Miller Electric CST 250 VRD manual Stick Start Procedure − Scratch Start Technique, Lift-Arc Start

4-3. Stick Start Procedure − Scratch Start Technique

1

2

3

With Stick selected, start arc as follows:

1Electrode

2Workpiece

3Arc

Drag electrode across workpiece like striking a match; lift electrode slightly after touching work. If arc goes out electrode was lifted to high. If electrode sticks to workpiece, use a quick twist to free it.

Normal open-circuit voltage is not present before electrode touches workpiece; only a low sensing voltage is present between electrode and workpiece. This allows electrode to touch workpiece without overheating, sticking, or getting contaminated.

4-4. Lift-Arc™Start Procedure

Lift-Arc Start Method

1 2

“Touch”	1 − 2
	Seconds

Do NOT Strike Like A Match!

Lift-Arc Start

With Lift-Arct selected, start arc as follows:

1TIG Electrode

2Workpiece

Turn gas on. Touch tungsten electrode to workpiece at weld start point. Hold electrode to workpiece for 1-2 seconds, and slowly lift electrode. Arc is formed when electrode is lifted.

Normal open-circuit voltage is not present before tungsten electrode touches workpiece; only a low sensing voltage is present between electrode and workpiece. The solid-state output contactor does not energize until after electrode is touching workpiece. This allows electrode to touch workpiece without overheating, sticking, or getting contaminated.

Application:

Lift-Arc is used for the DCEN GTAW process when HF Start method is not permitted, or to replace the scratch method.

OM-220 812 Page 21