28
Fig. 53
Fig. 54
Fig. 52
Fig. 56
c) TIG 4T
TIG 4T is a very popular process in Europe where
people typically use a momentary (arc on/off) switch
instead of a foot pedal.
Use the Select Mode button (
Fig. 11, A
) to toggle through
the menu until the LED next to 4T illuminates. You are
now in the TIG 4T welding mode.
The main difference between TIG 2T and TIG 4T is that
there is no option to control the maximum amperage
while welding. If you want to weld material and know
you need about 110 amps, you can dial the machine to
110 amps and weld.
In TIG 2T, when you press the momentary switch button
the machine welds and when you let go, the machine
stops. In TIG 4T, the process works different. Let’s take a
look at the sequencer.
If you press and hold the momentary switch button, the
pre-gas flow timer runs (
Fig. 52
) followed by arc
ignition at initial amps (Intl in
Fig. 53
stands for Initial).
Initial amps refers to a small (typically) percentage of
your amperage setting. In the
Fig. 52-54
example, we
selected a welding amperage of 110 amps, a pre-gas
flow value of 0.4 seconds, and an Intl Amps value of
10%, meaning that when you press and hold the
momentary switch button the pre-gas flow timer runs
for 0.4 seconds followed by arc ignition at 11 amps.
When you let go of the momentary switch button, the
machine goes into t1 (slope up), which we set to 1.5
seconds (
Fig. 54
).
With our selected t1 value, the machine ramps up from
11 amps to 110 amps in 1.5 seconds. Now, you can weld
as long as you want at 110 amps. When you finish
welding, press and hold the torch button again and the
machine goes into t2 (slope down).
As you can see in
Fig. 55
, we set t2 (slope down) to 3.5
seconds. Once the slope down timer runs out, the
machine goes into final amps (Fnl Amps in
Fig. 56
). The
final amps value is typically a small percentage of the
amperage setting just like the initial amps value. Final
amps guard against crater formation, cracks, and other
weld defects.
Fig. 55
