AWELCO Stanley VIP M175 Manuel D'utilisation page 6

4. WELDING GUIDE
4.1. GENERAL RULE
When welding on the lowest output settings, it is necessary to keep the arc as short as possible. This should be achieved by holding welding torch as
close as possible and at an angle of approximately 60 degrees to the workpiece. The arc length can be increased when welding on the highest
settings, an arc length up to 20 mm can be enough when welding on maximum settings.
4.2. GENERAL WELDING TIPS
From time to time, some faults may be observed in the weld owing to external influences rather due to welding machine's faults. Here are some that
you may come across :
· Porosity
Small holes in the weld, caused by break-down in gas coverage of the weld or sometimes by foreign bodies inclusion. Remedy is, usually, to grind out
the weld. Remember, check before the gas flux (about 8 liters/minutes), clean well the working place and finally incline the torch while welding.
· Spatter
Small balls of molten metal which come out of the arc. A little quantity is unavoidable, but it should be kept down to a minimum by selecting correct
settings and having a correct gas flow and by keeping the welding torch clean.
· Narrow heap welding
Can be caused by moving the torch too fast or by an incorrect gas flow.
· Very thick or wide welding
Can be caused by moving the torch too slowly.
· Wire burns back
It can be caused by wire feed slipping, loose or damaged welding tip, poor wire, nozzle held too close to work or voltage too high.
· Little penetration
It can be caused by moving torch too fast, too low voltage setting or incorrect feed setting, reversed polarity, insufficient blunting and distance between
strips. Take care of operational parameters adjustment and improve the preparation of the workpieces.
· Workpiece's piercing
It may be caused by moving the welding torch too slow, too high welding power or by an invalid wire feeding.
· Heavy spatter and porosity
It can be caused by nozzle too far from work, dirt on work or by low gas flow. You have to the two parameters, remeber that gas has not to be lower
than 7-8 liters/ min. and that the current of welding is appropriated to the wire you are using. It is advisable to have a pressure reducer of input and
output. On the manometer you can read the range expressed in liter.
· Welding arc instability
It may be caused by an insufficient welding voltage, irregular wire feed, insufficient protective welding gas.
FAULT
Wire isn't conveyed when Feed roll is
turning
Wire feeding in jerk or erratic way
No arc
Porous welding seams
The machine suddenly stops welding
operations after an extended and heavy
duty use
1) Dirt in liner and/or contact tip
2) The frition brake in the hub is too tightened
3) Faulty welding torch
1) Contact tip defect
2) Burns in contact tip
3) Dirt in feed roll groove
4) Feed roll's groove worn
1) Bad concat between earth clamp and workpiece
2) Short-circuit between contact tip and gas shroud
1) Failre of gas shield owing to spatters in gas shro
2) Wrong welding torch distance and/or inclination from
workpiece
3)
4) Too small gas flux
5) Humid workpieces
6) Heavily rusted workpieces
1) Welding machine overheated due to an excessive
use in stated duty cycle
This welding machine is for professional use only and is reserved for the industry.
FAULT FINDING
REASON
6
REMEDY
1) Blow with compressed air, replace contact tip
2) Loosen
3) Check sheating of torches wire guide
1) Replace
2) Replace
3) Clean
4) Replace
1) Tighten earth clamp and check connections
2) Clean, replace tip and/or shroud as necessary
1) Clean gas shroud from spatters
2) The length of stick out wire from tip must be 5 –
10mm. Inclination not less than 60 degrees in
relation to woekpiece
3) Increase flux of welding gas
4) Dry with heat producer
5) Clean workpieces from rust
1) Don't switch off the machine, let it cool down for
about 20/30 minutes