Kemppi 6258351, Operating Manual, Page: 8 / 24

EN
4. OperatiOn disturbanCes
the most common operation disturbances are as follows:
Welding wire does not run smoothly or wire is sticking in the wire liner (arc
length varies, you can feel shaking in the handle):
• Wire liner is dirty or blocked-up. Clean with compressed air. Replace wire
liner if necessary.
• Wrong wire liner or contact tip. Make sure that wire liner and contact tip
are according to recommendations for the welding wire in question.
• Contact tip has heatened up too much.
• Contact face of contact tip is damaged due to spatter or sparking caused
by impurities. Replace contact tip.
• Gun cable has too sharp bends, straighten.
• Welding wire has a lot of dirt, rust or bends etc., which increases friction
and results in contact disturbances.
• Check operation of the wire feed unit. Check that drive roll size and type
are suitable for wire in question. Check that drive roll pressure is not too
low or too high.
Gas shielding is bad (weld pool "is boiling", arc is unstable):
• On inner face of gas nozzle or in contact tip and contact tip holder there
is too much welding spatter; clean.
• In discharge hole for shielding gas there is spatter or other dirt; clean.
• There are impurities in shielding gas (moisture, air).
• There are impurities in base material (rust, base coat, grease).
• Pressure gathered in long gas hoses will cause a great flow of shielding
gas at welding start, which may cause turbulence or mixing of air into
shielding gas. The reason may also be a faulty or a faulty regulated relief
valve which lets too much pressure into gas hoses.
• Flow of shielding gas is too small or too big (causes turbulence). Use in
short arc range a flow of 8 – 15 l/min, in hot arc range 10 – 20 l/min.
• Distance of gun to work piece is too long. In short arc welding keep
the gas nozzle at a distance of 10 – 15 mm and in hot arc welding at a
distance of 15 – 30 mm to work piece.
• Angle of tilt of gun is too big.
• There is too much draught at welding place.
6
M
TP 350, 350P
, 500, 500P / © Kemppi O
y / 1225
mtp_350_500_1925810_1225.indd 6 2.7.2012 9:07:53