Miller Electric 140 Auto-Set Welding System User Manual


 
OM-225 311 Page 51
8-13. Troubleshooting − Burn-Through
Burn-Through − weld metal melting completely through base metal
resulting in holes where no metal remains.
S-0640
Possible Causes Corrective Actions
Excessive heat input. Select lower voltage range and reduce wire feed speed.
Increase and/or maintain steady travel speed.
Wrong polarity. Configure polarity as shown in Section 4-5. Always read and follow wire manufacturer’s
recommended polarity, and see Section 4-5.
8-14. Troubleshooting − Waviness Of Bead
Waviness Of Bead − weld metal that is not parallel and does not cover
joint formed by base metal.
S-0641
Possible Causes Corrective Actions
Welding wire extends too far out of nozzle. Be sure welding wire extends not more than 1/2 in (13 mm) beyond nozzle.
Unsteady hand. Support hand on solid surface or use two hands.
8-15. Troubleshooting − Distortion
Distortion − contraction of weld metal during welding that forces
base metal to move.
Base metal moves
in the direction of
the weld bead.
S-0642
Possible Causes Corrective Actions
Excessive heat input. Use restraint (clamp) to hold base metal in position.
Make tack welds along joint before starting welding operation.
Select lower voltage range and/or reduce wire feed speed.
Increase travel speed.
Weld in small segments and allow cooling between welds.