Tweco ArcMaster 401MST - Manual (Page 66)

ARCMASTER 401MST POWER SOURCE
4.02 Stick (SMAW) Welding Troubleshooting
FAULT CAUSE REMEDY
1 Welding current
fluctuations
ARC FORCE parameter is
set at a value that causes
the welding current to vary
excessively with the arc
length.
Reduce the ARC FORCE parameter until welding
current is reasonably constant while prohibit-
ing the electrode from sticking to the work piece
when you “dig” the electrode into the workpiece.
2 A gap is left by
failure of the weld
metal to fill the
root of the weld.
A Welding current too low A Increase welding current.
B Electrode too large for
joint.
B Use smaller diameter electrode.
C Insufficient gap. C Allow wider gap.
3 Non-metallic par-
ticles are trapped
in the weld metal.
A Non-metallic particles may
be trapped in undercut
from previous bead.
A If a bad undercut is present clean slag bout and
cover with a run from a smaller gauge electrode.
B Joint preparation too
restricted.
B Allow for adequate penetration and room for
cleaning out the slag.
C Irregular deposits allow
slag to be trapped.
C If very bad, chip or grind out irregularities.
D Lack of penetration with
slag trapped beneath weld
bead.
D Use smaller electrode with sufficient current to
give adequate penetration. Use suitable tools to
remove all slag from comers.
E Rust or mill scale is pre-
venting full fusion.
E Clean joint before welding.
F Wrong electrode for posi-
tion in which welding is
done.
F Use electrodes designed for position in which
welding is done, otherwise proper control of slag
is difficult.
Art: A-04971
Figure 1-Example of insufficient gap or incorrect sequence
BASIC WELDING GUIDE 4-10 Manual 0-5287