Miller Electric Maxstar 200 STR manual Process Control, Lift-ArcStart Procedure, Lift-Arc Start

5-2. Process Control

		CE Model	1	Process Control
			Rotate knob up to select the Stick
			process. Rotate knob down to se-
			lect the TIG Lift Arc process.
1	1		Stick (SMAW) - This is a DCEP (di-
			rect current electrode positive) pro-
			cess. Make connections according
			to Section 4-8.
			TIG Lift-Arct- This is a DCEN (di-
			rect	current electrode negative)
			process in which the electrode
			must come in contact with the work
			piece to initiate an arc (see Section

5-3). Make connections according to Section 4-7.

5-3. 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-Arctselected, start arc as follows:

1TIG Electrode

2Workpiece

Turn gas on. Touch tungsten elec- trode to workpiece at weld start point. Hold electrode to work- piece 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 with- out overheating, sticking, or getting contaminated.

Application:

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

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