sition 2 (torch trigger fully pressed):
- LED goes out
- Welding starts.

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Installation and commissioning
Fitting wearing
parts to the torch
body
1 2
3
** Screw on and tighten the gas noz-
zle as far as it will go
1
2
3

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Assembling Mul-
tilock welding
torches
NOTE!
Risk from incorrect assembly of the welding torch.
This can result in damage to the welding torch.
► Before fitting a torch body, ensure that the interface between the torch body and the
hosepack is clean and undamaged.
► In the case of water-cooled welding torches, increased resistance may arise when
tightening the union nut due to the construction of the welding torch.
► Always tighten the union nut on the torch body as far as it will go.
1
The torch body is in the 0° position when
the dowel pin (1) on the hosepack engages
in the locating hole (2) in the torch body.
2 3
* Ensure that the union nut is tightened as far as it will go.
(1)(2)
(2) (1)
1
1
2
0
*
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EN
Note regarding
the inner liner
with gas-cooled
welding torches
NOTE!
Risk from incorrect inner liner insert.
This can result in poor weld properties.
► If a gas-cooled welding torch is used with a plastic inner liner and bronze inner liner
insert instead of a steel inner liner, the performance data specified in the technical data
is reduced by 30%.
► To operate gas-cooled welding torches at maximum power, replace the 40 mm (1.575
in.) inner liner insert with the 300 mm (11.81 in.) inner liner insert.
1 2
Fitting the inner
liner inside the
torch hosepack
NOTE!
Ensure that the hosepack is straight when fitting the inner liner, otherwise the liner
might not be inserted correctly.
1 2
1
2
1
1
2

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3 4
5
* Steel inner liner
** Plastic inner liner
1 2
*** Screw the clamping nipple onto the inner liner as far as it will go. The inner liner
must be visible through the hole in the cap.
3
*
**
4
5
***
6
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EN
Connecting the
welding torch to
the wire-feed unit
1
* Only if the optional coolant connec-
tions are fitted in the wire-feed unit
and when using a water-cooled
welding torch.
Always connect the coolant hoses
according to their colour coding.
Connecting the
welding torch to
the power source
and the cooling
unit
1 2
* Only if the optional coolant connections are fitted in the cooling unit and when using
a water-cooled welding torch.
Always connect the coolant hoses according to their colour coding.
1
1
1
*
1
3
2
4
5
2
3

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Twisting the Mul-
tilock welding
torch body
CAUTION!
Risk of burns from hot coolant and hot torch body.
This can result in severe scalds.
► Before carrying out any work, allow the coolant and torch body to cool to room temper-
ature (+25 °C, +77 °F).
1 2
3 4
* Ensure that the union nut is tightened as far as it will go.
1
2x360°
1
1
1
2
1
2
1
1
3
*
0
4

17
EN
Changing the
torch body on a
Multilock welding
torch
CAUTION!
Risk of burns from hot coolant and hot torch body.
This can result in severe scalds.
► Before carrying out any work, allow the coolant and torch body to cool to room temper-
ature (+25 °C, +77 °F).
► Some coolant will always remain in the torch body. Only remove the torch body with
the gas nozzle pointing downwards
NOTE!
Risk from incorrect assembly of the welding torch.
This can result in serious damage to property.
► Before fitting a torch body, ensure that the interface between the torch body and the
hosepack is clean and undamaged.
1 2
The torch body is in the 0° position when the dowel pin (1) on the hosepack engages in the
locating hole (2) in the torch body.
1 2
* Ensure that the union nut is tightened as far as it will go.
1
(1)(2)
(2) (1)
2
1
3
0
*
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Care, maintenance and disposal
General Regular preventive maintenance of the welding torch is essential if trouble-free operation
is to be ensured. The welding torch is subjected to high temperatures and heavy soiling.
The welding torch therefore requires more frequent maintenance than other components
in the welding system.
NOTE!
Risk from improper handling of the wel-
ding torch.
This can result in serious damage.
► Do not strike the welding torch on hard
objects.
► Avoid scoring and scratches in the con-
tact tip in which welding spatter may be-
come firmly lodged.
Do not bend the torch body under any cir-
cumstances!
Recognising
faulty wearing
parts
1. Insulating parts
– Burned-off outside edges, notches
2. Nozzle fittings
– Burned-off outside edges, notches
– Heavily covered in welding spatter
3. Spatter guard
– Burned-off outside edges, notches
4. Contact tips
– Worn-out (oval) wire entry and wire exit holes
– Heavily covered in welding spatter
– Fusion penetration on the tip of the contact tube
5. Gas nozzles
– Heavily covered in welding spatter
– Burned-off outside edges
– Notches
1. 2. 3. 4. 5.

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EN
Maintenance at
every start-up
Maintenance
every time the
wirespool/basket-
type spool is
changed:
- Clean wirefeeding hose with reduced compressed air
- Recommended: replace the inner liner. Clean the wearing parts before fitting the new
inner liner
1 2
- Check wearing parts
- replace faulty wearing parts
- Remove welding spatter from gas nozzle
1 1
* Check the gas nozzle, spatter guard and insulation for damage and replace any
damaged components.
- Also at every start-up when using water-cooled welding torches:
- check all coolant connections for tightness (no leaks)
- check that the coolant can flow unhindered
1
2
1
2

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Troubleshooting
Troubleshooting No welding current
Power source mains switch is on, indicators on the power source are lit up, shielding gas
available
Cause: Grounding (earthing) connection is incorrect
Remedy: Establish a proper grounding (earthing) connection
Cause: There is a break in the current cable in the welding torch
Remedy: Replace welding torch
Nothing happens when the torch trigger is pressed
Power source mains switch is on, indicators on the power source are lit up
Cause: The FSC ('Fronius System Connector' central connector) is not plugged in
properly
Remedy: Push on the FSC as far as it will go
Cause: Welding torch or welding torch control line is faulty
Remedy: Replace welding torch
Cause: Interconnecting hosepack faulty or not connected properly
Remedy: Connect interconnecting hosepack properly
Replace faulty interconnecting hosepack
Cause: Faulty power source
Remedy: Contact After-Sales Service
No shielding gas
All other functions are OK
Cause: Gas cylinder is empty
Remedy: Change the gas cylinder
Cause: Gas pressure regulator is faulty
Remedy: Replace gas pressure regulator
Cause: The gas hose is not connected, or is damaged or kinked
Remedy: Fit gas hose, lay out straight Replace faulty gas hose
Cause: Welding torch is faulty
Remedy: Replace welding torch
Cause: Gas solenoid valve is faulty
Remedy: Contact After-Sales Service (arrange for gas solenoid valve to be replaced)