Firepower MST 180i Operating Manual page 61

Basic MIG Welding Troubleshooting
FAULT
1 Undercut
2 Lack of penetration
3 Lack of fusion
4 Excessive spatter
5 Irregular weld shape
6 Weld cracking
7 Cold weld puddle
8 Arc does not have a crisp
sound that short arc ex-
hibits when the wirefeed
speed and voltage are
adjusted correctly.
9 Poor weld result from
setup chart parameters
Manual 0-5339
CAUSE
A Welding arc voltage too high.
B Incorrect MIG Gun angle
C Excessive heat input
A Welding current too low
B Joint preparation too narrow or
gap too tight
C Shielding gas incorrect
Voltage too low
A Voltage too high
B Voltage too low
A Incorrect voltage and current
settings. Convex, voltage too
low. Concave, voltage too high.
B Wire is wandering.
C Incorrect shielding gas
D Insufficient or excessive heat
input
A Weld beads too small
B Weld penetration narrow and
deep
C Excessive weld stresses
D Excessive voltage
E Cooling rate too fast
A Loose welding cable connection. A Check all welding cable connections.
B Low primary voltage
C Fault in power source
The MIG Gun has been con-
nected to the wrong voltage
polarity on the front panel.
Contact tip has arc marks in the
bore causing excessive drag on
the wire
Table 4-4: MIG Welding Problems
4-7
REMEDY
A Decrease voltage or increase the wire feed
speed.
B Adjust angle.
C Increase the MIG Gun travel speed and/or
decrease welding current by decreasing the
voltage or decreasing the wire feed speed.
A Increase welding current by increasing wire
feed speed and increasing voltage.
B Increase joint angle or gap.
C Change to a gas which gives higher penetration.
Increase voltage.
A Decrease voltage or increase the wirespeed
control.
B Increase the voltage or decrease wirespeed.
A Adjust voltage and current by adjusting the
voltage control and the wirespeed control.
B Replace Velocity contact tip.
C Check shielding gas.
D Adjust the wirespeed control or the voltage
control.
A Decrease travel speed
B Reduce current and voltage and increase MIG Gun
travel speed or select a lower penetration shielding gas.
C Increase weld metal strength or revise design
D Decrease voltage.
E Slow the cooling rate by preheating part to be
welded or cool slowly.
B Contact supply authority.
C Have an Accredited Firepower Service Provider
to test then replace the faulty component.
Connect the MIG Gun to the positive (+) welding
terminal for solid wires and gas shielded
flux cored wires. Refer to the electrode wire
manufacturer for the correct polarity.
Replace the contact tip with only a Genuine
Firepower Velocity contact tip.
Firepower MST 180i
BASIC WELDING GUIDE