Thermal Arc Fabricator 140 Service Manual page 54

FABRICATOR 140, 180
FAULT
6 Weld cracking
7 Cold weld puddle
8 Arc does not have a crisp
sound that short arc
exhibits when the
wirefeed speed and
voltage are adjusted
correctly.
Manual 0-4992
CAUSE
A Weld beads too small
B Weld penetration
narrow and deep
C Excessive weld
stresses
D Excessive voltage
E Cooling rate too fast
A Faulty rectifier unit
B Loose welding cable
connection.
C Low Primary Voltage
The MIG torch has been
connected to the wrong
voltage polarity on the
front panel.
Table 5-1b: Welding Problems Continued
BASIC TROUBLESHOOTING
REMEDY
A Decrease travel speed
B Reduce current and voltage and increase MIG
torch travel speed or select a lower penetration
shielding gas.
C Increase weld metal strength or revise design
D Decrease voltage by reducing the voltage
selection switch.
E Slow the cooling rate by preheating part to be
welded or cool slowly.
A Have an Accredited THERMAL ARC Service
Agent to test then replace the faulty
component.
B Check all welding cable connections.
C Contact supply authority
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.
5-4 January 25, 2008