Lift-Arc Tig Procedure; Optional Low Open Circuit Voltage (Ocv) Welding Modes - Miller Red-D-Arc EXTREME 425 CC/CV Auto-Line Owner's Manual

6-4. Lift-Arc TIG Procedure

6-5.

Optional Low Open Circuit Voltage (OCV) Welding Modes

OM-234 199 Page 26
1
1 − 2
"Touch"
Seconds
Do NOT Strike Like A Match!
2
With Process Switch in the Lift-Arc
TIG position, start an arc as follows:
1 TIG Electrode
2 Workpiece
Touch tungsten electrode to work-
piece at weld start point, hold
electrode to workpiece for 1-2
seconds, and slowly lift electrode.
An arc will form 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.
Ref. S-156 279
Low OCV Operation
The unit can be optionally config-
ured for low open circuit voltage
(OCV) operation in Stick and
Scratch Start TIG modes. When the
unit is configured for low OCV op-
eration only a low sensing voltage
(approximately 15 VDC) is present
between the electrode and the
workpiece prior to the electrode
touching the workpiece. Consult a
Factory Authorized Service Agent
for information regarding how to
configure the unit for low OCV weld-
ing operation.