Tweco 180 Portable MIG User Manual
Page 54
FABRICATOR 140, 180
MAINTENANCE
Manual 0-4991
5-4
July 20, 2007
FAULT
CAUSE
REMEDY
6 Weld cracking
A Weld beads too small
A Decrease travel speed
B Weld penetration
narrow and deep
B Reduce current and voltage and increase MIG
torch travel speed or select a lower penetration
shielding gas.
C Excessive weld
stresses
C Increase weld metal strength or revise design
D Excessive voltage
D Decrease voltage by reducing the voltage
selection switch.
E Cooling rate too fast
E Slow the cooling rate by preheating part to be
welded or cool slowly.
7 Cold weld puddle
A Faulty rectifier unit
A Have an Accredited THERMAL ARC Service
Agent to test then replace the faulty
component.
B Loose welding cable
connection.
B Check all welding cable connections.
C Low Primary Voltage
C Contact supply authority
8 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. Refer to the electrode
wire manufacturer for the correct polarity.
Table 5-1b: Welding Problems Continued