Tweco 350 4R Wirefeeder - Manual (Page 49)

7-5 Manual 0-5182
service weldskill 250, 350
Service
7.07 Welding Problems
FAULT CAUSE REMEDY
1 Undercut A
B
C
Welding arc voltage too high.
Incorrect torch angle
Excessive heat input
A
B
C
Reduce voltage by reducing the
Voltage Control switch positions
or turn the Wirespeed control knob
anticlockwise.
Adjust angle
Increase the torch travel speed or
reduce welding current by reducing
the Voltage Control switch positions
and turn the Wirespeed control knob
anti-clockwise.
2 Lack of penetration A
B
C
Welding current too low
Joint preparation too narrow or
gap too tight
Shielding gas incorrect
A
B
C
Increase welding current by
increasing the Wirespeed control
knob clockwise and increasing
Voltage Control switch positions.
Increase joint angle or gap
Change to a gas which gives higher
penetration
3 Lack of fusion Arc voltage to low Increase Arc voltage by increasing
the Voltage Control switch positions.
4 Excessive spatter A
B
Arc voltage too high
Arc voltage too low
A
B
Lower voltage by reducing the
Voltage Control switch positions
or turn the Wirespeed control knob
anti-clockwise.
Raise voltage by increasing the
Voltage Control switches or turn the
Wirespeed control knob clockwise.
5 Irregular weld shape A
B
C
D
Incorrect voltage and current
settings. Convex, Arc voltage
too low
Concave, voltage too high
Wire is wandering
Incorrect shielding gas
Insufficient or excessive heat
input
A
B
C
D
Adjust voltage and current by
adjusting the Voltage Control switch
positions and the Wirespeed control
knob.
Replace contact tip
Check gas selection
Adjust the Wirespeed control knob
or the Voltage Control switch.
6 Arc does not have
a crisp sound that
short arc exhibits
when the wirefeed
speed and voltage are
adjusted correctly
The MIG torch has been
connected to the wrong voltage
polarity on the front panel
Connect the MIG torch to the
positive welding terminal (+) for
solid wires and gas shielded flux
cored wires.