OM-244 324 Page 17
4-2. Process Control
1
Process Control
Use the Process control to select
the Stick process (up), or the TIG
Lift Arc process (down).
Stick (SMAW)
- This is a DCEP (di-
rect current electrode positive) pro-
cess. Make connections according
to Section 3-11.
TIG Lift-Arc
t
- 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
4-3). Make connections according
to Section 3-10.
1
4-3. Lift-Arc Start Procedure
Lift-Arc Start
With Lift-Arc
t
selected, start arc
as follows:
1
TIG Electrode
2
Workpiece
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.
1
1
−
2
Seconds
“Touch”
Do NOT Strike Like A Match!
2
Lift-Arc Start Method
