Miller Electric 140 Auto-Set Troubleshooting − Burn-Through, Troubleshooting − Waviness Of Bead

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.

OM-225 311 Page 51